Esempio n. 1
0
    def getTGT(self, userName, requestPAC=True):

        clientName = Principal(userName, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        asReq = AS_REQ()

        domain = self.__domain.upper()
        serverName = Principal('krbtgt/%s' % domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        pacRequest = KERB_PA_PAC_REQUEST()
        pacRequest['include-pac'] = requestPAC
        encodedPacRequest = encoder.encode(pacRequest)

        asReq['pvno'] = 5
        asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

        asReq['padata'] = noValue
        asReq['padata'][0] = noValue
        asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        asReq['padata'][0]['padata-value'] = encodedPacRequest

        reqBody = seq_set(asReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.proxiable.value)
        reqBody['kdc-options'] = constants.encodeFlags(opts)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        seq_set(reqBody, 'cname', clientName.components_to_asn1)

        if domain == '':
            raise Exception('Empty Domain not allowed in Kerberos')

        reqBody['realm'] = domain

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['rtime'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)

        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value),)

        seq_set_iter(reqBody, 'etype', supportedCiphers)

        message = encoder.encode(asReq)

        try:
            r = sendReceive(message, domain, self.__kdcHost)
        except KerberosError, e:
            if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                # RC4 not available, OK, let's ask for newer types
                supportedCiphers = (int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value),
                                    int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value),)
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, self.__kdcHost)
            else:
                raise e
Esempio n. 2
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def getKerberosTGS(serverName, domain, kdcHost, tgt, cipher, sessionKey):

    # Decode the TGT
    try:
        decodedTGT = decoder.decode(tgt, asn1Spec = AS_REP())[0]
    except:
        decodedTGT = decoder.decode(tgt, asn1Spec = TGS_REP())[0]

    domain = domain.upper()
    # Extract the ticket from the TGT
    ticket = Ticket()
    ticket.from_asn1(decodedTGT['ticket'])

    apReq = AP_REQ()
    apReq['pvno'] = 5
    apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

    opts = list()
    apReq['ap-options'] =  constants.encodeFlags(opts)
    seq_set(apReq,'ticket', ticket.to_asn1)

    authenticator = Authenticator()
    authenticator['authenticator-vno'] = 5
    authenticator['crealm'] = str(decodedTGT['crealm'])

    clientName = Principal()
    clientName.from_asn1( decodedTGT, 'crealm', 'cname')

    seq_set(authenticator, 'cname', clientName.components_to_asn1)

    now = datetime.datetime.utcnow()
    authenticator['cusec'] =  now.microsecond
    authenticator['ctime'] = KerberosTime.to_asn1(now)

    encodedAuthenticator = encoder.encode(authenticator)

    # Key Usage 7
    # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
    # TGS authenticator subkey), encrypted with the TGS session
    # key (Section 5.5.1)
    encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)

    apReq['authenticator'] = None
    apReq['authenticator']['etype'] = cipher.enctype
    apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

    encodedApReq = encoder.encode(apReq)

    tgsReq = TGS_REQ()

    tgsReq['pvno'] =  5
    tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
    tgsReq['padata'] = None
    tgsReq['padata'][0] = None
    tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
    tgsReq['padata'][0]['padata-value'] = encodedApReq

    reqBody = seq_set(tgsReq, 'req-body')

    opts = list()
    opts.append( constants.KDCOptions.forwardable.value )
    opts.append( constants.KDCOptions.renewable.value )
    opts.append( constants.KDCOptions.renewable_ok.value )
    opts.append( constants.KDCOptions.canonicalize.value )

    reqBody['kdc-options'] = constants.encodeFlags(opts)
    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] = random.getrandbits(31)
    seq_set_iter(reqBody, 'etype',
                      (
                          int(constants.EncryptionTypes.rc4_hmac.value),
                          int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
                          int(cipher.enctype)
                       )
                )

    message = encoder.encode(tgsReq)

    r = sendReceive(message, domain, kdcHost)

    # Get the session key

    tgs = decoder.decode(r, asn1Spec = TGS_REP())[0]

    cipherText = tgs['enc-part']['cipher']

    # Key Usage 8
    # TGS-REP encrypted part (includes application session
    # key), encrypted with the TGS session key (Section 5.4.2)
    plainText = cipher.decrypt(sessionKey, 8, str(cipherText))

    encTGSRepPart = decoder.decode(plainText, asn1Spec = EncTGSRepPart())[0]

    newSessionKey = Key(encTGSRepPart['key']['keytype'], str(encTGSRepPart['key']['keyvalue']))
    # Creating new cipher based on received keytype
    cipher = _enctype_table[encTGSRepPart['key']['keytype']]

    # Check we've got what we asked for
    res = decoder.decode(r, asn1Spec = TGS_REP())[0]
    spn = Principal()
    spn.from_asn1(res['ticket'], 'realm', 'sname')

    if spn.components[0] == serverName.components[0]:
        # Yes.. bye bye
        return r, cipher, sessionKey, newSessionKey
    else:
        # Let's extract the Ticket, change the domain and keep asking
        domain = spn.components[1]
        return getKerberosTGS(serverName, domain, kdcHost, r, cipher, newSessionKey)
    
    return r, cipher, sessionKey, newSessionKey
Esempio n. 3
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    def getTGT(self, userName, requestPAC=True):

        clientName = Principal(userName, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        asReq = AS_REQ()

        domain = self.__domain.upper()
        serverName = Principal('krbtgt/%s' % domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        pacRequest = KERB_PA_PAC_REQUEST()
        pacRequest['include-pac'] = requestPAC
        encodedPacRequest = encoder.encode(pacRequest)

        asReq['pvno'] = 5
        asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

        asReq['padata'] = noValue
        asReq['padata'][0] = noValue
        asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        asReq['padata'][0]['padata-value'] = encodedPacRequest

        reqBody = seq_set(asReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.proxiable.value)
        reqBody['kdc-options'] = constants.encodeFlags(opts)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        seq_set(reqBody, 'cname', clientName.components_to_asn1)

        if domain == '':
            raise Exception('Empty Domain not allowed in Kerberos')

        reqBody['realm'] = domain

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['rtime'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)

        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value),)

        seq_set_iter(reqBody, 'etype', supportedCiphers)

        message = encoder.encode(asReq)

        try:
            r = sendReceive(message, domain, self.__kdcHost)
        except KerberosError as e:
            if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                # RC4 not available, OK, let's ask for newer types
                supportedCiphers = (int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value),
                                    int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value),)
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, self.__kdcHost)
            else:
                raise e

        # This should be the PREAUTH_FAILED packet or the actual TGT if the target principal has the
        # 'Do not require Kerberos preauthentication' set
        try:
            asRep = decoder.decode(r, asn1Spec=KRB_ERROR())[0]
        except:
            # Most of the times we shouldn't be here, is this a TGT?
            asRep = decoder.decode(r, asn1Spec=AS_REP())[0]
        else:
            # The user doesn't have UF_DONT_REQUIRE_PREAUTH set
            raise Exception('User %s doesn\'t have UF_DONT_REQUIRE_PREAUTH set' % userName)

        if self.__outputFormat == 'john':
            # Let's output the TGT enc-part/cipher in John format, in case somebody wants to use it.
            return '$krb5asrep$%s@%s:%s$%s' % (clientName, domain,
                                               hexlify(asRep['enc-part']['cipher'].asOctets()[:16]).decode(),
                                               hexlify(asRep['enc-part']['cipher'].asOctets()[16:]).decode())
        else:
            # Let's output the TGT enc-part/cipher in Hashcat format, in case somebody wants to use it.
            return '$krb5asrep$%d$%s@%s:%s$%s' % ( asRep['enc-part']['etype'], clientName, domain,
                                                   hexlify(asRep['enc-part']['cipher'].asOctets()[:16]).decode(),
                                                   hexlify(asRep['enc-part']['cipher'].asOctets()[16:]).decode())
Esempio n. 4
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    def doS4U(self, tgt, cipher, oldSessionKey, sessionKey):
        decodedTGT = decoder.decode(tgt, asn1Spec = AS_REP())[0]

        # Extract the ticket from the TGT
        ticket = Ticket()
        ticket.from_asn1(decodedTGT['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] =  constants.encodeFlags(opts)
        seq_set(apReq,'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1( decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('AUTHENTICATOR')
            print authenticator.prettyPrint()
            print ('\n')

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] =  5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)

        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
        # requests a service ticket to itself on behalf of a user. The user is
        # identified to the KDC by the user's name and realm.
        clientName = Principal(self.__options.impersonate, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        S4UByteArray = struct.pack('<I',constants.PrincipalNameType.NT_PRINCIPAL.value)
        S4UByteArray += self.__options.impersonate + self.__domain + 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('S4UByteArray')
            hexdump(S4UByteArray)

        # Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
        # with the following three parameters: the session key of the TGT of
        # the service performing the S4U2Self request, the message type value
        # of 17, and the byte array S4UByteArray.
        checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('CheckSum')
            hexdump(checkSum)

        paForUserEnc = PA_FOR_USER_ENC()
        seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
        paForUserEnc['userRealm'] = self.__domain
        paForUserEnc['cksum'] = noValue
        paForUserEnc['cksum']['cksumtype'] = int(constants.ChecksumTypes.hmac_md5.value)
        paForUserEnc['cksum']['checksum'] = checkSum
        paForUserEnc['auth-package'] = 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('PA_FOR_USER_ENC')
            print paForUserEnc.prettyPrint()

        encodedPaForUserEnc = encoder.encode(paForUserEnc)

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
        tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        opts.append( constants.KDCOptions.forwardable.value )
        opts.append( constants.KDCOptions.renewable.value )
        opts.append( constants.KDCOptions.canonicalize.value )

        reqBody['kdc-options'] = constants.encodeFlags(opts)

        serverName = Principal(self.__user, type=constants.PrincipalNameType.NT_UNKNOWN.value)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        reqBody['realm'] = str(decodedTGT['crealm'])

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype',
                      (int(cipher.enctype),int(constants.EncryptionTypes.rc4_hmac.value)))

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('Final TGS')
            print tgsReq.prettyPrint()

        logging.info('\tRequesting S4U2self')
        message = encoder.encode(tgsReq)

        r = sendReceive(message, self.__domain, None)

        tgs = decoder.decode(r, asn1Spec = TGS_REP())[0]

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('TGS_REP')
            print tgs.prettyPrint()

        ################################################################################
        # Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
        # So here I have a ST for me.. I now want a ST for another service
        # Extract the ticket from the TGT
        ticketTGT = Ticket()
        ticketTGT.from_asn1(decodedTGT['ticket'])

        ticket = Ticket()
        ticket.from_asn1(tgs['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] =  constants.encodeFlags(opts)
        seq_set(apReq,'ticket', ticketTGT.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1( decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] = 5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        # This specified we're doing S4U
        opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
        opts.append(constants.KDCOptions.canonicalize.value)
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)
        service2 = Principal(self.__options.spn, type=constants.PrincipalNameType.NT_SRV_INST.value)
        seq_set(reqBody, 'sname', service2.components_to_asn1)
        reqBody['realm'] = self.__domain

        myTicket = ticket.to_asn1(TicketAsn1())
        seq_set_iter(reqBody, 'additional-tickets', (myTicket,))

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype',
                         (
                             int(constants.EncryptionTypes.rc4_hmac.value),
                             int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
                             int(constants.EncryptionTypes.des_cbc_md5.value),
                             int(cipher.enctype)
                         )
                     )
        message = encoder.encode(tgsReq)

        logging.info('\tRequesting S4U2Proxy')
        r = sendReceive(message, self.__domain, None)

        tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

        cipherText = tgs['enc-part']['cipher']

        # Key Usage 8
        # TGS-REP encrypted part (includes application session
        # key), encrypted with the TGS session key (Section 5.4.2)
        plainText = cipher.decrypt(sessionKey, 8, str(cipherText))

        encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]

        newSessionKey = Key(encTGSRepPart['key']['keytype'], str(encTGSRepPart['key']['keyvalue']))

        # Creating new cipher based on received keytype
        cipher = _enctype_table[encTGSRepPart['key']['keytype']]

        return r, cipher, sessionKey, newSessionKey
Esempio n. 5
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def getKerberosTGS(serverName, domain, kdcHost, tgt, cipher, sessionKey):

    # Decode the TGT
    try:
        decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
    except:
        decodedTGT = decoder.decode(tgt, asn1Spec=TGS_REP())[0]

    domain = domain.upper()
    # Extract the ticket from the TGT
    ticket = Ticket()
    ticket.from_asn1(decodedTGT['ticket'])

    apReq = AP_REQ()
    apReq['pvno'] = 5
    apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

    opts = list()
    apReq['ap-options'] = constants.encodeFlags(opts)
    seq_set(apReq, 'ticket', ticket.to_asn1)

    authenticator = Authenticator()
    authenticator['authenticator-vno'] = 5
    authenticator['crealm'] = decodedTGT['crealm'].asOctets()

    clientName = Principal()
    clientName.from_asn1(decodedTGT, 'crealm', 'cname')

    seq_set(authenticator, 'cname', clientName.components_to_asn1)

    now = datetime.datetime.utcnow()
    authenticator['cusec'] = now.microsecond
    authenticator['ctime'] = KerberosTime.to_asn1(now)

    encodedAuthenticator = encoder.encode(authenticator)

    # Key Usage 7
    # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
    # TGS authenticator subkey), encrypted with the TGS session
    # key (Section 5.5.1)
    encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
                                                   encodedAuthenticator, None)

    apReq['authenticator'] = noValue
    apReq['authenticator']['etype'] = cipher.enctype
    apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

    encodedApReq = encoder.encode(apReq)

    tgsReq = TGS_REQ()

    tgsReq['pvno'] = 5
    tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
    tgsReq['padata'] = noValue
    tgsReq['padata'][0] = noValue
    tgsReq['padata'][0]['padata-type'] = int(
        constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
    tgsReq['padata'][0]['padata-value'] = encodedApReq

    reqBody = seq_set(tgsReq, 'req-body')

    opts = list()
    opts.append(constants.KDCOptions.forwardable.value)
    opts.append(constants.KDCOptions.renewable.value)
    opts.append(constants.KDCOptions.renewable_ok.value)
    opts.append(constants.KDCOptions.canonicalize.value)

    reqBody['kdc-options'] = constants.encodeFlags(opts)
    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] = rand.getrandbits(31)
    seq_set_iter(reqBody, 'etype',
                 (int(constants.EncryptionTypes.rc4_hmac.value),
                  int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
                  int(constants.EncryptionTypes.des_cbc_md5.value),
                  int(cipher.enctype)))

    message = encoder.encode(tgsReq)

    r = sendReceive(message, domain, kdcHost)

    # Get the session key

    tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

    cipherText = tgs['enc-part']['cipher']

    # Key Usage 8
    # TGS-REP encrypted part (includes application session
    # key), encrypted with the TGS session key (Section 5.4.2)
    plainText = cipher.decrypt(sessionKey, 8, cipherText)

    encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]

    newSessionKey = Key(encTGSRepPart['key']['keytype'],
                        encTGSRepPart['key']['keyvalue'].asOctets())
    # Creating new cipher based on received keytype
    cipher = _enctype_table[encTGSRepPart['key']['keytype']]

    # Check we've got what we asked for
    res = decoder.decode(r, asn1Spec=TGS_REP())[0]
    spn = Principal()
    spn.from_asn1(res['ticket'], 'realm', 'sname')

    if spn.components[0] == serverName.components[0]:
        # Yes.. bye bye
        return r, cipher, sessionKey, newSessionKey
    else:
        # Let's extract the Ticket, change the domain and keep asking
        domain = spn.components[1]
        return getKerberosTGS(serverName, domain, kdcHost, r, cipher,
                              newSessionKey)
Esempio n. 6
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def getKerberosTGT(clientName,
                   password,
                   domain,
                   lmhash,
                   nthash,
                   aesKey='',
                   kdcHost=None,
                   requestPAC=True):

    asReq = AS_REQ()

    domain = domain.upper()
    serverName = Principal('krbtgt/%s' % domain,
                           type=constants.PrincipalNameType.NT_PRINCIPAL.value)

    pacRequest = KERB_PA_PAC_REQUEST()
    pacRequest['include-pac'] = requestPAC
    encodedPacRequest = encoder.encode(pacRequest)

    asReq['pvno'] = 5
    asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

    asReq['padata'] = noValue
    asReq['padata'][0] = noValue
    asReq['padata'][0]['padata-type'] = int(
        constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][0]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append(constants.KDCOptions.forwardable.value)
    opts.append(constants.KDCOptions.renewable.value)
    opts.append(constants.KDCOptions.proxiable.value)
    reqBody['kdc-options'] = constants.encodeFlags(opts)

    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    seq_set(reqBody, 'cname', clientName.components_to_asn1)

    if domain == '':
        raise Exception('Empty Domain not allowed in Kerberos')

    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['rtime'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] = rand.getrandbits(31)

    # Yes.. this shouldn't happen but it's inherited from the past
    if aesKey is None:
        aesKey = ''

    if nthash == '':
        # This is still confusing. I thought KDC_ERR_ETYPE_NOSUPP was enough,
        # but I found some systems that accepts all ciphers, and trigger an error
        # when requesting subsequent TGS :(. More research needed.
        # So, in order to support more than one cypher, I'm setting aes first
        # since most of the systems would accept it. If we're lucky and
        # KDC_ERR_ETYPE_NOSUPP is returned, we will later try rc4.
        if aesKey != '':
            if len(aesKey) == 64:
                supportedCiphers = (int(
                    constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value), )
            else:
                supportedCiphers = (int(
                    constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value), )
        else:
            supportedCiphers = (int(
                constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value), )
    else:
        # We have hashes to try, only way is to request RC4 only
        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value), )

    seq_set_iter(reqBody, 'etype', supportedCiphers)

    message = encoder.encode(asReq)

    try:
        r = sendReceive(message, domain, kdcHost)
    except KerberosError as e:
        if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
            if supportedCiphers[0] in (
                    constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value,
                    constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value
            ) and aesKey is '':
                supportedCiphers = (int(
                    constants.EncryptionTypes.rc4_hmac.value), )
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, kdcHost)
            else:
                raise
        else:
            raise

    # This should be the PREAUTH_FAILED packet or the actual TGT if the target principal has the
    # 'Do not require Kerberos preauthentication' set
    preAuth = True
    try:
        asRep = decoder.decode(r, asn1Spec=KRB_ERROR())[0]
    except:
        # Most of the times we shouldn't be here, is this a TGT?
        asRep = decoder.decode(r, asn1Spec=AS_REP())[0]
        # Yes
        preAuth = False

    encryptionTypesData = dict()
    salt = ''
    if preAuth is False:
        # In theory, we should have the right credentials for the etype specified before.
        methods = asRep['padata']
        encryptionTypesData[supportedCiphers[
            0]] = salt  # handle RC4 fallback, we don't need any salt
        tgt = r
    else:
        methods = decoder.decode(asRep['e-data'], asn1Spec=METHOD_DATA())[0]

    for method in methods:
        if method[
                'padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO2.value:
            etypes2 = decoder.decode(method['padata-value'],
                                     asn1Spec=ETYPE_INFO2())[0]
            for etype2 in etypes2:
                try:
                    if etype2['salt'] is None or etype2['salt'].hasValue(
                    ) is False:
                        salt = ''
                    else:
                        salt = etype2['salt'].prettyPrint()
                except PyAsn1Error:
                    salt = ''

                encryptionTypesData[etype2['etype']] = b(salt)
        elif method[
                'padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO.value:
            etypes = decoder.decode(method['padata-value'],
                                    asn1Spec=ETYPE_INFO())[0]
            for etype in etypes:
                try:
                    if etype['salt'] is None or etype['salt'].hasValue(
                    ) is False:
                        salt = ''
                    else:
                        salt = etype['salt'].prettyPrint()
                except PyAsn1Error:
                    salt = ''

                encryptionTypesData[etype['etype']] = b(salt)

    enctype = supportedCiphers[0]

    cipher = _enctype_table[enctype]

    # Pass the hash/aes key :P
    if nthash != '' and (isinstance(nthash, bytes) and nthash != b''):
        key = Key(cipher.enctype, nthash)
    elif aesKey != '':
        key = Key(cipher.enctype, unhexlify(aesKey))
    else:
        key = cipher.string_to_key(password, encryptionTypesData[enctype],
                                   None)

    if preAuth is True:
        if enctype in encryptionTypesData is False:
            raise Exception('No Encryption Data Available!')

        # Let's build the timestamp
        timeStamp = PA_ENC_TS_ENC()

        now = datetime.datetime.utcnow()
        timeStamp['patimestamp'] = KerberosTime.to_asn1(now)
        timeStamp['pausec'] = now.microsecond

        # Encrypt the shyte
        encodedTimeStamp = encoder.encode(timeStamp)

        # Key Usage 1
        # AS-REQ PA-ENC-TIMESTAMP padata timestamp, encrypted with the
        # client key (Section 5.2.7.2)
        encriptedTimeStamp = cipher.encrypt(key, 1, encodedTimeStamp, None)

        encryptedData = EncryptedData()
        encryptedData['etype'] = cipher.enctype
        encryptedData['cipher'] = encriptedTimeStamp
        encodedEncryptedData = encoder.encode(encryptedData)

        # Now prepare the new AS_REQ again with the PADATA
        # ToDo: cannot we reuse the previous one?
        asReq = AS_REQ()

        asReq['pvno'] = 5
        asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

        asReq['padata'] = noValue
        asReq['padata'][0] = noValue
        asReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_ENC_TIMESTAMP.value)
        asReq['padata'][0]['padata-value'] = encodedEncryptedData

        asReq['padata'][1] = noValue
        asReq['padata'][1]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        asReq['padata'][1]['padata-value'] = encodedPacRequest

        reqBody = seq_set(asReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.proxiable.value)
        reqBody['kdc-options'] = constants.encodeFlags(opts)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        seq_set(reqBody, 'cname', clientName.components_to_asn1)

        reqBody['realm'] = domain

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['rtime'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = rand.getrandbits(31)

        seq_set_iter(reqBody, 'etype', ((int(cipher.enctype), )))

        try:
            tgt = sendReceive(encoder.encode(asReq), domain, kdcHost)
        except Exception as e:
            if str(e).find('KDC_ERR_ETYPE_NOSUPP') >= 0:
                if lmhash is '' and nthash is '' and (aesKey is ''
                                                      or aesKey is None):
                    from impacket.ntlm import compute_lmhash, compute_nthash
                    lmhash = compute_lmhash(password)
                    nthash = compute_nthash(password)
                    return getKerberosTGT(clientName, password, domain, lmhash,
                                          nthash, aesKey, kdcHost, requestPAC)
            raise

        asRep = decoder.decode(tgt, asn1Spec=AS_REP())[0]

    # So, we have the TGT, now extract the new session key and finish
    cipherText = asRep['enc-part']['cipher']

    if preAuth is False:
        # Let's output the TGT enc-part/cipher in John format, in case somebody wants to use it.
        LOG.debug('$krb5asrep$%d$%s@%s:%s$%s' %
                  (asRep['enc-part']['etype'], clientName, domain,
                   hexlify(asRep['enc-part']['cipher'].asOctets()[:16]),
                   hexlify(asRep['enc-part']['cipher'].asOctets()[16:])))
    # Key Usage 3
    # AS-REP encrypted part (includes TGS session key or
    # application session key), encrypted with the client key
    # (Section 5.4.2)
    try:
        plainText = cipher.decrypt(key, 3, cipherText)
    except InvalidChecksum as e:
        # probably bad password if preauth is disabled
        if preAuth is False:
            error_msg = "failed to decrypt session key: %s" % str(e)
            raise SessionKeyDecryptionError(error_msg, asRep, cipher, key,
                                            cipherText)
        raise
    encASRepPart = decoder.decode(plainText, asn1Spec=EncASRepPart())[0]

    # Get the session key and the ticket
    # We're assuming the cipher for this session key is the same
    # as the one we used before.
    # ToDo: change this
    sessionKey = Key(cipher.enctype,
                     encASRepPart['key']['keyvalue'].asOctets())

    # ToDo: Check Nonces!

    return tgt, cipher, key, sessionKey
Esempio n. 7
0
    def getKerberosTGS(self, serverName, domain, kdcHost, tgt, cipher, sessionKey, authTime):
        # Get out Golden PAC
        goldenPAC = self.getGoldenPAC(authTime)

        decodedTGT = decoder.decode(tgt, asn1Spec = AS_REP())[0]

        # Extract the ticket from the TGT
        ticket = Ticket()
        ticket.from_asn1(decodedTGT['ticket'])

        # Now put the goldenPac inside the AuthorizationData AD_IF_RELEVANT
        ifRelevant = AD_IF_RELEVANT()
        ifRelevant[0] = None
        ifRelevant[0]['ad-type'] = int(constants.AuthorizationDataType.AD_IF_RELEVANT.value)
        ifRelevant[0]['ad-data'] = goldenPAC

        encodedIfRelevant = encoder.encode(ifRelevant)

        # Key Usage 4
        # TGS-REQ KDC-REQ-BODY AuthorizationData, encrypted with
        # the TGS session key (Section 5.4.1)
        encryptedEncodedIfRelevant = cipher.encrypt(sessionKey, 4, encodedIfRelevant, None)

        tgsReq = TGS_REQ()
        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        opts.append( constants.KDCOptions.forwardable.value )
        opts.append( constants.KDCOptions.renewable.value )
        opts.append( constants.KDCOptions.proxiable.value )

        reqBody['kdc-options'] = constants.encodeFlags(opts)
        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        reqBody['realm'] = str(decodedTGT['crealm'])

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.SystemRandom().getrandbits(31)
        seq_set_iter(reqBody, 'etype', (cipher.enctype,))
        reqBody['enc-authorization-data'] = None
        reqBody['enc-authorization-data']['etype'] = int(cipher.enctype)
        reqBody['enc-authorization-data']['cipher'] = encryptedEncodedIfRelevant

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] =  constants.encodeFlags(opts)
        seq_set(apReq,'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1( decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow() 
        authenticator['cusec'] =  now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)

        apReq['authenticator'] = None
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq['pvno'] =  5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
        tgsReq['padata'] = None
        tgsReq['padata'][0] = None
        tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        pacRequest = KERB_PA_PAC_REQUEST()
        pacRequest['include-pac'] = False
        encodedPacRequest = encoder.encode(pacRequest)

        tgsReq['padata'][1] = None
        tgsReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        tgsReq['padata'][1]['padata-value'] = encodedPacRequest

        message = encoder.encode(tgsReq)

        r = sendReceive(message, domain, kdcHost)

        # Get the session key
        tgs = decoder.decode(r, asn1Spec = TGS_REP())[0]
        cipherText = tgs['enc-part']['cipher']

        # Key Usage 8
        # TGS-REP encrypted part (includes application session
        # key), encrypted with the TGS session key (Section 5.4.2)
        plainText = cipher.decrypt(sessionKey, 8, str(cipherText))

        encTGSRepPart = decoder.decode(plainText, asn1Spec = EncTGSRepPart())[0]

        newSessionKey = Key(cipher.enctype, str(encTGSRepPart['key']['keyvalue']))
    
        return r, cipher, sessionKey, newSessionKey
Esempio n. 8
0
    def doS4U(self, tgt, cipher, oldSessionKey, sessionKey, nthash, aesKey,
              kdcHost):
        decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
        # Extract the ticket from the TGT
        ticket = Ticket()
        ticket.from_asn1(decodedTGT['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1(decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('AUTHENTICATOR')
            print(authenticator.prettyPrint())
            print('\n')

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] = 5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)

        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
        # requests a service ticket to itself on behalf of a user. The user is
        # identified to the KDC by the user's name and realm.
        clientName = Principal(
            self.__options.impersonate,
            type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        S4UByteArray = struct.pack(
            '<I', constants.PrincipalNameType.NT_PRINCIPAL.value)
        S4UByteArray += b(self.__options.impersonate) + b(
            self.__domain) + b'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('S4UByteArray')
            hexdump(S4UByteArray)

        # Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
        # with the following three parameters: the session key of the TGT of
        # the service performing the S4U2Self request, the message type value
        # of 17, and the byte array S4UByteArray.
        checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('CheckSum')
            hexdump(checkSum)

        paForUserEnc = PA_FOR_USER_ENC()
        seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
        paForUserEnc['userRealm'] = self.__domain
        paForUserEnc['cksum'] = noValue
        paForUserEnc['cksum']['cksumtype'] = int(
            constants.ChecksumTypes.hmac_md5.value)
        paForUserEnc['cksum']['checksum'] = checkSum
        paForUserEnc['auth-package'] = 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('PA_FOR_USER_ENC')
            print(paForUserEnc.prettyPrint())

        encodedPaForUserEnc = encoder.encode(paForUserEnc)

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
        tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.canonicalize.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)

        serverName = Principal(
            self.__user, type=constants.PrincipalNameType.NT_UNKNOWN.value)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        reqBody['realm'] = str(decodedTGT['crealm'])

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype', (int(
            cipher.enctype), int(constants.EncryptionTypes.rc4_hmac.value)))

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('Final TGS')
            print(tgsReq.prettyPrint())

        logging.info('\tRequesting S4U2self')
        message = encoder.encode(tgsReq)

        r = sendReceive(message, self.__domain, kdcHost)

        tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('TGS_REP')
            print(tgs.prettyPrint())

        if self.__force_forwardable:
            # Convert hashes to binary form, just in case we're receiving strings
            if isinstance(nthash, str):
                try:
                    nthash = unhexlify(nthash)
                except TypeError:
                    pass
            if isinstance(aesKey, str):
                try:
                    aesKey = unhexlify(aesKey)
                except TypeError:
                    pass

            # Get the encrypted ticket returned in the TGS. It's encrypted with one of our keys
            cipherText = tgs['ticket']['enc-part']['cipher']

            # Check which cipher was used to encrypt the ticket. It's not always the same
            # This determines which of our keys we should use for decryption/re-encryption
            newCipher = _enctype_table[int(tgs['ticket']['enc-part']['etype'])]
            if newCipher.enctype == Enctype.RC4:
                key = Key(newCipher.enctype, nthash)
            else:
                key = Key(newCipher.enctype, aesKey)

            # Decrypt and decode the ticket
            # Key Usage 2
            # AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
            #  application session key), encrypted with the service key
            #  (section 5.4.2)
            plainText = newCipher.decrypt(key, 2, cipherText)
            encTicketPart = decoder.decode(plainText,
                                           asn1Spec=EncTicketPart())[0]

            # Print the flags in the ticket before modification
            logging.debug('\tService ticket from S4U2self flags: ' +
                          str(encTicketPart['flags']))
            logging.debug('\tService ticket from S4U2self is' + ('' if (
                encTicketPart['flags'][TicketFlags.forwardable.value] == 1
            ) else ' not') + ' forwardable')

            #Customize flags the forwardable flag is the only one that really matters
            logging.info('\tForcing the service ticket to be forwardable')
            #convert to string of bits
            flagBits = encTicketPart['flags'].asBinary()
            #Set the forwardable flag. Awkward binary string insertion
            flagBits = flagBits[:TicketFlags.forwardable.
                                value] + '1' + flagBits[TicketFlags.
                                                        forwardable.value + 1:]
            #Overwrite the value with the new bits
            encTicketPart['flags'] = encTicketPart['flags'].clone(
                value=flagBits)  #Update flags

            logging.debug('\tService ticket flags after modification: ' +
                          str(encTicketPart['flags']))
            logging.debug('\tService ticket now is' + ('' if (
                encTicketPart['flags'][TicketFlags.forwardable.value] == 1
            ) else ' not') + ' forwardable')

            # Re-encode and re-encrypt the ticket
            # Again, Key Usage 2
            encodedEncTicketPart = encoder.encode(encTicketPart)
            cipherText = newCipher.encrypt(key, 2, encodedEncTicketPart, None)

            #put it back in the TGS
            tgs['ticket']['enc-part']['cipher'] = cipherText

        ################################################################################
        # Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
        # So here I have a ST for me.. I now want a ST for another service
        # Extract the ticket from the TGT
        ticketTGT = Ticket()
        ticketTGT.from_asn1(decodedTGT['ticket'])

        #Get the service ticket
        ticket = Ticket()
        ticket.from_asn1(tgs['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticketTGT.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1(decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] = 5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # Add resource-based constrained delegation support
        paPacOptions = PA_PAC_OPTIONS()
        paPacOptions['flags'] = constants.encodeFlags(
            (constants.PAPacOptions.resource_based_constrained_delegation.
             value, ))

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1][
            'padata-type'] = constants.PreAuthenticationDataTypes.PA_PAC_OPTIONS.value
        tgsReq['padata'][1]['padata-value'] = encoder.encode(paPacOptions)

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        # This specified we're doing S4U
        opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
        opts.append(constants.KDCOptions.canonicalize.value)
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)
        service2 = Principal(
            self.__options.spn,
            type=constants.PrincipalNameType.NT_SRV_INST.value)
        seq_set(reqBody, 'sname', service2.components_to_asn1)
        reqBody['realm'] = self.__domain

        myTicket = ticket.to_asn1(TicketAsn1())
        seq_set_iter(reqBody, 'additional-tickets', (myTicket, ))

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype',
                     (int(constants.EncryptionTypes.rc4_hmac.value),
                      int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
                      int(constants.EncryptionTypes.des_cbc_md5.value),
                      int(cipher.enctype)))
        message = encoder.encode(tgsReq)

        logging.info('\tRequesting S4U2Proxy')
        r = sendReceive(message, self.__domain, kdcHost)

        tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

        cipherText = tgs['enc-part']['cipher']

        # Key Usage 8
        # TGS-REP encrypted part (includes application session
        # key), encrypted with the TGS session key (Section 5.4.2)
        plainText = cipher.decrypt(sessionKey, 8, cipherText)

        encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]

        newSessionKey = Key(encTGSRepPart['key']['keytype'],
                            encTGSRepPart['key']['keyvalue'])

        # Creating new cipher based on received keytype
        cipher = _enctype_table[encTGSRepPart['key']['keytype']]

        return r, cipher, sessionKey, newSessionKey
Esempio n. 9
0
def getKerberosTGT(clientName, password, domain, lmhash, nthash, aesKey='', kdcHost=None, requestPAC=True):
    
    asReq = AS_REQ()

    domain = domain.upper()
    serverName = Principal('krbtgt/%s'%domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)  

    pacRequest = KERB_PA_PAC_REQUEST()
    pacRequest['include-pac'] = requestPAC
    encodedPacRequest = encoder.encode(pacRequest)

    asReq['pvno'] = 5
    asReq['msg-type'] =  int(constants.ApplicationTagNumbers.AS_REQ.value)

    asReq['padata'] = noValue
    asReq['padata'][0] = noValue
    asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][0]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append( constants.KDCOptions.forwardable.value )
    opts.append( constants.KDCOptions.renewable.value )
    opts.append( constants.KDCOptions.proxiable.value )
    reqBody['kdc-options']  = constants.encodeFlags(opts)

    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    seq_set(reqBody, 'cname', clientName.components_to_asn1)

    if domain == '':
        raise Exception('Empty Domain not allowed in Kerberos')

    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['rtime'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] =  rand.getrandbits(31)

    # Yes.. this shouldn't happen but it's inherited from the past
    if aesKey is None:
        aesKey = ''

    if nthash == '':
        # This is still confusing. I thought KDC_ERR_ETYPE_NOSUPP was enough, 
        # but I found some systems that accepts all ciphers, and trigger an error 
        # when requesting subsequent TGS :(. More research needed.
        # So, in order to support more than one cypher, I'm setting aes first
        # since most of the systems would accept it. If we're lucky and 
        # KDC_ERR_ETYPE_NOSUPP is returned, we will later try rc4.
        if aesKey != '':
            if len(aesKey) == 64:
                supportedCiphers = (int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value),)
            else:
                supportedCiphers = (int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value),)
        else:
            supportedCiphers = (int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value),)
    else:
        # We have hashes to try, only way is to request RC4 only
        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value),)

    seq_set_iter(reqBody, 'etype', supportedCiphers)

    message = encoder.encode(asReq)

    try:
        r = sendReceive(message, domain, kdcHost)
    except KerberosError as e:
        if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
            if supportedCiphers[0] in (constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value, constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value) and aesKey is '':
                supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value),)
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, kdcHost)
            else: 
                raise 
        else:
            raise 

    # This should be the PREAUTH_FAILED packet or the actual TGT if the target principal has the
    # 'Do not require Kerberos preauthentication' set
    preAuth = True
    try:
        asRep = decoder.decode(r, asn1Spec = KRB_ERROR())[0]
    except:
        # Most of the times we shouldn't be here, is this a TGT?
        asRep = decoder.decode(r, asn1Spec=AS_REP())[0]
        # Yes
        preAuth = False

    encryptionTypesData = dict()
    salt = ''
    if preAuth is False:
        # In theory, we should have the right credentials for the etype specified before.
        methods = asRep['padata']
        encryptionTypesData[supportedCiphers[0]] = salt # handle RC4 fallback, we don't need any salt
        tgt = r
    else:
        methods = decoder.decode(asRep['e-data'], asn1Spec=METHOD_DATA())[0]

    for method in methods:
        if method['padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO2.value:
            etypes2 = decoder.decode(method['padata-value'], asn1Spec = ETYPE_INFO2())[0]
            for etype2 in etypes2:
                try:
                    if etype2['salt'] is None or etype2['salt'].hasValue() is False:
                        salt = ''
                    else:
                        salt = etype2['salt'].prettyPrint()
                except PyAsn1Error:
                    salt = ''

                encryptionTypesData[etype2['etype']] = b(salt)
        elif method['padata-type'] == constants.PreAuthenticationDataTypes.PA_ETYPE_INFO.value:
            etypes = decoder.decode(method['padata-value'], asn1Spec = ETYPE_INFO())[0]
            for etype in etypes:
                try:
                    if etype['salt'] is None or etype['salt'].hasValue() is False:
                        salt = ''
                    else:
                        salt = etype['salt'].prettyPrint()
                except PyAsn1Error:
                    salt = ''

                encryptionTypesData[etype['etype']] = b(salt)

    enctype = supportedCiphers[0]

    cipher = _enctype_table[enctype]

    # Pass the hash/aes key :P
    if nthash != '' and (isinstance(nthash, bytes) and nthash != b''):
        key = Key(cipher.enctype, nthash)
    elif aesKey != '':
        key = Key(cipher.enctype, unhexlify(aesKey))
    else:
        key = cipher.string_to_key(password, encryptionTypesData[enctype], None)

    if preAuth is True:
        if enctype in encryptionTypesData is False:
            raise Exception('No Encryption Data Available!')

        # Let's build the timestamp
        timeStamp = PA_ENC_TS_ENC()

        now = datetime.datetime.utcnow()
        timeStamp['patimestamp'] = KerberosTime.to_asn1(now)
        timeStamp['pausec'] = now.microsecond

        # Encrypt the shyte
        encodedTimeStamp = encoder.encode(timeStamp)

        # Key Usage 1
        # AS-REQ PA-ENC-TIMESTAMP padata timestamp, encrypted with the
        # client key (Section 5.2.7.2)
        encriptedTimeStamp = cipher.encrypt(key, 1, encodedTimeStamp, None)

        encryptedData = EncryptedData()
        encryptedData['etype'] = cipher.enctype
        encryptedData['cipher'] = encriptedTimeStamp
        encodedEncryptedData = encoder.encode(encryptedData)

        # Now prepare the new AS_REQ again with the PADATA
        # ToDo: cannot we reuse the previous one?
        asReq = AS_REQ()

        asReq['pvno'] = 5
        asReq['msg-type'] =  int(constants.ApplicationTagNumbers.AS_REQ.value)

        asReq['padata'] = noValue
        asReq['padata'][0] = noValue
        asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_ENC_TIMESTAMP.value)
        asReq['padata'][0]['padata-value'] = encodedEncryptedData

        asReq['padata'][1] = noValue
        asReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        asReq['padata'][1]['padata-value'] = encodedPacRequest

        reqBody = seq_set(asReq, 'req-body')

        opts = list()
        opts.append( constants.KDCOptions.forwardable.value )
        opts.append( constants.KDCOptions.renewable.value )
        opts.append( constants.KDCOptions.proxiable.value )
        reqBody['kdc-options'] = constants.encodeFlags(opts)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        seq_set(reqBody, 'cname', clientName.components_to_asn1)

        reqBody['realm'] =  domain

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['rtime'] =  KerberosTime.to_asn1(now)
        reqBody['nonce'] = rand.getrandbits(31)

        seq_set_iter(reqBody, 'etype', ( (int(cipher.enctype),)))

        try:
            tgt = sendReceive(encoder.encode(asReq), domain, kdcHost)
        except Exception as e:
            if str(e).find('KDC_ERR_ETYPE_NOSUPP') >= 0:
                if lmhash is '' and nthash is '' and (aesKey is '' or aesKey is None):
                    from impacket.ntlm import compute_lmhash, compute_nthash
                    lmhash = compute_lmhash(password)
                    nthash = compute_nthash(password)
                    return getKerberosTGT(clientName, password, domain, lmhash, nthash, aesKey, kdcHost, requestPAC)
            raise


        asRep = decoder.decode(tgt, asn1Spec = AS_REP())[0]

    # So, we have the TGT, now extract the new session key and finish
    cipherText = asRep['enc-part']['cipher']

    if preAuth is False:
        # Let's output the TGT enc-part/cipher in John format, in case somebody wants to use it.
        LOG.debug('$krb5asrep$%d$%s@%s:%s$%s' % (asRep['enc-part']['etype'],clientName, domain, hexlify(asRep['enc-part']['cipher'].asOctets()[:16]),
                                           hexlify(asRep['enc-part']['cipher'].asOctets()[16:])) )
    # Key Usage 3
    # AS-REP encrypted part (includes TGS session key or
    # application session key), encrypted with the client key
    # (Section 5.4.2)
    try:
        plainText = cipher.decrypt(key, 3, cipherText)
    except InvalidChecksum as e:
        # probably bad password if preauth is disabled
        if preAuth is False:
            error_msg = "failed to decrypt session key: %s" % str(e)
            raise SessionKeyDecryptionError(error_msg, asRep, cipher, key, cipherText)
        raise
    encASRepPart = decoder.decode(plainText, asn1Spec = EncASRepPart())[0]

    # Get the session key and the ticket
    # We're assuming the cipher for this session key is the same
    # as the one we used before.
    # ToDo: change this
    sessionKey = Key(cipher.enctype,encASRepPart['key']['keyvalue'].asOctets())

    # ToDo: Check Nonces!

    return tgt, cipher, key, sessionKey
Esempio n. 10
0
def verify_kerberos_password(user, password, domain, kdc_host=None, request_pac=True, host_names=None, source_ip=None):
    host_names = host_names or []
    clientName = Principal(user, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

    domain = domain.upper()
    serverName = Principal("krbtgt/%s" % domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

    pacRequest = KERB_PA_PAC_REQUEST()
    pacRequest["include-pac"] = request_pac
    encodedPacRequest = encoder.encode(pacRequest)

    enctype = constants.EncryptionTypes.rc4_hmac.value
    encryptionTypesData = None # RC4 doesn"t have salt
    cipher = _enctype_table[enctype]

    salt = encryptionTypesData[enctype] if encryptionTypesData else ''
    key = cipher.string_to_key(password, salt, None)

    # Let"s build the timestamp
    timeStamp = PA_ENC_TS_ENC()

    now = datetime.datetime.utcnow()
    timeStamp["patimestamp"] = KerberosTime.to_asn1(now)
    timeStamp["pausec"] = now.microsecond

    encodedTimeStamp = encoder.encode(timeStamp)

    # Key Usage 1
    # AS-REQ PA-ENC-TIMESTAMP padata timestamp, encrypted with the
    # client key (Section 5.2.7.2)
    encriptedTimeStamp = cipher.encrypt(key, 1, encodedTimeStamp, None)

    encryptedData = EncryptedData()
    encryptedData["etype"] = cipher.enctype
    encryptedData["cipher"] = encriptedTimeStamp
    encodedEncryptedData = encoder.encode(encryptedData)

    # Now prepare the new AS_REQ again with the PADATA
    # ToDo: cannot we reuse the previous one?
    asReq = AS_REQ()

    asReq['pvno'] = 5
    asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

    asReq['padata'] = noValue
    asReq['padata'][0] = noValue
    asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_ENC_TIMESTAMP.value)
    asReq['padata'][0]['padata-value'] = encodedEncryptedData

    asReq['padata'][1] = noValue
    asReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][1]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append(constants.KDCOptions.forwardable.value)
    opts.append(constants.KDCOptions.renewable.value)
    opts.append(constants.KDCOptions.proxiable.value)
    reqBody["kdc-options"] = constants.encodeFlags(opts)

    seq_set(reqBody, "sname", serverName.components_to_asn1)
    seq_set(reqBody, "cname", clientName.components_to_asn1)

    reqBody["realm"] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody["till"] = KerberosTime.to_asn1(now)
    reqBody["rtime"] = KerberosTime.to_asn1(now)
    reqBody["nonce"] = random.getrandbits(31)

    seq_set_iter(reqBody, "etype", ((int(cipher.enctype),)))

    try:
        tgt = sendReceive(encoder.encode(asReq), domain, kdc_host)
    except Exception as e:
        if str(e).find('KDC_ERR_PREAUTH_FAILED') >= 0:
            return False
        raise

    return True
Esempio n. 11
0
def getKerberosType1(username, password, domain, lmhash, nthash, aesKey='', TGT = None, TGS = None, targetName='', kdcHost = None, useCache = True):
    if TGT is None and TGS is None:
        if useCache is True:
            try:
                ccache = CCache.loadFile(os.getenv('KRB5CCNAME'))
            except Exception:
                # No cache present
                pass
            else:
                # retrieve domain information from CCache file if needed
                if domain == '':
                    domain = ccache.principal.realm['data'].decode('utf-8')
                    LOG.debug('Domain retrieved from CCache: %s' % domain)

                LOG.debug("Using Kerberos Cache: %s" % os.getenv('KRB5CCNAME'))
                principal = 'host/%s@%s' % (targetName.upper(), domain.upper())
                creds = ccache.getCredential(principal)
                if creds is None:
                    # Let's try for the TGT and go from there
                    principal = 'krbtgt/%s@%s' % (domain.upper(),domain.upper())
                    creds =  ccache.getCredential(principal)
                    if creds is not None:
                        TGT = creds.toTGT()
                        LOG.debug('Using TGT from cache')
                    else:
                        LOG.debug("No valid credentials found in cache. ")
                else:
                    TGS = creds.toTGS(principal)

                # retrieve user information from CCache file if needed
                if username == '' and creds is not None:
                    username = creds['client'].prettyPrint().split(b'@')[0]
                    LOG.debug('Username retrieved from CCache: %s' % username)
                elif username == '' and len(ccache.principal.components) > 0:
                    username = ccache.principal.components[0]['data']
                    LOG.debug('Username retrieved from CCache: %s' % username)

    # First of all, we need to get a TGT for the user
    userName = Principal(username, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
    while True:
        if TGT is None:
            if TGS is None:
                try:
                    tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(userName, password, domain, lmhash, nthash, aesKey, kdcHost)
                except KerberosError as e:
                    if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                        # We might face this if the target does not support AES 
                        # So, if that's the case we'll force using RC4 by converting
                        # the password to lm/nt hashes and hope for the best. If that's already
                        # done, byebye.
                        if lmhash is '' and nthash is '' and (aesKey is '' or aesKey is None) and TGT is None and TGS is None:
                            from impacket.ntlm import compute_lmhash, compute_nthash
                            LOG.debug('Got KDC_ERR_ETYPE_NOSUPP, fallback to RC4')
                            lmhash = compute_lmhash(password)
                            nthash = compute_nthash(password) 
                            continue
                        else:
                            raise 
                    else:
                        raise

        else:
            tgt = TGT['KDC_REP']
            cipher = TGT['cipher']
            sessionKey = TGT['sessionKey'] 

        # Now that we have the TGT, we should ask for a TGS for cifs

        if TGS is None:
            serverName = Principal('host/%s' % targetName, type=constants.PrincipalNameType.NT_SRV_INST.value)
            try:
                tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(serverName, domain, kdcHost, tgt, cipher, sessionKey)
            except KerberosError as e:
                if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                    # We might face this if the target does not support AES 
                    # So, if that's the case we'll force using RC4 by converting
                    # the password to lm/nt hashes and hope for the best. If that's already
                    # done, byebye.
                    if lmhash is '' and nthash is '' and (aesKey is '' or aesKey is None) and TGT is None and TGS is None:
                        from impacket.ntlm import compute_lmhash, compute_nthash
                        LOG.debug('Got KDC_ERR_ETYPE_NOSUPP, fallback to RC4')
                        lmhash = compute_lmhash(password)
                        nthash = compute_nthash(password) 
                    else:
                        raise 
                else:
                    raise 
            else:
                break
        else:
            tgs = TGS['KDC_REP']
            cipher = TGS['cipher']
            sessionKey = TGS['sessionKey'] 
            break

    # Let's build a NegTokenInit with a Kerberos REQ_AP

    blob = SPNEGO_NegTokenInit() 

    # Kerberos
    blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

    # Let's extract the ticket from the TGS
    tgs = decoder.decode(tgs, asn1Spec = TGS_REP())[0]
    ticket = Ticket()
    ticket.from_asn1(tgs['ticket'])
    
    # Now let's build the AP_REQ
    apReq = AP_REQ()
    apReq['pvno'] = 5
    apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

    opts = list()
    opts.append(constants.APOptions.mutual_required.value)
    apReq['ap-options'] = constants.encodeFlags(opts)
    seq_set(apReq,'ticket', ticket.to_asn1)

    authenticator = Authenticator()
    authenticator['authenticator-vno'] = 5
    authenticator['crealm'] = domain
    seq_set(authenticator, 'cname', userName.components_to_asn1)
    now = datetime.datetime.utcnow()

    authenticator['cusec'] = now.microsecond
    authenticator['ctime'] = KerberosTime.to_asn1(now)

    
    authenticator['cksum'] = noValue
    authenticator['cksum']['cksumtype'] = 0x8003

    chkField = CheckSumField()
    chkField['Lgth'] = 16

    chkField['Flags'] = GSS_C_CONF_FLAG | GSS_C_INTEG_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_DCE_STYLE
    #chkField['Flags'] = GSS_C_INTEG_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_DCE_STYLE
    authenticator['cksum']['checksum'] = chkField.getData()
    authenticator['seq-number'] = 0
    encodedAuthenticator = encoder.encode(authenticator)

    # Key Usage 11
    # AP-REQ Authenticator (includes application authenticator
    # subkey), encrypted with the application session key
    # (Section 5.5.1)
    encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11, encodedAuthenticator, None)

    apReq['authenticator'] = noValue
    apReq['authenticator']['etype'] = cipher.enctype
    apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

    blob['MechToken'] = struct.pack('B', ASN1_AID) + asn1encode( struct.pack('B', ASN1_OID) + asn1encode(
            TypesMech['KRB5 - Kerberos 5'] ) + KRB5_AP_REQ + encoder.encode(apReq))

    return cipher, sessionKey, blob.getData()
Esempio n. 12
0
    def getTGT(self, userName, requestPAC=True):

        clientName = Principal(
            userName, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        asReq = AS_REQ()

        domain = self.__domain.upper()
        serverName = Principal(
            'krbtgt/%s' % domain,
            type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        pacRequest = KERB_PA_PAC_REQUEST()
        pacRequest['include-pac'] = requestPAC
        encodedPacRequest = encoder.encode(pacRequest)

        asReq['pvno'] = 5
        asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

        asReq['padata'] = noValue
        asReq['padata'][0] = noValue
        asReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        asReq['padata'][0]['padata-value'] = encodedPacRequest

        reqBody = seq_set(asReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.proxiable.value)
        reqBody['kdc-options'] = constants.encodeFlags(opts)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        seq_set(reqBody, 'cname', clientName.components_to_asn1)

        if domain == '':
            raise Exception('Empty Domain not allowed in Kerberos')

        reqBody['realm'] = domain

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['rtime'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)

        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value), )

        seq_set_iter(reqBody, 'etype', supportedCiphers)

        message = encoder.encode(asReq)

        try:
            r = sendReceive(message, domain, self.__kdcHost)
        except KerberosError, e:
            if e.getErrorCode(
            ) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                # RC4 not available, OK, let's ask for newer types
                supportedCiphers = (
                    int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value
                        ),
                    int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value
                        ),
                )
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, self.__kdcHost)
            else:
                raise e
Esempio n. 13
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def ldap_kerberos(domain, kdc, tgt, username, ldapconnection, hostname):
    # Hackery to authenticate with ldap3 using impacket Kerberos stack
    # I originally wrote this for BloodHound.py, but it works fine (tm) here too

    username = Principal(username,
                         type=constants.PrincipalNameType.NT_PRINCIPAL.value)
    servername = Principal('ldap/%s' % hostname,
                           type=constants.PrincipalNameType.NT_SRV_INST.value)
    tgs, cipher, _, sessionkey = getKerberosTGS(servername, domain, kdc,
                                                tgt['KDC_REP'], tgt['cipher'],
                                                tgt['sessionKey'])

    # Let's build a NegTokenInit with a Kerberos AP_REQ
    blob = SPNEGO_NegTokenInit()

    # Kerberos
    blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

    # Let's extract the ticket from the TGS
    tgs = decoder.decode(tgs, asn1Spec=TGS_REP())[0]
    ticket = Ticket()
    ticket.from_asn1(tgs['ticket'])

    # Now let's build the AP_REQ
    apReq = AP_REQ()
    apReq['pvno'] = 5
    apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

    opts = []
    apReq['ap-options'] = constants.encodeFlags(opts)
    seq_set(apReq, 'ticket', ticket.to_asn1)

    authenticator = Authenticator()
    authenticator['authenticator-vno'] = 5
    authenticator['crealm'] = domain
    seq_set(authenticator, 'cname', username.components_to_asn1)
    now = datetime.datetime.utcnow()

    authenticator['cusec'] = now.microsecond
    authenticator['ctime'] = KerberosTime.to_asn1(now)

    encodedAuthenticator = encoder.encode(authenticator)

    # Key Usage 11
    # AP-REQ Authenticator (includes application authenticator
    # subkey), encrypted with the application session key
    # (Section 5.5.1)
    encryptedEncodedAuthenticator = cipher.encrypt(sessionkey, 11,
                                                   encodedAuthenticator, None)

    apReq['authenticator'] = noValue
    apReq['authenticator']['etype'] = cipher.enctype
    apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

    blob['MechToken'] = encoder.encode(apReq)

    # From here back to ldap3
    ldapconnection.open(read_server_info=False)
    request = bind_operation(ldapconnection.version, SASL, None, None,
                             ldapconnection.sasl_mechanism, blob.getData())
    response = ldapconnection.post_send_single_response(
        ldapconnection.send('bindRequest', request, None))[0]
    ldapconnection.result = response
    if response['result'] == 0:
        ldapconnection.bound = True
        ldapconnection.refresh_server_info()
    return response['result'] == 0
Esempio n. 14
0
def getKerberosType1(username, password, domain, lmhash, nthash, aesKey='', TGT = None, TGS = None, targetName='',
                     kdcHost = None, useCache = True):

    # Convert to binary form, just in case we're receiving strings
    if isinstance(lmhash, str):
        try:
            lmhash = bytes.fromhex(lmhash)
        except TypeError:
            pass
    if isinstance(nthash, str):
        try:
            nthash = bytes.fromhex(nthash)
        except TypeError:
            pass
    if isinstance(aesKey, str):
        try:
            aesKey = bytes.fromhex(aesKey)
        except TypeError:
            pass

    targetName = 'host/%s' % targetName
    if TGT is None and TGS is None:
        if useCache:
            domain, username, TGT, TGS = CCache.parseFile(domain, username, targetName)

    # First of all, we need to get a TGT for the user
    userName = Principal(username, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
    while True:
        if TGT is None:
            if TGS is None:
                try:
                    tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(userName, password, domain, lmhash, nthash, aesKey, kdcHost)
                except KerberosError as e:
                    if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                        # We might face this if the target does not support AES 
                        # So, if that's the case we'll force using RC4 by converting
                        # the password to lm/nt hashes and hope for the best. If that's already
                        # done, byebye.
                        if lmhash == b'' and nthash == b'' and (aesKey == b'' or aesKey is None) and TGT is None and TGS is None:
                            from impacket.ntlm import compute_lmhash, compute_nthash
                            LOG.debug('Got KDC_ERR_ETYPE_NOSUPP, fallback to RC4')
                            lmhash = compute_lmhash(password)
                            nthash = compute_nthash(password) 
                            continue
                        else:
                            raise 
                    else:
                        raise

        else:
            tgt = TGT['KDC_REP']
            cipher = TGT['cipher']
            sessionKey = TGT['sessionKey']

        # Now that we have the TGT, we should ask for a TGS for cifs
        if TGS is None:
            serverName = Principal(targetName, type=constants.PrincipalNameType.NT_SRV_INST.value)
            try:
                tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(serverName, domain, kdcHost, tgt, cipher, sessionKey)
            except KerberosError as e:
                if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                    # We might face this if the target does not support AES
                    # So, if that's the case we'll force using RC4 by converting
                    # the password to lm/nt hashes and hope for the best. If that's already
                    # done, byebye.
                    if lmhash == b'' and nthash == b'' and (aesKey == b'' or aesKey is None) and TGT is None and TGS is None:
                        from impacket.ntlm import compute_lmhash, compute_nthash
                        LOG.debug('Got KDC_ERR_ETYPE_NOSUPP, fallback to RC4')
                        lmhash = compute_lmhash(password)
                        nthash = compute_nthash(password)
                    else:
                        raise
                else:
                    raise
            else:
                break
        else:
            tgs = TGS['KDC_REP']
            cipher = TGS['cipher']
            sessionKey = TGS['sessionKey']
            break

    # Let's build a NegTokenInit with a Kerberos REQ_AP

    blob = SPNEGO_NegTokenInit()

    # Kerberos
    blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

    # Let's extract the ticket from the TGS
    tgs = decoder.decode(tgs, asn1Spec = TGS_REP())[0]
    ticket = Ticket()
    ticket.from_asn1(tgs['ticket'])

    # Now let's build the AP_REQ
    apReq = AP_REQ()
    apReq['pvno'] = 5
    apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

    opts = list()
    opts.append(constants.APOptions.mutual_required.value)
    apReq['ap-options'] = constants.encodeFlags(opts)
    seq_set(apReq,'ticket', ticket.to_asn1)

    authenticator = Authenticator()
    authenticator['authenticator-vno'] = 5
    authenticator['crealm'] = domain
    seq_set(authenticator, 'cname', userName.components_to_asn1)
    now = datetime.datetime.utcnow()

    authenticator['cusec'] = now.microsecond
    authenticator['ctime'] = KerberosTime.to_asn1(now)

    authenticator['cksum'] = noValue
    authenticator['cksum']['cksumtype'] = 0x8003

    chkField = CheckSumField()
    chkField['Lgth'] = 16

    chkField['Flags'] = GSS_C_CONF_FLAG | GSS_C_INTEG_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_DCE_STYLE
    #chkField['Flags'] = GSS_C_INTEG_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_DCE_STYLE
    authenticator['cksum']['checksum'] = chkField.getData()
    authenticator['seq-number'] = 0
    encodedAuthenticator = encoder.encode(authenticator)

    # Key Usage 11
    # AP-REQ Authenticator (includes application authenticator
    # subkey), encrypted with the application session key
    # (Section 5.5.1)
    encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11, encodedAuthenticator, None)

    apReq['authenticator'] = noValue
    apReq['authenticator']['etype'] = cipher.enctype
    apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

    blob['MechToken'] = struct.pack('B', ASN1_AID) + asn1encode( struct.pack('B', ASN1_OID) + asn1encode(
            TypesMech['KRB5 - Kerberos 5'] ) + KRB5_AP_REQ + encoder.encode(apReq))

    return cipher, sessionKey, blob.getData()
Esempio n. 15
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    def doS4U2ProxyWithAdditionalTicket(self, tgt, cipher, oldSessionKey,
                                        sessionKey, nthash, aesKey, kdcHost,
                                        additional_ticket_path):
        if not os.path.isfile(additional_ticket_path):
            logging.error("Ticket %s doesn't exist" % additional_ticket_path)
            exit(0)
        else:
            decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]
            logging.info("\tUsing additional ticket %s instead of S4U2Self" %
                         additional_ticket_path)
            ccache = CCache.loadFile(additional_ticket_path)
            principal = ccache.credentials[0].header['server'].prettyPrint()
            creds = ccache.getCredential(principal.decode())
            TGS = creds.toTGS(principal)

            tgs = decoder.decode(TGS['KDC_REP'], asn1Spec=TGS_REP())[0]

            if logging.getLogger().level == logging.DEBUG:
                logging.debug('TGS_REP')
                print(tgs.prettyPrint())

            if self.__force_forwardable:
                # Convert hashes to binary form, just in case we're receiving strings
                if isinstance(nthash, str):
                    try:
                        nthash = bytes.fromhex(nthash)
                    except TypeError:
                        pass
                if isinstance(aesKey, str):
                    try:
                        aesKey = bytes.fromhex(aesKey)
                    except TypeError:
                        pass

                # Compute NTHash and AESKey if they're not provided in arguments
                if self.__password != '' and self.__domain != '' and self.__user != '':
                    if not nthash:
                        nthash = compute_nthash(self.__password)
                        if logging.getLogger().level == logging.DEBUG:
                            logging.debug('NTHash')
                            print(nthash.hex())
                    if not aesKey:
                        salt = self.__domain.upper() + self.__user
                        aesKey = _AES256CTS.string_to_key(self.__password,
                                                          salt,
                                                          params=None).contents
                        if logging.getLogger().level == logging.DEBUG:
                            logging.debug('AESKey')
                            print(aesKey.hex())

                # Get the encrypted ticket returned in the TGS. It's encrypted with one of our keys
                cipherText = tgs['ticket']['enc-part']['cipher']

                # Check which cipher was used to encrypt the ticket. It's not always the same
                # This determines which of our keys we should use for decryption/re-encryption
                newCipher = _enctype_table[int(
                    tgs['ticket']['enc-part']['etype'])]
                if newCipher.enctype == Enctype.RC4:
                    key = Key(newCipher.enctype, nthash)
                else:
                    key = Key(newCipher.enctype, aesKey)

                # Decrypt and decode the ticket
                # Key Usage 2
                # AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
                #  application session key), encrypted with the service key
                #  (section 5.4.2)
                plainText = newCipher.decrypt(key, 2, cipherText)
                encTicketPart = decoder.decode(plainText,
                                               asn1Spec=EncTicketPart())[0]

                # Print the flags in the ticket before modification
                logging.debug('\tService ticket from S4U2self flags: ' +
                              str(encTicketPart['flags']))
                logging.debug('\tService ticket from S4U2self is' + ('' if (
                    encTicketPart['flags'][TicketFlags.forwardable.value] == 1
                ) else ' not') + ' forwardable')

                # Customize flags the forwardable flag is the only one that really matters
                logging.info('\tForcing the service ticket to be forwardable')
                # convert to string of bits
                flagBits = encTicketPart['flags'].asBinary()
                # Set the forwardable flag. Awkward binary string insertion
                flagBits = flagBits[:TicketFlags.forwardable.
                                    value] + '1' + flagBits[
                                        TicketFlags.forwardable.value + 1:]
                # Overwrite the value with the new bits
                encTicketPart['flags'] = encTicketPart['flags'].clone(
                    value=flagBits)  # Update flags

                logging.debug('\tService ticket flags after modification: ' +
                              str(encTicketPart['flags']))
                logging.debug('\tService ticket now is' + ('' if (
                    encTicketPart['flags'][TicketFlags.forwardable.value] == 1
                ) else ' not') + ' forwardable')

                # Re-encode and re-encrypt the ticket
                # Again, Key Usage 2
                encodedEncTicketPart = encoder.encode(encTicketPart)
                cipherText = newCipher.encrypt(key, 2, encodedEncTicketPart,
                                               None)

                # put it back in the TGS
                tgs['ticket']['enc-part']['cipher'] = cipherText

            ################################################################################
            # Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
            # So here I have a ST for me.. I now want a ST for another service
            # Extract the ticket from the TGT
            ticketTGT = Ticket()
            ticketTGT.from_asn1(decodedTGT['ticket'])

            # Get the service ticket
            ticket = Ticket()
            ticket.from_asn1(tgs['ticket'])

            apReq = AP_REQ()
            apReq['pvno'] = 5
            apReq['msg-type'] = int(
                constants.ApplicationTagNumbers.AP_REQ.value)

            opts = list()
            apReq['ap-options'] = constants.encodeFlags(opts)
            seq_set(apReq, 'ticket', ticketTGT.to_asn1)

            authenticator = Authenticator()
            authenticator['authenticator-vno'] = 5
            authenticator['crealm'] = str(decodedTGT['crealm'])

            clientName = Principal()
            clientName.from_asn1(decodedTGT, 'crealm', 'cname')

            seq_set(authenticator, 'cname', clientName.components_to_asn1)

            now = datetime.datetime.utcnow()
            authenticator['cusec'] = now.microsecond
            authenticator['ctime'] = KerberosTime.to_asn1(now)

            encodedAuthenticator = encoder.encode(authenticator)

            # Key Usage 7
            # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
            # TGS authenticator subkey), encrypted with the TGS session
            # key (Section 5.5.1)
            encryptedEncodedAuthenticator = cipher.encrypt(
                sessionKey, 7, encodedAuthenticator, None)

            apReq['authenticator'] = noValue
            apReq['authenticator']['etype'] = cipher.enctype
            apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

            encodedApReq = encoder.encode(apReq)

            tgsReq = TGS_REQ()

            tgsReq['pvno'] = 5
            tgsReq['msg-type'] = int(
                constants.ApplicationTagNumbers.TGS_REQ.value)
            tgsReq['padata'] = noValue
            tgsReq['padata'][0] = noValue
            tgsReq['padata'][0]['padata-type'] = int(
                constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
            tgsReq['padata'][0]['padata-value'] = encodedApReq

            # Add resource-based constrained delegation support
            paPacOptions = PA_PAC_OPTIONS()
            paPacOptions['flags'] = constants.encodeFlags(
                (constants.PAPacOptions.resource_based_constrained_delegation.
                 value, ))

            tgsReq['padata'][1] = noValue
            tgsReq['padata'][1][
                'padata-type'] = constants.PreAuthenticationDataTypes.PA_PAC_OPTIONS.value
            tgsReq['padata'][1]['padata-value'] = encoder.encode(paPacOptions)

            reqBody = seq_set(tgsReq, 'req-body')

            opts = list()
            # This specified we're doing S4U
            opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
            opts.append(constants.KDCOptions.canonicalize.value)
            opts.append(constants.KDCOptions.forwardable.value)
            opts.append(constants.KDCOptions.renewable.value)

            reqBody['kdc-options'] = constants.encodeFlags(opts)
            service2 = Principal(
                self.__options.spn,
                type=constants.PrincipalNameType.NT_SRV_INST.value)
            seq_set(reqBody, 'sname', service2.components_to_asn1)
            reqBody['realm'] = self.__domain

            myTicket = ticket.to_asn1(TicketAsn1())
            seq_set_iter(reqBody, 'additional-tickets', (myTicket, ))

            now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

            reqBody['till'] = KerberosTime.to_asn1(now)
            reqBody['nonce'] = random.getrandbits(31)
            seq_set_iter(
                reqBody, 'etype',
                (int(constants.EncryptionTypes.rc4_hmac.value),
                 int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
                 int(constants.EncryptionTypes.des_cbc_md5.value),
                 int(cipher.enctype)))
            message = encoder.encode(tgsReq)

            logging.info('\tRequesting S4U2Proxy')
            r = sendReceive(message, self.__domain, kdcHost)

            tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

            cipherText = tgs['enc-part']['cipher']

            # Key Usage 8
            # TGS-REP encrypted part (includes application session
            # key), encrypted with the TGS session key (Section 5.4.2)
            plainText = cipher.decrypt(sessionKey, 8, cipherText)

            encTGSRepPart = decoder.decode(plainText,
                                           asn1Spec=EncTGSRepPart())[0]

            newSessionKey = Key(encTGSRepPart['key']['keytype'],
                                encTGSRepPart['key']['keyvalue'])

            # Creating new cipher based on received keytype
            cipher = _enctype_table[encTGSRepPart['key']['keytype']]

            return r, cipher, sessionKey, newSessionKey
Esempio n. 16
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    def kerberosLogin(self,
                      user,
                      password,
                      domain='',
                      lmhash='',
                      nthash='',
                      aesKey='',
                      kdcHost=None,
                      TGT=None,
                      TGS=None,
                      useCache=True):
        """
        logins into the target system explicitly using Kerberos. Hashes are used if RC4_HMAC is supported.

        :param string user: username
        :param string password: password for the user
        :param string domain: domain where the account is valid for (required)
        :param string lmhash: LMHASH used to authenticate using hashes (password is not used)
        :param string nthash: NTHASH used to authenticate using hashes (password is not used)
        :param string aesKey: aes256-cts-hmac-sha1-96 or aes128-cts-hmac-sha1-96 used for Kerberos authentication
        :param string kdcHost: hostname or IP Address for the KDC. If None, the domain will be used (it needs to resolve tho)
        :param struct TGT: If there's a TGT available, send the structure here and it will be used
        :param struct TGS: same for TGS. See smb3.py for the format
        :param bool useCache: whether or not we should use the ccache for credentials lookup. If TGT or TGS are specified this is False

        :return: True, raises a LDAPSessionError if error.
        """

        if lmhash != '' or nthash != '':
            if len(lmhash) % 2: lmhash = '0%s' % lmhash
            if len(nthash) % 2: nthash = '0%s' % nthash
            try:  # just in case they were converted already
                lmhash = unhexlify(lmhash)
                nthash = unhexlify(nthash)
            except:
                pass

        # Importing down here so pyasn1 is not required if kerberos is not used.
        from impacket.krb5.ccache import CCache
        from impacket.krb5.asn1 import AP_REQ, Authenticator, TGS_REP, seq_set
        from impacket.krb5.kerberosv5 import getKerberosTGT, getKerberosTGS
        from impacket.krb5 import constants
        from impacket.krb5.types import Principal, KerberosTime, Ticket
        from pyasn1.codec.der import decoder, encoder
        import datetime

        if TGT is not None or TGS is not None:
            useCache = False

        if useCache is True:
            try:
                ccache = CCache.loadFile(os.getenv('KRB5CCNAME'))
            except:
                # No cache present
                pass
            else:
                # retrieve user and domain information from CCache file if needed
                if user == '' and len(ccache.principal.components) > 0:
                    user = ccache.principal.components[0]['data']
                if domain == '':
                    domain = ccache.principal.realm['data']
                LOG.debug("Using Kerberos Cache: %s" % os.getenv('KRB5CCNAME'))
                principal = 'ldap/%s@%s' % (self._dstHost.upper(),
                                            domain.upper())
                creds = ccache.getCredential(principal)
                if creds is None:
                    # Let's try for the TGT and go from there
                    principal = 'krbtgt/%s@%s' % (domain.upper(),
                                                  domain.upper())
                    creds = ccache.getCredential(principal)
                    if creds is not None:
                        TGT = creds.toTGT()
                        LOG.debug('Using TGT from cache')
                    else:
                        LOG.debug("No valid credentials found in cache. ")
                else:
                    TGS = creds.toTGS()
                    LOG.debug('Using TGS from cache')

        # First of all, we need to get a TGT for the user
        userName = Principal(
            user, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
        if TGT is None:
            if TGS is None:
                tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
                    userName, password, domain, lmhash, nthash, aesKey,
                    kdcHost)
        else:
            tgt = TGT['KDC_REP']
            cipher = TGT['cipher']
            sessionKey = TGT['sessionKey']

        if TGS is None:
            serverName = Principal(
                'ldap/%s' % self._dstHost,
                type=constants.PrincipalNameType.NT_SRV_INST.value)
            tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(
                serverName, domain, kdcHost, tgt, cipher, sessionKey)
        else:
            tgs = TGS['KDC_REP']
            cipher = TGS['cipher']
            sessionKey = TGS['sessionKey']

            # Let's build a NegTokenInit with a Kerberos REQ_AP

        blob = SPNEGO_NegTokenInit()

        # Kerberos
        blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

        # Let's extract the ticket from the TGS
        tgs = decoder.decode(tgs, asn1Spec=TGS_REP())[0]
        ticket = Ticket()
        ticket.from_asn1(tgs['ticket'])

        # Now let's build the AP_REQ
        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = domain
        seq_set(authenticator, 'cname', userName.components_to_asn1)
        now = datetime.datetime.utcnow()

        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 11
        # AP-REQ Authenticator (includes application authenticator
        # subkey), encrypted with the application session key
        # (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = None
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        blob['MechToken'] = encoder.encode(apReq)

        # Done with the Kerberos saga, now let's get into LDAP

        bindRequest = BindRequest()
        bindRequest['version'] = Integer7Bit(3)
        bindRequest['name'] = LDAPDN(user)
        credentials = SaslCredentials()
        credentials['mechanism'] = LDAPString('GSSAPI')
        credentials['credentials'] = blob.getData()
        bindRequest['authentication'] = AuthenticationChoice(
        ).setComponentByName('sasl', credentials)

        resp = self.sendReceive(bindRequest)[0]['protocolOp']

        if resp['bindResponse']['resultCode'] != 0:
            raise LDAPSessionError(
                errorString='%s:%s' %
                (resp['bindResponse']['resultCode'].prettyPrint(),
                 resp['bindResponse']['diagnosticMessage']))

        return True
Esempio n. 17
0
    def customizeTicket(self, kdcRep, pacInfos):
        logging.info('Customizing ticket for %s/%s' % (self.__domain, self.__target))
        encTicketPart = EncTicketPart()

        flags = list()
        flags.append(TicketFlags.forwardable.value)
        flags.append(TicketFlags.proxiable.value)
        flags.append(TicketFlags.renewable.value)
        flags.append(TicketFlags.initial.value)
        flags.append(TicketFlags.pre_authent.value)
        encTicketPart['flags'] = encodeFlags(flags)
        encTicketPart['key'] = None
        encTicketPart['key']['keytype'] = kdcRep['ticket']['enc-part']['etype']

        if encTicketPart['key']['keytype'] == EncryptionTypes.aes128_cts_hmac_sha1_96.value:
            encTicketPart['key']['keyvalue'] = ''.join([random.choice(string.letters) for _ in range(16)])
        elif encTicketPart['key']['keytype'] == EncryptionTypes.aes256_cts_hmac_sha1_96.value:
            encTicketPart['key']['keyvalue'] = ''.join([random.choice(string.letters) for _ in range(32)])
        else:
            encTicketPart['key']['keyvalue'] = ''.join([random.choice(string.letters) for _ in range(16)])

        encTicketPart['crealm'] = self.__domain.upper()
        encTicketPart['cname'] = None
        encTicketPart['cname']['name-type'] = PrincipalNameType.NT_PRINCIPAL.value
        encTicketPart['cname']['name-string'] = None
        encTicketPart['cname']['name-string'][0] = self.__target

        encTicketPart['transited'] = None
        encTicketPart['transited']['tr-type'] = 0
        encTicketPart['transited']['contents'] = ''

        encTicketPart['authtime'] = KerberosTime.to_asn1(datetime.datetime.utcnow())
        encTicketPart['starttime'] = KerberosTime.to_asn1(datetime.datetime.utcnow())
        # Let's extend the ticket's validity a lil bit
        ticketDuration = datetime.datetime.utcnow() + datetime.timedelta(days=int(self.__options.duration))
        encTicketPart['endtime'] = KerberosTime.to_asn1(ticketDuration)
        encTicketPart['renew-till'] = KerberosTime.to_asn1(ticketDuration)
        encTicketPart['authorization-data'] = None
        encTicketPart['authorization-data'][0] = None
        encTicketPart['authorization-data'][0]['ad-type'] = AuthorizationDataType.AD_IF_RELEVANT.value
        encTicketPart['authorization-data'][0]['ad-data'] = None

        # Let's locate the KERB_VALIDATION_INFO and Checksums
        if pacInfos.has_key(PAC_LOGON_INFO):
            data = pacInfos[PAC_LOGON_INFO]
            validationInfo = VALIDATION_INFO()
            validationInfo.fromString(pacInfos[PAC_LOGON_INFO])
            lenVal = len(validationInfo.getData())
            validationInfo.fromStringReferents(data[lenVal:], lenVal)

            aTime = timegm(strptime(str(encTicketPart['authtime']), '%Y%m%d%H%M%SZ'))

            unixTime = self.getFileTime(aTime)

            kerbdata = KERB_VALIDATION_INFO()

            kerbdata['LogonTime']['dwLowDateTime'] = unixTime & 0xffffffff
            kerbdata['LogonTime']['dwHighDateTime'] = unixTime >> 32

            # Let's adjust username and other data
            validationInfo['Data']['LogonDomainName'] = self.__domain.upper()
            validationInfo['Data']['EffectiveName'] = self.__target
            # Our Golden Well-known groups! :)
            groups = self.__options.groups.split(',')
            validationInfo['Data']['GroupIds'] = list()
            validationInfo['Data']['GroupCount'] = len(groups)

            for group in groups:
                groupMembership = GROUP_MEMBERSHIP()
                groupId = NDRULONG()
                groupId['Data'] = int(group)
                groupMembership['RelativeId'] = groupId
                groupMembership['Attributes'] = SE_GROUP_MANDATORY | SE_GROUP_ENABLED_BY_DEFAULT | SE_GROUP_ENABLED
                validationInfo['Data']['GroupIds'].append(groupMembership)

            # Let's add the extraSid
            if self.__options.extra_sid is not None:
                if validationInfo['Data']['SidCount'] == 0:
                    # Let's be sure user's flag specify we have extra sids.
                    validationInfo['Data']['UserFlags'] |= 0x20
                    validationInfo['Data']['ExtraSids'] = PKERB_SID_AND_ATTRIBUTES_ARRAY()

                validationInfo['Data']['SidCount'] += 1

                sidRecord = KERB_SID_AND_ATTRIBUTES()

                sid = RPC_SID()
                sid.fromCanonical(self.__options.extra_sid)

                sidRecord['Sid'] = sid
                sidRecord['Attributes'] = SE_GROUP_MANDATORY | SE_GROUP_ENABLED_BY_DEFAULT | SE_GROUP_ENABLED

                # And, let's append the magicSid
                validationInfo['Data']['ExtraSids'].append(sidRecord)
            else:
                validationInfo['Data']['ExtraSids'] = NULL

            validationInfoBlob  = validationInfo.getData() + validationInfo.getDataReferents()
            pacInfos[PAC_LOGON_INFO] = validationInfoBlob

            if logging.getLogger().level == logging.DEBUG:
                logging.debug('VALIDATION_INFO after making it gold')
                validationInfo.dump()
                print ('\n')
        else:
            raise Exception('PAC_LOGON_INFO not found! Aborting')

        logging.info('\tPAC_LOGON_INFO')

        # Let's now clear the checksums
        if pacInfos.has_key(PAC_SERVER_CHECKSUM):
            serverChecksum = PAC_SIGNATURE_DATA(pacInfos[PAC_SERVER_CHECKSUM])
            if serverChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes256.value:
                serverChecksum['Signature'] = '\x00' * 12
            elif serverChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes128.value:
                serverChecksum['Signature'] = '\x00' * 12
            else:
                serverChecksum['Signature'] = '\x00' * 16
            pacInfos[PAC_SERVER_CHECKSUM] = serverChecksum.getData()
        else:
            raise Exception('PAC_SERVER_CHECKSUM not found! Aborting')

        if pacInfos.has_key(PAC_PRIVSVR_CHECKSUM):
            privSvrChecksum = PAC_SIGNATURE_DATA(pacInfos[PAC_PRIVSVR_CHECKSUM])
            privSvrChecksum['Signature'] = '\x00' * 12
            if privSvrChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes256.value:
                privSvrChecksum['Signature'] = '\x00' * 12
            elif privSvrChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes128.value:
                privSvrChecksum['Signature'] = '\x00' * 12
            else:
                privSvrChecksum['Signature'] = '\x00' * 16
            pacInfos[PAC_PRIVSVR_CHECKSUM] = privSvrChecksum.getData()
        else:
            raise Exception('PAC_PRIVSVR_CHECKSUM not found! Aborting')

        if pacInfos.has_key(PAC_CLIENT_INFO_TYPE):
            pacClientInfo = PAC_CLIENT_INFO(pacInfos[PAC_CLIENT_INFO_TYPE])
            pacClientInfo['ClientId'] = unixTime
            pacInfos[PAC_CLIENT_INFO_TYPE] = pacClientInfo.getData()
        else:
            raise Exception('PAC_CLIENT_INFO_TYPE not found! Aborting')

        logging.info('\tPAC_CLIENT_INFO_TYPE')
        logging.info('\tEncTicketPart')

        encASRepPart = EncASRepPart()
        encASRepPart['key'] = None
        encASRepPart['key']['keytype'] = encTicketPart['key']['keytype']
        encASRepPart['key']['keyvalue'] = encTicketPart['key']['keyvalue']
        encASRepPart['last-req'] = None
        encASRepPart['last-req'][0] = None
        encASRepPart['last-req'][0]['lr-type'] = 0
        encASRepPart['last-req'][0]['lr-value'] = KerberosTime.to_asn1(datetime.datetime.utcnow())
        encASRepPart['nonce'] = 123456789
        encASRepPart['key-expiration'] = KerberosTime.to_asn1(ticketDuration)
        encASRepPart['flags'] = encodeFlags(flags)
        encASRepPart['authtime'] = encTicketPart['authtime']
        encASRepPart['endtime'] = encTicketPart['endtime']
        encASRepPart['starttime'] = encTicketPart['starttime']
        encASRepPart['renew-till'] = encTicketPart['renew-till']
        encASRepPart['srealm'] = self.__domain.upper()
        encASRepPart['sname'] = None
        encASRepPart['sname']['name-type'] = PrincipalNameType.NT_PRINCIPAL.value
        encASRepPart['sname']['name-string'] = None
        encASRepPart['sname']['name-string'][0] = 'krbtgt'
        encASRepPart['sname']['name-string'][1] = self.__domain.upper()
        logging.info('\tEncAsRepPart')

        return encASRepPart, encTicketPart, pacInfos
    def customizeTicket(self, kdcRep, pacInfos):
        logging.info('Customizing ticket for %s/%s' % (self.__domain, self.__target))
        encTicketPart = EncTicketPart()

        flags = list()
        flags.append(TicketFlags.forwardable.value)
        flags.append(TicketFlags.proxiable.value)
        flags.append(TicketFlags.renewable.value)
        if self.__domain == self.__server: 
            flags.append(TicketFlags.initial.value)
        flags.append(TicketFlags.pre_authent.value)
        encTicketPart['flags'] = encodeFlags(flags)
        encTicketPart['key'] = noValue
        encTicketPart['key']['keytype'] = kdcRep['ticket']['enc-part']['etype']

        if encTicketPart['key']['keytype'] == EncryptionTypes.aes128_cts_hmac_sha1_96.value:
            encTicketPart['key']['keyvalue'] = ''.join([random.choice(string.letters) for _ in range(16)])
        elif encTicketPart['key']['keytype'] == EncryptionTypes.aes256_cts_hmac_sha1_96.value:
            encTicketPart['key']['keyvalue'] = ''.join([random.choice(string.letters) for _ in range(32)])
        else:
            encTicketPart['key']['keyvalue'] = ''.join([random.choice(string.letters) for _ in range(16)])

        encTicketPart['crealm'] = self.__domain.upper()
        encTicketPart['cname'] = noValue
        encTicketPart['cname']['name-type'] = PrincipalNameType.NT_PRINCIPAL.value
        encTicketPart['cname']['name-string'] = noValue
        encTicketPart['cname']['name-string'][0] = self.__target

        encTicketPart['transited'] = noValue
        encTicketPart['transited']['tr-type'] = 0
        encTicketPart['transited']['contents'] = ''

        encTicketPart['authtime'] = KerberosTime.to_asn1(datetime.datetime.utcnow())
        encTicketPart['starttime'] = KerberosTime.to_asn1(datetime.datetime.utcnow())
        # Let's extend the ticket's validity a lil bit
        ticketDuration = datetime.datetime.utcnow() + datetime.timedelta(days=int(self.__options.duration))
        encTicketPart['endtime'] = KerberosTime.to_asn1(ticketDuration)
        encTicketPart['renew-till'] = KerberosTime.to_asn1(ticketDuration)
        encTicketPart['authorization-data'] = noValue
        encTicketPart['authorization-data'][0] = noValue
        encTicketPart['authorization-data'][0]['ad-type'] = AuthorizationDataType.AD_IF_RELEVANT.value
        encTicketPart['authorization-data'][0]['ad-data'] = noValue

        # Let's locate the KERB_VALIDATION_INFO and Checksums
        if pacInfos.has_key(PAC_LOGON_INFO):
            data = pacInfos[PAC_LOGON_INFO]
            validationInfo = VALIDATION_INFO()
            validationInfo.fromString(pacInfos[PAC_LOGON_INFO])
            lenVal = len(validationInfo.getData())
            validationInfo.fromStringReferents(data[lenVal:], lenVal)

            aTime = timegm(strptime(str(encTicketPart['authtime']), '%Y%m%d%H%M%SZ'))

            unixTime = self.getFileTime(aTime)

            kerbdata = KERB_VALIDATION_INFO()

            kerbdata['LogonTime']['dwLowDateTime'] = unixTime & 0xffffffff
            kerbdata['LogonTime']['dwHighDateTime'] = unixTime >> 32

            # Let's adjust username and other data
            validationInfo['Data']['LogonDomainName'] = self.__domain.upper()
            validationInfo['Data']['EffectiveName'] = self.__target
            # Our Golden Well-known groups! :)
            groups = self.__options.groups.split(',')
            validationInfo['Data']['GroupIds'] = list()
            validationInfo['Data']['GroupCount'] = len(groups)

            for group in groups:
                groupMembership = GROUP_MEMBERSHIP()
                groupId = NDRULONG()
                groupId['Data'] = int(group)
                groupMembership['RelativeId'] = groupId
                groupMembership['Attributes'] = SE_GROUP_MANDATORY | SE_GROUP_ENABLED_BY_DEFAULT | SE_GROUP_ENABLED
                validationInfo['Data']['GroupIds'].append(groupMembership)

            # Let's add the extraSid
            if self.__options.extra_sid is not None:
                extrasids = self.__options.extra_sid.split(',')
                if validationInfo['Data']['SidCount'] == 0:
                    # Let's be sure user's flag specify we have extra sids.
                    validationInfo['Data']['UserFlags'] |= 0x20
                    validationInfo['Data']['ExtraSids'] = PKERB_SID_AND_ATTRIBUTES_ARRAY()
                for extrasid in extrasids:
                    validationInfo['Data']['SidCount'] += 1

                    sidRecord = KERB_SID_AND_ATTRIBUTES()

                    sid = RPC_SID()
                    sid.fromCanonical(extrasid)

                    sidRecord['Sid'] = sid
                    sidRecord['Attributes'] = SE_GROUP_MANDATORY | SE_GROUP_ENABLED_BY_DEFAULT | SE_GROUP_ENABLED

                    # And, let's append the magicSid
                    validationInfo['Data']['ExtraSids'].append(sidRecord)
            else:
                validationInfo['Data']['ExtraSids'] = NULL

            validationInfoBlob  = validationInfo.getData() + validationInfo.getDataReferents()
            pacInfos[PAC_LOGON_INFO] = validationInfoBlob

            if logging.getLogger().level == logging.DEBUG:
                logging.debug('VALIDATION_INFO after making it gold')
                validationInfo.dump()
                print ('\n')
        else:
            raise Exception('PAC_LOGON_INFO not found! Aborting')

        logging.info('\tPAC_LOGON_INFO')

        # Let's now clear the checksums
        if pacInfos.has_key(PAC_SERVER_CHECKSUM):
            serverChecksum = PAC_SIGNATURE_DATA(pacInfos[PAC_SERVER_CHECKSUM])
            if serverChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes256.value:
                serverChecksum['Signature'] = '\x00' * 12
            elif serverChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes128.value:
                serverChecksum['Signature'] = '\x00' * 12
            else:
                serverChecksum['Signature'] = '\x00' * 16
            pacInfos[PAC_SERVER_CHECKSUM] = serverChecksum.getData()
        else:
            raise Exception('PAC_SERVER_CHECKSUM not found! Aborting')

        if pacInfos.has_key(PAC_PRIVSVR_CHECKSUM):
            privSvrChecksum = PAC_SIGNATURE_DATA(pacInfos[PAC_PRIVSVR_CHECKSUM])
            privSvrChecksum['Signature'] = '\x00' * 12
            if privSvrChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes256.value:
                privSvrChecksum['Signature'] = '\x00' * 12
            elif privSvrChecksum['SignatureType'] == ChecksumTypes.hmac_sha1_96_aes128.value:
                privSvrChecksum['Signature'] = '\x00' * 12
            else:
                privSvrChecksum['Signature'] = '\x00' * 16
            pacInfos[PAC_PRIVSVR_CHECKSUM] = privSvrChecksum.getData()
        else:
            raise Exception('PAC_PRIVSVR_CHECKSUM not found! Aborting')

        if pacInfos.has_key(PAC_CLIENT_INFO_TYPE):
            pacClientInfo = PAC_CLIENT_INFO(pacInfos[PAC_CLIENT_INFO_TYPE])
            pacClientInfo['ClientId'] = unixTime
            pacInfos[PAC_CLIENT_INFO_TYPE] = pacClientInfo.getData()
        else:
            raise Exception('PAC_CLIENT_INFO_TYPE not found! Aborting')

        logging.info('\tPAC_CLIENT_INFO_TYPE')
        logging.info('\tEncTicketPart')

        if self.__domain == self.__server:
            encRepPart = EncASRepPart()
        else:
            encRepPart = EncTGSRepPart()

        encRepPart['key'] = noValue
        encRepPart['key']['keytype'] = encTicketPart['key']['keytype']
        encRepPart['key']['keyvalue'] = encTicketPart['key']['keyvalue']
        encRepPart['last-req'] = noValue
        encRepPart['last-req'][0] = noValue
        encRepPart['last-req'][0]['lr-type'] = 0
        encRepPart['last-req'][0]['lr-value'] = KerberosTime.to_asn1(datetime.datetime.utcnow())
        encRepPart['nonce'] = 123456789
        encRepPart['key-expiration'] = KerberosTime.to_asn1(ticketDuration)
        encRepPart['flags'] = encodeFlags(flags)
        encRepPart['authtime'] = encTicketPart['authtime']
        encRepPart['endtime'] = encTicketPart['endtime']
        encRepPart['starttime'] = encTicketPart['starttime']
        encRepPart['renew-till'] = encTicketPart['renew-till']
        encRepPart['srealm'] = self.__domain.upper()
        encRepPart['sname'] = noValue
        encRepPart['sname']['name-string'] = noValue
        encRepPart['sname']['name-string'][0] = self.__service

        if self.__domain == self.__server:
            encRepPart['sname']['name-type'] = PrincipalNameType.NT_SRV_INST.value
            encRepPart['sname']['name-string'][1] = self.__domain.upper()
            logging.info('\tEncAsRepPart')
        else:
            encRepPart['sname']['name-type'] = PrincipalNameType.NT_PRINCIPAL.value
            encRepPart['sname']['name-string'][1] = self.__server
            logging.info('\tEncTGSRepPart')

        return encRepPart, encTicketPart, pacInfos
Esempio n. 19
0
    asReq['padata'][0]['padata-type'] = int(
        constants.PreAuthenticationDataTypes.PA_ENC_TIMESTAMP.value)
    asReq['padata'][0]['padata-value'] = encodedEncryptedData

    asReq['padata'][1] = None
    asReq['padata'][1]['padata-type'] = int(
        constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][1]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append(constants.KDCOptions.forwardable.value)
    opts.append(constants.KDCOptions.renewable.value)
    opts.append(constants.KDCOptions.proxiable.value)
    reqBody['kdc-options'] = constants.encodeFlags(opts)

    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    seq_set(reqBody, 'cname', clientName.components_to_asn1)

    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['rtime'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] = random.getrandbits(31)

    seq_set_iter(reqBody, 'etype', ((int(cipher.enctype), )))

    try:
        tgt = sendReceive(encoder.encode(asReq), domain, kdcHost)
Esempio n. 20
0
def getKerberosType1(username,
                     password,
                     domain,
                     lmhash,
                     nthash,
                     aesKey='',
                     TGT=None,
                     TGS=None,
                     targetName='',
                     kdcHost=None,
                     useCache=True):
    if TGT is None and TGS is None:
        if useCache is True:
            try:
                ccache = CCache.loadFile(os.getenv('KRB5CCNAME'))
            except Exception:
                # No cache present
                pass
            else:
                # retrieve domain information from CCache file if needed
                if domain == '':
                    domain = ccache.principal.realm['data'].decode('utf-8')
                    LOG.debug('Domain retrieved from CCache: %s' % domain)

                LOG.debug("Using Kerberos Cache: %s" % os.getenv('KRB5CCNAME'))
                principal = 'host/%s@%s' % (targetName.upper(), domain.upper())
                creds = ccache.getCredential(principal)
                if creds is None:
                    # Let's try for the TGT and go from there
                    principal = 'krbtgt/%s@%s' % (domain.upper(),
                                                  domain.upper())
                    creds = ccache.getCredential(principal)
                    if creds is not None:
                        TGT = creds.toTGT()
                        LOG.debug('Using TGT from cache')
                    else:
                        LOG.debug("No valid credentials found in cache. ")
                else:
                    TGS = creds.toTGS(principal)

                # retrieve user information from CCache file if needed
                if username == '' and creds is not None:
                    username = creds['client'].prettyPrint().split(b'@')[0]
                    LOG.debug('Username retrieved from CCache: %s' % username)
                elif username == '' and len(ccache.principal.components) > 0:
                    username = ccache.principal.components[0]['data']
                    LOG.debug('Username retrieved from CCache: %s' % username)

    # First of all, we need to get a TGT for the user
    userName = Principal(username,
                         type=constants.PrincipalNameType.NT_PRINCIPAL.value)
    while True:
        if TGT is None:
            if TGS is None:
                try:
                    tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
                        userName, password, domain, lmhash, nthash, aesKey,
                        kdcHost)
                except KerberosError as e:
                    if e.getErrorCode(
                    ) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                        # We might face this if the target does not support AES
                        # So, if that's the case we'll force using RC4 by converting
                        # the password to lm/nt hashes and hope for the best. If that's already
                        # done, byebye.
                        if lmhash is '' and nthash is '' and (
                                aesKey is '' or aesKey is None
                        ) and TGT is None and TGS is None:
                            from impacket.ntlm import compute_lmhash, compute_nthash
                            LOG.debug(
                                'Got KDC_ERR_ETYPE_NOSUPP, fallback to RC4')
                            lmhash = compute_lmhash(password)
                            nthash = compute_nthash(password)
                            continue
                        else:
                            raise
                    else:
                        raise

        else:
            tgt = TGT['KDC_REP']
            cipher = TGT['cipher']
            sessionKey = TGT['sessionKey']

        # Now that we have the TGT, we should ask for a TGS for cifs

        if TGS is None:
            serverName = Principal(
                'host/%s' % targetName,
                type=constants.PrincipalNameType.NT_SRV_INST.value)
            try:
                tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(
                    serverName, domain, kdcHost, tgt, cipher, sessionKey)
            except KerberosError as e:
                if e.getErrorCode(
                ) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                    # We might face this if the target does not support AES
                    # So, if that's the case we'll force using RC4 by converting
                    # the password to lm/nt hashes and hope for the best. If that's already
                    # done, byebye.
                    if lmhash is '' and nthash is '' and (
                            aesKey is ''
                            or aesKey is None) and TGT is None and TGS is None:
                        from impacket.ntlm import compute_lmhash, compute_nthash
                        LOG.debug('Got KDC_ERR_ETYPE_NOSUPP, fallback to RC4')
                        lmhash = compute_lmhash(password)
                        nthash = compute_nthash(password)
                    else:
                        raise
                else:
                    raise
            else:
                break
        else:
            tgs = TGS['KDC_REP']
            cipher = TGS['cipher']
            sessionKey = TGS['sessionKey']
            break

    # Let's build a NegTokenInit with a Kerberos REQ_AP

    blob = SPNEGO_NegTokenInit()

    # Kerberos
    blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

    # Let's extract the ticket from the TGS
    tgs = decoder.decode(tgs, asn1Spec=TGS_REP())[0]
    ticket = Ticket()
    ticket.from_asn1(tgs['ticket'])

    # Now let's build the AP_REQ
    apReq = AP_REQ()
    apReq['pvno'] = 5
    apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

    opts = list()
    opts.append(constants.APOptions.mutual_required.value)
    apReq['ap-options'] = constants.encodeFlags(opts)
    seq_set(apReq, 'ticket', ticket.to_asn1)

    authenticator = Authenticator()
    authenticator['authenticator-vno'] = 5
    authenticator['crealm'] = domain
    seq_set(authenticator, 'cname', userName.components_to_asn1)
    now = datetime.datetime.utcnow()

    authenticator['cusec'] = now.microsecond
    authenticator['ctime'] = KerberosTime.to_asn1(now)

    authenticator['cksum'] = noValue
    authenticator['cksum']['cksumtype'] = 0x8003

    chkField = CheckSumField()
    chkField['Lgth'] = 16

    chkField[
        'Flags'] = GSS_C_CONF_FLAG | GSS_C_INTEG_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_DCE_STYLE
    #chkField['Flags'] = GSS_C_INTEG_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_DCE_STYLE
    authenticator['cksum']['checksum'] = chkField.getData()
    authenticator['seq-number'] = 0
    encodedAuthenticator = encoder.encode(authenticator)

    # Key Usage 11
    # AP-REQ Authenticator (includes application authenticator
    # subkey), encrypted with the application session key
    # (Section 5.5.1)
    encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11,
                                                   encodedAuthenticator, None)

    apReq['authenticator'] = noValue
    apReq['authenticator']['etype'] = cipher.enctype
    apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

    blob['MechToken'] = struct.pack('B', ASN1_AID) + asn1encode(
        struct.pack('B', ASN1_OID) +
        asn1encode(TypesMech['KRB5 - Kerberos 5']) + KRB5_AP_REQ +
        encoder.encode(apReq))

    return cipher, sessionKey, blob.getData()
Esempio n. 21
0
def getKerberosTGT(clientName,
                   password,
                   domain,
                   lmhash,
                   nthash,
                   aesKey='',
                   kdcHost=None,
                   requestPAC=True):

    asReq = AS_REQ()

    domain = domain.upper()
    serverName = Principal('krbtgt/%s' % domain,
                           type=constants.PrincipalNameType.NT_PRINCIPAL.value)

    pacRequest = KERB_PA_PAC_REQUEST()
    pacRequest['include-pac'] = requestPAC
    encodedPacRequest = encoder.encode(pacRequest)

    asReq['pvno'] = 5
    asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)
    asReq['padata'] = None
    asReq['padata'][0] = None
    asReq['padata'][0]['padata-type'] = int(
        constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][0]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append(constants.KDCOptions.forwardable.value)
    opts.append(constants.KDCOptions.renewable.value)
    opts.append(constants.KDCOptions.proxiable.value)
    reqBody['kdc-options'] = constants.encodeFlags(opts)

    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    seq_set(reqBody, 'cname', clientName.components_to_asn1)

    if domain == '':
        raise Exception('Empty Domain not allowed in Kerberos')

    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['rtime'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] = random.getrandbits(31)

    # Yes.. this shouldn't happend but it's inherited from the past
    if aesKey is None:
        aesKey = ''

    if nthash == '':
        # This is still confusing. I thought KDC_ERR_ETYPE_NOSUPP was enough,
        # but I found some systems that accepts all ciphers, and trigger an error
        # when requesting subsequent TGS :(. More research needed.
        # So, in order to support more than one cypher, I'm setting aes first
        # since most of the systems would accept it. If we're lucky and
        # KDC_ERR_ETYPE_NOSUPP is returned, we will later try rc4.
        if aesKey != '':
            if len(aesKey) == 64:
                supportedCiphers = (int(
                    constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value), )
            else:
                supportedCiphers = (int(
                    constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value), )
        else:
            supportedCiphers = (int(
                constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value), )
    else:
        # We have hashes to try, only way is to request RC4 only
        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value), )

    seq_set_iter(reqBody, 'etype', supportedCiphers)

    message = encoder.encode(asReq)

    try:
        r = sendReceive(message, domain, kdcHost)
    except KerberosError, e:
        if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
            if supportedCiphers[0] in (
                    constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value,
                    constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value
            ) and aesKey is '':
                supportedCiphers = (int(
                    constants.EncryptionTypes.rc4_hmac.value), )
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, kdcHost)
            else:
                raise
        else:
            raise
Esempio n. 22
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    def doS4U(self, tgt, cipher, oldSessionKey, sessionKey, kdcHost):
        decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]

        # Extract the ticket from the TGT
        ticket = Ticket()
        ticket.from_asn1(decodedTGT['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1(decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('AUTHENTICATOR')
            print(authenticator.prettyPrint())
            print('\n')

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] = 5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)

        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
        # requests a service ticket to itself on behalf of a user. The user is
        # identified to the KDC by the user's name and realm.
        clientName = Principal(
            self.__options.impersonate,
            type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        S4UByteArray = struct.pack(
            '<I', constants.PrincipalNameType.NT_PRINCIPAL.value)
        S4UByteArray += b(self.__options.impersonate) + b(
            self.__domain) + b'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('S4UByteArray')
            hexdump(S4UByteArray)

        # Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
        # with the following three parameters: the session key of the TGT of
        # the service performing the S4U2Self request, the message type value
        # of 17, and the byte array S4UByteArray.
        checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('CheckSum')
            hexdump(checkSum)

        paForUserEnc = PA_FOR_USER_ENC()
        seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
        paForUserEnc['userRealm'] = self.__domain
        paForUserEnc['cksum'] = noValue
        paForUserEnc['cksum']['cksumtype'] = int(
            constants.ChecksumTypes.hmac_md5.value)
        paForUserEnc['cksum']['checksum'] = checkSum
        paForUserEnc['auth-package'] = 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('PA_FOR_USER_ENC')
            print(paForUserEnc.prettyPrint())

        encodedPaForUserEnc = encoder.encode(paForUserEnc)

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
        tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.canonicalize.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)

        serverName = Principal(
            self.__user, type=constants.PrincipalNameType.NT_UNKNOWN.value)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        reqBody['realm'] = str(decodedTGT['crealm'])

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype', (int(
            cipher.enctype), int(constants.EncryptionTypes.rc4_hmac.value)))

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('Final TGS')
            print(tgsReq.prettyPrint())

        logging.info('\tRequesting S4U2self')
        message = encoder.encode(tgsReq)

        r = sendReceive(message, self.__domain, kdcHost)

        tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('TGS_REP')
            print(tgs.prettyPrint())

        ################################################################################
        # Up until here was all the S4USelf stuff. Now let's start with S4U2Proxy
        # So here I have a ST for me.. I now want a ST for another service
        # Extract the ticket from the TGT
        ticketTGT = Ticket()
        ticketTGT.from_asn1(decodedTGT['ticket'])

        ticket = Ticket()
        ticket.from_asn1(tgs['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticketTGT.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1(decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] = 5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)
        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # Add resource-based constrained delegation support
        paPacOptions = PA_PAC_OPTIONS()
        paPacOptions['flags'] = constants.encodeFlags(
            (constants.PAPacOptions.resource_based_constrained_delegation.
             value, ))

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1][
            'padata-type'] = constants.PreAuthenticationDataTypes.PA_PAC_OPTIONS.value
        tgsReq['padata'][1]['padata-value'] = encoder.encode(paPacOptions)

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        # This specified we're doing S4U
        opts.append(constants.KDCOptions.cname_in_addl_tkt.value)
        opts.append(constants.KDCOptions.canonicalize.value)
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)
        service2 = Principal(
            self.__options.spn,
            type=constants.PrincipalNameType.NT_SRV_INST.value)
        seq_set(reqBody, 'sname', service2.components_to_asn1)
        reqBody['realm'] = self.__domain

        myTicket = ticket.to_asn1(TicketAsn1())
        seq_set_iter(reqBody, 'additional-tickets', (myTicket, ))

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype',
                     (int(constants.EncryptionTypes.rc4_hmac.value),
                      int(constants.EncryptionTypes.des3_cbc_sha1_kd.value),
                      int(constants.EncryptionTypes.des_cbc_md5.value),
                      int(cipher.enctype)))
        message = encoder.encode(tgsReq)

        logging.info('\tRequesting S4U2Proxy')
        r = sendReceive(message, self.__domain, kdcHost)

        tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

        cipherText = tgs['enc-part']['cipher']

        # Key Usage 8
        # TGS-REP encrypted part (includes application session
        # key), encrypted with the TGS session key (Section 5.4.2)
        plainText = cipher.decrypt(sessionKey, 8, cipherText)

        encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]

        newSessionKey = Key(encTGSRepPart['key']['keytype'],
                            encTGSRepPart['key']['keyvalue'])

        # Creating new cipher based on received keytype
        cipher = _enctype_table[encTGSRepPart['key']['keytype']]

        return r, cipher, sessionKey, newSessionKey
Esempio n. 23
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    def getTGT(self, userName, requestPAC=True):

        clientName = Principal(
            userName, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        asReq = AS_REQ()

        domain = self.__domain.upper()
        serverName = Principal(
            'krbtgt/%s' % domain,
            type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        pacRequest = KERB_PA_PAC_REQUEST()
        pacRequest['include-pac'] = requestPAC
        encodedPacRequest = encoder.encode(pacRequest)

        asReq['pvno'] = 5
        asReq['msg-type'] = int(constants.ApplicationTagNumbers.AS_REQ.value)

        asReq['padata'] = noValue
        asReq['padata'][0] = noValue
        asReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
        asReq['padata'][0]['padata-value'] = encodedPacRequest

        reqBody = seq_set(asReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.proxiable.value)
        reqBody['kdc-options'] = constants.encodeFlags(opts)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        seq_set(reqBody, 'cname', clientName.components_to_asn1)

        if domain == '':
            raise Exception('Empty Domain not allowed in Kerberos')

        reqBody['realm'] = domain

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['rtime'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)

        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value), )

        seq_set_iter(reqBody, 'etype', supportedCiphers)

        message = encoder.encode(asReq)

        try:
            r = sendReceive(message, domain, self.__kdcHost)
        except KerberosError as e:
            if e.getErrorCode(
            ) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                # RC4 not available, OK, let's ask for newer types
                supportedCiphers = (
                    int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value
                        ),
                    int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value
                        ),
                )
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, self.__kdcHost)
            else:
                raise e

        # This should be the PREAUTH_FAILED packet or the actual TGT if the target principal has the
        # 'Do not require Kerberos preauthentication' set
        try:
            asRep = decoder.decode(r, asn1Spec=KRB_ERROR())[0]
        except:
            # Most of the times we shouldn't be here, is this a TGT?
            asRep = decoder.decode(r, asn1Spec=AS_REP())[0]
        else:
            # The user doesn't have UF_DONT_REQUIRE_PREAUTH set
            raise Exception(
                'User %s doesn\'t have UF_DONT_REQUIRE_PREAUTH set' % userName)

        if self.__outputFormat == 'john':
            # Let's output the TGT enc-part/cipher in John format, in case somebody wants to use it.
            return '$krb5asrep$%s@%s:%s$%s' % (
                clientName, domain,
                hexlify(asRep['enc-part']['cipher'].asOctets()[:16]).decode(),
                hexlify(asRep['enc-part']['cipher'].asOctets()[16:]).decode())
        else:
            # Let's output the TGT enc-part/cipher in Hashcat format, in case somebody wants to use it.
            return '$krb5asrep$%d$%s@%s:%s$%s' % (
                asRep['enc-part']['etype'], clientName, domain,
                hexlify(asRep['enc-part']['cipher'].asOctets()[:16]).decode(),
                hexlify(asRep['enc-part']['cipher'].asOctets()[16:]).decode())
Esempio n. 24
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    def kerberosLogin(self, user, password, domain='', lmhash='', nthash='', aesKey='', kdcHost=None, TGT=None,
                      TGS=None, useCache=True):
        """
        logins into the target system explicitly using Kerberos. Hashes are used if RC4_HMAC is supported.

        :param string user: username
        :param string password: password for the user
        :param string domain: domain where the account is valid for (required)
        :param string lmhash: LMHASH used to authenticate using hashes (password is not used)
        :param string nthash: NTHASH used to authenticate using hashes (password is not used)
        :param string aesKey: aes256-cts-hmac-sha1-96 or aes128-cts-hmac-sha1-96 used for Kerberos authentication
        :param string kdcHost: hostname or IP Address for the KDC. If None, the domain will be used (it needs to resolve tho)
        :param struct TGT: If there's a TGT available, send the structure here and it will be used
        :param struct TGS: same for TGS. See smb3.py for the format
        :param bool useCache: whether or not we should use the ccache for credentials lookup. If TGT or TGS are specified this is False

        :return: True, raises a LDAPSessionError if error.
        """

        if lmhash != '' or nthash != '':
            if len(lmhash) % 2:     lmhash = '0%s' % lmhash
            if len(nthash) % 2:     nthash = '0%s' % nthash
            try:  # just in case they were converted already
                lmhash = unhexlify(lmhash)
                nthash = unhexlify(nthash)
            except:
                pass

        # Importing down here so pyasn1 is not required if kerberos is not used.
        from impacket.krb5.ccache import CCache
        from impacket.krb5.asn1 import AP_REQ, Authenticator, TGS_REP, seq_set
        from impacket.krb5.kerberosv5 import getKerberosTGT, getKerberosTGS
        from impacket.krb5 import constants
        from impacket.krb5.types import Principal, KerberosTime, Ticket
        from pyasn1.codec.der import decoder, encoder
        import datetime

        if TGT is not None or TGS is not None:
            useCache = False

        if useCache is True:
            try:
                ccache = CCache.loadFile(os.getenv('KRB5CCNAME'))
            except:
                # No cache present
                pass
            else:
                # retrieve user and domain information from CCache file if needed
                if user == '' and len(ccache.principal.components) > 0:
                    user = ccache.principal.components[0]['data']
                if domain == '':
                    domain = ccache.principal.realm['data']
                LOG.debug("Using Kerberos Cache: %s" % os.getenv('KRB5CCNAME'))
                principal = 'ldap/%s@%s' % (self._dstHost.upper(), domain.upper())
                creds = ccache.getCredential(principal)
                if creds is None:
                    # Let's try for the TGT and go from there
                    principal = 'krbtgt/%s@%s' % (domain.upper(), domain.upper())
                    creds = ccache.getCredential(principal)
                    if creds is not None:
                        TGT = creds.toTGT()
                        LOG.debug('Using TGT from cache')
                    else:
                        LOG.debug("No valid credentials found in cache. ")
                else:
                    TGS = creds.toTGS()
                    LOG.debug('Using TGS from cache')

        # First of all, we need to get a TGT for the user
        userName = Principal(user, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
        if TGT is None:
            if TGS is None:
                tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(userName, password, domain, lmhash, nthash,
                                                                        aesKey, kdcHost)
        else:
            tgt = TGT['KDC_REP']
            cipher = TGT['cipher']
            sessionKey = TGT['sessionKey']

        if TGS is None:
            serverName = Principal('ldap/%s' % self._dstHost,
                                   type=constants.PrincipalNameType.NT_SRV_INST.value)
            tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(serverName, domain, kdcHost, tgt, cipher,
                                                                    sessionKey)
        else:
            tgs = TGS['KDC_REP']
            cipher = TGS['cipher']
            sessionKey = TGS['sessionKey']

            # Let's build a NegTokenInit with a Kerberos REQ_AP

        blob = SPNEGO_NegTokenInit()

        # Kerberos
        blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

        # Let's extract the ticket from the TGS
        tgs = decoder.decode(tgs, asn1Spec=TGS_REP())[0]
        ticket = Ticket()
        ticket.from_asn1(tgs['ticket'])

        # Now let's build the AP_REQ
        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = domain
        seq_set(authenticator, 'cname', userName.components_to_asn1)
        now = datetime.datetime.utcnow()

        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 11
        # AP-REQ Authenticator (includes application authenticator
        # subkey), encrypted with the application session key
        # (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11, encodedAuthenticator, None)

        apReq['authenticator'] = None
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        blob['MechToken'] = encoder.encode(apReq)

        # Done with the Kerberos saga, now let's get into LDAP

        bindRequest = BindRequest()
        bindRequest['version'] = Integer7Bit(3)
        bindRequest['name'] = LDAPDN(user)
        credentials = SaslCredentials()
        credentials['mechanism'] = LDAPString('GSS-SPNEGO')
        credentials['credentials'] = Credentials(blob.getData())
        bindRequest['authentication'] = AuthenticationChoice().setComponentByName('sasl', credentials)

        resp = self.sendReceive('bindRequest', bindRequest)[0]['protocolOp']

        if resp['bindResponse']['resultCode'] != 0:
            raise LDAPSessionError(errorString='Error in bindRequest -> %s:%s' % (
                resp['bindResponse']['resultCode'].prettyPrint(), resp['bindResponse']['diagnosticMessage']))

        return True
Esempio n. 25
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    def dump(self):
        # Try all requested protocols until one works.

        userName = Principal(
            self.__username,
            type=constants.PrincipalNameType.NT_PRINCIPAL.value)
        tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
            userName, self.__password, self.__domain, unhexlify(self.__lmhash),
            unhexlify(self.__nthash))

        decodedTGT = decoder.decode(tgt, asn1Spec=AS_REP())[0]

        # Extract the ticket from the TGT
        ticket = Ticket()
        ticket.from_asn1(decodedTGT['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1(decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('AUTHENTICATOR')
            print(authenticator.prettyPrint())
            print('\n')

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] = 5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)

        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
        # requests a service ticket to itself on behalf of a user. The user is
        # identified to the KDC by the user's name and realm.
        clientName = Principal(
            self.__behalfUser,
            type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        S4UByteArray = struct.pack(
            '<I', constants.PrincipalNameType.NT_PRINCIPAL.value)
        S4UByteArray += b(self.__behalfUser) + b(self.__domain) + b'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('S4UByteArray')
            hexdump(S4UByteArray)

        # Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
        # with the following three parameters: the session key of the TGT of
        # the service performing the S4U2Self request, the message type value
        # of 17, and the byte array S4UByteArray.
        checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('CheckSum')
            hexdump(checkSum)

        paForUserEnc = PA_FOR_USER_ENC()
        seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
        paForUserEnc['userRealm'] = self.__domain
        paForUserEnc['cksum'] = noValue
        paForUserEnc['cksum']['cksumtype'] = int(
            constants.ChecksumTypes.hmac_md5.value)
        paForUserEnc['cksum']['checksum'] = checkSum
        paForUserEnc['auth-package'] = 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('PA_FOR_USER_ENC')
            print(paForUserEnc.prettyPrint())

        encodedPaForUserEnc = encoder.encode(paForUserEnc)

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1]['padata-type'] = int(
            constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
        tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        opts.append(constants.KDCOptions.forwardable.value)
        opts.append(constants.KDCOptions.renewable.value)
        opts.append(constants.KDCOptions.renewable_ok.value)
        opts.append(constants.KDCOptions.canonicalize.value)
        opts.append(constants.KDCOptions.enc_tkt_in_skey.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)

        serverName = Principal(
            self.__username, type=constants.PrincipalNameType.NT_UNKNOWN.value)
        #serverName = Principal('krbtgt/%s' % domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        reqBody['realm'] = str(decodedTGT['crealm'])

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype', (int(
            cipher.enctype), int(constants.EncryptionTypes.rc4_hmac.value)))

        # If you comment these two lines plus enc_tkt_in_skey as option, it is bassically a S4USelf
        myTicket = ticket.to_asn1(TicketAsn1())
        seq_set_iter(reqBody, 'additional-tickets', (myTicket, ))

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('Final TGS')
            print(tgsReq.prettyPrint())

        message = encoder.encode(tgsReq)

        r = sendReceive(message, self.__domain, None)

        tgs = decoder.decode(r, asn1Spec=TGS_REP())[0]

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('TGS_REP')
            print(tgs.prettyPrint())

        cipherText = tgs['ticket']['enc-part']['cipher']

        # Key Usage 2
        # AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
        #  application session key), encrypted with the service key
        #  (section 5.4.2)

        newCipher = _enctype_table[int(tgs['ticket']['enc-part']['etype'])]

        # Pass the hash/aes key :P
        if self.__nthash != '' and (isinstance(self.__nthash, bytes)
                                    and self.__nthash != b''):
            key = Key(newCipher.enctype, unhexlify(self.__nthash))
        else:
            if newCipher.enctype == Enctype.RC4:
                key = newCipher.string_to_key(password, '', None)
            else:
                key = newCipher.string_to_key(
                    password,
                    self.__domain.upper() + self.__username, None)

        try:
            # If is was plain U2U, this is the key
            plainText = newCipher.decrypt(key, 2, str(cipherText))
        except:
            # S4USelf + U2U uses this other key
            plainText = cipher.decrypt(sessionKey, 2, cipherText)

        self.printPac(plainText)
Esempio n. 26
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    def dump(self, addr):
        # Try all requested protocols until one works.

        userName = Principal(self.__username, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
        tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(userName, self.__password, self.__domain,
                                                                self.__lmhash.decode('hex'), self.__nthash.decode('hex'))

        decodedTGT = decoder.decode(tgt, asn1Spec = AS_REP())[0]

        # Extract the ticket from the TGT
        ticket = Ticket()
        ticket.from_asn1(decodedTGT['ticket'])

        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = list()
        apReq['ap-options'] =  constants.encodeFlags(opts)
        seq_set(apReq,'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = str(decodedTGT['crealm'])

        clientName = Principal()
        clientName.from_asn1( decodedTGT, 'crealm', 'cname')

        seq_set(authenticator, 'cname', clientName.components_to_asn1)

        now = datetime.datetime.utcnow()
        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('AUTHENTICATOR')
            print authenticator.prettyPrint()
            print ('\n')

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 7
        # TGS-REQ PA-TGS-REQ padata AP-REQ Authenticator (includes
        # TGS authenticator subkey), encrypted with the TGS session
        # key (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 7, encodedAuthenticator, None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        encodedApReq = encoder.encode(apReq)

        tgsReq = TGS_REQ()

        tgsReq['pvno'] =  5
        tgsReq['msg-type'] = int(constants.ApplicationTagNumbers.TGS_REQ.value)

        tgsReq['padata'] = noValue
        tgsReq['padata'][0] = noValue
        tgsReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_TGS_REQ.value)
        tgsReq['padata'][0]['padata-value'] = encodedApReq

        # In the S4U2self KRB_TGS_REQ/KRB_TGS_REP protocol extension, a service
        # requests a service ticket to itself on behalf of a user. The user is
        # identified to the KDC by the user's name and realm.
        clientName = Principal(self.__behalfUser, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        S4UByteArray = struct.pack('<I',constants.PrincipalNameType.NT_PRINCIPAL.value)
        S4UByteArray += self.__behalfUser + self.__domain + 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('S4UByteArray')
            hexdump(S4UByteArray)

        # Finally cksum is computed by calling the KERB_CHECKSUM_HMAC_MD5 hash
        # with the following three parameters: the session key of the TGT of
        # the service performing the S4U2Self request, the message type value
        # of 17, and the byte array S4UByteArray.
        checkSum = _HMACMD5.checksum(sessionKey, 17, S4UByteArray)

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('CheckSum')
            hexdump(checkSum)

        paForUserEnc = PA_FOR_USER_ENC()
        seq_set(paForUserEnc, 'userName', clientName.components_to_asn1)
        paForUserEnc['userRealm'] = self.__domain
        paForUserEnc['cksum'] = noValue
        paForUserEnc['cksum']['cksumtype'] = int(constants.ChecksumTypes.hmac_md5.value)
        paForUserEnc['cksum']['checksum'] = checkSum
        paForUserEnc['auth-package'] = 'Kerberos'

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('PA_FOR_USER_ENC')
            print paForUserEnc.prettyPrint()

        encodedPaForUserEnc = encoder.encode(paForUserEnc)

        tgsReq['padata'][1] = noValue
        tgsReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_FOR_USER.value)
        tgsReq['padata'][1]['padata-value'] = encodedPaForUserEnc

        reqBody = seq_set(tgsReq, 'req-body')

        opts = list()
        opts.append( constants.KDCOptions.forwardable.value )
        opts.append( constants.KDCOptions.renewable.value )
        opts.append( constants.KDCOptions.renewable_ok.value )
        opts.append( constants.KDCOptions.canonicalize.value )
        opts.append(constants.KDCOptions.enc_tkt_in_skey.value)

        reqBody['kdc-options'] = constants.encodeFlags(opts)

        serverName = Principal(self.__username, type=constants.PrincipalNameType.NT_UNKNOWN.value)
        #serverName = Principal('krbtgt/%s' % domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)

        seq_set(reqBody, 'sname', serverName.components_to_asn1)
        reqBody['realm'] = str(decodedTGT['crealm'])

        now = datetime.datetime.utcnow() + datetime.timedelta(days=1)

        reqBody['till'] = KerberosTime.to_asn1(now)
        reqBody['nonce'] = random.getrandbits(31)
        seq_set_iter(reqBody, 'etype',
                      (int(cipher.enctype),int(constants.EncryptionTypes.rc4_hmac.value)))

        # If you comment these two lines plus enc_tkt_in_skey as option, it is bassically a S4USelf
        myTicket = ticket.to_asn1(TicketAsn1())
        seq_set_iter(reqBody, 'additional-tickets', (myTicket,))

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('Final TGS')
            print tgsReq.prettyPrint()

        message = encoder.encode(tgsReq)

        r = sendReceive(message, self.__domain, None)

        tgs = decoder.decode(r, asn1Spec = TGS_REP())[0]

        if logging.getLogger().level == logging.DEBUG:
            logging.debug('TGS_REP')
            print tgs.prettyPrint()

        cipherText = tgs['ticket']['enc-part']['cipher']

        # Key Usage 2
        # AS-REP Ticket and TGS-REP Ticket (includes tgs session key or
        #  application session key), encrypted with the service key
        #  (section 5.4.2)

        newCipher = _enctype_table[int(tgs['ticket']['enc-part']['etype'])]

        # Pass the hash/aes key :P
        if self.__nthash != '':
            key = Key(newCipher.enctype, self.__nthash.decode('hex'))
        else:
            if newCipher.enctype == Enctype.RC4:
                key = newCipher.string_to_key(password, '', None)
            else:
                key = newCipher.string_to_key(password, self.__domain.upper()+self.__username, None)

        try:
            # If is was plain U2U, this is the key
            plainText = newCipher.decrypt(key, 2, str(cipherText))
        except:
            # S4USelf + U2U uses this other key
            plainText = cipher.decrypt(sessionKey, 2, str(cipherText))

        self.printPac(plainText)
Esempio n. 27
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    def enumKerbPre(self):
        # Build user array
        users = []
        self.conn.search(
            self.dc_string[:-1],
            '(&(samaccounttype=805306368)(userAccountControl:1.2.840.113556.1.4.803:=4194304))',
            attributes=self.ldapProps,
            search_scope=SUBTREE)
        for entry in self.conn.entries:
            users.append(
                str(entry['sAMAccountName']) + '@{0}'.format(self.server))
        if len(users) == 0:
            print(
                '[ ' + colored('OK', 'green') +
                ' ] Found {0} accounts that does not require Kerberos preauthentication'
                .format(len(users)))
        elif len(users) == 1:
            print(
                '[ ' + colored('OK', 'yellow') +
                ' ] Found {0} account that does not require Kerberos preauthentication'
                .format(len(users)))
        else:
            print(
                '[ ' + colored('OK', 'yellow') +
                ' ] Found {0} accounts that does not require Kerberos preauthentication'
                .format(len(users)))

        hashes = []
        # Build request for Tickets
        for usr in users:
            clientName = Principal(
                usr, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
            asReq = AS_REQ()
            domain = str(self.server).upper()
            serverName = Principal(
                'krbtgt/{0}'.format(domain),
                type=constants.PrincipalNameType.NT_PRINCIPAL.value)
            pacReq = KERB_PA_PAC_REQUEST()
            pacReq['include-pac'] = True
            encodedPacReq = encoder.encode(pacReq)
            asReq['pvno'] = 5
            asReq['msg-type'] = int(
                constants.ApplicationTagNumbers.AS_REQ.value)
            asReq['padata'] = noValue
            asReq['padata'][0] = noValue
            asReq['padata'][0]['padata-type'] = int(
                constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
            asReq['padata'][0]['padata-value'] = encodedPacReq

            requestBody = seq_set(asReq, 'req-body')

            options = list()
            options.append(constants.KDCOptions.forwardable.value)
            options.append(constants.KDCOptions.renewable.value)
            options.append(constants.KDCOptions.proxiable.value)
            requestBody['kdc-options'] = constants.encodeFlags(options)

            seq_set(requestBody, 'sname', serverName.components_to_asn1)
            seq_set(requestBody, 'cname', clientName.components_to_asn1)

            requestBody['realm'] = domain

            now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
            requestBody['till'] = KerberosTime.to_asn1(now)
            requestBody['rtime'] = KerberosTime.to_asn1(now)
            requestBody['nonce'] = random.getrandbits(31)

            supportedCiphers = (int(
                constants.EncryptionTypes.rc4_hmac.value), )

            seq_set_iter(requestBody, 'etype', supportedCiphers)

            msg = encoder.encode(asReq)

            try:
                response = sendReceive(msg, domain, self.server)
            except KerberosError as e:
                if e.getErrorCode(
                ) == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
                    supportedCiphers = (
                        int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.
                            value),
                        int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.
                            value),
                    )
                    seq_set_iter(requestBody, 'etype', supportedCiphers)
                    msg = encoder.encode(asReq)
                    response = sendReceive(msg, domain, self.server)
                else:
                    print(e)
                    continue

            asRep = decoder.decode(response, asn1Spec=AS_REP())[0]

            hashes.append('$krb5asrep${0}@{1}:{2}${3}'.format(
                usr, domain,
                hexlify(asRep['enc-part']['cipher'].asOctets()[:16]).decode(),
                hexlify(asRep['enc-part']['cipher'].asOctets()[16:]).decode()))

        if len(hashes) > 0:
            with open('{0}-jtr-hashes'.format(self.server), 'w') as f:
                for h in hashes:
                    f.write(str(h) + '\n')

            print('[ ' + colored('OK', 'yellow') +
                  ' ] Wrote all hashes to {0}-jtr-hashes'.format(self.server))
        else:
            print('[ ' + colored('OK', 'green') + ' ] Got 0 hashes')
Esempio n. 28
0
    asReq['padata'] = None
    asReq['padata'][0] = None
    asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_ENC_TIMESTAMP.value)
    asReq['padata'][0]['padata-value'] = encodedEncryptedData

    asReq['padata'][1] = None
    asReq['padata'][1]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][1]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append( constants.KDCOptions.forwardable.value )
    opts.append( constants.KDCOptions.renewable.value )
    opts.append( constants.KDCOptions.proxiable.value )
    reqBody['kdc-options'] = constants.encodeFlags(opts)

    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    seq_set(reqBody, 'cname', clientName.components_to_asn1)

    reqBody['realm'] =  domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['rtime'] =  KerberosTime.to_asn1(now)
    reqBody['nonce'] = random.getrandbits(31)

    seq_set_iter(reqBody, 'etype', ( (int(cipher.enctype),)))

    try:
        tgt = sendReceive(encoder.encode(asReq), domain, kdcHost) 
Esempio n. 29
0
    def LDAP3KerberosLogin(self,
                           connection,
                           user,
                           password,
                           domain='',
                           lmhash='',
                           nthash='',
                           aesKey='',
                           kdcHost=None,
                           TGT=None,
                           TGS=None,
                           useCache=True):
        from pyasn1.codec.ber import encoder, decoder
        from pyasn1.type.univ import noValue
        """
        logins into the target system explicitly using Kerberos. Hashes are used if RC4_HMAC is supported.

        :param string user: username
        :param string password: password for the user
        :param string domain: domain where the account is valid for (required)
        :param string lmhash: LMHASH used to authenticate using hashes (password is not used)
        :param string nthash: NTHASH used to authenticate using hashes (password is not used)
        :param string aesKey: aes256-cts-hmac-sha1-96 or aes128-cts-hmac-sha1-96 used for Kerberos authentication
        :param string kdcHost: hostname or IP Address for the KDC. If None, the domain will be used (it needs to resolve tho)
        :param struct TGT: If there's a TGT available, send the structure here and it will be used
        :param struct TGS: same for TGS. See smb3.py for the format
        :param bool useCache: whether or not we should use the ccache for credentials lookup. If TGT or TGS are specified this is False

        :return: True, raises an Exception if error.
        """

        if lmhash != '' or nthash != '':
            if len(lmhash) % 2:
                lmhash = '0' + lmhash
            if len(nthash) % 2:
                nthash = '0' + nthash
            try:  # just in case they were converted already
                lmhash = unhexlify(lmhash)
                nthash = unhexlify(nthash)
            except TypeError:
                pass

        # Importing down here so pyasn1 is not required if kerberos is not used.
        from impacket.krb5.ccache import CCache
        from impacket.krb5.asn1 import AP_REQ, Authenticator, TGS_REP, seq_set
        from impacket.krb5.kerberosv5 import getKerberosTGT, getKerberosTGS
        from impacket.krb5 import constants
        from impacket.krb5.types import Principal, KerberosTime, Ticket
        import datetime

        if TGT is not None or TGS is not None:
            useCache = False

        targetName = 'ldap/%s' % self.__target
        if useCache:
            domain, user, TGT, TGS = CCache.parseFile(domain, user, targetName)

        # First of all, we need to get a TGT for the user
        userName = Principal(
            user, type=constants.PrincipalNameType.NT_PRINCIPAL.value)
        if TGT is None:
            if TGS is None:
                tgt, cipher, oldSessionKey, sessionKey = getKerberosTGT(
                    userName, password, domain, lmhash, nthash, aesKey,
                    kdcHost)
        else:
            tgt = TGT['KDC_REP']
            cipher = TGT['cipher']
            sessionKey = TGT['sessionKey']

        if TGS is None:
            serverName = Principal(
                targetName, type=constants.PrincipalNameType.NT_SRV_INST.value)
            tgs, cipher, oldSessionKey, sessionKey = getKerberosTGS(
                serverName, domain, kdcHost, tgt, cipher, sessionKey)
        else:
            tgs = TGS['KDC_REP']
            cipher = TGS['cipher']
            sessionKey = TGS['sessionKey']

            # Let's build a NegTokenInit with a Kerberos REQ_AP

        blob = SPNEGO_NegTokenInit()

        # Kerberos
        blob['MechTypes'] = [TypesMech['MS KRB5 - Microsoft Kerberos 5']]

        # Let's extract the ticket from the TGS
        tgs = decoder.decode(tgs, asn1Spec=TGS_REP())[0]
        ticket = Ticket()
        ticket.from_asn1(tgs['ticket'])

        # Now let's build the AP_REQ
        apReq = AP_REQ()
        apReq['pvno'] = 5
        apReq['msg-type'] = int(constants.ApplicationTagNumbers.AP_REQ.value)

        opts = []
        apReq['ap-options'] = constants.encodeFlags(opts)
        seq_set(apReq, 'ticket', ticket.to_asn1)

        authenticator = Authenticator()
        authenticator['authenticator-vno'] = 5
        authenticator['crealm'] = domain
        seq_set(authenticator, 'cname', userName.components_to_asn1)
        now = datetime.datetime.utcnow()

        authenticator['cusec'] = now.microsecond
        authenticator['ctime'] = KerberosTime.to_asn1(now)

        encodedAuthenticator = encoder.encode(authenticator)

        # Key Usage 11
        # AP-REQ Authenticator (includes application authenticator
        # subkey), encrypted with the application session key
        # (Section 5.5.1)
        encryptedEncodedAuthenticator = cipher.encrypt(sessionKey, 11,
                                                       encodedAuthenticator,
                                                       None)

        apReq['authenticator'] = noValue
        apReq['authenticator']['etype'] = cipher.enctype
        apReq['authenticator']['cipher'] = encryptedEncodedAuthenticator

        blob['MechToken'] = encoder.encode(apReq)

        request = ldap3.operation.bind.bind_operation(connection.version,
                                                      ldap3.SASL, user, None,
                                                      'GSS-SPNEGO',
                                                      blob.getData())

        # Done with the Kerberos saga, now let's get into LDAP
        # try to open connection if closed
        if connection.closed:
            connection.open(read_server_info=False)

        connection.sasl_in_progress = True
        response = connection.post_send_single_response(
            connection.send('bindRequest', request, None))
        connection.sasl_in_progress = False
        if response[0]['result'] != 0:
            raise Exception(response)

        connection.bound = True

        return True
Esempio n. 30
0
def getKerberosTGT(clientName, password, domain, lmhash, nthash, aesKey='', kdcHost=None, requestPAC=True):
    
    asReq = AS_REQ()

    domain = domain.upper()
    serverName = Principal('krbtgt/%s'%domain, type=constants.PrincipalNameType.NT_PRINCIPAL.value)  

    pacRequest = KERB_PA_PAC_REQUEST()
    pacRequest['include-pac'] = requestPAC
    encodedPacRequest = encoder.encode(pacRequest)

    asReq['pvno'] = 5
    asReq['msg-type'] =  int(constants.ApplicationTagNumbers.AS_REQ.value)
    asReq['padata'] = None
    asReq['padata'][0] = None
    asReq['padata'][0]['padata-type'] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq['padata'][0]['padata-value'] = encodedPacRequest

    reqBody = seq_set(asReq, 'req-body')

    opts = list()
    opts.append( constants.KDCOptions.forwardable.value )
    opts.append( constants.KDCOptions.renewable.value )
    opts.append( constants.KDCOptions.proxiable.value )
    reqBody['kdc-options']  = constants.encodeFlags(opts)

    seq_set(reqBody, 'sname', serverName.components_to_asn1)
    seq_set(reqBody, 'cname', clientName.components_to_asn1)

    if domain == '':
        raise Exception('Empty Domain not allowed in Kerberos')

    reqBody['realm'] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody['till'] = KerberosTime.to_asn1(now)
    reqBody['rtime'] = KerberosTime.to_asn1(now)
    reqBody['nonce'] =  random.getrandbits(31)

    # Yes.. this shouldn't happend but it's inherited from the past
    if aesKey is None:
        aesKey = ''

    if nthash == '':
        # This is still confusing. I thought KDC_ERR_ETYPE_NOSUPP was enough, 
        # but I found some systems that accepts all ciphers, and trigger an error 
        # when requesting subsequent TGS :(. More research needed.
        # So, in order to support more than one cypher, I'm setting aes first
        # since most of the systems would accept it. If we're lucky and 
        # KDC_ERR_ETYPE_NOSUPP is returned, we will later try rc4.
        if aesKey != '':
            if len(aesKey) == 64:
                supportedCiphers = (int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value),)
            else:
                supportedCiphers = (int(constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value),)
        else:
            supportedCiphers = (int(constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value),)
    else:
        # We have hashes to try, only way is to request RC4 only
        supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value),)

    seq_set_iter(reqBody, 'etype', supportedCiphers)

    message = encoder.encode(asReq)

    try:
        r = sendReceive(message, domain, kdcHost)
    except KerberosError, e:
        if e.getErrorCode() == constants.ErrorCodes.KDC_ERR_ETYPE_NOSUPP.value:
            if supportedCiphers[0] in (constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value, constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value) and aesKey is '':
                supportedCiphers = (int(constants.EncryptionTypes.rc4_hmac.value),)
                seq_set_iter(reqBody, 'etype', supportedCiphers)
                message = encoder.encode(asReq)
                r = sendReceive(message, domain, kdcHost)
            else: 
                raise 
        else:
            raise 
Esempio n. 31
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    asReq["padata"] = None
    asReq["padata"][0] = None
    asReq["padata"][0]["padata-type"] = int(constants.PreAuthenticationDataTypes.PA_ENC_TIMESTAMP.value)
    asReq["padata"][0]["padata-value"] = encodedEncryptedData

    asReq["padata"][1] = None
    asReq["padata"][1]["padata-type"] = int(constants.PreAuthenticationDataTypes.PA_PAC_REQUEST.value)
    asReq["padata"][1]["padata-value"] = encodedPacRequest

    reqBody = seq_set(asReq, "req-body")

    opts = list()
    opts.append(constants.KDCOptions.forwardable.value)
    opts.append(constants.KDCOptions.renewable.value)
    opts.append(constants.KDCOptions.proxiable.value)
    reqBody["kdc-options"] = constants.encodeFlags(opts)

    seq_set(reqBody, "sname", serverName.components_to_asn1)
    seq_set(reqBody, "cname", clientName.components_to_asn1)

    reqBody["realm"] = domain

    now = datetime.datetime.utcnow() + datetime.timedelta(days=1)
    reqBody["till"] = KerberosTime.to_asn1(now)
    reqBody["rtime"] = KerberosTime.to_asn1(now)
    reqBody["nonce"] = random.getrandbits(31)

    seq_set_iter(reqBody, "etype", ((int(cipher.enctype),)))

    try:
        tgt = sendReceive(encoder.encode(asReq), domain, kdcHost)