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'] = 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(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(cipher.enctype, str(encTGSRepPart['key']['keyvalue'])) return r, cipher, sessionKey, newSessionKey
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'] = 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(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(cipher.enctype, str(encTGSRepPart['key']['keyvalue'])) return r, cipher, sessionKey, newSessionKey
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
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