Esempio n. 1
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    def tgt_from_ccache(self, override_etype=None):
        try:
            if self.ccache is None:
                raise Exception('No CCACHE file found')

            our_user = str(
                self.usercreds.username) + '@' + self.usercreds.domain
            for tgt, keystruct in self.ccache.get_all_tgt():
                ticket_for = tgt['cname']['name-string'][0] + '@' + tgt[
                    'crealm']
                if ticket_for.upper() == our_user.upper():
                    logger.debug('Found TGT for user %s' % our_user)
                    self.kerberos_TGT = tgt
                    self.kerberos_TGT_encpart = tgt['enc-part']
                    self.kerberos_session_key = Key(keystruct['keytype'],
                                                    keystruct['keyvalue'])
                    self.kerberos_cipher = _enctype_table[keystruct['keytype']]
                    self.kerberos_cipher_type = keystruct['keytype']

                    return True, None

            logger.debug('No TGT found for user %s' % our_user)
            raise Exception('No TGT found for user %s' % our_user)

        except Exception as e:
            return None, e
Esempio n. 2
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    async def run(self, cred: KerberosCredential, override_etype=[23]):
        """
		override_etype: list : list of supported encryption types
		"""
        try:
            kcomm = AIOKerberosClient(cred, self.target)
            await kcomm.get_TGT(override_etype=override_etype,
                                decrypt_tgt=False)
            return TGTTicket2hashcat(kcomm.kerberos_TGT)
        except Exception as e:
            logger.debug('Error while roasting client %s/%s Reason: %s' %
                         (cred.domain, cred.username, str(e)))
Esempio n. 3
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    def add_kirbi(self, krbcred, override_pp=True, include_expired=False):
        c = Credential()
        enc_credinfo = EncKrbCredPart.load(
            krbcred['enc-part']['cipher']).native
        ticket_info = enc_credinfo['ticket-info'][0]
        """
		if ticket_info['endtime'] < datetime.datetime.now(datetime.timezone.utc):
			if include_expired == True:
				logging.debug('This ticket has most likely expired, but include_expired is forcing me to add it to cache! This can cause problems!')
			else:
				logging.debug('This ticket has most likely expired, skipping')
				return
		"""

        c.client = CCACHEPrincipal.from_asn1(ticket_info['pname'],
                                             ticket_info['prealm'])
        if override_pp == True:
            self.primary_principal = c.client

        #yaaaaay 4 additional weirdness!!!!
        #if sname name-string contains a realm as well htne impacket will crash miserably :(
        if len(ticket_info['sname']['name-string']
               ) > 2 and ticket_info['sname']['name-string'][-1].upper(
               ) == ticket_info['srealm'].upper():
            logger.debug('SNAME contains the realm as well, trimming it')
            t = ticket_info['sname']
            t['name-string'] = t['name-string'][:-1]
            c.server = CCACHEPrincipal.from_asn1(t, ticket_info['srealm'])
        else:
            c.server = CCACHEPrincipal.from_asn1(ticket_info['sname'],
                                                 ticket_info['srealm'])

        c.time = Times.from_asn1(ticket_info)
        c.key = Keyblock.from_asn1(ticket_info['key'])
        c.is_skey = 0  #not sure!

        c.tktflags = TicketFlags(ticket_info['flags']).cast(
            core.IntegerBitString).native
        c.num_address = 0
        c.num_authdata = 0
        c.ticket = CCACHEOctetString.from_asn1(
            Ticket(krbcred['tickets']
                   [0]).dump())  #kirbi only stores one ticket per file
        c.second_ticket = CCACHEOctetString.empty()

        self.credentials.append(c)
Esempio n. 4
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    def tgs_from_ccache(self, spn_user, override_etype):
        try:
            if self.ccache is None:
                raise Exception('No CCACHE file found')

            for tgs, keystruct in self.ccache.get_all_tgs():
                ticket_for = ('/'.join(tgs['ticket']['sname']['name-string'])
                              ) + '@' + tgs['ticket']['realm']

                if ticket_for.upper() == str(spn_user).upper():
                    logger.debug('Found TGS for user %s' % ticket_for)
                    key = Key(keystruct['keytype'], keystruct['keyvalue'])
                    tgs = TGS_REP(tgs).native
                    return tgs, tgs['enc-part'], key, None

            logger.debug('No TGS found for user %s' % ticket_for)
            raise Exception('No TGS found for user %s' % ticket_for)

        except Exception as e:
            return None, None, None, e
Esempio n. 5
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    async def run(self, spns, override_etype=[2, 3, 16, 23, 17, 18]):
        try:
            kcomm = AIOKerberosClient(self.cred, self.target)
            await kcomm.get_TGT(override_etype=override_etype,
                                decrypt_tgt=False)
        except Exception as e:
            logger.exception('a')
            logger.debug('Error logging in! Reason: %s' % (str(e)))

        results = []
        for spn in spns:
            try:
                tgs, _, _ = await kcomm.get_TGS(spn,
                                                override_etype=override_etype)
                results.append(TGSTicket2hashcat(tgs))
            except Exception as e:
                logger.exception('b')
                logger.debug(
                    'Failed to get TGS ticket for user %s/%s/%s! Reason: %s' %
                    (spn.domain, str(spn.service), spn.username, str(e)))
                continue

        return results
Esempio n. 6
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    def do_preauth(self, rep):
        #now getting server's supported encryption methods

        supp_enc_methods = collections.OrderedDict()
        for enc_method in METHOD_DATA.load(rep['e-data']).native:
            data_type = PaDataType(enc_method['padata-type'])

            if data_type == PaDataType.ETYPE_INFO or data_type == PaDataType.ETYPE_INFO2:
                if data_type == PaDataType.ETYPE_INFO:
                    enc_info_list = ETYPE_INFO.load(enc_method['padata-value'])

                elif data_type == PaDataType.ETYPE_INFO2:
                    enc_info_list = ETYPE_INFO2.load(
                        enc_method['padata-value'])

                for enc_info in enc_info_list.native:
                    supp_enc_methods[EncryptionType(
                        enc_info['etype'])] = enc_info['salt']
                    logger.debug(
                        'Server supports encryption type %s with salt %s' %
                        (EncryptionType(
                            enc_info['etype']).name, enc_info['salt']))

        logger.debug('Constructing TGT request with auth data')
        #now to create an AS_REQ with encrypted timestamp for authentication
        pa_data_1 = {}
        pa_data_1['padata-type'] = int(PADATA_TYPE('PA-PAC-REQUEST'))
        pa_data_1['padata-value'] = PA_PAC_REQUEST({
            'include-pac': True
        }).dump()

        now = datetime.datetime.now(datetime.timezone.utc)
        #creating timestamp asn1
        timestamp = PA_ENC_TS_ENC({
            'patimestamp': now.replace(microsecond=0),
            'pausec': now.microsecond
        }).dump()

        supp_enc = self.usercreds.get_preferred_enctype(supp_enc_methods)
        logger.debug('Selecting common encryption type: %s' % supp_enc.name)
        self.kerberos_cipher = _enctype_table[supp_enc.value]
        self.kerberos_cipher_type = supp_enc.value
        if 'salt' in enc_info and enc_info['salt'] is not None:
            self.server_salt = enc_info['salt'].encode()
        self.kerberos_key = Key(
            self.kerberos_cipher.enctype,
            self.usercreds.get_key_for_enctype(supp_enc,
                                               salt=self.server_salt))
        enc_timestamp = self.kerberos_cipher.encrypt(self.kerberos_key, 1,
                                                     timestamp, None)

        pa_data_2 = {}
        pa_data_2['padata-type'] = int(PADATA_TYPE('ENC-TIMESTAMP'))
        pa_data_2['padata-value'] = EncryptedData({
            'etype': supp_enc.value,
            'cipher': enc_timestamp
        }).dump()

        kdc_req_body = {}
        kdc_req_body['kdc-options'] = KDCOptions(
            set(['forwardable', 'renewable', 'proxiable']))
        kdc_req_body['cname'] = PrincipalName({
            'name-type':
            NAME_TYPE.PRINCIPAL.value,
            'name-string': [self.usercreds.username]
        })
        kdc_req_body['realm'] = self.usercreds.domain.upper()
        kdc_req_body['sname'] = PrincipalName({
            'name-type':
            NAME_TYPE.PRINCIPAL.value,
            'name-string': ['krbtgt', self.usercreds.domain.upper()]
        })
        kdc_req_body['till'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        kdc_req_body['rtime'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        kdc_req_body['nonce'] = secrets.randbits(31)
        kdc_req_body['etype'] = [supp_enc.value]

        kdc_req = {}
        kdc_req['pvno'] = krb5_pvno
        kdc_req['msg-type'] = MESSAGE_TYPE.KRB_AS_REQ.value
        kdc_req['padata'] = [pa_data_2, pa_data_1]
        kdc_req['req-body'] = KDC_REQ_BODY(kdc_req_body)

        req = AS_REQ(kdc_req)

        logger.debug('Sending TGT request to server')
        return self.ksoc.sendrecv(req.dump())
Esempio n. 7
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    def S4U2proxy(self,
                  s4uself_ticket,
                  spn_user,
                  supp_enc_methods=[
                      EncryptionType.DES_CBC_CRC, EncryptionType.DES_CBC_MD4,
                      EncryptionType.DES_CBC_MD5, EncryptionType.DES3_CBC_SHA1,
                      EncryptionType.ARCFOUR_HMAC_MD5,
                      EncryptionType.AES256_CTS_HMAC_SHA1_96,
                      EncryptionType.AES128_CTS_HMAC_SHA1_96
                  ]):
        logger.debug('[S4U2proxy] Impersonating %s' %
                     '/'.join(spn_user.get_principalname()))
        now = datetime.datetime.now(datetime.timezone.utc)
        supp_enc = self.usercreds.get_preferred_enctype(supp_enc_methods)

        pa_pac_opts = {}
        pa_pac_opts['padata-type'] = int(PADATA_TYPE('PA-PAC-OPTIONS'))
        pa_pac_opts['padata-value'] = PA_PAC_OPTIONS({
            'value':
            PA_PAC_OPTIONSTypes(set(['resource-based constrained delegation']))
        }).dump()

        authenticator_data = {}
        authenticator_data['authenticator-vno'] = krb5_pvno
        authenticator_data['crealm'] = Realm(self.kerberos_TGT['crealm'])
        authenticator_data['cname'] = self.kerberos_TGT['cname']
        authenticator_data['cusec'] = now.microsecond
        authenticator_data['ctime'] = now.replace(microsecond=0)

        authenticator_data_enc = self.kerberos_cipher.encrypt(
            self.kerberos_session_key, 7,
            Authenticator(authenticator_data).dump(), None)

        ap_req = {}
        ap_req['pvno'] = krb5_pvno
        ap_req['msg-type'] = MESSAGE_TYPE.KRB_AP_REQ.value
        ap_req['ap-options'] = APOptions(set())
        ap_req['ticket'] = Ticket(self.kerberos_TGT['ticket'])
        ap_req['authenticator'] = EncryptedData({
            'etype':
            self.kerberos_cipher_type,
            'cipher':
            authenticator_data_enc
        })

        pa_tgs_req = {}
        pa_tgs_req['padata-type'] = PaDataType.TGS_REQ.value
        pa_tgs_req['padata-value'] = AP_REQ(ap_req).dump()

        krb_tgs_body = {}
        krb_tgs_body['kdc-options'] = KDCOptions(
            set([
                'forwardable', 'renewable', 'constrained-delegation',
                'canonicalize'
            ]))
        krb_tgs_body['sname'] = PrincipalName({
            'name-type':
            NAME_TYPE.SRV_INST.value,
            'name-string':
            spn_user.get_principalname()
        })
        krb_tgs_body['realm'] = self.usercreds.domain.upper()
        krb_tgs_body['till'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        krb_tgs_body['nonce'] = secrets.randbits(31)
        krb_tgs_body['etype'] = [
            supp_enc.value
        ]  #selecting according to server's preferences
        krb_tgs_body['additional-tickets'] = [s4uself_ticket]

        krb_tgs_req = {}
        krb_tgs_req['pvno'] = krb5_pvno
        krb_tgs_req['msg-type'] = MESSAGE_TYPE.KRB_TGS_REQ.value
        krb_tgs_req['padata'] = [pa_tgs_req, pa_pac_opts]
        krb_tgs_req['req-body'] = KDC_REQ_BODY(krb_tgs_body)

        req = TGS_REQ(krb_tgs_req)
        logger.debug('[S4U2proxy] Sending request to server')
        try:
            reply = self.ksoc.sendrecv(req.dump())
        except KerberosError as e:
            if e.errorcode.value == 16:
                logger.error(
                    'S4U2proxy: Failed to get S4U2proxy! Error code (16) indicates that delegation is not enabled for this account! Full error: %s'
                    % e)

            raise e
        logger.debug('[S4U2proxy] Got server reply, decrypting...')
        tgs = reply.native

        encTGSRepPart = EncTGSRepPart.load(
            self.kerberos_cipher.decrypt(self.kerberos_session_key, 8,
                                         tgs['enc-part']['cipher'])).native
        key = Key(encTGSRepPart['key']['keytype'],
                  encTGSRepPart['key']['keyvalue'])

        self.ccache.add_tgs(tgs, encTGSRepPart)
        logger.debug('[S4U2proxy] Got valid TGS reply')

        return tgs, encTGSRepPart, key
Esempio n. 8
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    def S4U2self(self,
                 user_to_impersonate,
                 supp_enc_methods=[
                     EncryptionType.DES_CBC_CRC, EncryptionType.DES_CBC_MD4,
                     EncryptionType.DES_CBC_MD5, EncryptionType.DES3_CBC_SHA1,
                     EncryptionType.ARCFOUR_HMAC_MD5,
                     EncryptionType.AES256_CTS_HMAC_SHA1_96,
                     EncryptionType.AES128_CTS_HMAC_SHA1_96
                 ]):
        """
		user_to_impersonate : KerberosTarget class
		"""

        if not self.kerberos_TGT:
            logger.debug('[S4U2self] TGT is not available! Fetching TGT...')
            self.get_TGT()

        supp_enc = self.usercreds.get_preferred_enctype(supp_enc_methods)
        auth_package_name = 'Kerberos'
        now = datetime.datetime.now(datetime.timezone.utc)

        ###### Calculating authenticator data
        authenticator_data = {}
        authenticator_data['authenticator-vno'] = krb5_pvno
        authenticator_data['crealm'] = Realm(self.kerberos_TGT['crealm'])
        authenticator_data['cname'] = self.kerberos_TGT['cname']
        authenticator_data['cusec'] = now.microsecond
        authenticator_data['ctime'] = now.replace(microsecond=0)

        authenticator_data_enc = self.kerberos_cipher.encrypt(
            self.kerberos_session_key, 7,
            Authenticator(authenticator_data).dump(), None)

        ap_req = {}
        ap_req['pvno'] = krb5_pvno
        ap_req['msg-type'] = MESSAGE_TYPE.KRB_AP_REQ.value
        ap_req['ap-options'] = APOptions(set())
        ap_req['ticket'] = Ticket(self.kerberos_TGT['ticket'])
        ap_req['authenticator'] = EncryptedData({
            'etype':
            self.kerberos_cipher_type,
            'cipher':
            authenticator_data_enc
        })

        pa_data_auth = {}
        pa_data_auth['padata-type'] = PaDataType.TGS_REQ.value
        pa_data_auth['padata-value'] = AP_REQ(ap_req).dump()

        ###### Calculating checksum data

        S4UByteArray = NAME_TYPE.PRINCIPAL.value.to_bytes(4,
                                                          'little',
                                                          signed=False)
        S4UByteArray += user_to_impersonate.username.encode()
        S4UByteArray += user_to_impersonate.domain.encode()
        S4UByteArray += auth_package_name.encode()
        logger.debug('[S4U2self] S4UByteArray: %s' % S4UByteArray.hex())
        logger.debug('[S4U2self] S4UByteArray: %s' % S4UByteArray)

        chksum_data = _HMACMD5.checksum(self.kerberos_session_key, 17,
                                        S4UByteArray)
        logger.debug('[S4U2self] chksum_data: %s' % chksum_data.hex())

        chksum = {}
        chksum['cksumtype'] = int(CKSUMTYPE('HMAC_MD5'))
        chksum['checksum'] = chksum_data

        ###### Filling out PA-FOR-USER data for impersonation
        pa_for_user_enc = {}
        pa_for_user_enc['userName'] = PrincipalName({
            'name-type':
            NAME_TYPE.PRINCIPAL.value,
            'name-string':
            user_to_impersonate.get_principalname()
        })
        pa_for_user_enc['userRealm'] = user_to_impersonate.domain
        pa_for_user_enc['cksum'] = Checksum(chksum)
        pa_for_user_enc['auth-package'] = auth_package_name

        pa_for_user = {}
        pa_for_user['padata-type'] = int(PADATA_TYPE('PA-FOR-USER'))
        pa_for_user['padata-value'] = PA_FOR_USER_ENC(pa_for_user_enc).dump()

        ###### Constructing body

        krb_tgs_body = {}
        krb_tgs_body['kdc-options'] = KDCOptions(
            set(['forwardable', 'renewable', 'canonicalize']))
        krb_tgs_body['sname'] = PrincipalName({
            'name-type':
            NAME_TYPE.UNKNOWN.value,
            'name-string': [self.usercreds.username]
        })
        krb_tgs_body['realm'] = self.usercreds.domain.upper()
        krb_tgs_body['till'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        krb_tgs_body['nonce'] = secrets.randbits(31)
        krb_tgs_body['etype'] = [
            supp_enc.value
        ]  #selecting according to server's preferences

        krb_tgs_req = {}
        krb_tgs_req['pvno'] = krb5_pvno
        krb_tgs_req['msg-type'] = MESSAGE_TYPE.KRB_TGS_REQ.value
        krb_tgs_req['padata'] = [pa_data_auth, pa_for_user]
        krb_tgs_req['req-body'] = KDC_REQ_BODY(krb_tgs_body)

        req = TGS_REQ(krb_tgs_req)

        logger.debug('[S4U2self] Sending request to server')
        try:
            reply = self.ksoc.sendrecv(req.dump())
        except KerberosError as e:
            if e.errorcode.value == 16:
                logger.error(
                    '[S4U2self] Failed to get S4U2self! Error code (16) indicates that delegation is not enabled for this account! Full error: %s'
                    % e)

            raise e

        logger.debug('[S4U2self] Got reply, decrypting...')
        tgs = reply.native

        encTGSRepPart = EncTGSRepPart.load(
            self.kerberos_cipher.decrypt(self.kerberos_session_key, 8,
                                         tgs['enc-part']['cipher'])).native
        key = Key(encTGSRepPart['key']['keytype'],
                  encTGSRepPart['key']['keyvalue'])

        self.ccache.add_tgs(tgs, encTGSRepPart)
        logger.debug('[S4U2self] Got valid TGS reply')
        self.kerberos_TGS = tgs
        return tgs, encTGSRepPart, key
Esempio n. 9
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    def get_TGS(self, spn_user, override_etype=None, is_linux=False):
        """
		Requests a TGS ticket for the specified user.
		Returns the TGS ticket, end the decrpyted encTGSRepPart.

		spn_user: KerberosTarget: the service user you want to get TGS for.
		override_etype: None or list of etype values (int) Used mostly for kerberoasting, will override the AP_REQ supported etype values (which is derived from the TGT) to be able to recieve whatever tgs tiecket 
		"""

        logger.debug('[getTGS] Constructing request for user %s' %
                     spn_user.get_formatted_pname())
        now = datetime.datetime.now(datetime.timezone.utc)
        kdc_req_body = {}
        kdc_req_body['kdc-options'] = KDCOptions(
            set(['forwardable', 'renewable', 'renewable_ok', 'canonicalize']))
        kdc_req_body['realm'] = spn_user.domain.upper()
        kdc_req_body['sname'] = PrincipalName({
            'name-type':
            NAME_TYPE.SRV_INST.value,
            'name-string':
            spn_user.get_principalname()
        })
        kdc_req_body['till'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        kdc_req_body['nonce'] = secrets.randbits(31)
        if override_etype:
            kdc_req_body['etype'] = override_etype
        else:
            kdc_req_body['etype'] = [self.kerberos_cipher_type]

        authenticator_data = {}
        authenticator_data['authenticator-vno'] = krb5_pvno
        authenticator_data['crealm'] = Realm(self.kerberos_TGT['crealm'])
        authenticator_data['cname'] = self.kerberos_TGT['cname']
        authenticator_data['cusec'] = now.microsecond
        authenticator_data['ctime'] = now.replace(microsecond=0)
        authenticator_data['seq-number'] = 0

        if is_linux:
            ac = AuthenticatorChecksum()
            ac.flags = 0
            ac.channel_binding = b'\x00' * 16

            chksum = {}
            chksum['cksumtype'] = 0x8003
            chksum['checksum'] = ac.to_bytes()

            authenticator_data['cksum'] = Checksum(chksum)
        else:
            from pycquery_krb.protocol.encryption import Enctype, Cksumtype, make_checksum
            if Enctype.AES256 == self.kerberos_session_key.enctype:
                authenticator_data['cksum'] = Checksum({
                    'cksumtype':
                    Cksumtype.SHA1_AES256,
                    'checksum':
                    make_checksum(Cksumtype.SHA1_AES256,
                                  self.kerberos_session_key, 6,
                                  KDC_REQ_BODY(kdc_req_body).dump())
                })

        authenticator_data_enc = self.kerberos_cipher.encrypt(
            self.kerberos_session_key, 7,
            Authenticator(authenticator_data).dump(), None)

        ap_req = {}
        ap_req['pvno'] = krb5_pvno
        ap_req['msg-type'] = MESSAGE_TYPE.KRB_AP_REQ.value
        ap_req['ap-options'] = APOptions(set())
        ap_req['ticket'] = Ticket(self.kerberos_TGT['ticket'])
        ap_req['authenticator'] = EncryptedData({
            'etype':
            self.kerberos_cipher_type,
            'cipher':
            authenticator_data_enc
        })

        pa_data_1 = {}
        pa_data_1['padata-type'] = PaDataType.TGS_REQ.value
        pa_data_1['padata-value'] = AP_REQ(ap_req).dump()

        kdc_req = {}
        kdc_req['pvno'] = krb5_pvno
        kdc_req['msg-type'] = MESSAGE_TYPE.KRB_TGS_REQ.value
        kdc_req['padata'] = [pa_data_1]
        kdc_req['req-body'] = KDC_REQ_BODY(kdc_req_body)

        req = TGS_REQ(kdc_req)
        logger.debug('[getTGS] Constructing request to server')
        rep = self.ksoc.sendrecv(req.dump())
        logger.debug('[getTGS] Got reply, decrypting...')
        tgs = rep.native

        encTGSRepPart = EncTGSRepPart.load(
            self.kerberos_cipher.decrypt(self.kerberos_session_key, 8,
                                         tgs['enc-part']['cipher'])).native
        key = Key(encTGSRepPart['key']['keytype'],
                  encTGSRepPart['key']['keyvalue'])

        self.ccache.add_tgs(tgs, encTGSRepPart)
        logger.debug('[getTGS] Got valid reply')
        self.kerberos_TGS = tgs
        return tgs, encTGSRepPart, key
Esempio n. 10
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    def get_TGT(self, override_etype=None, decrypt_tgt=True):
        """
		decrypt_tgt: used for asreproast attacks
		Steps performed:
			1. Send and empty (no encrypted timestamp) AS_REQ with all the encryption types we support
			2. Depending on the response (either error or AS_REP with TGT) we either send another AS_REQ with the encrypted data or return the TGT (or fail miserably)
			3. PROFIT
		"""
        logger.debug(
            '[getTGT] Generating initial TGT without authentication data')
        now = datetime.datetime.now(datetime.timezone.utc)
        kdc_req_body = {}
        kdc_req_body['kdc-options'] = KDCOptions(
            set(['forwardable', 'renewable', 'proxiable']))
        kdc_req_body['cname'] = PrincipalName({
            'name-type':
            NAME_TYPE.PRINCIPAL.value,
            'name-string': [self.usercreds.username]
        })
        kdc_req_body['realm'] = self.usercreds.domain.upper()
        kdc_req_body['sname'] = PrincipalName({
            'name-type':
            NAME_TYPE.PRINCIPAL.value,
            'name-string': ['krbtgt', self.usercreds.domain.upper()]
        })
        kdc_req_body['till'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        kdc_req_body['rtime'] = (now + datetime.timedelta(days=1)).replace(
            microsecond=0)
        kdc_req_body['nonce'] = secrets.randbits(31)
        if override_etype is None:
            kdc_req_body['etype'] = self.usercreds.get_supported_enctypes()
        else:
            kdc_req_body['etype'] = override_etype

        pa_data_1 = {}
        pa_data_1['padata-type'] = int(PADATA_TYPE('PA-PAC-REQUEST'))
        pa_data_1['padata-value'] = PA_PAC_REQUEST({
            'include-pac': True
        }).dump()

        kdc_req = {}
        kdc_req['pvno'] = krb5_pvno
        kdc_req['msg-type'] = MESSAGE_TYPE.KRB_AS_REQ.value
        kdc_req['padata'] = [pa_data_1]
        kdc_req['req-body'] = KDC_REQ_BODY(kdc_req_body)

        req = AS_REQ(kdc_req)

        logger.debug('[getTGT] Sending initial TGT to %s' %
                     self.ksoc.get_addr_str())
        rep = self.ksoc.sendrecv(req.dump(), throw=False)

        if rep.name != 'KRB_ERROR':
            #user can do kerberos auth without preauthentication!
            self.kerberos_TGT = rep.native

            etype = self.kerberos_TGT['enc-part']['etype']

            #if we want to roast the asrep (tgt rep) part then we dont even have the proper keys to decrypt
            #so we just return, the asrep can be extracted from this object anyhow
            if decrypt_tgt == False:
                return

            self.kerberos_cipher = _enctype_table[etype]
            self.kerberos_cipher_type = etype
            encryption_type = EncryptionType(self.kerberos_cipher.enctype)
            enctype = self.usercreds.get_key_for_enctype(encryption_type)
            self.kerberos_key = Key(self.kerberos_cipher.enctype, enctype)

        else:
            if rep.native[
                    'error-code'] != KerberosErrorCode.KDC_ERR_PREAUTH_REQUIRED.value:
                raise KerberosError(rep)
            rep = rep.native
            logger.debug(
                '[getTGT] Got reply from server, asking to provide auth data')

            rep = self.do_preauth(rep)
            logger.debug('[getTGT] Got valid response from server')
            rep = rep.native
            self.kerberos_TGT = rep

        cipherText = self.kerberos_TGT['enc-part']['cipher']
        temp = self.kerberos_cipher.decrypt(self.kerberos_key, 3, cipherText)
        try:
            self.kerberos_TGT_encpart = EncASRepPart.load(temp).native
        except Exception as e:
            logger.debug('[getTGT] EncAsRepPart load failed, is this linux?')
            try:
                self.kerberos_TGT_encpart = EncTGSRepPart.load(temp).native
            except Exception as e:
                logger.error(
                    '[getTGT] Failed to load decrypted part of the reply!')
                raise e

        self.kerberos_session_key = Key(
            self.kerberos_cipher.enctype,
            self.kerberos_TGT_encpart['key']['keyvalue'])
        self.ccache.add_tgt(self.kerberos_TGT,
                            self.kerberos_TGT_encpart,
                            override_pp=True)
        logger.debug('[getTGT] Got valid TGT')

        return