def fromTGS(self, tgs, oldSessionKey, sessionKey):
self.headers = []
header = Header()
header['tag'] = 1
header['taglen'] = 8
header['tagdata'] = '\xff\xff\xff\xff\x00\x00\x00\x00'
self.headers.append(header)
decodedTGS = decoder.decode(tgs, asn1Spec=TGS_REP())[0]
tmpPrincipal = types.Principal()
tmpPrincipal.from_asn1(decodedTGS, 'crealm', 'cname')
self.principal = Principal()
self.principal.fromPrincipal(tmpPrincipal)
# Now let's add the credential
cipherText = decodedTGS['enc-part']['cipher']
cipher = crypto._enctype_table[decodedTGS['enc-part']['etype']]
# Key Usage 8
# TGS-REP encrypted part (includes application session
# key), encrypted with the TGS session key (Section 5.4.2)
plainText = cipher.decrypt(oldSessionKey, 8, str(cipherText))
encTGSRepPart = decoder.decode(plainText, asn1Spec=EncTGSRepPart())[0]
credential = Credential()
server = types.Principal()
server.from_asn1(encTGSRepPart, 'srealm', 'sname')
tmpServer = Principal()
tmpServer.fromPrincipal(server)
credential['client'] = self.principal
credential['server'] = tmpServer
credential['is_skey'] = 0
credential['key'] = KeyBlock()
credential['key']['keytype'] = int(encTGSRepPart['key']['keytype'])
credential['key']['keyvalue'] = str(encTGSRepPart['key']['keyvalue'])
credential['key']['keylen'] = len(credential['key']['keyvalue'])
credential['time'] = Times()
credential['time']['authtime'] = self.toTimeStamp(
types.KerberosTime.from_asn1(encTGSRepPart['authtime']))
credential['time']['starttime'] = self.toTimeStamp(
types.KerberosTime.from_asn1(encTGSRepPart['starttime']))
credential['time']['endtime'] = self.toTimeStamp(
types.KerberosTime.from_asn1(encTGSRepPart['endtime']))
credential['time']['renew_till'] = self.toTimeStamp(
types.KerberosTime.from_asn1(encTGSRepPart['renew-till']))
flags = self.reverseFlags(encTGSRepPart['flags'])
credential['tktflags'] = flags
credential['num_address'] = 0
credential.ticket = CountedOctetString()
credential.ticket['data'] = encoder.encode(decodedTGS['ticket'].clone(
tagSet=Ticket.tagSet, cloneValueFlag=True))
credential.ticket['length'] = len(credential.ticket['data'])
credential.secondTicket = CountedOctetString()
credential.secondTicket['data'] = ''
credential.secondTicket['length'] = 0
self.credentials.append(credential)
def toPrincipal(self):
return types.Principal(self.prettyPrint(),
type=self.header['name_type'])
