From: Gary Lockyer Date: Mon, 22 Sep 2025 03:40:58 +0000 (+1200) Subject: tests:s4:kdc Add tests for pkinit certificate mapping X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0245610b09f8ad4307fbed3143a581e603172fc4;p=thirdparty%2Fsamba.git tests:s4:kdc Add tests for pkinit certificate mapping Tests for pkinit with "strong certificate binding enforcement" See: https://support.microsoft.com/en-us/topic/ kb5014754-certificate-based-authentication-changes-on-windows-domain -controllers-ad2c23b0-15d8-4340-a468-4d4f3b188f16 KB5014754: Certificate-based authentication changes on Windows domain controllers Test environment configuration: ad_dc none ad_dc_ntcfs compatibility ad_dc_smb1 full Signed-off-by: Gary Lockyer Reviewed-by: Jennifer Sutton --- diff --git a/python/samba/tests/krb5/key_trust_tests.py b/python/samba/tests/krb5/key_trust_tests.py index 78410b822eb..07c62485dea 100755 --- a/python/samba/tests/krb5/key_trust_tests.py +++ b/python/samba/tests/krb5/key_trust_tests.py @@ -166,7 +166,7 @@ class KeyTrustTests(KDCBaseTest): self._pkinit_req( client_creds, target_creds, - certificate, + certificate = certificate, expect_error=KDC_ERR_CLIENT_NOT_TRUSTED, ) diff --git a/python/samba/tests/krb5/pkinit_certificate_mapping_tests.py b/python/samba/tests/krb5/pkinit_certificate_mapping_tests.py new file mode 100755 index 00000000000..3116c59cc6d --- /dev/null +++ b/python/samba/tests/krb5/pkinit_certificate_mapping_tests.py @@ -0,0 +1,1170 @@ +#!/usr/bin/env python3 +# +# Tests for pkinit with "strong certificate binding enforcement" +# See: https://support.microsoft.com/en-us/topic/ +# kb5014754-certificate-based-authentication-changes-on-windows-domain +# -controllers-ad2c23b0-15d8-4340-a468-4d4f3b188f16 +# KB5014754: Certificate-based authentication changes on Windows +# domain controllers +# +# Based on pkinit_tests.py +# +# Copyright (C) Gary Lockyer 2025 +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . +# + +import sys +import os + +sys.path.insert(0, "bin/python") +os.environ["PYTHONUNBUFFERED"] = "1" + +from datetime import datetime, timedelta + +from pyasn1.type import univ + +from cryptography import x509 +from cryptography.hazmat.primitives.serialization import pkcs12 +from cryptography.hazmat.backends import default_backend +from cryptography.hazmat.primitives import hashes, serialization +from cryptography.hazmat.primitives.asymmetric import dh, padding +from cryptography.x509.oid import NameOID + +from samba.domain.models import User +import samba.tests +from samba.dcerpc import security +from samba.param import LoadParm +from samba.tests.krb5 import kcrypto +from samba.tests.krb5.kdc_base_test import KDCBaseTest +from samba.tests.krb5.raw_testcase import PkInit, RawKerberosTest +from samba.tests.krb5.rfc4120_constants import ( + DES_EDE3_CBC, + KDC_ERR_CERTIFICATE_MISMATCH, + KU_PA_ENC_TIMESTAMP, + NT_PRINCIPAL, + NT_SRV_INST, + PADATA_AS_FRESHNESS, + PADATA_ENC_TIMESTAMP, + PADATA_PK_AS_REP_19, + PADATA_PK_AS_REQ, +) +import samba.tests.krb5.rfc4120_pyasn1 as krb5_asn1 + +SidType = RawKerberosTest.SidType + +global_asn1_print = False +global_hexdump = False + + +class PkInitCertificateMappingTests(KDCBaseTest): + @classmethod + def setUpClass(cls): + super().setUpClass() + + def setUp(self): + super().setUp() + self.do_asn1_print = global_asn1_print + self.do_hexdump = global_hexdump + + # + # get_loadparm loads the client smb.conf + # we need to load the server smb.conf to get the server + # settings. + + server_conf = os.getenv("SERVERCONFFILE") + lp = LoadParm(filename_for_non_global_lp=server_conf) + + compensation = lp.get("certificate backdating compensation") + # Convert the compensation to seconds, and add 1 hour (3600 seconds) + backdating = (compensation * 60) + 3600 + self.backdating = timedelta(0, backdating, 0) + + enforcement = lp.get("strong certificate binding enforcement") + if enforcement is None: + enforcement = "full" + + # Set the expected results based on the server configuration + if enforcement == "full": + # Full enforcement, only Strong bindings should succeed + self.STRONG_EXPECTED_RESULT = 0 + self.WEAK_EXPECTED_RESULT = KDC_ERR_CERTIFICATE_MISMATCH + self.WEAK_EXPECTED_RESULT_BEFORE = KDC_ERR_CERTIFICATE_MISMATCH + self.NONE_EXPECTED_RESULT = KDC_ERR_CERTIFICATE_MISMATCH + self.NAME_FAIL_RESULT = KDC_ERR_CERTIFICATE_MISMATCH + elif enforcement == "compatibility": + # Compatibility enforcement. + # Strong bindings should succeed + # Weak bindings should succeed if the certificate was created + # after the user accounts creation minus the backdating compensation + self.STRONG_EXPECTED_RESULT = 0 + self.WEAK_EXPECTED_RESULT = 0 + self.WEAK_EXPECTED_RESULT_BEFORE = KDC_ERR_CERTIFICATE_MISMATCH + self.NONE_EXPECTED_RESULT = KDC_ERR_CERTIFICATE_MISMATCH + self.NAME_FAIL_RESULT = KDC_ERR_CERTIFICATE_MISMATCH + else: + # Enforcement is none, no certificate binding checks performed + # all tests should succeed + self.STRONG_EXPECTED_RESULT = 0 + self.WEAK_EXPECTED_RESULT = 0 + self.WEAK_EXPECTED_RESULT_BEFORE = 0 + self.NONE_EXPECTED_RESULT = 0 + self.NAME_FAIL_RESULT = 0 + + def test_no_mapping(self): + """ + Test PKINIT logon with a user account, and no certificate mappings + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.NONE_EXPECTED_RESULT, + ) + + def test_computer_account_no_mapping(self): + """ + Test PKINIT logon with a computer account and no certificate mappings + """ + + client_creds = self._get_creds(self.AccountType.COMPUTER) + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.NONE_EXPECTED_RESULT, + ) + + def test_subject_name(self): + """ + Test PKINIT logon with a user account + and the weak mapping subject name + certificate created after the start of the compensation window + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + identity = f"X509:{self._rfc4514_string(certificate.subject)}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.WEAK_EXPECTED_RESULT, + ) + + def test_subject_name_before(self): + """ + Test PKINIT logon with a user account + and the weak mapping subject name + certificate created before the start of the compensation window + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + now = datetime.now() + not_before = now - self.backdating + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [], not_before + ) + + identity = f"X509:{self._rfc4514_string(certificate.subject)}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.WEAK_EXPECTED_RESULT_BEFORE, + ) + + def test_subject_name_reversed(self): + """ + Test PKINIT logon with a user account + and the weak mapping subject name + certificate created after the start of the compensation window + however the subject name has been reversed. + + NOTE:This currently fails, as normalization/canonicalization of + the subject and issuer name is not currently implemented + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + # Reverse the order of the subject name components + components = self._rfc4514_string(certificate.subject).split(",") + components.reverse() + subject = ",".join(components) + identity = f"X509:{subject}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.NAME_FAIL_RESULT, + ) + + def test_issuer_subject(self): + """ + Test PKINIT logon with a user account + and the weak mapping issuer and subject name + certificate created after the start of the compensation window + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + identity = ( + "X509:" + f"{self._rfc4514_string(certificate.issuer)}" + f"{self._rfc4514_string(certificate.subject)}" + ) + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.WEAK_EXPECTED_RESULT, + ) + + def test_issuer_subject_before(self): + """ + Test PKINIT logon with a user account + and the weak mapping issuer and subject name + certificate created before the start of the compensation window + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + now = datetime.now() + not_before = now - self.backdating + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [], not_before + ) + + identity = ( + "X509:" + f"{self._rfc4514_string(certificate.issuer)}" + f"{self._rfc4514_string(certificate.subject)}" + ) + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.WEAK_EXPECTED_RESULT_BEFORE, + ) + + def test_rfc822(self): + """ + Test PKINIT logon with a user account + and the weak mapping rfc822 (email address) + certificate created after the start of the compensation window + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + email = "testad@test.samba.org" + san = x509.RFC822Name(email) + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [san] + ) + + identity = f"X509:{email}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.WEAK_EXPECTED_RESULT, + ) + + def test_rfc822_before(self): + """ + Test PKINIT logon with a user account + and the weak mapping rfc822 (email address) + certificate created before the start of the compensation window + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + now = datetime.now() + not_before = now - self.backdating + # Create a certificate for the client signed by the CA. + email = "testad@test.samba.org" + san = x509.RFC822Name(email) + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [san], not_before + ) + + identity = f"X509:{email}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.WEAK_EXPECTED_RESULT_BEFORE, + ) + + def test_issuer_serial_number(self): + """ + Test PKINIT logon with a user account + and the strong mapping issuer and subject name + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + serial = hex(certificate.serial_number)[2:] + if len(serial) % 2: + # Add a leading 0 if needed + serial = '0' + serial + identity = f"X509:{self._rfc4514_string(certificate.issuer)}{serial}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.STRONG_EXPECTED_RESULT, + ) + + def test_subject_key_identifier(self): + """ + Test PKINIT logon with a user account + and the strong mapping subject key identifier + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + ski = x509.SubjectKeyIdentifier.from_public_key( + certificate.public_key()) + identity = f"X509:{ski.digest.hex()}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.STRONG_EXPECTED_RESULT, + ) + + def test_public_key(self): + """ + Test PKINIT logon with a user account + and the strong mapping public key + """ + + client_creds = self._get_creds() + target_creds = self.get_service_creds() + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + client_creds, ca_cert, ca_private_key, None, [] + ) + + hash = x509.SubjectKeyIdentifier.from_public_key(certificate.public_key()) + identity = f"X509:{hash.digest.hex()}" + self._add_altSecurityIdentities(client_creds, identity) + + self._pkinit_req( + client_creds, + target_creds, + certificate=certificate, + expect_error=self.STRONG_EXPECTED_RESULT, + ) + + def _rfc4514_string(self, name): + """ + Convert an X509 name to it's RFC 4514 form, however we need + to fix the generated names to match heimdals expectations + """ + ns = name.rfc4514_string() + ns = ns.replace("1.2.840.113549.1.9.1", "emailAddress") + ns = ns.replace("ST=", "S=") + return ns + + def _add_altSecurityIdentities(self, creds, identity): + """ + Update the altSecurityIdentities attribute of the account under test + """ + user = User.find(self.get_samdb(), creds.get_username()) + self.assertIsNotNone(user) + if user is not None: + user.alt_security_identities = identity + user.save(self.get_samdb()) + + def _get_creds( + self, + account_type=KDCBaseTest.AccountType.USER, + use_cache=False, + smartcard_required=False, + assigned_policy=None, + ): + """Return credentials with an account having a UPN for performing + PK-INIT.""" + samdb = self.get_samdb() + realm = samdb.domain_dns_name().upper() + + opts = { + "upn": f"{{account}}.{realm}@{realm}", + "smartcard_required": smartcard_required, + } + if assigned_policy is not None: + opts["assigned_policy"] = str(assigned_policy.dn) + return self.get_cached_creds( + account_type=account_type, opts=opts, use_cache=use_cache + ) + + def _as_req( + self, + creds, + target_creds, + *, + expect_error=0, + expect_status=False, + expected_status=None, + expect_edata=False, + etypes=None, + freshness=None, + send_enc_ts=False, + ): + if send_enc_ts: + if creds.get_password() is None: + # Try the NT hash if there isn't a password + preauth_key = self.PasswordKey_from_creds(creds, kcrypto.Enctype.RC4) + else: + preauth_key = self.PasswordKey_from_creds(creds, kcrypto.Enctype.AES256) + else: + preauth_key = None + + if freshness is not None or send_enc_ts: + + def generate_padata_fn(_kdc_exchange_dict, _callback_dict, req_body): + padata = [] + + if freshness is not None: + freshness_padata = self.PA_DATA_create( + PADATA_AS_FRESHNESS, freshness + ) + padata.append(freshness_padata) + + if send_enc_ts: + patime, pausec = self.get_KerberosTimeWithUsec() + enc_ts = self.PA_ENC_TS_ENC_create(patime, pausec) + enc_ts = self.der_encode(enc_ts, asn1Spec=krb5_asn1.PA_ENC_TS_ENC()) + + enc_ts = self.EncryptedData_create( + preauth_key, KU_PA_ENC_TIMESTAMP, enc_ts + ) + enc_ts = self.der_encode(enc_ts, asn1Spec=krb5_asn1.EncryptedData()) + + enc_ts = self.PA_DATA_create(PADATA_ENC_TIMESTAMP, enc_ts) + + padata.append(enc_ts) + + return padata, req_body + else: + generate_padata_fn = None + + user_name = creds.get_username() + cname = self.PrincipalName_create( + name_type=NT_PRINCIPAL, names=user_name.split("/") + ) + + target_name = target_creds.get_username() + target_realm = target_creds.get_realm() + + if target_name == "krbtgt": + sname = self.PrincipalName_create( + name_type=NT_SRV_INST, names=["krbtgt", target_realm] + ) + else: + sname = self.PrincipalName_create( + name_type=NT_PRINCIPAL, names=["host", target_name[:-1]] + ) + + if expect_error: + check_error_fn = self.generic_check_kdc_error + check_rep_fn = None + + expected_sname = sname + else: + check_error_fn = None + check_rep_fn = self.generic_check_kdc_rep + + if target_name == "krbtgt": + expected_sname = sname + else: + expected_sname = self.PrincipalName_create( + name_type=NT_PRINCIPAL, names=[target_name] + ) + + kdc_options = "forwardable,renewable,canonicalize,renewable-ok" + kdc_options = krb5_asn1.KDCOptions(kdc_options) + + ticket_decryption_key = self.TicketDecryptionKey_from_creds(target_creds) + + kdc_exchange_dict = self.as_exchange_dict( + creds=creds, + expected_crealm=creds.get_realm(), + expected_cname=cname, + expected_srealm=target_realm, + expected_sname=expected_sname, + expected_supported_etypes=target_creds.tgs_supported_enctypes, + ticket_decryption_key=ticket_decryption_key, + generate_padata_fn=generate_padata_fn, + check_error_fn=check_error_fn, + check_rep_fn=check_rep_fn, + check_kdc_private_fn=self.generic_check_kdc_private, + expected_error_mode=expect_error, + expected_salt=creds.get_salt(), + preauth_key=preauth_key, + kdc_options=str(kdc_options), + expect_edata=expect_edata, + expect_status=expect_status, + expected_status=expected_status, + ) + + till = self.get_KerberosTime(offset=36000) + + if etypes is None: + etypes = ( + kcrypto.Enctype.AES256, + kcrypto.Enctype.RC4, + ) + + rep = self._generic_kdc_exchange( + kdc_exchange_dict, + cname=cname, + realm=target_realm, + sname=sname, + till_time=till, + etypes=etypes, + ) + if expect_error: + self.check_error_rep(rep, expect_error) + else: + self.check_as_reply(rep) + + return kdc_exchange_dict + + def get_ca_cert_and_private_key(self): + # The password with which to try to encrypt the certificate or private + # key specified on the command line. + ca_pass = samba.tests.env_get_var_value("CA_PASS", allow_missing=True) + if ca_pass is not None: + ca_pass = ca_pass.encode("utf-8") + + # The root certificate of the CA, with which we can issue new + # certificates. + ca_cert_path = samba.tests.env_get_var_value("CA_CERT") + with open(ca_cert_path, mode="rb") as f: + ca_cert_data = f.read() + + try: + # If the certificate file is in the PKCS#12 format (such as is + # found in a .pfx file) try to get the private key and the + # certificate all in one go. + ca_private_key, ca_cert, _additional_ca_certs = ( + pkcs12.load_key_and_certificates( + ca_cert_data, ca_pass, default_backend() + ) + ) + except ValueError: + # Fall back to loading a PEM-encoded certificate. + ca_private_key = None + ca_cert = x509.load_pem_x509_certificate( + ca_cert_data, default_backend() + ) + + # If we didn’t get the private key, do that now. + if ca_private_key is None: + ca_private_key_path = samba.tests.env_get_var_value("CA_PRIVATE_KEY") + with open(ca_private_key_path, mode="rb") as f: + ca_private_key = serialization.load_pem_private_key( + f.read(), password=ca_pass, backend=default_backend() + ) + + return ca_cert, ca_private_key + + def create_certificate( + self, + creds, + ca_cert, + ca_private_key, + certificate_signature=None, + san=[], + notBefore=None, + ): + if certificate_signature is None: + certificate_signature = hashes.SHA256 + + user_name = creds.get_username() + + builder = x509.CertificateBuilder() + + # Add the subject name. + cert_name = f"{user_name}@{creds.get_realm().lower()}" + builder = builder.subject_name( + x509.Name( + [ + # Note that the subject name is used in certificate mappings + x509.NameAttribute(NameOID.COUNTRY_NAME, "US"), + x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, "SambaState"), + x509.NameAttribute(NameOID.ORGANIZATION_NAME, "SambaSelfTesting"), + x509.NameAttribute(NameOID.ORGANIZATIONAL_UNIT_NAME, "Users"), + x509.NameAttribute(NameOID.COMMON_NAME, f"{cert_name}"), + ] + ) + ) + + # The new certificate must be issued by the root CA. + builder = builder.issuer_name(ca_cert.issuer) + + # Note that if the certificate predates the existence of the account + # in AD, Authentication will fail unless there is a valid strong mapping + # See https://support.microsoft.com/en-us/topic/kb5014754-certificate-based-authentication-changes-on-windows-domain-controllers-ad2c23b0-15d8-4340-a468-4d4f3b188f16#ID0EFR + one_day = timedelta(1, 0, 0) + if notBefore is None: + builder = builder.not_valid_before(datetime.today() - one_day) + else: + builder = builder.not_valid_before(notBefore) + builder = builder.not_valid_after(datetime.today() + (one_day * 30)) + + builder = builder.serial_number(x509.random_serial_number()) + + public_key = creds.get_public_key() + builder = builder.public_key(public_key) + + # Add the SubjectAlternativeName. Windows uses this to map the account + # to the certificate. + id_pkinit_ms_san = x509.ObjectIdentifier(str(krb5_asn1.id_pkinit_ms_san)) + encoded_upn = self.der_encode(creds.get_upn(), asn1Spec=krb5_asn1.MS_UPN_SAN()) + ms_upn_san = x509.OtherName(id_pkinit_ms_san, encoded_upn) + alt_names = san + alt_names.append(ms_upn_san) + builder = builder.add_extension( + x509.SubjectAlternativeName(alt_names), + critical=False, + ) + + builder = builder.add_extension( + x509.BasicConstraints(ca=False, path_length=None), + critical=True, + ) + + # The key identifier is used to identify the certificate. + subject_key_id = x509.SubjectKeyIdentifier.from_public_key(public_key) + builder = builder.add_extension( + subject_key_id, + critical=True, + ) + + # Add the key usages for which this certificate is valid. Windows + # doesn’t actually require this extension to be present. + builder = builder.add_extension( + # Heimdal requires that the certificate be valid for digital + # signatures. + x509.KeyUsage( + digital_signature=True, + content_commitment=False, + key_encipherment=False, + data_encipherment=False, + key_agreement=False, + key_cert_sign=False, + crl_sign=False, + encipher_only=False, + decipher_only=False, + ), + critical=True, + ) + + # Windows doesn’t require this extension to be present either; but if + # it is, Windows will not accept the certificate unless either client + # authentication or smartcard logon is specified, returning + # KDC_ERR_INCONSISTENT_KEY_PURPOSE otherwise. + builder = builder.add_extension( + x509.ExtendedKeyUsage( + [ + x509.oid.ExtendedKeyUsageOID.CLIENT_AUTH, + ] + ), + critical=False, + ) + + # If the certificate predates (as ours does) the existence of the + # account that presents it Windows will refuse to accept it unless + # there exists a strong mapping from one to the other. This strong + # mapping will in this case take the form of a certificate extension + # described in [MS-WCCE] 2.2.2.7.7.4 (szOID_NTDS_CA_SECURITY_EXT) and + # containing the account’s SID. + + # Encode this structure manually until we are able to produce the same + # ASN.1 encoding that Windows does. + + encoded_sid = creds.get_sid().encode("utf-8") + + # The OCTET STRING tag, followed by length and encoded SID… + security_ext = bytes([0x04]) + self.asn1_length(encoded_sid) + (encoded_sid) + + # …enclosed in a construct tagged with the application-specific value + # 0… + security_ext = bytes([0xA0]) + self.asn1_length(security_ext) + (security_ext) + + # …preceded by the extension OID… + encoded_oid = self.der_encode( + krb5_asn1.szOID_NTDS_OBJECTSID, univ.ObjectIdentifier() + ) + security_ext = encoded_oid + security_ext + + # …and another application-specific tag 0… + # (This is the part about which I’m unsure. This length is not just of + # the OID, but of the entire structure so far, as if there’s some + # nesting going on. So far I haven’t been able to replicate this with + # pyasn1.) + security_ext = bytes([0xA0]) + self.asn1_length(security_ext) + (security_ext) + + # …all enclosed in a structure with a SEQUENCE tag. + security_ext = bytes([0x30]) + self.asn1_length(security_ext) + (security_ext) + + # Add the security extension to the certificate. + builder = builder.add_extension( + x509.UnrecognizedExtension( + x509.ObjectIdentifier(str(krb5_asn1.szOID_NTDS_CA_SECURITY_EXT)), + security_ext, + ), + critical=False, + ) + + # Sign the certificate with the CA’s private key. Windows accepts both + # SHA1 and SHA256 hashes. + certificate = builder.sign( + private_key=ca_private_key, + algorithm=certificate_signature(), + backend=default_backend(), + ) + + return certificate + + def _pkinit_req( + self, + creds, + target_creds, + *, + certificate=None, + expect_error=0, + expect_edata=False, + expected_status=None, + using_pkinit=PkInit.PUBLIC_KEY, + etypes=None, + pk_nonce=None, + supported_cms_types=None, + signature_algorithm=None, + certificate_signature=None, + freshness_token=None, + win2k_variant=False, + expect_matching_nt_hash_in_pac=True, + target_sname=None, + ): + self.assertIsNot(using_pkinit, PkInit.NOT_USED) + + if signature_algorithm is None: + # This algorithm must be one of ‘sig_algs’ for it to be supported + # by Heimdal. + signature_algorithm = krb5_asn1.sha1WithRSAEncryption + + signature_algorithm_id = self.AlgorithmIdentifier_create(signature_algorithm) + + if certificate is None: + ca_cert, ca_private_key = self.get_ca_cert_and_private_key() + + # Create a certificate for the client signed by the CA. + certificate = self.create_certificate( + creds, ca_cert, ca_private_key, certificate_signature + ) + + private_key = creds.get_private_key() + + if using_pkinit is PkInit.DIFFIE_HELLMAN: + # This is the 2048-bit MODP Group from RFC 3526. Heimdal refers to + # it as “rfc3526-MODP-group14”. + p, g = ( + 32317006071311007300338913926423828248817941241140239112842009751400741706634354222619689417363569347117901737909704191754605873209195028853758986185622153212175412514901774520270235796078236248884246189477587641105928646099411723245426622522193230540919037680524235519125679715870117001058055877651038861847280257976054903569732561526167081339361799541336476559160368317896729073178384589680639671900977202194168647225871031411336429319536193471636533209717077448227988588565369208645296636077250268955505928362751121174096972998068410554359584866583291642136218231078990999448652468262416972035911852507045361090559, + 2, + ) + + numbers = dh.DHParameterNumbers(p, g) + dh_params = numbers.parameters(default_backend()) + + dh_private_key = dh_params.generate_private_key() + + preauth_key = dh_private_key + else: + preauth_key = private_key + + if pk_nonce is None: + pk_nonce = self.get_Nonce() + + def generate_pk_padata(_kdc_exchange_dict, _callback_dict, req_body): + if win2k_variant: + digest = None + else: + checksum_blob = self.der_encode( + req_body, asn1Spec=krb5_asn1.KDC_REQ_BODY() + ) + + # Calculate the SHA1 checksum over the KDC-REQ-BODY. This checksum + # is required to be present in the authenticator, and must be SHA1. + digest = hashes.Hash(hashes.SHA1(), default_backend()) + digest.update(checksum_blob) + digest = digest.finalize() + + ctime, cusec = self.get_KerberosTimeWithUsec() + + if win2k_variant: + krbtgt_sname = self.get_krbtgt_sname() + krbtgt_realm = self.get_krbtgt_creds().get_realm() + else: + krbtgt_sname = None + krbtgt_realm = None + + # Create the authenticator, which shows that we had possession of + # the private key at some point. + authenticator_obj = self.PKAuthenticator_create( + cusec, + ctime, + pk_nonce, + pa_checksum=digest, + freshness_token=freshness_token, + kdc_name=krbtgt_sname, + kdc_realm=krbtgt_realm, + win2k_variant=win2k_variant, + ) + + if using_pkinit is PkInit.DIFFIE_HELLMAN: + dh_public_key = dh_private_key.public_key() + + encoded_dh_public_key = dh_public_key.public_bytes( + serialization.Encoding.DER, + serialization.PublicFormat.SubjectPublicKeyInfo, + ) + decoded_dh_public_key = self.der_decode( + encoded_dh_public_key, asn1Spec=krb5_asn1.SubjectPublicKeyInfo() + ) + dh_public_key_bitstring = decoded_dh_public_key["subjectPublicKey"] + + # Encode the Diffie-Hellman parameters. + params = dh_params.parameter_bytes( + serialization.Encoding.DER, serialization.ParameterFormat.PKCS3 + ) + + pk_algorithm = self.AlgorithmIdentifier_create( + krb5_asn1.dhpublicnumber, parameters=params + ) + + # Create the structure containing information about the public + # key of the certificate that we shall present. + client_public_value = self.SubjectPublicKeyInfo_create( + pk_algorithm, dh_public_key_bitstring + ) + else: + client_public_value = None + + # An optional set of algorithms supported by the client in + # decreasing order of preference. For whatever reason, if this + # field is missing or empty, Windows will respond with a slightly + # differently encoded ReplyKeyPack, wrapping it first in a + # ContentInfo structure. + nonlocal supported_cms_types + if win2k_variant: + self.assertIsNone(supported_cms_types) + elif supported_cms_types is False: + # Exclude this field. + supported_cms_types = None + elif supported_cms_types is None: + supported_cms_types = [ + self.AlgorithmIdentifier_create( + krb5_asn1.id_pkcs1_sha256WithRSAEncryption + ), + ] + + # The client may include this field if it wishes to reuse DH keys + # or allow the KDC to do so. + client_dh_nonce = None + + auth_pack_obj = self.AuthPack_create( + authenticator_obj, + client_public_value=client_public_value, + supported_cms_types=supported_cms_types, + client_dh_nonce=client_dh_nonce, + win2k_variant=win2k_variant, + ) + + asn1_spec = ( + krb5_asn1.AuthPack_Win2k if win2k_variant else krb5_asn1.AuthPack + ) + auth_pack = self.der_encode(auth_pack_obj, asn1Spec=asn1_spec()) + + signature_hash = self.hash_from_algorithm(signature_algorithm) + + pad = padding.PKCS1v15() + signed = private_key.sign( + auth_pack, padding=pad, algorithm=signature_hash() + ) + + encap_content_info_obj = self.EncapsulatedContentInfo_create( + krb5_asn1.id_pkinit_authData, auth_pack + ) + + subject_key_id = certificate.extensions.get_extension_for_oid( + x509.ExtensionOID.SUBJECT_KEY_IDENTIFIER + ) + signer_identifier = self.SignerIdentifier_create( + subject_key_id=subject_key_id.value.digest + ) + + signer_info = self.SignerInfo_create( + signer_identifier, + signature_algorithm_id, + signature_algorithm_id, + signed, + signed_attrs=[ + # Note: these attributes are optional. + krb5_asn1.id_pkinit_authData, + krb5_asn1.id_messageDigest, + ], + ) + + encoded_cert = certificate.public_bytes(serialization.Encoding.DER) + decoded_cert = self.der_decode( + encoded_cert, asn1Spec=krb5_asn1.CertificateChoices() + ) + + signed_auth_pack = self.SignedData_create( + [signature_algorithm_id], + encap_content_info_obj, + signer_infos=[signer_info], + certificates=[decoded_cert], + crls=None, + ) + + signed_auth_pack = self.der_encode( + signed_auth_pack, asn1Spec=krb5_asn1.SignedData() + ) + + pk_as_req = self.PK_AS_REQ_create( + signed_auth_pack, + # This contains a list of CAs, + # trusted by the client, that can + # be used to certify the KDC. + trusted_certifiers=None, + kdc_pk_id=None, + win2k_variant=win2k_variant, + ) + + pa_type = PADATA_PK_AS_REP_19 if win2k_variant else PADATA_PK_AS_REQ + padata = [self.PA_DATA_create(pa_type, pk_as_req)] + + return padata, req_body + + user_name = creds.get_username() + cname = self.PrincipalName_create( + name_type=NT_PRINCIPAL, names=user_name.split("/") + ) + + target_name = target_creds.get_username() + target_realm = target_creds.get_realm() + + expected_sname = target_sname + if target_sname is None: + target_name = target_creds.get_username() + if target_name == "krbtgt": + target_sname = self.PrincipalName_create( + name_type=NT_SRV_INST, names=["krbtgt", target_realm] + ) + expected_sname = target_sname + else: + target_sname = self.PrincipalName_create( + name_type=NT_PRINCIPAL, names=["host", target_name[:-1]] + ) + + expected_sname = self.PrincipalName_create( + name_type=NT_PRINCIPAL, names=[target_name] + ) + + if expect_error: + check_error_fn = self.generic_check_kdc_error + check_rep_fn = None + + expected_sname = target_sname + else: + check_error_fn = None + check_rep_fn = self.generic_check_kdc_rep + + kdc_options = "forwardable,renewable,canonicalize,renewable-ok" + kdc_options = krb5_asn1.KDCOptions(kdc_options) + + ticket_decryption_key = self.TicketDecryptionKey_from_creds(target_creds) + + if freshness_token is None: + expected_groups = None + unexpected_groups = { + ( + security.SID_FRESH_PUBLIC_KEY_IDENTITY, + SidType.EXTRA_SID, + security.SE_GROUP_DEFAULT_FLAGS, + ) + } + else: + expected_groups = { + ( + security.SID_FRESH_PUBLIC_KEY_IDENTITY, + SidType.EXTRA_SID, + security.SE_GROUP_DEFAULT_FLAGS, + ), + ..., + } + unexpected_groups = None + + kdc_exchange_dict = self.as_exchange_dict( + creds=creds, + client_cert=certificate, + expected_crealm=creds.get_realm(), + expected_cname=cname, + expected_srealm=target_realm, + expected_sname=expected_sname, + expected_supported_etypes=target_creds.tgs_supported_enctypes, + expected_groups=expected_groups, + unexpected_groups=unexpected_groups, + ticket_decryption_key=ticket_decryption_key, + generate_padata_fn=generate_pk_padata, + check_error_fn=check_error_fn, + check_rep_fn=check_rep_fn, + check_kdc_private_fn=self.generic_check_kdc_private, + expected_error_mode=expect_error, + expected_salt=creds.get_salt(), + preauth_key=preauth_key, + kdc_options=str(kdc_options), + using_pkinit=using_pkinit, + pk_nonce=pk_nonce, + expect_edata=expect_edata, + expected_status=expected_status, + expect_matching_nt_hash_in_pac=expect_matching_nt_hash_in_pac, + ) + + till = self.get_KerberosTime(offset=36000) + + if etypes is None: + etypes = ( + kcrypto.Enctype.AES256, + kcrypto.Enctype.RC4, + ) + + if using_pkinit is PkInit.PUBLIC_KEY: + # DES-EDE3-CBC is required for public-key PK-INIT to work on + # Windows. + etypes += (DES_EDE3_CBC,) + + rep = self._generic_kdc_exchange( + kdc_exchange_dict, + cname=cname, + realm=target_realm, + sname=target_sname, + till_time=till, + etypes=etypes, + ) + if expect_error: + self.check_error_rep(rep, expect_error) + return None + + self.check_as_reply(rep) + return kdc_exchange_dict + + +if __name__ == "__main__": + global_asn1_print = False + global_hexdump = False + import unittest + + unittest.main() diff --git a/python/samba/tests/krb5/rfc4120_constants.py b/python/samba/tests/krb5/rfc4120_constants.py index e263db70306..c42a38ffa59 100644 --- a/python/samba/tests/krb5/rfc4120_constants.py +++ b/python/samba/tests/krb5/rfc4120_constants.py @@ -117,6 +117,7 @@ KDC_ERR_GENERIC = 60 KDC_ERR_CLIENT_NOT_TRUSTED = 62 KDC_ERR_INVALID_SIG = 64 KDC_ERR_DH_KEY_PARAMETERS_NOT_ACCEPTED = 65 +KDC_ERR_CERTIFICATE_MISMATCH = 66 KDC_ERR_WRONG_REALM = 68 KDC_ERR_CANT_VERIFY_CERTIFICATE = 70 KDC_ERR_INVALID_CERTIFICATE = 71 diff --git a/selftest/knownfail b/selftest/knownfail index ab2d79d7114..0e42fbd3b9c 100644 --- a/selftest/knownfail +++ b/selftest/knownfail @@ -338,3 +338,21 @@ # We currently don't send referrals for LDAP modify of non-replicated attrs ^samba4.ldap.rodc.python\(rodc\).__main__.RodcTests.test_modify_nonreplicated.* + +# Certificate mapping +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_computer_account_no_mapping\(ad_dc_ntvfs\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_issuer_subject_before\(ad_dc_ntvfs\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_no_mapping\(ad_dc_ntvfs\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_rfc822_before\(ad_dc_ntvfs\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_subject_name_before\(ad_dc_ntvfs\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_subject_name_reversed\(ad_dc_ntvfs\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_computer_account_no_mapping\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_issuer_subject\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_issuer_subject_before\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_no_mapping\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_rfc822\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_rfc822_before\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_subject_name\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_subject_name_before\(ad_dc_smb1\) +^samba.tests.krb5.pkinit_certificate_mapping_tests..*.test_subject_name_reversed\(ad_dc_smb1\) + diff --git a/selftest/knownfail_mit_kdc b/selftest/knownfail_mit_kdc index 2b590553fed..c32e3b523c5 100644 --- a/selftest/knownfail_mit_kdc +++ b/selftest/knownfail_mit_kdc @@ -18,3 +18,6 @@ # MIT does not currently support key trust logons. # ^samba.tests.krb5.key_trust_tests.* +# +# MIT does not currently support Windows certificate mappings for PKINIT +^samba.tests.krb5.pkinit_certificate_mapping_tests.* diff --git a/source4/selftest/tests.py b/source4/selftest/tests.py index 576785f7b83..06f2ff08d64 100755 --- a/source4/selftest/tests.py +++ b/source4/selftest/tests.py @@ -2148,6 +2148,24 @@ planoldpythontestsuite( 'ad_dc', 'samba.tests.krb5.pkinit_tests', environ=krb5_environ) + +# strong certificate binding enforcement = none +planoldpythontestsuite( + 'ad_dc', + 'samba.tests.krb5.pkinit_certificate_mapping_tests', + environ=krb5_environ) +# strong certificate binding enforcement = compatibility +planoldpythontestsuite( + 'ad_dc_ntvfs', + 'samba.tests.krb5.pkinit_certificate_mapping_tests', + environ=krb5_environ) +# strong certificate binding enforcement = full +# the default. +planoldpythontestsuite( + 'ad_dc_smb1', + 'samba.tests.krb5.pkinit_certificate_mapping_tests', + environ=krb5_environ) + planoldpythontestsuite( 'ad_dc', 'samba.tests.krb5.key_trust_tests',