def _validate_cert_chain(self, cert_chain):
# type: (bytes) -> None
"""Validate the certificate chain.
This method checks if the passed in certificate chain is valid.
A :py:class:`VerificationException` is raised if the certificate
chain is not valid.
The end certificate is read, using the
:py:func:`cryptography.x509.load_pem_x509_certificate` method.
The x509 backend is set as default to the
:py:class:`cryptography.hazmat.backends.default_backend`
instance.
:param cert_chain: Certificate chain to be validated
:type cert_chain: bytes
:return: None
:raises: :py:class:`VerificationException` if certificate chain is
not valid
"""
try:
end_cert = None
intermediate_certs = []
for type_name, headers, der_bytes in pem.unarmor(
cert_chain, multiple=True):
if end_cert is None:
end_cert = der_bytes
else:
intermediate_certs.append(der_bytes)
validator = CertificateValidator(end_cert, intermediate_certs)
validator.validate_usage(key_usage={'digital_signature'})
except (PathError, ValidationError) as e:
raise VerificationException("Certificate chain is not valid", e)
def _check_certificate(self, certificate):
_, _, certificate_bytes = pem.unarmor(
certificate.encode(), multiple=False)
certificate = x509.Certificate.load(certificate_bytes)
trust_roots = []
with open(self.ca_crt, 'rb') as f:
for _, _, der_bytes in pem.unarmor(f.read(), multiple=True):
trust_roots.append(der_bytes)
crls = []
with open(settings.CA_CRL, 'rb') as f:
crls.append(f.read())
context = ValidationContext(crls=crls,
trust_roots=trust_roots)
try:
validator = CertificateValidator(
certificate, validation_context=context)
result = validator.validate_usage(
set(['digital_signature'])
)
dev = True
except errors.PathValidationError as e:
logger.debug("SimpleCA: validate PathValidationError %r" % (e))
dev = False
except errors.PathBuildingError as e:
logger.debug("SimpleCA: validate PathBuildingError %r" % (e))
dev = False
logger.info("SimpleCA: validate cert %r == %r" %
(certificate.serial_number, dev))
return dev
def test_cert_constraint_issuer(requests_mock):
vc = live_testing_vc(requests_mock)
signer_validation_path = CertificateValidator(
FROM_CA.signing_cert, FROM_CA.cert_registry,
validation_context=vc).validate_usage(set())
tsa_validation_path = CertificateValidator(
DUMMY_TS.tsa_cert, FROM_CA.cert_registry,
validation_context=vc).validate_usage(set())
scc = fields.SigCertConstraints(flags=fields.SigCertConstraintFlags.ISSUER,
issuers=[ROOT_CERT])
scc.satisfied_by(FROM_CA.signing_cert, signer_validation_path)
scc.satisfied_by(DUMMY_TS.tsa_cert, tsa_validation_path)
with pytest.raises(UnacceptableSignerError):
scc.satisfied_by(FROM_CA.signing_cert, None)
scc = fields.SigCertConstraints(flags=fields.SigCertConstraintFlags.ISSUER,
issuers=[INTERM_CERT])
scc.satisfied_by(FROM_CA.signing_cert, signer_validation_path)
with pytest.raises(UnacceptableSignerError):
scc.satisfied_by(DUMMY_TS.tsa_cert, tsa_validation_path)
scc = fields.SigCertConstraints(
flags=fields.SigCertConstraintFlags.ISSUER,
issuers=[INTERM_CERT, SELF_SIGN.signing_cert])
scc.satisfied_by(FROM_CA.signing_cert, signer_validation_path)
with pytest.raises(UnacceptableSignerError):
scc.satisfied_by(DUMMY_TS.tsa_cert, tsa_validation_path)
scc = fields.SigCertConstraints(issuers=[INTERM_CERT])
scc.satisfied_by(FROM_CA.signing_cert, signer_validation_path)
scc.satisfied_by(DUMMY_TS.tsa_cert, tsa_validation_path)
def validate_vmc(self):
try:
end_entity_cert = None
intermediates = []
with open(self.vmc_file, 'rb') as f:
for type_name, headers, der_bytes in pem.unarmor(
f.read(), multiple=True):
if end_entity_cert is None:
end_entity_cert = der_bytes
else:
intermediates.append(der_bytes)
validator = CertificateValidator(end_entity_cert, intermediates)
validated = validator.validate_usage(set(['digital_signature']))
# print(intermediates)
except errors.PathValidationError as PathValidationError:
self.vmc_response["errors"].append("Error: " +
str(PathValidationError))
print(PathValidationError)
except errors.RevokedError as RevokedError:
self.vmc_response["errors"].append(
"Error: Certificate Revoked.\n" + str(RevokedError))
print(RevokedError)
except errors.InvalidCertificateError as InvalidCertificateError:
self.vmc_response["errors"].append(
"Error: Certificate Is Invalid.\n" +
str(InvalidCertificateError))
print(InvalidCertificateError)
except errors.PathBuildingError as PathBuildingError:
self.vmc_response["errors"].append("Error: Cannot Build Path.\n" +
str(PathBuildingError))
print(PathBuildingError)
except Exception as e:
self.vmc_response["errors"].append(
"Error: Validation Exception.\n" + str(e))
print(e)
def test_cert_constraint_composite(requests_mock):
vc = live_testing_vc(requests_mock)
signer_validation_path = CertificateValidator(
FROM_CA.signing_cert, FROM_CA.cert_registry,
validation_context=vc).validate_usage(set())
tsa_validation_path = CertificateValidator(
DUMMY_TS.tsa_cert, FROM_CA.cert_registry,
validation_context=vc).validate_usage(set())
from asn1crypto import x509
scc = fields.SigCertConstraints(flags=fields.SigCertConstraintFlags.ISSUER
| fields.SigCertConstraintFlags.SUBJECT_DN,
issuers=[INTERM_CERT],
subject_dn=x509.Name.build({
'common_name':
'Lord Testerino',
'country_name':
'BE'
}))
scc.satisfied_by(FROM_CA.signing_cert, signer_validation_path)
with pytest.raises(UnacceptableSignerError):
scc.satisfied_by(DUMMY_TS.tsa_cert, tsa_validation_path)
from asn1crypto import x509
scc = fields.SigCertConstraints(flags=fields.SigCertConstraintFlags.ISSUER
| fields.SigCertConstraintFlags.SUBJECT_DN,
issuers=[INTERM_CERT],
subject_dn=x509.Name.build({
'common_name':
'Alice & Bob',
'country_name':
'BE'
}))
with pytest.raises(UnacceptableSignerError):
scc.satisfied_by(FROM_CA.signing_cert, signer_validation_path)
def test_basic_certificate_validator_tls_expired(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
validator = CertificateValidator(cert, other_certs)
with self.assertRaisesRegexp(PathValidationError, 'expired'):
validator.validate_tls('codexns.io')
def test_basic_certificate_validator_tls_expired(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
validator = CertificateValidator(cert, other_certs)
with self.assertRaisesRegexp(PathValidationError, 'expired'):
validator.validate_tls('codexns.io')
def verify(self, certificate):
"""Verifies the certificate, and its chain.
:param Certificate certificate: The certificate to verify
:return: A valid certificate chain for this certificate.
:rtype: Iterable[Certificate]
:raises AuthenticodeVerificationError: When the certificate could not be verified.
"""
# we keep track of our asn1 objects to make sure we return Certificate objects when we're done
to_check_asn1cert = certificate.to_asn1crypto
all_certs = {to_check_asn1cert: certificate}
# we need to get lists of our intermediates and trusted certificates
intermediates, trust_roots = [], []
for store in self.stores:
for cert in store:
asn1cert = cert.to_asn1crypto
# we short-circuit the check here to ensure we do not check too much possibilities
(trust_roots
if store.trusted else intermediates).append(asn1cert)
all_certs[asn1cert] = cert
# construct the context and validator for certvalidator
timestamp = self.timestamp
context = ValidationContext(
trust_roots=list(trust_roots),
moment=timestamp,
weak_hash_algos=set() if self.allow_legacy else None,
revocation_mode=self.revocation_mode,
allow_fetching=self.allow_fetching,
crl_fetch_params={'timeout': self.fetch_timeout},
ocsp_fetch_params={'timeout': self.fetch_timeout},
crls=self.crls,
ocsps=self.ocsps)
validator = CertificateValidator(
end_entity_cert=to_check_asn1cert,
intermediate_certs=list(intermediates),
validation_context=context)
# verify the chain
try:
chain = validator.validate_usage(
key_usage=set(self.key_usages) if self.key_usages else set(),
extended_key_usage=set(self.extended_key_usages)
if self.extended_key_usages else set(),
extended_optional=self.optional_eku)
except Exception as e:
raise VerificationError("Chain verification from %s failed: %s" %
(certificate, e))
signify_chain = [all_certs[x] for x in chain]
self.verify_trust(signify_chain[0])
return signify_chain
def test_basic_certificate_validator_tls_invalid_hostname(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
moment = datetime(2015, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
with self.assertRaisesRegexp(PathValidationError, 'not valid'):
validator.validate_tls('google.com')
def test_basic_certificate_validator_tls(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
moment = datetime(2015, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
path = validator.validate_tls('codexns.io')
self.assertEqual(3, len(path))
def test_crl_without_update_field(self):
cert = self._load_cert_object('microsoft_armored.crt')
root_certificates = self._load_trust_roots(
os.path.join(fixtures_dir, 'root_certs'))
moment = datetime(2009, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(trust_roots=root_certificates,
moment=moment,
allow_fetching=True)
validator = CertificateValidator(cert, validation_context=context)
validator.validate_usage(set(['digital_signature']),
set(['code_signing']), False)
def test_basic_certificate_validator_tls_invalid_key_usage(self):
cert = self._load_cert_object('mozilla.org.crt')
other_certs = [self._load_cert_object('digicert-sha2-secure-server-ca.crt')]
moment = datetime(2019, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
with self.assertRaisesRegex(PathValidationError, 'for the purpose'):
validator.validate_usage(set(['crl_sign']))
def test_basic_certificate_validator_tls_invalid_hostname(self):
cert = self._load_cert_object('mozilla.org.crt')
other_certs = [self._load_cert_object('digicert-sha2-secure-server-ca.crt')]
moment = datetime(2019, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
with self.assertRaisesRegex(PathValidationError, 'not valid'):
validator.validate_tls('google.com')
def test_basic_certificate_validator_tls(self):
cert = self._load_cert_object('mozilla.org.crt')
other_certs = [self._load_cert_object('digicert-sha2-secure-server-ca.crt')]
moment = datetime(2019, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
path = validator.validate_tls('www.mozilla.org')
self.assertEqual(3, len(path))
def test_basic_certificate_validator_tls(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
moment = datetime(2015, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
path = validator.validate_tls('codexns.io')
self.assertEqual(3, len(path))
def test_basic_certificate_validator_tls_invalid_key_usage(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
moment = datetime(2015, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
with self.assertRaisesRegexp(PathValidationError, 'for the purpose'):
validator.validate_usage(set(['crl_sign']))
def test_basic_certificate_validator_tls_invalid_key_usage(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
moment = datetime(2015, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
with self.assertRaisesRegexp(PathValidationError, 'for the purpose'):
validator.validate_usage(set(['crl_sign']))
def test_basic_certificate_validator_tls_invalid_hostname(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
moment = datetime(2015, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(moment=moment)
validator = CertificateValidator(cert, other_certs, context)
with self.assertRaisesRegexp(PathValidationError, 'not valid'):
validator.validate_tls('google.com')
def validate_certificate(self, ca_certs: List[bytes]) -> bool:
if not ca_certs:
raise ValueError("ca_certs should be set.")
if not self._cert:
return False
ctx = ValidationContext(trust_roots=ca_certs)
try:
validator = CertificateValidator(self._cert, self._intermediates, validation_context=ctx)
validator.validate_usage(set(["digital_signature"]), extended_optional=True)
except Exception as err:
raise VerifyError("Failed to validate the certificate bound to the key.") from err
return True
def test_crl_without_update_field_hard_fail(self):
cert = self._load_cert_object('microsoft_armored.crt')
root_certificates = self._load_trust_roots(
os.path.join(fixtures_dir, 'root_certs'))
moment = datetime(2009, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(trust_roots=root_certificates,
moment=moment,
allow_fetching=True,
revocation_mode='hard-fail')
validator = CertificateValidator(cert, validation_context=context)
with self.assertRaisesRegexp(
PathValidationError,
'nextUpdate field is expected to be present in CRL'):
validator.validate_usage(set(['digital_signature']),
set(['code_signing']), False)
def _validate_cms_signature(sig_blob: SignatureBlob, cd_hash: bytes):
assert sig_blob.cms
signed_data = sig_blob.cms["content"]
assert isinstance(signed_data, SignedData)
assert len(signed_data["signer_infos"]) == 1
# Get certificates
cert_chain = []
for cert in signed_data["certificates"]:
c = cert.chosen
assert isinstance(c, Certificate)
cert_chain.append(c)
# Get algorithms used
signer_info = signed_data["signer_infos"][0]
digest_alg = signer_info["digest_algorithm"]["algorithm"].native
sig_alg = signer_info["signature_algorithm"]["algorithm"].native
# Get message and signature
signed_attrs = signer_info["signed_attrs"]
sig = signer_info["signature"].contents
# Check the hash of CodeDirectory matches what is in the signature
message_digest = None
for attr in sig_blob.cms["content"]["signer_infos"][0]["signed_attrs"]:
if attr["type"].native == "message_digest":
message_digest = attr["values"][0].native
if message_digest != cd_hash:
raise Exception(
f"CodeDirectory Hash mismatch. Expected {message_digest.hex()}, Calculated {cd_hash.hex()}"
)
if message_digest is None:
raise Exception("message_digest not found in signature")
# Validate the certificate chain
validation_context = ValidationContext(
trust_roots=APPLE_ROOTS,
allow_fetching=False,
additional_critical_extensions=APPLE_CERT_CRIT_EXTS,
)
validator = CertificateValidator(cert_chain[-1], cert_chain[0:-1],
validation_context)
validator.validate_usage({"digital_signature"}, {"code_signing"})
# Check the signature
pubkey = asymmetric.load_public_key(cert_chain[-1].public_key)
signed_msg = _sort_attributes(signed_attrs).dump()
asymmetric.rsa_pkcs1v15_verify(pubkey, sig, signed_msg, digest_alg)
def validate_cert_usage(cls,
validator: CertificateValidator,
key_usage_settings: KeyUsageConstraints = None):
key_usage_settings = key_usage_settings or KeyUsageConstraints()
key_usage_settings = KeyUsageConstraints(
key_usage=(cls.key_usage if key_usage_settings.key_usage is None
else key_usage_settings.key_usage),
extd_key_usage=(cls.extd_key_usage
if key_usage_settings.extd_key_usage is None else
key_usage_settings.extd_key_usage))
cert: x509.Certificate = validator._certificate
revoked = trusted = False
path = None
try:
# validate usage without going through certvalidator
key_usage_settings.validate(cert)
path = validator.validate_usage(key_usage=set())
trusted = True
except InvalidCertificateError as e:
# TODO accumulate these somewhere
logger.warning(e)
except RevokedError:
revoked = True
except (PathValidationError, PathBuildingError) as e:
logger.warning(e)
if not trusted:
subj = cert.subject.human_friendly
logger.warning(f"Chain of trust validation for {subj} failed.")
return trusted, revoked, path
def validation_paths(self, validation_context):
"""
Produce validation paths for the certificates gathered by this
:class:`.TimeStamper`.
This is internal API.
:param validation_context:
The validation context to apply.
:return:
A generator producing validation paths.
"""
for cert in self._certs.values():
validator = CertificateValidator(
cert,
intermediate_certs=self.cert_registry,
validation_context=validation_context)
yield validator.validate_usage(set(), {"time_stamping"})
def verify(self, certificate):
"""Verifies the certificate, and its chain.
:param Certificate certificate: The certificate to verify
:return: A valid certificate chain for this certificate.
:rtype: Iterable[Certificate]
:raises AuthenticodeVerificationError: When the certificate could not be verified.
"""
# we keep track of our asn1 objects to make sure we return Certificate objects when we're done
to_check_asn1cert = certificate.to_asn1crypto
all_certs = {to_check_asn1cert: certificate}
# we need to get lists of our intermediates and trusted certificates
intermediates, trust_roots = [], []
for store in self.stores:
for cert in store:
asn1cert = cert.to_asn1crypto
(trust_roots
if store.trusted else intermediates).append(asn1cert)
all_certs[asn1cert] = cert
# construct the context and validator for certvalidator
context = ValidationContext(
trust_roots=list(trust_roots),
moment=self.timestamp,
weak_hash_algos=set() if self.allow_legacy else None)
validator = CertificateValidator(
end_entity_cert=to_check_asn1cert,
intermediate_certs=list(intermediates),
validation_context=context)
# verify the chain
try:
chain = validator.validate_usage(
key_usage=set(self.key_usages) if self.key_usages else set(),
extended_key_usage=set(self.extended_key_usages)
if self.extended_key_usages else set(),
extended_optional=self.optional_eku)
except Exception as e:
raise VerificationError("Chain verification from %s failed: %s" %
(certificate, e))
else:
return [all_certs[x] for x in chain]
def validate_vmc(self):
try:
end_entity_cert = None
intermediates = []
with open(self.vmc_file, 'rb') as f:
readfile = f.read()
# Create parsed data for expiry and embedded svg check
self.parsed_vmc = self.parse_vmc_cert(readfile)
for type_name, headers, der_bytes in pem.unarmor(
readfile, multiple=True):
if end_entity_cert is None:
end_entity_cert = der_bytes
else:
intermediates.append(der_bytes)
validator = CertificateValidator(end_entity_cert, intermediates)
validated = validator.validate_usage(
set(['digital_signature'])
# ,extended_key_usage=set(["server_auth", "client_auth"])
)
if validated:
print("Certificate Validated")
except errors.PathValidationError as PathValidationError:
self.vmc_response["errors"].append("Warning: " +
str(PathValidationError))
print(PathValidationError)
except errors.RevokedError as RevokedError:
self.vmc_response["errors"].append(
"Warning: Certificate Revoked.\n" + str(RevokedError))
print(RevokedError)
except errors.InvalidCertificateError as InvalidCertificateError:
self.vmc_response["errors"].append(
"Warning: Certificate Is Invalid.\n" +
str(InvalidCertificateError))
print(InvalidCertificateError)
except errors.PathBuildingError as PathBuildingError:
# self.vmc_response["errors"].append("Warning: Cannot Build Path.\n"+str(PathBuildingError))
print(PathBuildingError)
except Exception as e:
self.vmc_response["errors"].append(
"Warning: Validation Exception.\n" + str(e))
print(e)
def verify_chain(certificate: Union[str, x509.Certificate], ca: str):
if isinstance(certificate, x509.Certificate):
pem = certificate.public_bytes(serialization.Encoding.PEM)
else:
if certificate.startswith("-----BEGIN CERTIFICATE-----"):
pem = certificate.encode()
else:
with open(certificate, "rb") as my_file:
pem = my_file.read()
# cert = x509.load_pem_x509_certificate(pem, default_backend())
with open(ca, "rb") as my_file:
pem_ca = my_file.read()
# ca = x509.load_pem_x509_certificate(pem_ca, default_backend())
trust_roots = [pem_ca]
context = ValidationContext(trust_roots=trust_roots)
validator = CertificateValidator(pem, validation_context=context)
return validator.validate_usage({"digital_signature"})
def test_basic_certificate_validator_tls_whitelist(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
context = ValidationContext(whitelisted_certs=[cert.sha1_fingerprint])
validator = CertificateValidator(cert, other_certs, context)
# If whitelist does not work, this will raise exception for expiration
validator.validate_tls('codexns.io')
# If whitelist does not work, this will raise exception for hostname
validator.validate_tls('google.com')
# If whitelist does not work, this will raise exception for key usage
validator.validate_usage(set(['crl_sign']))
def test_basic_certificate_validator_tls_whitelist(self):
cert = self._load_cert_object('codex.crt')
other_certs = [self._load_cert_object('GeoTrust_EV_SSL_CA_-_G4.crt')]
context = ValidationContext(whitelisted_certs=[cert.sha1_fingerprint])
validator = CertificateValidator(cert, other_certs, context)
# If whitelist does not work, this will raise exception for expiration
validator.validate_tls('codexns.io')
# If whitelist does not work, this will raise exception for hostname
validator.validate_tls('google.com')
# If whitelist does not work, this will raise exception for key usage
validator.validate_usage(set(['crl_sign']))
def test_basic_certificate_validator_tls_whitelist(self):
cert = self._load_cert_object('mozilla.org.crt')
other_certs = [self._load_cert_object('digicert-sha2-secure-server-ca.crt')]
moment = datetime(2020, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
context = ValidationContext(
whitelisted_certs=[cert.sha1_fingerprint],
moment=moment
)
validator = CertificateValidator(cert, other_certs, context)
# If whitelist does not work, this will raise exception for expiration
validator.validate_tls('www.mozilla.org')
# If whitelist does not work, this will raise exception for hostname
validator.validate_tls('google.com')
# If whitelist does not work, this will raise exception for key usage
validator.validate_usage(set(['crl_sign']))
def validate_cert_usage(cls, validator: CertificateValidator):
revoked = trusted = False
path = None
try:
path = validator.validate_usage(
key_usage=cls.key_usage, extended_key_usage=cls.extd_key_usage)
trusted = True
except InvalidCertificateError as e:
# TODO accumulate these somewhere
logger.warning(e)
except RevokedError:
revoked = True
except (PathValidationError, PathBuildingError) as e:
logger.warning(e)
if not trusted:
subj = validator._certificate.subject.human_friendly
logger.warning(f"Chain of trust validation for {subj} failed.")
return trusted, revoked, path
def _validate_chain_certvalidator(self, tlslite_connection):
"""Validate server certificate chain using 3rd party certvalidator library which uses oscrypt/libcrypto
Note: oscrypt uses ctypes find_library() which does not work in certain distributions such as alpine.
(e.g. see https://github.com/docker-library/python/issues/111)
On such systems, users will have to rely on other server cert validation approaches such as using openssl
or turning it off completely.
"""
try:
from certvalidator import CertificateValidator
from certvalidator import ValidationContext
from asn1crypto import x509, pem
# validate server certificate chain
session = tlslite_connection.sock.session
assert type(session.serverCertChain.x509List) == list
# get the end-entity cert
file_bytes = session.serverCertChain.x509List[0].bytes
end_entity_cert = x509.Certificate.load(str(file_bytes))
def cert_files_exist(path, file_names):
file_names = [os.path.join(path, f) for f in file_names]
for f in file_names:
if not os.path.isfile(f):
return False
return True
def get_cert_bytes(cert_dir, file_names):
file_names = [os.path.join(cert_dir, f) for f in file_names]
result = []
for fname in file_names:
arr = open(fname, "rb").read()
cert_bytes = pem.unarmor(arr)[2]
result.append(cert_bytes)
return result
intermediate_cert_names = [
"comodo_ca_intermediate.pem",
"sectigo_ca_intermediate.pem",
]
extra_trust_names = [
"scalyr_agent_ca_root.pem",
"addtrust_external_ca_root.pem",
]
# Determine the directory containing the certs.
# First check the directory containing the _ca_file
# but if we don't find the intermediate/extra certs there
# then look in the relative `certs` directory. The latter
# will typically be required if running directly from source
all_cert_names = intermediate_cert_names + extra_trust_names
cert_dir = os.path.dirname(self._ca_file)
if not cert_files_exist(cert_dir, all_cert_names):
path = os.path.dirname(os.path.abspath(__file__))
path = os.path.abspath(path + "../../certs")
if cert_files_exist(path, all_cert_names):
cert_dir = path
trust_roots = None
intermediate_certs = get_cert_bytes(cert_dir, intermediate_cert_names)
extra_trust_roots = get_cert_bytes(cert_dir, extra_trust_names)
if trust_roots:
context = ValidationContext(
trust_roots=trust_roots,
extra_trust_roots=extra_trust_roots,
other_certs=intermediate_certs,
# whitelisted_certs=[end_entity_cert.sha1_fingerprint],
)
else:
context = ValidationContext(
extra_trust_roots=extra_trust_roots,
other_certs=intermediate_certs,
# whitelisted_certs=[end_entity_cert.sha1_fingerprint],
)
validator = CertificateValidator(
end_entity_cert, validation_context=context
)
validator.validate_tls(six.text_type(self._host))
log.info(
"Scalyr server cert chain successfully validated via certvalidator library"
)
except Exception as ce:
log.exception("Error validating server certificate chain: %s" % ce)
raise
def run():
"""
Runs through TLS hosts in the Alexa top 1000 to test TLS functionality
:return:
A bool - if the test succeeded without any socket errors
"""
task_start = time.time()
success = 0
tls_errors = 0
socket_errors = 0
mismatch_info = []
context = ValidationContext(allow_fetching=True)
with open(os.path.join(fixtures_dir, 'alexa_top_1000.csv'), 'rb') as f:
for line in f:
domain = line.decode('utf-8').rstrip()
os_result = None
cv_result = None
os_message = None
cv_message = None
try:
os_start = time.time()
con = tls.TLSSocket(domain, 443, timeout=3)
con.close()
success += 1
os_result = 'OK'
os_message = 'Success'
_color('green', 'OK', domain, os_start)
except (TLSVerificationError) as e:
tls_errors += 1
os_result = 'TLS'
os_message = str_cls(e)
_color('yellow', 'TLS', domain, os_start, str_cls(e))
except (socket.error) as e:
socket_errors += 1
os_result = 'SOCK'
os_message = str_cls(e)
_color('red', 'SOCK', domain, os_start, str_cls(e))
try:
cv_start = time.time()
session = tls.TLSSession(manual_validation=True)
con = tls.TLSSocket(domain, 443, timeout=3, session=session)
validator = CertificateValidator(con.certificate,
con.intermediates, context)
validator.validate_tls(domain)
con.close()
success += 1
cv_result = 'OK'
cv_message = 'Success'
_color('green', 'OK', domain, cv_start)
except (PathValidationError, PathBuildingError) as e:
tls_errors += 1
cv_result = 'TLS'
cv_message = str_cls(e)
_color('yellow', 'TLS', domain, cv_start, str_cls(e))
except (socket.error) as e:
socket_errors += 1
cv_result = 'SOCK'
cv_message = str_cls(e)
_color('red', 'SOCK', domain, cv_start, str_cls(e))
if os_result != cv_result:
mismatch_info.append(
[domain, os_result, os_message, cv_result, cv_message])
total_time = time.time() - task_start
total_domains = success + tls_errors + socket_errors
stats = []
if success > 0:
stats.append('%d [%sOK%s]' % (success, Fore.GREEN, Fore.RESET))
if tls_errors > 0:
stats.append('%d [%sTLS%s]' % (tls_errors, Fore.YELLOW, Fore.RESET))
if socket_errors > 0:
stats.append('%d [%sSOCK%s]' % (socket_errors, Fore.RED, Fore.RESET))
print('')
print('Checked %d domains in %.3f seconds - %s' %
(total_domains, total_time, ' '.join(stats)))
if mismatch_info:
print('')
for info in mismatch_info:
os_result = '[%s] %s' % (info[1], info[2])
cv_result = '[%s] %s' % (info[3], info[4])
_color(
'red', 'DIFF',
'oscrypto and certvalidator results for %s are different' %
info[0], None, os_result, cv_result)
return socket_errors == 0
def run():
"""
Runs through TLS hosts in the Alexa top 1000 to test TLS functionality
:return:
A bool - if the test succeeded without any socket errors
"""
task_start = time.time()
success = 0
tls_errors = 0
socket_errors = 0
mismatch_info = []
context = ValidationContext(allow_fetching=True)
with open(os.path.join(fixtures_dir, 'alexa_top_1000.csv'), 'rb') as f:
for line in f:
domain = line.decode('utf-8').rstrip()
os_result = None
cv_result = None
os_message = None
cv_message = None
try:
os_start = time.time()
con = tls.TLSSocket(domain, 443, timeout=3)
con.close()
success += 1
os_result = 'OK'
os_message = 'Success'
_color('green', 'OK', domain, os_start)
except (TLSVerificationError) as e:
tls_errors += 1
os_result = 'TLS'
os_message = str_cls(e)
_color('yellow', 'TLS', domain, os_start, str_cls(e))
except (socket.error) as e:
socket_errors += 1
os_result = 'SOCK'
os_message = str_cls(e)
_color('red', 'SOCK', domain, os_start, str_cls(e))
try:
cv_start = time.time()
session = tls.TLSSession(manual_validation=True)
con = tls.TLSSocket(domain, 443, timeout=3, session=session)
validator = CertificateValidator(con.certificate, con.intermediates, context)
validator.validate_tls(domain)
con.close()
success += 1
cv_result = 'OK'
cv_message = 'Success'
_color('green', 'OK', domain, cv_start)
except (PathValidationError, PathBuildingError) as e:
tls_errors += 1
cv_result = 'TLS'
cv_message = str_cls(e)
_color('yellow', 'TLS', domain, cv_start, str_cls(e))
except (socket.error) as e:
socket_errors += 1
cv_result = 'SOCK'
cv_message = str_cls(e)
_color('red', 'SOCK', domain, cv_start, str_cls(e))
if os_result != cv_result:
mismatch_info.append([
domain,
os_result,
os_message,
cv_result,
cv_message
])
total_time = time.time() - task_start
total_domains = success + tls_errors + socket_errors
stats = []
if success > 0:
stats.append('%d [%sOK%s]' % (success, Fore.GREEN, Fore.RESET))
if tls_errors > 0:
stats.append('%d [%sTLS%s]' % (tls_errors, Fore.YELLOW, Fore.RESET))
if socket_errors > 0:
stats.append('%d [%sSOCK%s]' % (socket_errors, Fore.RED, Fore.RESET))
print('')
print('Checked %d domains in %.3f seconds - %s' % (total_domains, total_time, ' '.join(stats)))
if mismatch_info:
print('')
for info in mismatch_info:
os_result = '[%s] %s' % (info[1], info[2])
cv_result = '[%s] %s' % (info[3], info[4])
_color(
'red',
'DIFF',
'oscrypto and certvalidator results for %s are different' % info[0],
None,
os_result,
cv_result
)
return socket_errors == 0
def verify_bib(self, ctr, bib):
addl_protected = b''
addl_unprotected = {}
aad_scope = 0x7
for param in bib.payload.parameters:
if param.type_code == 3:
addl_protected = bytes(param.value)
elif param.type_code == 4:
addl_unprotected = dict(param.value)
elif param.type_code == 5:
aad_scope = int(param.value)
addl_protected_map = cbor2.loads(
addl_protected) if addl_protected else {}
dupe_keys = set(addl_protected_map.keys()).intersection(
set(addl_unprotected.keys()))
if dupe_keys:
LOGGER.warning('Duplicate keys in additional headers: %s',
dupe_keys)
return StatusReport.ReasonCode.FAILED_SEC
addl_headers = dict(addl_protected_map)
addl_headers.update(addl_unprotected)
bundle_at = DtnTimeField.dtntime_to_datetime(
ctr.bundle.primary.create_ts.getfieldval('dtntime'))
val_ctx = ValidationContext(
trust_roots=[
cert.public_bytes(serialization.Encoding.DER)
for cert in self._ca_certs
],
other_certs=[
cert.public_bytes(serialization.Encoding.DER)
for cert in self._cert_chain
],
moment=bundle_at,
)
LOGGER.debug('Validating certificates at time %s', bundle_at)
failure = None
for (ix, blk_num) in enumerate(bib.payload.targets):
target_blk = ctr.block_num(blk_num)
for result in bib.payload.results[ix].results:
msg_cls = CoseMessage._COSE_MSG_ID[result.type_code]
# replace detached payload
msg_enc = bytes(result.getfieldval('value'))
msg_dec = cbor2.loads(msg_enc)
LOGGER.debug('Received COSE message\n%s',
encode_diagnostic(msg_dec))
msg_dec[2] = target_blk.getfieldval('btsd')
msg_obj = msg_cls.from_cose_obj(msg_dec)
msg_obj.external_aad = CoseContext.get_bpsec_cose_aad(
ctr, target_blk, bib, aad_scope, addl_protected)
# use additional headers as defaults
for (key, val) in msg_cls._parse_header(addl_headers).items():
msg_obj.uhdr.setdefault(key, val)
LOGGER.info('full uhdr %s', msg_obj.uhdr)
x5t_item = msg_obj.get_attr(headers.X5t)
x5t = X5T.decode(x5t_item) if x5t_item else None
x5chain_item = msg_obj.get_attr(headers.X5chain)
if isinstance(x5chain_item, bytes):
x5chain = [x5chain_item]
else:
x5chain = x5chain_item
LOGGER.info('Validating X5t %s and X5chain length %d',
x5t.encode() if x5t else None,
len(x5chain) if x5chain else 0)
if x5t is None and x5chain:
# Only one possible end-entity cert
LOGGER.warning('No X5T in header, assuming single chain')
found_chain = x5chain
else:
try:
found_chain = x5chain if x5t.matches(
x5chain[0]) else None
if not found_chain:
raise RuntimeError(
'No chain matcing end-entity cert for {}'.
format(x5t.encode()))
LOGGER.debug(
'Found chain matcing end-entity cert for %s',
x5t.encode())
except Exception as err:
LOGGER.error(
'Failed to find cert chain for block num %d: %s',
blk_num, err)
failure = StatusReport.ReasonCode.FAILED_SEC
continue
LOGGER.debug('Validating chain with %d certs against %d CAs',
len(found_chain), len(self._ca_certs))
try:
val = CertificateValidator(
end_entity_cert=found_chain[0],
intermediate_certs=found_chain[1:],
validation_context=val_ctx)
val.validate_usage(
key_usage={'digital_signature'},
extended_key_usage={'1.3.6.1.5.5.7.3.35'},
extended_optional=True)
except Exception as err:
LOGGER.error('Failed to verify chain on block num %d: %s',
blk_num, err)
failure = StatusReport.ReasonCode.FAILED_SEC
continue
peer_nodeid = bib.payload.source
end_cert = x509.load_der_x509_certificate(
found_chain[0], default_backend())
authn_nodeid = tcpcl.session.match_id(
peer_nodeid, end_cert, x509.UniformResourceIdentifier,
LOGGER, 'NODE-ID')
if not authn_nodeid:
LOGGER.error(
'Failed to authenticate peer "%s" on block num %d',
peer_nodeid, blk_num)
failure = StatusReport.ReasonCode.FAILED_SEC
# Continue on to verification
try:
msg_obj.key = self.extract_cose_key(end_cert.public_key())
msg_obj.verify_signature()
LOGGER.info('Verified signature on block num %d', blk_num)
except Exception as err:
LOGGER.error(
'Failed to verify signature on block num %d: %s',
blk_num, err)
failure = StatusReport.ReasonCode.FAILED_SEC
return failure
def valider_x509_enveloppe(self,
enveloppe: EnveloppeCertificat,
date_reference: datetime.datetime = None):
"""
Valide une enveloppe
:param enveloppe:
:param date_reference:
:param ignorer_date: Charger le certificat en utilisation date courante ou fin de periode de validite
:return: Resultat de validation (toujours valide)
:raises certvalidator.errors.PathBuildingError: Si le path est invalide
"""
cert_pem = enveloppe.certificat_pem.encode('utf-8')
inter_list = list()
# self._logger.debug("CERT PEM :\n%s" % enveloppe.certificat_pem)
for pem in enveloppe.reste_chaine_pem:
# self._logger.debug("Chaine PEM :\n%s" % pem.strip())
inter_list.append(pem.strip().encode('utf-8'))
if date_reference is not None:
# batir un contexte avec la date
validation_context = ValidationContext(
moment=date_reference, trust_roots=[self.__cert_millegrille])
else:
validation_context = self.__validation_context
# Verifier le certificat - noter qu'une exception est lancee en cas de probleme
try:
validator = CertificateValidator(
cert_pem,
intermediate_certs=inter_list,
validation_context=validation_context)
resultat = validator.validate_usage({'digital_signature'})
enveloppe.set_est_verifie(True)
except PathValidationError as pve:
msg = pve.args[0]
if 'expired' in msg:
self._logger.info(
"Un des certificats est expire, verifier en fonction de la date de reference"
)
# Le certificat est expire, on fait la validation pour la fin de la periode de validite
date_reference = pytz.UTC.localize(enveloppe.not_valid_after)
validation_context = ValidationContext(
moment=date_reference,
trust_roots=[self.__cert_millegrille])
validator = CertificateValidator(
cert_pem,
intermediate_certs=inter_list,
validation_context=validation_context)
try:
resultat = validator.validate_usage({'digital_signature'})
enveloppe.set_est_verifie(True)
raise CertificatExpire(
) # La chaine est valide pour une date anterieure
except PathValidationError as pve:
if self._logger.isEnabledFor(logging.DEBUG):
self._logger.exception(
"Erreur validation path certificat")
else:
self._logger.info(
"Erreur validation path certificat : %s", str(pve))
else:
if self._logger.isEnabledFor(logging.DEBUG):
self._logger.exception("Erreur validation path certificat")
else:
self._logger.info("Erreur validation path certificat : %s",
str(pve))
raise pve
except PathBuildingError as pbe:
# Verifier si on a une millegrille tierce
dernier_cert_pem = inter_list[-1]
dernier_cert = EnveloppeCertificat(certificat_pem=dernier_cert_pem)
if dernier_cert.is_rootCA:
idmg = dernier_cert.idmg
# Verifier si le idmg est dans la liste des idmg autorises
autorisation = self.__autorisations_idmg.get(idmg)
if autorisation is None:
# Pas autorise, lancer l'exception
raise pbe
elif autorisation.get('domaines_permis'):
# Valider la chaine en fonction de la racine fournie
if date_reference is not None:
# batir un contexte avec la date
validation_context = ValidationContext(
moment=date_reference,
trust_roots=[
self.__cert_millegrille, dernier_cert_pem
])
else:
validation_context = ValidationContext(trust_roots=[
self.__cert_millegrille, dernier_cert_pem
])
validator = CertificateValidator(
cert_pem,
intermediate_certs=inter_list,
validation_context=validation_context)
validator.validate_usage({'digital_signature'})
# Valide, on lance une exception pour indiquer la condition de validite (business rule)
raise AutorisationConditionnelleDomaine(
autorisation['domaines_permis'], idmg, enveloppe)
return resultat
def verify_chain(self, key_usage: Set[str]):
val = CertificateValidator(
end_entity_cert=self.cert_chain[0],
intermediate_certs=self.cert_chain[1:],
)
return val.validate_usage(key_usage)