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X.509 Reference
===============
.. currentmodule:: cryptography.x509
.. testsetup::
pem_crl_data = b"""
-----BEGIN X509 CRL-----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-----END X509 CRL-----
""".strip()
pem_req_data = b"""
-----BEGIN CERTIFICATE REQUEST-----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-----END CERTIFICATE REQUEST-----
""".strip()
pem_data = b"""
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
""".strip()
cryptography_cert_pem = b"""
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
""".strip()
Loading Certificates
~~~~~~~~~~~~~~~~~~~~
.. function:: load_pem_x509_certificate(data, backend)
.. versionadded:: 0.7
Deserialize a certificate from PEM encoded data. PEM certificates are
base64 decoded and have delimiters that look like
``-----BEGIN CERTIFICATE-----``.
:param bytes data: The PEM encoded certificate data.
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: An instance of :class:`~cryptography.x509.Certificate`.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> cert = x509.load_pem_x509_certificate(pem_data, default_backend())
>>> cert.serial_number
2
.. function:: load_der_x509_certificate(data, backend)
.. versionadded:: 0.7
Deserialize a certificate from DER encoded data. DER is a binary format
and is commonly found in files with the ``.cer`` extension (although file
extensions are not a guarantee of encoding type).
:param bytes data: The DER encoded certificate data.
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: An instance of :class:`~cryptography.x509.Certificate`.
Loading Certificate Revocation Lists
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. function:: load_pem_x509_crl(data, backend)
.. versionadded:: 1.1
Deserialize a certificate revocation list (CRL) from PEM encoded data. PEM
requests are base64 decoded and have delimiters that look like
``-----BEGIN X509 CRL-----``.
:param bytes data: The PEM encoded request data.
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: An instance of
:class:`~cryptography.x509.CertificateRevocationList`.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> crl = x509.load_pem_x509_crl(pem_crl_data, default_backend())
>>> isinstance(crl.signature_hash_algorithm, hashes.SHA256)
True
.. function:: load_der_x509_crl(data, backend)
.. versionadded:: 1.1
Deserialize a certificate revocation list (CRL) from DER encoded data. DER
is a binary format.
:param bytes data: The DER encoded request data.
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: An instance of
:class:`~cryptography.x509.CertificateRevocationList`.
Loading Certificate Signing Requests
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. function:: load_pem_x509_csr(data, backend)
.. versionadded:: 0.9
Deserialize a certificate signing request (CSR) from PEM encoded data. PEM
requests are base64 decoded and have delimiters that look like
``-----BEGIN CERTIFICATE REQUEST-----``. This format is also known as
PKCS#10.
:param bytes data: The PEM encoded request data.
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: An instance of
:class:`~cryptography.x509.CertificateSigningRequest`.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> csr = x509.load_pem_x509_csr(pem_req_data, default_backend())
>>> isinstance(csr.signature_hash_algorithm, hashes.SHA1)
True
.. function:: load_der_x509_csr(data, backend)
.. versionadded:: 0.9
Deserialize a certificate signing request (CSR) from DER encoded data. DER
is a binary format and is not commonly used with CSRs.
:param bytes data: The DER encoded request data.
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: An instance of
:class:`~cryptography.x509.CertificateSigningRequest`.
X.509 Certificate Object
~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: Certificate
.. versionadded:: 0.7
.. attribute:: version
:type: :class:`~cryptography.x509.Version`
The certificate version as an enumeration. Version 3 certificates are
the latest version and also the only type you should see in practice.
:raises cryptography.x509.InvalidVersion: If the version in the
certificate is not a known
:class:`X.509 version <cryptography.x509.Version>`.
.. doctest::
>>> cert.version
<Version.v3: 2>
.. method:: fingerprint(algorithm)
:param algorithm: The
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`
that will be used to generate the fingerprint.
:return bytes: The fingerprint using the supplied hash algorithm, as
bytes.
.. doctest::
>>> from cryptography.hazmat.primitives import hashes
>>> cert.fingerprint(hashes.SHA256())
b'\x86\xd2\x187Gc\xfc\xe7}[+E9\x8d\xb4\x8f\x10\xe5S\xda\x18u\xbe}a\x03\x08[\xac\xa04?'
.. attribute:: serial_number
:type: int
The serial as a Python integer.
.. doctest::
>>> cert.serial_number
2
.. method:: public_key()
The public key associated with the certificate.
:returns:
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey`
.. doctest::
>>> from cryptography.hazmat.primitives.asymmetric import rsa
>>> public_key = cert.public_key()
>>> isinstance(public_key, rsa.RSAPublicKey)
True
.. attribute:: not_valid_before
:type: :class:`datetime.datetime`
A naïve datetime representing the beginning of the validity period for
the certificate in UTC. This value is inclusive.
.. doctest::
>>> cert.not_valid_before
datetime.datetime(2010, 1, 1, 8, 30)
.. attribute:: not_valid_after
:type: :class:`datetime.datetime`
A naïve datetime representing the end of the validity period for the
certificate in UTC. This value is inclusive.
.. doctest::
>>> cert.not_valid_after
datetime.datetime(2030, 12, 31, 8, 30)
.. attribute:: issuer
.. versionadded:: 0.8
:type: :class:`Name`
The :class:`Name` of the issuer.
.. attribute:: subject
.. versionadded:: 0.8
:type: :class:`Name`
The :class:`Name` of the subject.
.. attribute:: signature_hash_algorithm
:type: :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`
Returns the
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm` which
was used in signing this certificate.
.. doctest::
>>> from cryptography.hazmat.primitives import hashes
>>> isinstance(cert.signature_hash_algorithm, hashes.SHA256)
True
.. attribute:: signature_algorithm_oid
.. versionadded:: 1.6
:type: :class:`ObjectIdentifier`
Returns the :class:`ObjectIdentifier` of the signature algorithm used
to sign the certificate. This will be one of the OIDs from
:class:`~cryptography.x509.oid.SignatureAlgorithmOID`.
.. doctest::
>>> cert.signature_algorithm_oid
<ObjectIdentifier(oid=1.2.840.113549.1.1.11, name=sha256WithRSAEncryption)>
.. attribute:: extensions
:type: :class:`Extensions`
The extensions encoded in the certificate.
:raises cryptography.x509.DuplicateExtension: If more than one
extension of the same type is found within the certificate.
:raises cryptography.x509.UnsupportedGeneralNameType: If an extension
contains a general name that is not supported.
:raises UnicodeError: If an extension contains IDNA encoding that is
invalid or not compliant with IDNA 2008.
.. doctest::
>>> for ext in cert.extensions:
... print(ext)
<Extension(oid=<ObjectIdentifier(oid=2.5.29.35, name=authorityKeyIdentifier)>, critical=False, value=<AuthorityKeyIdentifier(key_identifier=b'\xe4}_\xd1\\\x95\x86\x08,\x05\xae\xbeu\xb6e\xa7\xd9]\xa8f', authority_cert_issuer=None, authority_cert_serial_number=None)>)>
<Extension(oid=<ObjectIdentifier(oid=2.5.29.14, name=subjectKeyIdentifier)>, critical=False, value=<SubjectKeyIdentifier(digest=b'X\x01\x84$\x1b\xbc+R\x94J=\xa5\x10r\x14Q\xf5\xaf:\xc9')>)>
<Extension(oid=<ObjectIdentifier(oid=2.5.29.15, name=keyUsage)>, critical=True, value=<KeyUsage(digital_signature=False, content_commitment=False, key_encipherment=False, data_encipherment=False, key_agreement=False, key_cert_sign=True, crl_sign=True, encipher_only=None, decipher_only=None)>)>
<Extension(oid=<ObjectIdentifier(oid=2.5.29.32, name=certificatePolicies)>, critical=False, value=<CertificatePolicies([<PolicyInformation(policy_identifier=<ObjectIdentifier(oid=2.16.840.1.101.3.2.1.48.1, name=Unknown OID)>, policy_qualifiers=None)>])>)>
<Extension(oid=<ObjectIdentifier(oid=2.5.29.19, name=basicConstraints)>, critical=True, value=<BasicConstraints(ca=True, path_length=None)>)>
.. attribute:: signature
.. versionadded:: 1.2
:type: bytes
The bytes of the certificate's signature.
.. attribute:: tbs_certificate_bytes
.. versionadded:: 1.2
:type: bytes
The DER encoded bytes payload (as defined by :rfc:`5280`) that is hashed
and then signed by the private key of the certificate's issuer. This
data may be used to validate a signature, but use extreme caution as
certificate validation is a complex problem that involves much more
than just signature checks.
.. method:: public_bytes(encoding)
.. versionadded:: 1.0
:param encoding: The
:class:`~cryptography.hazmat.primitives.serialization.Encoding`
that will be used to serialize the certificate.
:return bytes: The data that can be written to a file or sent
over the network to be verified by clients.
X.509 CRL (Certificate Revocation List) Object
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: CertificateRevocationList
.. versionadded:: 1.0
A CertificateRevocationList is an object representing a list of revoked
certificates. The object is iterable and will yield the RevokedCertificate
objects stored in this CRL.
.. doctest::
>>> len(crl)
1
>>> revoked_certificate = crl[0]
>>> type(revoked_certificate)
<class 'cryptography.hazmat.backends.openssl.x509._RevokedCertificate'>
>>> for r in crl:
... print(r.serial_number)
0
.. method:: fingerprint(algorithm)
:param algorithm: The
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`
that will be used to generate the fingerprint.
:return bytes: The fingerprint using the supplied hash algorithm, as
bytes.
.. doctest::
>>> from cryptography.hazmat.primitives import hashes
>>> crl.fingerprint(hashes.SHA256())
b'e\xcf.\xc4:\x83?1\xdc\xf3\xfc\x95\xd7\xb3\x87\xb3\x8e\xf8\xb93!\x87\x07\x9d\x1b\xb4!\xb9\xe4W\xf4\x1f'
.. method:: get_revoked_certificate_by_serial_number(serial_number)
.. versionadded:: 2.3
:param serial_number: The serial as a Python integer.
:returns: :class:`~cryptography.x509.RevokedCertificate` if the
``serial_number`` is present in the CRL or ``None`` if it
is not.
.. attribute:: signature_hash_algorithm
:type: :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`
Returns the
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm` which
was used in signing this CRL.
.. doctest::
>>> from cryptography.hazmat.primitives import hashes
>>> isinstance(crl.signature_hash_algorithm, hashes.SHA256)
True
.. attribute:: signature_algorithm_oid
.. versionadded:: 1.6
:type: :class:`ObjectIdentifier`
Returns the :class:`ObjectIdentifier` of the signature algorithm used
to sign the CRL. This will be one of the OIDs from
:class:`~cryptography.x509.oid.SignatureAlgorithmOID`.
.. doctest::
>>> crl.signature_algorithm_oid
<ObjectIdentifier(oid=1.2.840.113549.1.1.11, name=sha256WithRSAEncryption)>
.. attribute:: issuer
:type: :class:`Name`
The :class:`Name` of the issuer.
.. doctest::
>>> crl.issuer
<Name([<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.6, name=countryName)>, value='US')>, <NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.3, name=commonName)>, value='cryptography.io')>])>
.. attribute:: next_update
:type: :class:`datetime.datetime`
A naïve datetime representing when the next update to this CRL is
expected.
.. doctest::
>>> crl.next_update
datetime.datetime(2016, 1, 1, 0, 0)
.. attribute:: last_update
:type: :class:`datetime.datetime`
A naïve datetime representing when the this CRL was last updated.
.. doctest::
>>> crl.last_update
datetime.datetime(2015, 1, 1, 0, 0)
.. attribute:: extensions
:type: :class:`Extensions`
The extensions encoded in the CRL.
.. attribute:: signature
.. versionadded:: 1.2
:type: bytes
The bytes of the CRL's signature.
.. attribute:: tbs_certlist_bytes
.. versionadded:: 1.2
:type: bytes
The DER encoded bytes payload (as defined by :rfc:`5280`) that is hashed
and then signed by the private key of the CRL's issuer. This data may be
used to validate a signature, but use extreme caution as CRL validation
is a complex problem that involves much more than just signature checks.
.. method:: public_bytes(encoding)
.. versionadded:: 1.2
:param encoding: The
:class:`~cryptography.hazmat.primitives.serialization.Encoding`
that will be used to serialize the certificate revocation list.
:return bytes: The data that can be written to a file or sent
over the network and used as part of a certificate verification
process.
.. method:: is_signature_valid(public_key)
.. versionadded:: 2.1
.. warning::
Checking the validity of the signature on the CRL is insufficient
to know if the CRL should be trusted. More details are available
in :rfc:`5280`.
Returns True if the CRL signature is correct for given public key,
False otherwise.
X.509 Certificate Builder
~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: CertificateBuilder
.. versionadded:: 1.0
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> from cryptography.hazmat.primitives.asymmetric import rsa
>>> from cryptography.x509.oid import NameOID
>>> import datetime
>>> one_day = datetime.timedelta(1, 0, 0)
>>> private_key = rsa.generate_private_key(
... public_exponent=65537,
... key_size=2048,
... backend=default_backend()
... )
>>> public_key = private_key.public_key()
>>> builder = x509.CertificateBuilder()
>>> builder = builder.subject_name(x509.Name([
... x509.NameAttribute(NameOID.COMMON_NAME, u'cryptography.io'),
... ]))
>>> builder = builder.issuer_name(x509.Name([
... x509.NameAttribute(NameOID.COMMON_NAME, u'cryptography.io'),
... ]))
>>> builder = builder.not_valid_before(datetime.datetime.today() - one_day)
>>> builder = builder.not_valid_after(datetime.datetime(2018, 8, 2))
>>> builder = builder.serial_number(x509.random_serial_number())
>>> builder = builder.public_key(public_key)
>>> builder = builder.add_extension(
... x509.SubjectAlternativeName(
... [x509.DNSName(u'cryptography.io')]
... ),
... critical=False
... )
>>> builder = builder.add_extension(
... x509.BasicConstraints(ca=False, path_length=None), critical=True,
... )
>>> certificate = builder.sign(
... private_key=private_key, algorithm=hashes.SHA256(),
... backend=default_backend()
... )
>>> isinstance(certificate, x509.Certificate)
True
.. method:: issuer_name(name)
Sets the issuer's distinguished name.
:param name: The :class:`~cryptography.x509.Name` that describes the
issuer (CA).
.. method:: subject_name(name)
Sets the subject's distinguished name.
:param name: The :class:`~cryptography.x509.Name` that describes the
subject.
.. method:: public_key(public_key)
Sets the subject's public key.
:param public_key: The subject's public key. This can be one of
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey`,
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey`
.. method:: serial_number(serial_number)
Sets the certificate's serial number (an integer). The CA's policy
determines how it attributes serial numbers to certificates. This
number must uniquely identify the certificate given the issuer.
`CABForum Guidelines`_ require entropy in the serial number
to provide protection against hash collision attacks. For more
information on secure random number generation, see
:doc:`/random-numbers`.
:param serial_number: Integer number that will be used by the CA to
identify this certificate (most notably during certificate
revocation checking). Users should consider using
:func:`~cryptography.x509.random_serial_number` when possible.
.. method:: not_valid_before(time)
Sets the certificate's activation time. This is the time from which
clients can start trusting the certificate. It may be different from
the time at which the certificate was created.
:param time: The :class:`datetime.datetime` object (in UTC) that marks the
activation time for the certificate. The certificate may not be
trusted clients if it is used before this time.
.. method:: not_valid_after(time)
Sets the certificate's expiration time. This is the time from which
clients should no longer trust the certificate. The CA's policy will
determine how long the certificate should remain in use.
:param time: The :class:`datetime.datetime` object (in UTC) that marks the
expiration time for the certificate. The certificate may not be
trusted clients if it is used after this time.
.. method:: add_extension(extension, critical)
Adds an X.509 extension to the certificate.
:param extension: An extension conforming to the
:class:`~cryptography.x509.ExtensionType` interface.
:param critical: Set to ``True`` if the extension must be understood and
handled by whoever reads the certificate.
.. method:: sign(private_key, algorithm, backend)
Sign the certificate using the CA's private key.
:param private_key: The
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey`,
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey`
that will be used to sign the certificate.
:param algorithm: The
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm` that
will be used to generate the signature.
:param backend: Backend that will be used to build the certificate.
Must support the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: :class:`~cryptography.x509.Certificate`
X.509 CSR (Certificate Signing Request) Object
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: CertificateSigningRequest
.. versionadded:: 0.9
.. method:: public_key()
The public key associated with the request.
:returns:
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey`
.. doctest::
>>> from cryptography.hazmat.primitives.asymmetric import rsa
>>> public_key = csr.public_key()
>>> isinstance(public_key, rsa.RSAPublicKey)
True
.. attribute:: subject
:type: :class:`Name`
The :class:`Name` of the subject.
.. attribute:: signature_hash_algorithm
:type: :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`
Returns the
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm` which
was used in signing this request.
.. doctest::
>>> from cryptography.hazmat.primitives import hashes
>>> isinstance(csr.signature_hash_algorithm, hashes.SHA1)
True
.. attribute:: signature_algorithm_oid
.. versionadded:: 1.6
:type: :class:`ObjectIdentifier`
Returns the :class:`ObjectIdentifier` of the signature algorithm used
to sign the request. This will be one of the OIDs from
:class:`~cryptography.x509.oid.SignatureAlgorithmOID`.
.. doctest::
>>> csr.signature_algorithm_oid
<ObjectIdentifier(oid=1.2.840.113549.1.1.5, name=sha1WithRSAEncryption)>
.. attribute:: extensions
:type: :class:`Extensions`
The extensions encoded in the certificate signing request.
:raises cryptography.x509.DuplicateExtension: If more than one
extension of the same type is found within the certificate signing request.
:raises cryptography.x509.UnsupportedGeneralNameType: If an extension
contains a general name that is not supported.
:raises UnicodeError: If an extension contains IDNA encoding that is
invalid or not compliant with IDNA 2008.
.. method:: public_bytes(encoding)
.. versionadded:: 1.0
:param encoding: The
:class:`~cryptography.hazmat.primitives.serialization.Encoding`
that will be used to serialize the certificate request.
:return bytes: The data that can be written to a file or sent
over the network to be signed by the certificate
authority.
.. attribute:: signature
.. versionadded:: 1.2
:type: bytes
The bytes of the certificate signing request's signature.
.. attribute:: tbs_certrequest_bytes
.. versionadded:: 1.2
:type: bytes
The DER encoded bytes payload (as defined by :rfc:`2986`) that is
hashed and then signed by the private key (corresponding to the public
key embedded in the CSR). This data may be used to validate the CSR
signature.
.. attribute:: is_signature_valid
.. versionadded:: 1.3
Returns True if the CSR signature is correct, False otherwise.
X.509 Certificate Revocation List Builder
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: CertificateRevocationListBuilder
.. versionadded:: 1.2
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> from cryptography.hazmat.primitives.asymmetric import rsa
>>> from cryptography.x509.oid import NameOID
>>> import datetime
>>> one_day = datetime.timedelta(1, 0, 0)
>>> private_key = rsa.generate_private_key(
... public_exponent=65537,
... key_size=2048,
... backend=default_backend()
... )
>>> builder = x509.CertificateRevocationListBuilder()
>>> builder = builder.issuer_name(x509.Name([
... x509.NameAttribute(NameOID.COMMON_NAME, u'cryptography.io CA'),
... ]))
>>> builder = builder.last_update(datetime.datetime.today())
>>> builder = builder.next_update(datetime.datetime.today() + one_day)
>>> revoked_cert = x509.RevokedCertificateBuilder().serial_number(
... 333
... ).revocation_date(
... datetime.datetime.today()
... ).build(default_backend())
>>> builder = builder.add_revoked_certificate(revoked_cert)
>>> crl = builder.sign(
... private_key=private_key, algorithm=hashes.SHA256(),
... backend=default_backend()
... )
>>> len(crl)
1
.. method:: issuer_name(name)
Sets the issuer's distinguished name.
:param name: The :class:`~cryptography.x509.Name` that describes the
issuer (CA).
.. method:: last_update(time)
Sets this CRL's activation time. This is the time from which
clients can start trusting this CRL. It may be different from
the time at which this CRL was created. This is also known as the
``thisUpdate`` time.
:param time: The :class:`datetime.datetime` object (in UTC) that marks
the activation time for this CRL. The CRL may not be trusted if it
is used before this time.
.. method:: next_update(time)
Sets this CRL's next update time. This is the time by which
a new CRL will be issued. The CA is allowed to issue a new CRL before
this date, however clients are not required to check for it.
:param time: The :class:`datetime.datetime` object (in UTC) that marks
the next update time for this CRL.
.. method:: add_extension(extension, critical)
Adds an X.509 extension to this CRL.
:param extension: An extension with the
:class:`~cryptography.x509.ExtensionType` interface.
:param critical: Set to ``True`` if the extension must be understood and
handled by whoever reads the CRL.
.. method:: add_revoked_certificate(revoked_certificate)
Adds a revoked certificate to this CRL.
:param revoked_certificate: An instance of
:class:`~cryptography.x509.RevokedCertificate`. These can be
obtained from an existing CRL or created with
:class:`~cryptography.x509.RevokedCertificateBuilder`.
.. method:: sign(private_key, algorithm, backend)
Sign this CRL using the CA's private key.
:param private_key: The
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey`,
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey`
that will be used to sign the certificate.
:param algorithm: The
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm` that
will be used to generate the signature.
:param backend: Backend that will be used to build the CRL.
Must support the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: :class:`~cryptography.x509.CertificateRevocationList`
X.509 Revoked Certificate Object
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: RevokedCertificate
.. versionadded:: 1.0
.. attribute:: serial_number
:type: :class:`int`
An integer representing the serial number of the revoked certificate.
.. doctest::
>>> revoked_certificate.serial_number
0
.. attribute:: revocation_date
:type: :class:`datetime.datetime`
A naïve datetime representing the date this certificates was revoked.
.. doctest::
>>> revoked_certificate.revocation_date
datetime.datetime(2015, 1, 1, 0, 0)
.. attribute:: extensions
:type: :class:`Extensions`
The extensions encoded in the revoked certificate.
.. doctest::
>>> for ext in revoked_certificate.extensions:
... print(ext)
<Extension(oid=<ObjectIdentifier(oid=2.5.29.24, name=invalidityDate)>, critical=False, value=<InvalidityDate(invalidity_date=2015-01-01 00:00:00)>)>
<Extension(oid=<ObjectIdentifier(oid=2.5.29.21, name=cRLReason)>, critical=False, value=<CRLReason(reason=ReasonFlags.key_compromise)>)>
X.509 Revoked Certificate Builder
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: RevokedCertificateBuilder
This class is used to create :class:`~cryptography.x509.RevokedCertificate`
objects that can be used with the
:class:`~cryptography.x509.CertificateRevocationListBuilder`.
.. versionadded:: 1.2
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> import datetime
>>> builder = x509.RevokedCertificateBuilder()
>>> builder = builder.revocation_date(datetime.datetime.today())
>>> builder = builder.serial_number(3333)
>>> revoked_certificate = builder.build(default_backend())
>>> isinstance(revoked_certificate, x509.RevokedCertificate)
True
.. method:: serial_number(serial_number)
Sets the revoked certificate's serial number.
:param serial_number: Integer number that is used to identify the
revoked certificate.
.. method:: revocation_date(time)
Sets the certificate's revocation date.
:param time: The :class:`datetime.datetime` object (in UTC) that marks the
revocation time for the certificate.
.. method:: add_extension(extension, critical)
Adds an X.509 extension to this revoked certificate.
:param extension: An instance of one of the
:ref:`CRL entry extensions <crl_entry_extensions>`.
:param critical: Set to ``True`` if the extension must be understood and
handled.
.. method:: build(backend)
Create a revoked certificate object using the provided backend.
:param backend: Backend that will be used to build the revoked
certificate. Must support the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:returns: :class:`~cryptography.x509.RevokedCertificate`
X.509 CSR (Certificate Signing Request) Builder Object
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: CertificateSigningRequestBuilder
.. versionadded:: 1.0
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> from cryptography.hazmat.primitives.asymmetric import rsa
>>> from cryptography.x509.oid import NameOID
>>> private_key = rsa.generate_private_key(
... public_exponent=65537,
... key_size=2048,
... backend=default_backend()
... )
>>> builder = x509.CertificateSigningRequestBuilder()
>>> builder = builder.subject_name(x509.Name([
... x509.NameAttribute(NameOID.COMMON_NAME, u'cryptography.io'),
... ]))
>>> builder = builder.add_extension(
... x509.BasicConstraints(ca=False, path_length=None), critical=True,
... )
>>> request = builder.sign(
... private_key, hashes.SHA256(), default_backend()
... )
>>> isinstance(request, x509.CertificateSigningRequest)
True
.. method:: subject_name(name)
:param name: The :class:`~cryptography.x509.Name` of the certificate
subject.
:returns: A new
:class:`~cryptography.x509.CertificateSigningRequestBuilder`.
.. method:: add_extension(extension, critical)
:param extension: An extension conforming to the
:class:`~cryptography.x509.ExtensionType` interface.
:param critical: Set to `True` if the extension must be understood and
handled by whoever reads the certificate.
:returns: A new
:class:`~cryptography.x509.CertificateSigningRequestBuilder`.
.. method:: sign(private_key, algorithm, backend)
:param backend: Backend that will be used to sign the request.
Must support the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:param private_key: The
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey`,
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey` or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey`
that will be used to sign the request. When the request is
signed by a certificate authority, the private key's associated
public key will be stored in the resulting certificate.
:param algorithm: The
:class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`
that will be used to generate the request signature.
:returns: A new
:class:`~cryptography.x509.CertificateSigningRequest`.
.. class:: Name
.. versionadded:: 0.8
An X509 Name is an ordered list of attributes. The object is iterable to
get every attribute or you can use :meth:`Name.get_attributes_for_oid` to
obtain the specific type you want. Names are sometimes represented as a
slash or comma delimited string (e.g. ``/CN=mydomain.com/O=My Org/C=US`` or
``CN=mydomain.com, O=My Org, C=US``).
Technically, a Name is a list of *sets* of attributes, called *Relative
Distinguished Names* or *RDNs*, although multi-valued RDNs are rarely
encountered. The iteration order of values within a multi-valued RDN is
preserved. If you need to handle multi-valued RDNs, the ``rdns`` property
gives access to an ordered list of :class:`RelativeDistinguishedName`
objects.
A Name can be initialized with an iterable of :class:`NameAttribute` (the
common case where each RDN has a single attribute) or an iterable of
:class:`RelativeDistinguishedName` objects (in the rare case of
multi-valued RDNs).
.. doctest::
>>> len(cert.subject)
3
>>> for attribute in cert.subject:
... print(attribute)
<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.6, name=countryName)>, value='US')>
<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.10, name=organizationName)>, value='Test Certificates 2011')>
<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.3, name=commonName)>, value='Good CA')>
.. attribute:: rdns
.. versionadded:: 1.6
:type: list of :class:`RelativeDistinguishedName`
.. method:: get_attributes_for_oid(oid)
:param oid: An :class:`ObjectIdentifier` instance.
:returns: A list of :class:`NameAttribute` instances that match the
OID provided. If nothing matches an empty list will be returned.
.. doctest::
>>> cert.subject.get_attributes_for_oid(NameOID.COMMON_NAME)
[<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.3, name=commonName)>, value='Good CA')>]
.. method:: public_bytes(backend)
.. versionadded:: 1.6
:param backend: A backend supporting the
:class:`~cryptography.hazmat.backends.interfaces.X509Backend`
interface.
:return bytes: The DER encoded name.
.. class:: Version
.. versionadded:: 0.7
An enumeration for X.509 versions.
.. attribute:: v1
For version 1 X.509 certificates.
.. attribute:: v3
For version 3 X.509 certificates.
.. class:: NameAttribute
.. versionadded:: 0.8
An X.509 name consists of a list of :class:`RelativeDistinguishedName`
instances, which consist of a set of :class:`NameAttribute` instances.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
The attribute OID.
.. attribute:: value
:type: :term:`text`
The value of the attribute.
.. class:: RelativeDistinguishedName(attributes)
.. versionadded:: 1.6
A relative distinguished name is a non-empty set of name attributes. The
object is iterable to get every attribute, preserving the original order.
Passing duplicate attributes to the constructor raises ``ValueError``.
.. method:: get_attributes_for_oid(oid)
:param oid: An :class:`ObjectIdentifier` instance.
:returns: A list of :class:`NameAttribute` instances that match the OID
provided. The list should contain zero or one values.
.. class:: ObjectIdentifier
.. versionadded:: 0.8
Object identifiers (frequently seen abbreviated as OID) identify the type
of a value (see: :class:`NameAttribute`).
.. attribute:: dotted_string
:type: :class:`str`
The dotted string value of the OID (e.g. ``"2.5.4.3"``)
.. _general_name_classes:
General Name Classes
~~~~~~~~~~~~~~~~~~~~
.. class:: GeneralName
.. versionadded:: 0.9
This is the generic interface that all the following classes are registered
against.
.. class:: RFC822Name(value)
.. versionadded:: 0.9
.. versionchanged:: 2.1
.. warning::
Starting with version 2.1 :term:`U-label` input is deprecated. If
passing an internationalized domain name (IDN) you should first IDNA
encode the value and then pass the result as a string. Accessing
``value`` will return the :term:`A-label` encoded form even if you pass
a U-label. This breaks backwards compatibility, but only for
internationalized domain names.
This corresponds to an email address. For example, ``user@example.com``.
:param value: The email address. If the address contains an
internationalized domain name then it must be encoded to an
:term:`A-label` string before being passed.
.. attribute:: value
:type: :term:`text`
.. class:: DNSName(value)
.. versionadded:: 0.9
.. versionchanged:: 2.1
.. warning::
Starting with version 2.1 :term:`U-label` input is deprecated. If
passing an internationalized domain name (IDN) you should first IDNA
encode the value and then pass the result as a string. Accessing
``value`` will return the :term:`A-label` encoded form even if you pass
a U-label. This breaks backwards compatibility, but only for
internationalized domain names.
This corresponds to a domain name. For example, ``cryptography.io``.
:param value: The domain name. If it is an internationalized domain
name then it must be encoded to an :term:`A-label` string before being
passed.
:type: :term:`text`
.. attribute:: value
:type: :term:`text`
.. class:: DirectoryName(value)
.. versionadded:: 0.9
This corresponds to a directory name.
.. attribute:: value
:type: :class:`Name`
.. class:: UniformResourceIdentifier(value)
.. versionadded:: 0.9
.. versionchanged:: 2.1
.. warning::
Starting with version 2.1 :term:`U-label` input is deprecated. If
passing an internationalized domain name (IDN) you should first IDNA
encode the value and then pass the result as a string. Accessing
``value`` will return the :term:`A-label` encoded form even if you pass
a U-label. This breaks backwards compatibility, but only for
internationalized domain names.
This corresponds to a uniform resource identifier. For example,
``https://cryptography.io``.
:param value: The URI. If it contains an internationalized domain
name then it must be encoded to an :term:`A-label` string before
being passed.
.. attribute:: value
:type: :term:`text`
.. class:: IPAddress(value)
.. versionadded:: 0.9
This corresponds to an IP address.
.. attribute:: value
:type: :class:`~ipaddress.IPv4Address`,
:class:`~ipaddress.IPv6Address`, :class:`~ipaddress.IPv4Network`,
or :class:`~ipaddress.IPv6Network`.
.. class:: RegisteredID(value)
.. versionadded:: 0.9
This corresponds to a registered ID.
.. attribute:: value
:type: :class:`ObjectIdentifier`
.. class:: OtherName(type_id, value)
.. versionadded:: 1.0
This corresponds to an ``otherName.`` An ``otherName`` has a type identifier and a value represented in binary DER format.
.. attribute:: type_id
:type: :class:`ObjectIdentifier`
.. attribute:: value
:type: `bytes`
X.509 Extensions
~~~~~~~~~~~~~~~~
.. class:: Extensions
.. versionadded:: 0.9
An X.509 Extensions instance is an ordered list of extensions. The object
is iterable to get every extension.
.. method:: get_extension_for_oid(oid)
:param oid: An :class:`ObjectIdentifier` instance.
:returns: An instance of the extension class.
:raises cryptography.x509.ExtensionNotFound: If the certificate does
not have the extension requested.
.. doctest::
>>> from cryptography.x509.oid import ExtensionOID
>>> cert.extensions.get_extension_for_oid(ExtensionOID.BASIC_CONSTRAINTS)
<Extension(oid=<ObjectIdentifier(oid=2.5.29.19, name=basicConstraints)>, critical=True, value=<BasicConstraints(ca=True, path_length=None)>)>
.. method:: get_extension_for_class(extclass)
.. versionadded:: 1.1
:param extclass: An extension class.
:returns: An instance of the extension class.
:raises cryptography.x509.ExtensionNotFound: If the certificate does
not have the extension requested.
.. doctest::
>>> from cryptography import x509
>>> cert.extensions.get_extension_for_class(x509.BasicConstraints)
<Extension(oid=<ObjectIdentifier(oid=2.5.29.19, name=basicConstraints)>, critical=True, value=<BasicConstraints(ca=True, path_length=None)>)>
.. class:: Extension
.. versionadded:: 0.9
.. attribute:: oid
:type: :class:`ObjectIdentifier`
One of the :class:`~cryptography.x509.oid.ExtensionOID` OIDs.
.. attribute:: critical
:type: bool
Determines whether a given extension is critical or not. :rfc:`5280`
requires that "A certificate-using system MUST reject the certificate
if it encounters a critical extension it does not recognize or a
critical extension that contains information that it cannot process".
.. attribute:: value
Returns an instance of the extension type corresponding to the OID.
.. class:: ExtensionType
.. versionadded:: 1.0
This is the interface against which all the following extension types are
registered.
.. class:: KeyUsage(digital_signature, content_commitment, key_encipherment, data_encipherment, key_agreement, key_cert_sign, crl_sign, encipher_only, decipher_only)
.. versionadded:: 0.9
The key usage extension defines the purpose of the key contained in the
certificate. The usage restriction might be employed when a key that could
be used for more than one operation is to be restricted.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.KEY_USAGE`.
.. attribute:: digital_signature
:type: bool
This purpose is set to true when the subject public key is used for verifying
digital signatures, other than signatures on certificates
(``key_cert_sign``) and CRLs (``crl_sign``).
.. attribute:: content_commitment
:type: bool
This purpose is set to true when the subject public key is used for verifying
digital signatures, other than signatures on certificates
(``key_cert_sign``) and CRLs (``crl_sign``). It is used to provide a
non-repudiation service that protects against the signing entity
falsely denying some action. In the case of later conflict, a
reliable third party may determine the authenticity of the signed
data. This was called ``non_repudiation`` in older revisions of the
X.509 specification.
.. attribute:: key_encipherment
:type: bool
This purpose is set to true when the subject public key is used for
enciphering private or secret keys.
.. attribute:: data_encipherment
:type: bool
This purpose is set to true when the subject public key is used for
directly enciphering raw user data without the use of an intermediate
symmetric cipher.
.. attribute:: key_agreement
:type: bool
This purpose is set to true when the subject public key is used for key
agreement. For example, when a Diffie-Hellman key is to be used for
key management, then this purpose is set to true.
.. attribute:: key_cert_sign
:type: bool
This purpose is set to true when the subject public key is used for
verifying signatures on public key certificates. If this purpose is set
to true then ``ca`` must be true in the :class:`BasicConstraints`
extension.
.. attribute:: crl_sign
:type: bool
This purpose is set to true when the subject public key is used for
verifying signatures on certificate revocation lists.
.. attribute:: encipher_only
:type: bool
When this purposes is set to true and the ``key_agreement`` purpose is
also set, the subject public key may be used only for enciphering data
while performing key agreement.
:raises ValueError: This is raised if accessed when ``key_agreement``
is false.
.. attribute:: decipher_only
:type: bool
When this purposes is set to true and the ``key_agreement`` purpose is
also set, the subject public key may be used only for deciphering data
while performing key agreement.
:raises ValueError: This is raised if accessed when ``key_agreement``
is false.
.. class:: BasicConstraints(ca, path_length)
.. versionadded:: 0.9
Basic constraints is an X.509 extension type that defines whether a given
certificate is allowed to sign additional certificates and what path
length restrictions may exist.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.BASIC_CONSTRAINTS`.
.. attribute:: ca
:type: bool
Whether the certificate can sign certificates.
.. attribute:: path_length
:type: int or None
The maximum path length for certificates subordinate to this
certificate. This attribute only has meaning if ``ca`` is true.
If ``ca`` is true then a path length of None means there's no
restriction on the number of subordinate CAs in the certificate chain.
If it is zero or greater then it defines the maximum length for a
subordinate CA's certificate chain. For example, a ``path_length`` of 1
means the certificate can sign a subordinate CA, but the subordinate CA
is not allowed to create subordinates with ``ca`` set to true.
.. class:: ExtendedKeyUsage(usages)
.. versionadded:: 0.9
This extension indicates one or more purposes for which the certified
public key may be used, in addition to or in place of the basic
purposes indicated in the key usage extension. The object is
iterable to obtain the list of
:class:`~cryptography.x509.oid.ExtendedKeyUsageOID` OIDs present.
:param list usages: A list of
:class:`~cryptography.x509.oid.ExtendedKeyUsageOID` OIDs.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.EXTENDED_KEY_USAGE`.
.. class:: OCSPNoCheck()
.. versionadded:: 1.0
This presence of this extension indicates that an OCSP client can trust a
responder for the lifetime of the responder's certificate. CAs issuing
such a certificate should realize that a compromise of the responder's key
is as serious as the compromise of a CA key used to sign CRLs, at least for
the validity period of this certificate. CA's may choose to issue this type
of certificate with a very short lifetime and renew it frequently. This
extension is only relevant when the certificate is an authorized OCSP
responder.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.OCSP_NO_CHECK`.
.. class:: TLSFeature(features)
.. versionadded:: 2.1
The TLS Feature extension is defined in :rfc:`7633` and is used in
certificates for OCSP Must-Staple. The object is iterable to get every
element.
:param list features: A list of features to enable from the
:class:`~cryptography.x509.TLSFeatureType` enum. At this time only
``status_request`` or ``status_request_v2`` are allowed.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.TLS_FEATURE`.
.. class:: TLSFeatureType
.. versionadded:: 2.1
An enumeration of TLS Feature types.
.. attribute:: status_request
This feature type is defined in :rfc:`6066` and, when embedded in
an X.509 certificate, signals to the client that it should require
a stapled OCSP response in the TLS handshake. Commonly known as OCSP
Must-Staple in certificates.
.. attribute:: status_request_v2
This feature type is defined in :rfc:`6961`. This value is not
commonly used and if you want to enable OCSP Must-Staple you should
use ``status_request``.
.. class:: NameConstraints(permitted_subtrees, excluded_subtrees)
.. versionadded:: 1.0
The name constraints extension, which only has meaning in a CA certificate,
defines a name space within which all subject names in certificates issued
beneath the CA certificate must (or must not) be in. For specific details
on the way this extension should be processed see :rfc:`5280`.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.NAME_CONSTRAINTS`.
.. attribute:: permitted_subtrees
:type: list of :class:`GeneralName` objects or None
The set of permitted name patterns. If a name matches this and an
element in ``excluded_subtrees`` it is invalid. At least one of
``permitted_subtrees`` and ``excluded_subtrees`` will be non-None.
.. attribute:: excluded_subtrees
:type: list of :class:`GeneralName` objects or None
Any name matching a restriction in the ``excluded_subtrees`` field is
invalid regardless of information appearing in the
``permitted_subtrees``. At least one of ``permitted_subtrees`` and
``excluded_subtrees`` will be non-None.
.. class:: AuthorityKeyIdentifier(key_identifier, authority_cert_issuer, authority_cert_serial_number)
.. versionadded:: 0.9
The authority key identifier extension provides a means of identifying the
public key corresponding to the private key used to sign a certificate.
This extension is typically used to assist in determining the appropriate
certificate chain. For more information about generation and use of this
extension see `RFC 5280 section 4.2.1.1`_.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.AUTHORITY_KEY_IDENTIFIER`.
.. attribute:: key_identifier
:type: bytes
A value derived from the public key used to verify the certificate's
signature.
.. attribute:: authority_cert_issuer
:type: A list of :class:`GeneralName` instances or None
The :class:`Name` of the issuer's issuer.
.. attribute:: authority_cert_serial_number
:type: int or None
The serial number of the issuer's issuer.
.. classmethod:: from_issuer_public_key(public_key)
.. versionadded:: 1.0
.. note::
This method should be used if the issuer certificate does not
contain a :class:`~cryptography.x509.SubjectKeyIdentifier`.
Otherwise, use
:meth:`~cryptography.x509.AuthorityKeyIdentifier.from_issuer_subject_key_identifier`.
Creates a new AuthorityKeyIdentifier instance using the public key
provided to generate the appropriate digest. This should be the
**issuer's public key**. The resulting object will contain
:attr:`~cryptography.x509.AuthorityKeyIdentifier.key_identifier`, but
:attr:`~cryptography.x509.AuthorityKeyIdentifier.authority_cert_issuer`
and
:attr:`~cryptography.x509.AuthorityKeyIdentifier.authority_cert_serial_number`
will be None.
The generated ``key_identifier`` is the SHA1 hash of the ``subjectPublicKey``
ASN.1 bit string. This is the first recommendation in :rfc:`5280`
section 4.2.1.2.
:param public_key: One of
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey`
,
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey`
, or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey`.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> issuer_cert = x509.load_pem_x509_certificate(pem_data, default_backend())
>>> x509.AuthorityKeyIdentifier.from_issuer_public_key(issuer_cert.public_key())
<AuthorityKeyIdentifier(key_identifier=b'X\x01\x84$\x1b\xbc+R\x94J=\xa5\x10r\x14Q\xf5\xaf:\xc9', authority_cert_issuer=None, authority_cert_serial_number=None)>
.. classmethod:: from_issuer_subject_key_identifier(ski)
.. versionadded:: 1.3
.. note::
This method should be used if the issuer certificate contains a
:class:`~cryptography.x509.SubjectKeyIdentifier`. Otherwise, use
:meth:`~cryptography.x509.AuthorityKeyIdentifier.from_issuer_public_key`.
Creates a new AuthorityKeyIdentifier instance using the
SubjectKeyIdentifier from the issuer certificate. The resulting object
will contain
:attr:`~cryptography.x509.AuthorityKeyIdentifier.key_identifier`, but
:attr:`~cryptography.x509.AuthorityKeyIdentifier.authority_cert_issuer`
and
:attr:`~cryptography.x509.AuthorityKeyIdentifier.authority_cert_serial_number`
will be None.
:param ski: The
:class:`~cryptography.x509.SubjectKeyIdentifier` from the issuer
certificate.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> issuer_cert = x509.load_pem_x509_certificate(pem_data, default_backend())
>>> ski = issuer_cert.extensions.get_extension_for_class(x509.SubjectKeyIdentifier)
>>> x509.AuthorityKeyIdentifier.from_issuer_subject_key_identifier(ski)
<AuthorityKeyIdentifier(key_identifier=b'X\x01\x84$\x1b\xbc+R\x94J=\xa5\x10r\x14Q\xf5\xaf:\xc9', authority_cert_issuer=None, authority_cert_serial_number=None)>
.. class:: SubjectKeyIdentifier(digest)
.. versionadded:: 0.9
The subject key identifier extension provides a means of identifying
certificates that contain a particular public key.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.SUBJECT_KEY_IDENTIFIER`.
.. attribute:: digest
:type: bytes
The binary value of the identifier.
.. classmethod:: from_public_key(public_key)
.. versionadded:: 1.0
Creates a new SubjectKeyIdentifier instance using the public key
provided to generate the appropriate digest. This should be the public
key that is in the certificate. The generated digest is the SHA1 hash
of the ``subjectPublicKey`` ASN.1 bit string. This is the first
recommendation in :rfc:`5280` section 4.2.1.2.
:param public_key: One of
:class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey`
,
:class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey`
, or
:class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey`.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> csr = x509.load_pem_x509_csr(pem_req_data, default_backend())
>>> x509.SubjectKeyIdentifier.from_public_key(csr.public_key())
<SubjectKeyIdentifier(digest=b'\xdb\xaa\xf0\x06\x11\xdbD\xfe\xbf\x93\x03\x8av\x88WP7\xa6\x91\xf7')>
.. class:: SubjectAlternativeName(general_names)
.. versionadded:: 0.9
Subject alternative name is an X.509 extension that provides a list of
:ref:`general name <general_name_classes>` instances that provide a set
of identities for which the certificate is valid. The object is iterable to
get every element.
:param list general_names: A list of :class:`GeneralName` instances.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.SUBJECT_ALTERNATIVE_NAME`.
.. method:: get_values_for_type(type)
:param type: A :class:`GeneralName` instance. This is one of the
:ref:`general name classes <general_name_classes>`.
:returns: A list of values extracted from the matched general names.
The type of the returned values depends on the :class:`GeneralName`.
.. doctest::
>>> from cryptography import x509
>>> from cryptography.hazmat.backends import default_backend
>>> from cryptography.hazmat.primitives import hashes
>>> cert = x509.load_pem_x509_certificate(cryptography_cert_pem, default_backend())
>>> # Get the subjectAltName extension from the certificate
>>> ext = cert.extensions.get_extension_for_oid(ExtensionOID.SUBJECT_ALTERNATIVE_NAME)
>>> # Get the dNSName entries from the SAN extension
>>> ext.value.get_values_for_type(x509.DNSName)
['www.cryptography.io', 'cryptography.io']
.. class:: IssuerAlternativeName(general_names)
.. versionadded:: 1.0
Issuer alternative name is an X.509 extension that provides a list of
:ref:`general name <general_name_classes>` instances that provide a set
of identities for the certificate issuer. The object is iterable to
get every element.
:param list general_names: A list of :class:`GeneralName` instances.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.ISSUER_ALTERNATIVE_NAME`.
.. method:: get_values_for_type(type)
:param type: A :class:`GeneralName` instance. This is one of the
:ref:`general name classes <general_name_classes>`.
:returns: A list of values extracted from the matched general names.
.. class:: PrecertificateSignedCertificateTimestamps(scts)
.. versionadded:: 2.0
This extension contains
:class:`~cryptography.x509.certificate_transparency.SignedCertificateTimestamp`
instances which were issued for the pre-certificate corresponding to this
certificate. These can be used to verify that the certificate is included
in a public Certificate Transparency log.
It is an iterable containing one or more
:class:`~cryptography.x509.certificate_transparency.SignedCertificateTimestamp`
objects.
:param list scts: A ``list`` of
:class:`~cryptography.x509.certificate_transparency.SignedCertificateTimestamp`
objects.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.PRECERT_SIGNED_CERTIFICATE_TIMESTAMPS`.
.. class:: DeltaCRLIndicator(crl_number)
.. versionadded:: 2.1
The delta CRL indicator is a CRL extension that identifies a CRL as being
a delta CRL. Delta CRLs contain updates to revocation information
previously distributed, rather than all the information that would appear
in a complete CRL.
:param int crl_number: The CRL number of the complete CRL that the
delta CRL is updating.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.DELTA_CRL_INDICATOR`.
.. attribute:: crl_number
:type: int
.. class:: AuthorityInformationAccess(descriptions)
.. versionadded:: 0.9
The authority information access extension indicates how to access
information and services for the issuer of the certificate in which
the extension appears. Information and services may include online
validation services (such as OCSP) and issuer data. It is an iterable,
containing one or more :class:`~cryptography.x509.AccessDescription`
instances.
:param list descriptions: A list of :class:`AccessDescription` objects.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.AUTHORITY_INFORMATION_ACCESS`.
.. class:: AccessDescription(access_method, access_location)
.. versionadded:: 0.9
.. attribute:: access_method
:type: :class:`ObjectIdentifier`
The access method defines what the ``access_location`` means. It must
be either
:attr:`~cryptography.x509.oid.AuthorityInformationAccessOID.OCSP` or
:attr:`~cryptography.x509.oid.AuthorityInformationAccessOID.CA_ISSUERS`.
If it is
:attr:`~cryptography.x509.oid.AuthorityInformationAccessOID.OCSP`
the access location will be where to obtain OCSP
information for the certificate. If it is
:attr:`~cryptography.x509.oid.AuthorityInformationAccessOID.CA_ISSUERS`
the access location will provide additional information about the
issuing certificate.
.. attribute:: access_location
:type: :class:`GeneralName`
Where to access the information defined by the access method.
.. class:: FreshestCRL(distribution_points)
.. versionadded:: 2.1
The freshest CRL extension (also known as Delta CRL Distribution Point)
identifies how delta CRL information is obtained. It is an iterable,
containing one or more :class:`DistributionPoint` instances.
:param list distribution_points: A list of :class:`DistributionPoint`
instances.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.FRESHEST_CRL`.
.. class:: CRLDistributionPoints(distribution_points)
.. versionadded:: 0.9
The CRL distribution points extension identifies how CRL information is
obtained. It is an iterable, containing one or more
:class:`DistributionPoint` instances.
:param list distribution_points: A list of :class:`DistributionPoint`
instances.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.CRL_DISTRIBUTION_POINTS`.
.. class:: DistributionPoint(full_name, relative_name, reasons, crl_issuer)
.. versionadded:: 0.9
.. attribute:: full_name
:type: list of :class:`GeneralName` instances or None
This field describes methods to retrieve the CRL. At most one of
``full_name`` or ``relative_name`` will be non-None.
.. attribute:: relative_name
:type: :class:`RelativeDistinguishedName` or None
This field describes methods to retrieve the CRL relative to the CRL
issuer. At most one of ``full_name`` or ``relative_name`` will be
non-None.
.. versionchanged:: 1.6
Changed from :class:`Name` to :class:`RelativeDistinguishedName`.
.. attribute:: crl_issuer
:type: list of :class:`GeneralName` instances or None
Information about the issuer of the CRL.
.. attribute:: reasons
:type: frozenset of :class:`ReasonFlags` or None
The reasons a given distribution point may be used for when performing
revocation checks.
.. class:: ReasonFlags
.. versionadded:: 0.9
An enumeration for CRL reasons.
.. attribute:: unspecified
It is unspecified why the certificate was revoked. This reason cannot
be used as a reason flag in a :class:`DistributionPoint`.
.. attribute:: key_compromise
This reason indicates that the private key was compromised.
.. attribute:: ca_compromise
This reason indicates that the CA issuing the certificate was
compromised.
.. attribute:: affiliation_changed
This reason indicates that the subject's name or other information has
changed.
.. attribute:: superseded
This reason indicates that a certificate has been superseded.
.. attribute:: cessation_of_operation
This reason indicates that the certificate is no longer required.
.. attribute:: certificate_hold
This reason indicates that the certificate is on hold.
.. attribute:: privilege_withdrawn
This reason indicates that the privilege granted by this certificate
have been withdrawn.
.. attribute:: aa_compromise
When an attribute authority has been compromised.
.. attribute:: remove_from_crl
This reason indicates that the certificate was on hold and should be
removed from the CRL. This reason cannot be used as a reason flag
in a :class:`DistributionPoint`.
.. class:: InhibitAnyPolicy(skip_certs)
.. versionadded:: 1.0
The inhibit ``anyPolicy`` extension indicates that the special OID
:attr:`~cryptography.x509.oid.CertificatePoliciesOID.ANY_POLICY`, is not
considered an explicit match for other :class:`CertificatePolicies` except
when it appears in an intermediate self-issued CA certificate. The value
indicates the number of additional non-self-issued certificates that may
appear in the path before
:attr:`~cryptography.x509.oid.CertificatePoliciesOID.ANY_POLICY` is no
longer permitted. For example, a value of one indicates that
:attr:`~cryptography.x509.oid.CertificatePoliciesOID.ANY_POLICY` may be
processed in certificates issued by the subject of this certificate, but
not in additional certificates in the path.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.INHIBIT_ANY_POLICY`.
.. attribute:: skip_certs
:type: int
.. class:: PolicyConstraints
.. versionadded:: 1.3
The policy constraints extension is used to inhibit policy mapping or
require that each certificate in a chain contain an acceptable policy
identifier. For more information about the use of this extension see
:rfc:`5280`.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns :attr:`~cryptography.x509.oid.ExtensionOID.POLICY_CONSTRAINTS`.
.. attribute:: require_explicit_policy
:type: int or None
If this field is not None, the value indicates the number of additional
certificates that may appear in the chain before an explicit policy is
required for the entire path. When an explicit policy is required, it
is necessary for all certificates in the chain to contain an acceptable
policy identifier in the certificate policies extension. An
acceptable policy identifier is the identifier of a policy required
by the user of the certification path or the identifier of a policy
that has been declared equivalent through policy mapping.
.. attribute:: inhibit_policy_mapping
:type: int or None
If this field is not None, the value indicates the number of additional
certificates that may appear in the chain before policy mapping is no
longer permitted. For example, a value of one indicates that policy
mapping may be processed in certificates issued by the subject of this
certificate, but not in additional certificates in the chain.
.. class:: CRLNumber(crl_number)
.. versionadded:: 1.2
The CRL number is a CRL extension that conveys a monotonically increasing
sequence number for a given CRL scope and CRL issuer. This extension allows
users to easily determine when a particular CRL supersedes another CRL.
:rfc:`5280` requires that this extension be present in conforming CRLs.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.CRL_NUMBER`.
.. attribute:: crl_number
:type: int
.. class:: UnrecognizedExtension
.. versionadded:: 1.2
A generic extension class used to hold the raw value of extensions that
``cryptography`` does not know how to parse.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns the OID associated with this extension.
.. attribute:: value
:type: byte
Returns the DER encoded bytes payload of the extension.
.. class:: CertificatePolicies(policies)
.. versionadded:: 0.9
The certificate policies extension is an iterable, containing one or more
:class:`PolicyInformation` instances.
:param list policies: A list of :class:`PolicyInformation` instances.
.. attribute:: oid
.. versionadded:: 1.0
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.ExtensionOID.CERTIFICATE_POLICIES`.
Certificate Policies Classes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
These classes may be present within a :class:`CertificatePolicies` instance.
.. class:: PolicyInformation(policy_identifier, policy_qualifiers)
.. versionadded:: 0.9
Contains a policy identifier and an optional list of qualifiers.
.. attribute:: policy_identifier
:type: :class:`ObjectIdentifier`
.. attribute:: policy_qualifiers
:type: list
A list consisting of :term:`text` and/or :class:`UserNotice` objects.
If the value is text it is a pointer to the practice statement
published by the certificate authority. If it is a user notice it is
meant for display to the relying party when the certificate is
used.
.. class:: UserNotice(notice_reference, explicit_text)
.. versionadded:: 0.9
User notices are intended for display to a relying party when a certificate
is used. In practice, few if any UIs expose this data and it is a rarely
encoded component.
.. attribute:: notice_reference
:type: :class:`NoticeReference` or None
The notice reference field names an organization and identifies,
by number, a particular statement prepared by that organization.
.. attribute:: explicit_text
This field includes an arbitrary textual statement directly in the
certificate.
:type: :term:`text`
.. class:: NoticeReference(organization, notice_numbers)
Notice reference can name an organization and provide information about
notices related to the certificate. For example, it might identify the
organization name and notice number 1. Application software could
have a notice file containing the current set of notices for the named
organization; the application would then extract the notice text from the
file and display it. In practice this is rarely seen.
.. versionadded:: 0.9
.. attribute:: organization
:type: :term:`text`
.. attribute:: notice_numbers
:type: list
A list of integers.
.. _crl_entry_extensions:
CRL Entry Extensions
~~~~~~~~~~~~~~~~~~~~
These extensions are only valid within a :class:`RevokedCertificate` object.
.. class:: CertificateIssuer(general_names)
.. versionadded:: 1.2
The certificate issuer is an extension that is only valid inside
:class:`~cryptography.x509.RevokedCertificate` objects. If the
``indirectCRL`` property of the parent CRL's IssuingDistributionPoint
extension is set, then this extension identifies the certificate issuer
associated with the revoked certificate. The object is iterable to get
every element.
:param list general_names: A list of :class:`GeneralName` instances.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.CRLEntryExtensionOID.CERTIFICATE_ISSUER`.
.. method:: get_values_for_type(type)
:param type: A :class:`GeneralName` instance. This is one of the
:ref:`general name classes <general_name_classes>`.
:returns: A list of values extracted from the matched general names.
The type of the returned values depends on the :class:`GeneralName`.
.. class:: CRLReason(reason)
.. versionadded:: 1.2
CRL reason (also known as ``reasonCode``) is an extension that is only
valid inside :class:`~cryptography.x509.RevokedCertificate` objects. It
identifies a reason for the certificate revocation.
:param reason: An element from :class:`~cryptography.x509.ReasonFlags`.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.CRLEntryExtensionOID.CRL_REASON`.
.. attribute:: reason
:type: An element from :class:`~cryptography.x509.ReasonFlags`
.. class:: InvalidityDate(invalidity_date)
.. versionadded:: 1.2
Invalidity date is an extension that is only valid inside
:class:`~cryptography.x509.RevokedCertificate` objects. It provides
the date on which it is known or suspected that the private key was
compromised or that the certificate otherwise became invalid.
This date may be earlier than the revocation date in the CRL entry,
which is the date at which the CA processed the revocation.
:param invalidity_date: The :class:`datetime.datetime` when it is known
or suspected that the private key was compromised.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns
:attr:`~cryptography.x509.oid.CRLEntryExtensionOID.INVALIDITY_DATE`.
.. attribute:: invalidity_date
:type: :class:`datetime.datetime`
Object Identifiers
~~~~~~~~~~~~~~~~~~
X.509 elements are frequently identified by :class:`ObjectIdentifier`
instances. The following common OIDs are available as constants.
.. currentmodule:: cryptography.x509.oid
.. class:: NameOID
These OIDs are typically seen in X.509 names.
.. versionadded:: 1.0
.. attribute:: COMMON_NAME
Corresponds to the dotted string ``"2.5.4.3"``. Historically the domain
name would be encoded here for server certificates. :rfc:`2818`
deprecates this practice and names of that type should now be located
in a :class:`~cryptography.x509.SubjectAlternativeName` extension.
.. attribute:: COUNTRY_NAME
Corresponds to the dotted string ``"2.5.4.6"``.
.. attribute:: LOCALITY_NAME
Corresponds to the dotted string ``"2.5.4.7"``.
.. attribute:: STATE_OR_PROVINCE_NAME
Corresponds to the dotted string ``"2.5.4.8"``.
.. attribute:: STREET_ADDRESS
.. versionadded:: 1.6
Corresponds to the dotted string ``"2.5.4.9"``.
.. attribute:: ORGANIZATION_NAME
Corresponds to the dotted string ``"2.5.4.10"``.
.. attribute:: ORGANIZATIONAL_UNIT_NAME
Corresponds to the dotted string ``"2.5.4.11"``.
.. attribute:: SERIAL_NUMBER
Corresponds to the dotted string ``"2.5.4.5"``. This is distinct from
the serial number of the certificate itself (which can be obtained with
:func:`~cryptography.x509.Certificate.serial_number`).
.. attribute:: SURNAME
Corresponds to the dotted string ``"2.5.4.4"``.
.. attribute:: GIVEN_NAME
Corresponds to the dotted string ``"2.5.4.42"``.
.. attribute:: TITLE
Corresponds to the dotted string ``"2.5.4.12"``.
.. attribute:: GENERATION_QUALIFIER
Corresponds to the dotted string ``"2.5.4.44"``.
.. attribute:: X500_UNIQUE_IDENTIFIER
.. versionadded:: 1.6
Corresponds to the dotted string ``"2.5.4.45"``.
.. attribute:: DN_QUALIFIER
Corresponds to the dotted string ``"2.5.4.46"``. This specifies
disambiguating information to add to the relative distinguished name of an
entry. See :rfc:`2256`.
.. attribute:: PSEUDONYM
Corresponds to the dotted string ``"2.5.4.65"``.
.. attribute:: USER_ID
.. versionadded:: 1.6
Corresponds to the dotted string ``"0.9.2342.19200300.100.1.1"``.
.. attribute:: DOMAIN_COMPONENT
Corresponds to the dotted string ``"0.9.2342.19200300.100.1.25"``. A string
holding one component of a domain name. See :rfc:`4519`.
.. attribute:: EMAIL_ADDRESS
Corresponds to the dotted string ``"1.2.840.113549.1.9.1"``.
.. attribute:: JURISDICTION_COUNTRY_NAME
Corresponds to the dotted string ``"1.3.6.1.4.1.311.60.2.1.3"``.
.. attribute:: JURISDICTION_LOCALITY_NAME
Corresponds to the dotted string ``"1.3.6.1.4.1.311.60.2.1.1"``.
.. attribute:: JURISDICTION_STATE_OR_PROVINCE_NAME
Corresponds to the dotted string ``"1.3.6.1.4.1.311.60.2.1.2"``.
.. attribute:: BUSINESS_CATEGORY
Corresponds to the dotted string ``"2.5.4.15"``.
.. attribute:: POSTAL_ADDRESS
.. versionadded:: 1.6
Corresponds to the dotted string ``"2.5.4.16"``.
.. attribute:: POSTAL_CODE
.. versionadded:: 1.6
Corresponds to the dotted string ``"2.5.4.17"``.
.. class:: SignatureAlgorithmOID
.. versionadded:: 1.0
.. attribute:: RSA_WITH_MD5
Corresponds to the dotted string ``"1.2.840.113549.1.1.4"``. This is
an MD5 digest signed by an RSA key.
.. attribute:: RSA_WITH_SHA1
Corresponds to the dotted string ``"1.2.840.113549.1.1.5"``. This is
a SHA1 digest signed by an RSA key.
.. attribute:: RSA_WITH_SHA224
Corresponds to the dotted string ``"1.2.840.113549.1.1.14"``. This is
a SHA224 digest signed by an RSA key.
.. attribute:: RSA_WITH_SHA256
Corresponds to the dotted string ``"1.2.840.113549.1.1.11"``. This is
a SHA256 digest signed by an RSA key.
.. attribute:: RSA_WITH_SHA384
Corresponds to the dotted string ``"1.2.840.113549.1.1.12"``. This is
a SHA384 digest signed by an RSA key.
.. attribute:: RSA_WITH_SHA512
Corresponds to the dotted string ``"1.2.840.113549.1.1.13"``. This is
a SHA512 digest signed by an RSA key.
.. attribute:: RSASSA_PSS
.. versionadded:: 2.3
Corresponds to the dotted string ``"1.2.840.113549.1.1.10"``. This is
signed by an RSA key using the Probabilistic Signature Scheme (PSS)
padding from RFC 4055. The hash function and padding are defined by
signature algorithm parameters.
.. attribute:: ECDSA_WITH_SHA1
Corresponds to the dotted string ``"1.2.840.10045.4.1"``. This is a SHA1
digest signed by an ECDSA key.
.. attribute:: ECDSA_WITH_SHA224
Corresponds to the dotted string ``"1.2.840.10045.4.3.1"``. This is
a SHA224 digest signed by an ECDSA key.
.. attribute:: ECDSA_WITH_SHA256
Corresponds to the dotted string ``"1.2.840.10045.4.3.2"``. This is
a SHA256 digest signed by an ECDSA key.
.. attribute:: ECDSA_WITH_SHA384
Corresponds to the dotted string ``"1.2.840.10045.4.3.3"``. This is
a SHA384 digest signed by an ECDSA key.
.. attribute:: ECDSA_WITH_SHA512
Corresponds to the dotted string ``"1.2.840.10045.4.3.4"``. This is
a SHA512 digest signed by an ECDSA key.
.. attribute:: DSA_WITH_SHA1
Corresponds to the dotted string ``"1.2.840.10040.4.3"``. This is
a SHA1 digest signed by a DSA key.
.. attribute:: DSA_WITH_SHA224
Corresponds to the dotted string ``"2.16.840.1.101.3.4.3.1"``. This is
a SHA224 digest signed by a DSA key.
.. attribute:: DSA_WITH_SHA256
Corresponds to the dotted string ``"2.16.840.1.101.3.4.3.2"``. This is
a SHA256 digest signed by a DSA key.
.. class:: ExtendedKeyUsageOID
.. versionadded:: 1.0
.. attribute:: SERVER_AUTH
Corresponds to the dotted string ``"1.3.6.1.5.5.7.3.1"``. This is used
to denote that a certificate may be used for TLS web server
authentication.
.. attribute:: CLIENT_AUTH
Corresponds to the dotted string ``"1.3.6.1.5.5.7.3.2"``. This is used
to denote that a certificate may be used for TLS web client
authentication.
.. attribute:: CODE_SIGNING
Corresponds to the dotted string ``"1.3.6.1.5.5.7.3.3"``. This is used
to denote that a certificate may be used for code signing.
.. attribute:: EMAIL_PROTECTION
Corresponds to the dotted string ``"1.3.6.1.5.5.7.3.4"``. This is used
to denote that a certificate may be used for email protection.
.. attribute:: TIME_STAMPING
Corresponds to the dotted string ``"1.3.6.1.5.5.7.3.8"``. This is used
to denote that a certificate may be used for time stamping.
.. attribute:: OCSP_SIGNING
Corresponds to the dotted string ``"1.3.6.1.5.5.7.3.9"``. This is used
to denote that a certificate may be used for signing OCSP responses.
.. attribute:: ANY_EXTENDED_KEY_USAGE
.. versionadded:: 2.0
Corresponds to the dotted string ``"2.5.29.37.0"``. This is used to
denote that a certificate may be used for _any_ purposes.
.. class:: AuthorityInformationAccessOID
.. versionadded:: 1.0
.. attribute:: OCSP
Corresponds to the dotted string ``"1.3.6.1.5.5.7.48.1"``. Used as the
identifier for OCSP data in
:class:`~cryptography.x509.AccessDescription` objects.
.. attribute:: CA_ISSUERS
Corresponds to the dotted string ``"1.3.6.1.5.5.7.48.2"``. Used as the
identifier for CA issuer data in
:class:`~cryptography.x509.AccessDescription` objects.
.. class:: CertificatePoliciesOID
.. versionadded:: 1.0
.. attribute:: CPS_QUALIFIER
Corresponds to the dotted string ``"1.3.6.1.5.5.7.2.1"``.
.. attribute:: CPS_USER_NOTICE
Corresponds to the dotted string ``"1.3.6.1.5.5.7.2.2"``.
.. attribute:: ANY_POLICY
Corresponds to the dotted string ``"2.5.29.32.0"``.
.. class:: ExtensionOID
.. versionadded:: 1.0
.. attribute:: BASIC_CONSTRAINTS
Corresponds to the dotted string ``"2.5.29.19"``. The identifier for the
:class:`~cryptography.x509.BasicConstraints` extension type.
.. attribute:: KEY_USAGE
Corresponds to the dotted string ``"2.5.29.15"``. The identifier for the
:class:`~cryptography.x509.KeyUsage` extension type.
.. attribute:: SUBJECT_ALTERNATIVE_NAME
Corresponds to the dotted string ``"2.5.29.17"``. The identifier for the
:class:`~cryptography.x509.SubjectAlternativeName` extension type.
.. attribute:: ISSUER_ALTERNATIVE_NAME
Corresponds to the dotted string ``"2.5.29.18"``. The identifier for the
:class:`~cryptography.x509.IssuerAlternativeName` extension type.
.. attribute:: SUBJECT_KEY_IDENTIFIER
Corresponds to the dotted string ``"2.5.29.14"``. The identifier for the
:class:`~cryptography.x509.SubjectKeyIdentifier` extension type.
.. attribute:: NAME_CONSTRAINTS
Corresponds to the dotted string ``"2.5.29.30"``. The identifier for the
:class:`~cryptography.x509.NameConstraints` extension type.
.. attribute:: CRL_DISTRIBUTION_POINTS
Corresponds to the dotted string ``"2.5.29.31"``. The identifier for the
:class:`~cryptography.x509.CRLDistributionPoints` extension type.
.. attribute:: CERTIFICATE_POLICIES
Corresponds to the dotted string ``"2.5.29.32"``. The identifier for the
:class:`~cryptography.x509.CertificatePolicies` extension type.
.. attribute:: AUTHORITY_KEY_IDENTIFIER
Corresponds to the dotted string ``"2.5.29.35"``. The identifier for the
:class:`~cryptography.x509.AuthorityKeyIdentifier` extension type.
.. attribute:: EXTENDED_KEY_USAGE
Corresponds to the dotted string ``"2.5.29.37"``. The identifier for the
:class:`~cryptography.x509.ExtendedKeyUsage` extension type.
.. attribute:: AUTHORITY_INFORMATION_ACCESS
Corresponds to the dotted string ``"1.3.6.1.5.5.7.1.1"``. The identifier
for the :class:`~cryptography.x509.AuthorityInformationAccess` extension
type.
.. attribute:: INHIBIT_ANY_POLICY
Corresponds to the dotted string ``"2.5.29.54"``. The identifier
for the :class:`~cryptography.x509.InhibitAnyPolicy` extension type.
.. attribute:: OCSP_NO_CHECK
Corresponds to the dotted string ``"1.3.6.1.5.5.7.48.1.5"``. The
identifier for the :class:`~cryptography.x509.OCSPNoCheck` extension
type.
.. attribute:: TLS_FEATURE
Corresponds to the dotted string ``"1.3.6.1.5.5.7.1.24"``. The
identifier for the :class:`~cryptography.x509.TLSFeature` extension
type.
.. attribute:: CRL_NUMBER
Corresponds to the dotted string ``"2.5.29.20"``. The identifier for
the ``CRLNumber`` extension type. This extension only has meaning
for certificate revocation lists.
.. attribute:: DELTA_CRL_INDICATOR
.. versionadded:: 2.1
Corresponds to the dotted string ``"2.5.29.27"``. The identifier for
the ``DeltaCRLIndicator`` extension type. This extension only has
meaning for certificate revocation lists.
.. attribute:: PRECERT_SIGNED_CERTIFICATE_TIMESTAMPS
.. versionadded:: 1.9
Corresponds to the dotted string ``"1.3.6.1.4.1.11129.2.4.2"``.
.. attribute:: POLICY_CONSTRAINTS
Corresponds to the dotted string ``"2.5.29.36"``. The identifier for the
:class:`~cryptography.x509.PolicyConstraints` extension type.
.. attribute:: FRESHEST_CRL
Corresponds to the dotted string ``"2.5.29.46"``. The identifier for the
:class:`~cryptography.x509.FreshestCRL` extension type.
.. class:: CRLEntryExtensionOID
.. versionadded:: 1.2
.. attribute:: CERTIFICATE_ISSUER
Corresponds to the dotted string ``"2.5.29.29"``.
.. attribute:: CRL_REASON
Corresponds to the dotted string ``"2.5.29.21"``.
.. attribute:: INVALIDITY_DATE
Corresponds to the dotted string ``"2.5.29.24"``.
Helper Functions
~~~~~~~~~~~~~~~~
.. currentmodule:: cryptography.x509
.. function:: random_serial_number()
.. versionadded:: 1.6
Generates a random serial number suitable for use when constructing
certificates.
Exceptions
~~~~~~~~~~
.. currentmodule:: cryptography.x509
.. class:: InvalidVersion
This is raised when an X.509 certificate has an invalid version number.
.. attribute:: parsed_version
:type: int
Returns the raw version that was parsed from the certificate.
.. class:: DuplicateExtension
This is raised when more than one X.509 extension of the same type is
found within a certificate.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns the OID.
.. class:: ExtensionNotFound
This is raised when calling :meth:`Extensions.get_extension_for_oid` with
an extension OID that is not present in the certificate.
.. attribute:: oid
:type: :class:`ObjectIdentifier`
Returns the OID.
.. class:: UnsupportedGeneralNameType
This is raised when a certificate contains an unsupported general name
type in an extension.
.. attribute:: type
:type: int
The integer value of the unsupported type. The complete list of
types can be found in `RFC 5280 section 4.2.1.6`_.
.. _`RFC 5280 section 4.2.1.1`: https://tools.ietf.org/html/rfc5280#section-4.2.1.1
.. _`RFC 5280 section 4.2.1.6`: https://tools.ietf.org/html/rfc5280#section-4.2.1.6
.. _`CABForum Guidelines`: https://cabforum.org/baseline-requirements-documents/