X.509 Reference =============== .. currentmodule:: cryptography.x509 .. testsetup:: pem_crl_data = b""" -----BEGIN X509 CRL----- MIIBtDCBnQIBAjANBgkqhkiG9w0BAQsFADAnMQswCQYDVQQGEwJVUzEYMBYGA1UE AwwPY3J5cHRvZ3JhcGh5LmlvGA8yMDE1MDEwMTAwMDAwMFoYDzIwMTYwMTAxMDAw MDAwWjA+MDwCAQAYDzIwMTUwMTAxMDAwMDAwWjAmMBgGA1UdGAQRGA8yMDE1MDEw MTAwMDAwMFowCgYDVR0VBAMKAQEwDQYJKoZIhvcNAQELBQADggEBABRA4ww50Lz5 zk1j2+aluC4HPHqb7o06h4pTDcCGeXUKXIGeP5ntGGmIoxa26sNoLeOr8+5b43Gf yWraHertllOwaOpNFEe+YZFaE9femtoDbf+GLMvRx/0wDfd3KxPoXnXKMXb2d1w4 RCLgmkYx6JyvS+5ciuLQVIKC+l7jwIUeZFLJMUJ8msM4pFYoGameeZmtjMbd/TNg cVBfmZxNMHuLladJxvSo2esARo0TYPhYsgrREKoHwhpzSxdynjn4bOVkILfguwsN qtEEMZFEv5Kb0GqRp2+Iagv2S6dg9JGvxVdsoGjaB6EbYSZ3Psx4aODasIn11uwo X4B9vUQNXqc= -----END X509 CRL----- """.strip() pem_req_data = b""" -----BEGIN CERTIFICATE REQUEST----- MIIC0zCCAbsCAQAwWTELMAkGA1UEBhMCVVMxETAPBgNVBAgMCElsbGlub2lzMRAw DgYDVQQHDAdDaGljYWdvMREwDwYDVQQKDAhyNTA5IExMQzESMBAGA1UEAwwJaGVs bG8uY29tMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqhZx+Mo9VRd9 vsnWWa6NBCws21rZ0+1B/JGgB4hDsZS7iDE4Bj5z4idheFRtl8bBbdjPknq7BfoF 8v15Zq/Zv7i2xMSDL+LUrTBZezRd4bRTGqCm6YJ5EYkhqdcqeZleHCFImguHoq1J Fh0+kObQrTHXw3ZP57a3o1IvyIUA3nNoCBL0QQhwBXaDXOojMKNR+bqB5ve8GS1y Elr0AM/+cJsfaIahNQUgFKx3Eu3GeEOMKYOAG1lycgdQdmTUybLrT3U7vkClTseM xHg1r5En7ALjONIhqRuq3rddYahrP8HXozb3zUy3cJ7P6IeaosuvNzvMXOX9P6HD Ha9urDAJ1wIDAQABoDUwMwYJKoZIhvcNAQkOMSYwJDAiBgNVHREEGzAZggl3b3Js ZC5jb22CDHdoYXRldmVyLmNvbTANBgkqhkiG9w0BAQUFAAOCAQEAS4Ro6h+z52SK YSLCYARpnEu/rmh4jdqndt8naqcNb6uLx9mlKZ2W9on9XDjnSdQD9q+ZP5aZfESw R0+rJhW9ZrNa/g1pt6M24ihclHYDAxYMWxT1z/TXXGM3TmZZ6gfYlNE1kkBuODHa UYsR/1Ht1E1EsmmUimt2n+zQR2K8T9Coa+boaUW/GsTEuz1aaJAkj5ZvTDiIhRG4 AOCqFZOLAQmCCNgJnnspD9hDz/Ons085LF5wnYjN4/Nsk5tS6AGs3xjZ3jPoOGGn 82WQ9m4dBGoVDZXsobVTaN592JEYwN5iu72zRn7Einb4V4H5y3yD2dD4yWPlt4pk 5wFkeYsZEA== -----END CERTIFICATE REQUEST----- """.strip() pem_data = b""" -----BEGIN CERTIFICATE----- MIIDfDCCAmSgAwIBAgIBAjANBgkqhkiG9w0BAQsFADBFMQswCQYDVQQGEwJVUzEf MB0GA1UEChMWVGVzdCBDZXJ0aWZpY2F0ZXMgMjAxMTEVMBMGA1UEAxMMVHJ1c3Qg QW5jaG9yMB4XDTEwMDEwMTA4MzAwMFoXDTMwMTIzMTA4MzAwMFowQDELMAkGA1UE BhMCVVMxHzAdBgNVBAoTFlRlc3QgQ2VydGlmaWNhdGVzIDIwMTExEDAOBgNVBAMT B0dvb2QgQ0EwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCQWJpHYo37 Xfb7oJSPe+WvfTlzIG21WQ7MyMbGtK/m8mejCzR6c+f/pJhEH/OcDSMsXq8h5kXa BGqWK+vSwD/Pzp5OYGptXmGPcthDtAwlrafkGOS4GqIJ8+k9XGKs+vQUXJKsOk47 RuzD6PZupq4s16xaLVqYbUC26UcY08GpnoLNHJZS/EmXw1ZZ3d4YZjNlpIpWFNHn UGmdiGKXUPX/9H0fVjIAaQwjnGAbpgyCumWgzIwPpX+ElFOUr3z7BoVnFKhIXze+ VmQGSWxZxvWDUN90Ul0tLEpLgk3OVxUB4VUGuf15OJOpgo1xibINPmWt14Vda2N9 yrNKloJGZNqLAgMBAAGjfDB6MB8GA1UdIwQYMBaAFOR9X9FclYYILAWuvnW2ZafZ XahmMB0GA1UdDgQWBBRYAYQkG7wrUpRKPaUQchRR9a86yTAOBgNVHQ8BAf8EBAMC AQYwFwYDVR0gBBAwDjAMBgpghkgBZQMCATABMA8GA1UdEwEB/wQFMAMBAf8wDQYJ KoZIhvcNAQELBQADggEBADWHlxbmdTXNwBL/llwhQqwnazK7CC2WsXBBqgNPWj7m tvQ+aLG8/50Qc2Sun7o2VnwF9D18UUe8Gj3uPUYH+oSI1vDdyKcjmMbKRU4rk0eo 3UHNDXwqIVc9CQS9smyV+x1HCwL4TTrq+LXLKx/qVij0Yqk+UJfAtrg2jnYKXsCu FMBQQnWCGrwa1g1TphRp/RmYHnMynYFmZrXtzFz+U9XEA7C+gPq4kqDI/iVfIT1s 6lBtdB50lrDVwl2oYfAvW/6sC2se2QleZidUmrziVNP4oEeXINokU6T6p//HM1FG QYw2jOvpKcKtWCSAnegEbgsGYzATKjmPJPJ0npHFqzM= -----END CERTIFICATE----- """.strip() cryptography_cert_pem = b""" -----BEGIN CERTIFICATE----- MIIFvTCCBKWgAwIBAgICPyAwDQYJKoZIhvcNAQELBQAwRzELMAkGA1UEBhMCVVMx FjAUBgNVBAoTDUdlb1RydXN0IEluYy4xIDAeBgNVBAMTF1JhcGlkU1NMIFNIQTI1 NiBDQSAtIEczMB4XDTE0MTAxNTEyMDkzMloXDTE4MTExNjAxMTUwM1owgZcxEzAR BgNVBAsTCkdUNDg3NDI5NjUxMTAvBgNVBAsTKFNlZSB3d3cucmFwaWRzc2wuY29t L3Jlc291cmNlcy9jcHMgKGMpMTQxLzAtBgNVBAsTJkRvbWFpbiBDb250cm9sIFZh bGlkYXRlZCAtIFJhcGlkU1NMKFIpMRwwGgYDVQQDExN3d3cuY3J5cHRvZ3JhcGh5 LmlvMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAom/FebKJIot7Sp3s itG1sicpe3thCssjI+g1JDAS7I3GLVNmbms1DOdIIqwf01gZkzzXBN2+9sOnyRaR PPfCe1jTr3dk2y6rPE559vPa1nZQkhlzlhMhlPyjaT+S7g4Tio4qV2sCBZU01DZJ CaksfohN+5BNVWoJzTbOcrHOEJ+M8B484KlBCiSxqf9cyNQKru4W3bHaCVNVJ8eu 6i6KyhzLa0L7yK3LXwwXVs583C0/vwFhccGWsFODqD/9xHUzsBIshE8HKjdjDi7Y 3BFQzVUQFjBB50NSZfAA/jcdt1blxJouc7z9T8Oklh+V5DDBowgAsrT4b6Z2Fq6/ r7D1GqivLK/ypUQmxq2WXWAUBb/Q6xHgxASxI4Br+CByIUQJsm8L2jzc7k+mF4hW ltAIUkbo8fGiVnat0505YJgxWEDKOLc4Gda6d/7GVd5AvKrz242bUqeaWo6e4MTx diku2Ma3rhdcr044Qvfh9hGyjqNjvhWY/I+VRWgihU7JrYvgwFdJqsQ5eiKT4OHi gsejvWwkZzDtiQ+aQTrzM1FsY2swJBJsLSX4ofohlVRlIJCn/ME+XErj553431Lu YQ5SzMd3nXzN78Vj6qzTfMUUY72UoT1/AcFiUMobgIqrrmwuNxfrkbVE2b6Bga74 FsJX63prvrJ41kuHK/16RQBM7fcCAwEAAaOCAWAwggFcMB8GA1UdIwQYMBaAFMOc 8/zTRgg0u85Gf6B8W/PiCMtZMFcGCCsGAQUFBwEBBEswSTAfBggrBgEFBQcwAYYT aHR0cDovL2d2LnN5bWNkLmNvbTAmBggrBgEFBQcwAoYaaHR0cDovL2d2LnN5bWNi LmNvbS9ndi5jcnQwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGAQUFBwMB BggrBgEFBQcDAjAvBgNVHREEKDAmghN3d3cuY3J5cHRvZ3JhcGh5Lmlvgg9jcnlw dG9ncmFwaHkuaW8wKwYDVR0fBCQwIjAgoB6gHIYaaHR0cDovL2d2LnN5bWNiLmNv bS9ndi5jcmwwDAYDVR0TAQH/BAIwADBFBgNVHSAEPjA8MDoGCmCGSAGG+EUBBzYw LDAqBggrBgEFBQcCARYeaHR0cHM6Ly93d3cucmFwaWRzc2wuY29tL2xlZ2FsMA0G CSqGSIb3DQEBCwUAA4IBAQAzIYO2jx7h17FBT74tJ2zbV9OKqGb7QF8y3wUtP4xc dH80vprI/Cfji8s86kr77aAvAqjDjaVjHn7UzebhSUivvRPmfzRgyWBacomnXTSt Xlt2dp2nDQuwGyK2vB7dMfKnQAkxwq1sYUXznB8i0IhhCAoXp01QGPKq51YoIlnF 7DRMk6iEaL1SJbkIrLsCQyZFDf0xtfW9DqXugMMLoxeCsBhZJQzNyS2ryirrv9LH aK3+6IZjrcyy9bkpz/gzJucyhU+75c4My/mnRCrtItRbCQuiI5pd5poDowm+HH9i GVI9+0lAFwxOUnOnwsoI40iOoxjLMGB+CgFLKCGUcWxP -----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 `. .. doctest:: >>> cert.version .. 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()) '\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:: 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.UnsupportedExtension: If the certificate contains an extension that is not supported. :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) , critical=False, value=)> , critical=False, value=)> , critical=True, value=)> , critical=False, value=, policy_qualifiers=None)>])>)> , critical=True, value=)> .. 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) >>> 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()) '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' .. 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:: issuer :type: :class:`Name` The :class:`Name` of the issuer. .. doctest:: >>> crl.issuer , value=u'US')>, , value=u'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. 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 >>> import uuid >>> 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(int(uuid.uuid4())) >>> builder = builder.public_key(public_key) >>> 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. The only requirement is that this number uniquely identify the certificate given the issuer. :param serial_number: Integer number that will be used by the CA to identify this certificate (most notably during certificate revocation checking). Users are encouraged to use a method of generating 20 bytes of entropy, e.g., UUID4. For more information on secure random number generation, see :doc:`/random-numbers`. .. 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:: 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.UnsupportedExtension: If the certificate signing request contains an extension that is not supported. :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) , critical=False, value=)> , critical=False, value=)> 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 `. :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``). .. doctest:: >>> len(cert.subject) 3 >>> for attribute in cert.subject: ... print(attribute) , value=u'US')> , value=u'Test Certificates 2011')> , value=u'Good CA')> .. 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) [, value=u'Good CA')>] .. 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 NameAttribute instances. .. attribute:: oid :type: :class:`ObjectIdentifier` The attribute OID. .. attribute:: value :type: :term:`text` The value of the attribute. .. 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 This corresponds to an email address. For example, ``user@example.com``. .. attribute:: value :type: :term:`text` .. class:: DNSName(value) .. versionadded:: 0.9 This corresponds to a domain name. For example, ``cryptography.io``. .. 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 This corresponds to a uniform resource identifier. For example, ``https://cryptography.io``. The URI is parsed and IDNA decoded (see :rfc:`5895`). .. note:: URIs that do not contain ``://`` in them will not be decoded. .. 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) , critical=True, value=)> .. 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) , critical=True, value=)> .. 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:: 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: :class:`Name` 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()) .. 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) .. 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()) .. class:: SubjectAlternativeName(general_names) .. versionadded:: 0.9 Subject alternative name is an X.509 extension that provides a list of :ref:`general name ` 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` provider. This is one of the :ref:`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) [u'www.cryptography.io', u'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 ` 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` provider. This is one of the :ref:`general name classes `. :returns: A list of values extracted from the matched general names. .. 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:: 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:`Name` 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. .. 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 **non-critical** extensions that ``cryptography`` does not know how to parse. Extensions marked critical will raise :class:`~cryptography.x509.UnsupportedExtension`. .. 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 `. :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: A value from the :class:`~cryptography.x509.oid.CRLEntryExtensionOID` enum. .. 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:: 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:: 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:: 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"``. .. 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:: 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. .. 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:: 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:: POLICY_CONSTRAINTS Corresponds to the dotted string ``"2.5.29.36"``. The identifier for the :class:`~cryptography.x509.PolicyConstraints` 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"``. 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:: UnsupportedExtension This is raised when a certificate contains an unsupported extension type that is marked ``critical``. .. 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