X.509 ===== .. currentmodule:: cryptography.x509 .. testsetup:: 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() X.509 is an ITU-T standard for a `public key infrastructure`_. X.509v3 is defined in :rfc:`5280` (which obsoletes :rfc:`2459` and :rfc:`3280`). X.509 certificates are commonly used in protocols like `TLS`_. 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`. .. 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`. .. doctest:: >>> from cryptography import x509 >>> from cryptography.hazmat.backends import default_backend >>> cert = x509.load_pem_x509_certificate(pem_data, default_backend()) >>> cert.serial 2 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`. .. 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`. .. 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 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 :type: int The serial as a Python integer. .. doctest:: >>> cert.serial 2 .. method:: public_key() :type: :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey` or :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey` or :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey` The public key associated with the certificate. .. 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=)> .. method:: public_bytes(encoding) :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 .. 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. .. 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. .. attribute:: issuer :type: :class:`Name` The :class:`Name` of the issuer. .. attribute:: next_update :type: :class:`datetime.datetime` A naïve datetime representing when the next update to this CRL is expected. .. attribute:: last_update :type: :class:`datetime.datetime` A naïve datetime representing when the this CRL was last updated. .. attribute:: revoked_certificates :type: list of :class:`RevokedCertificate` The revoked certificates listed in this CRL. .. attribute:: extensions :type: :class:`Extensions` The extensions encoded in the CRL. X.509 CSR (Certificate Signing Request) Object ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. class:: CertificateSigningRequest .. versionadded:: 0.9 .. method:: public_key() :type: :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey` or :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey` or :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey` The public key associated with the request. .. 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 .. method:: public_bytes(encoding) :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. 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. .. attribute:: revocation_date :type: :class:`datetime.datetime` A naïve datetime representing the date this certificates was revoked. .. attribute:: extensions :type: :class:`Extensions` The extensions encoded in the revoked certificate. .. 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(x509.OID_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 .. versionadded:: 0.9 This corresponds to an email address. For example, ``user@example.com``. .. attribute:: value :type: :term:`text` .. class:: DNSName .. versionadded:: 0.9 This corresponds to a domain name. For example, ``cryptography.io``. .. attribute:: value :type: :term:`text` .. class:: DirectoryName .. versionadded:: 0.9 This corresponds to a directory name. .. attribute:: value :type: :class:`Name` .. class:: UniformResourceIdentifier .. 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 .. 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 .. versionadded:: 0.9 This corresponds to a registered ID. .. attribute:: value :type: :class:`ObjectIdentifier` 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:: >>> cert.extensions.get_extension_for_oid(x509.OID_BASIC_CONSTRAINTS) , critical=True, value=)> .. class:: Extension .. versionadded:: 0.9 .. attribute:: oid :type: :class:`ObjectIdentifier` The :ref:`extension OID `. .. 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:: KeyUsage .. 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. It corresponds to :data:`OID_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 .. 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. It corresponds to :data:`OID_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 .. 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 :ref:`extended key usage OIDs `. .. 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. .. class:: AuthorityKeyIdentifier .. 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:: 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. .. class:: SubjectKeyIdentifier .. versionadded:: 0.9 The subject key identifier extension provides a means of identifying certificates that contain a particular public key. .. attribute:: digest :type: bytes The binary value of the identifier. .. class:: SubjectAlternativeName .. 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. .. 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. .. 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(x509.OID_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:: AuthorityInformationAccess .. 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:`AccessDescription` instances. .. class:: AccessDescription .. versionadded:: 0.9 .. attribute:: access_method :type: :class:`ObjectIdentifier` The access method defines what the ``access_location`` means. It must be either :data:`OID_OCSP` or :data:`OID_CA_ISSUERS`. If it is :data:`OID_OCSP` the access location will be where to obtain OCSP information for the certificate. If it is :data:`OID_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 .. 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. .. class:: DistributionPoint .. 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:: CertificatePolicies .. versionadded:: 0.9 The certificate policies extension is an iterable, containing one or more :class:`PolicyInformation` instances. Certificate Policies Classes ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These classes may be present within a :class:`CertificatePolicies` instance. .. class:: PolicyInformation .. 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 .. 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 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. Object Identifiers ~~~~~~~~~~~~~~~~~~ X.509 elements are frequently identified by :class:`ObjectIdentifier` instances. The following common OIDs are available as constants. Name OIDs ~~~~~~~~~ .. data:: OID_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 SubjectAlternativeName extension. This OID is typically seen in X.509 names. .. data:: OID_COUNTRY_NAME Corresponds to the dotted string ``"2.5.4.6"``. This OID is typically seen in X.509 names. .. data:: OID_LOCALITY_NAME Corresponds to the dotted string ``"2.5.4.7"``. This OID is typically seen in X.509 names. .. data:: OID_STATE_OR_PROVINCE_NAME Corresponds to the dotted string ``"2.5.4.8"``. This OID is typically seen in X.509 names. .. data:: OID_ORGANIZATION_NAME Corresponds to the dotted string ``"2.5.4.10"``. This OID is typically seen in X.509 names. .. data:: OID_ORGANIZATIONAL_UNIT_NAME Corresponds to the dotted string ``"2.5.4.11"``. This OID is typically seen in X.509 names. .. data:: OID_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:`Certificate.serial`). This OID is typically seen in X.509 names. .. data:: OID_SURNAME Corresponds to the dotted string ``"2.5.4.4"``. This OID is typically seen in X.509 names. .. data:: OID_GIVEN_NAME Corresponds to the dotted string ``"2.5.4.42"``. This OID is typically seen in X.509 names. .. data:: OID_TITLE Corresponds to the dotted string ``"2.5.4.12"``. This OID is typically seen in X.509 names. .. data:: OID_GENERATION_QUALIFIER Corresponds to the dotted string ``"2.5.4.44"``. This OID is typically seen in X.509 names. .. data:: OID_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`. This OID is typically seen in X.509 names. .. data:: OID_PSEUDONYM Corresponds to the dotted string ``"2.5.4.65"``. This OID is typically seen in X.509 names. .. data:: OID_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`. This OID is typically seen in X.509 names. .. data:: OID_EMAIL_ADDRESS Corresponds to the dotted string ``"1.2.840.113549.1.9.1"``. This OID is typically seen in X.509 names. Signature Algorithm OIDs ~~~~~~~~~~~~~~~~~~~~~~~~ .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_DSA_WITH_SHA1 Corresponds to the dotted string ``"1.2.840.10040.4.3"``. This is a SHA1 digest signed by a DSA key. .. data:: OID_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. .. data:: OID_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. .. _eku_oids: Extended Key Usage OIDs ~~~~~~~~~~~~~~~~~~~~~~~ .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. .. data:: OID_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. Authority Information Access OIDs ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. data:: OID_OCSP Corresponds to the dotted string ``"1.3.6.1.5.5.7.48.1"``. Used as the identifier for OCSP data in :class:`AccessDescription` objects. .. data:: OID_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:`AccessDescription` objects. Policy Qualifier OIDs ~~~~~~~~~~~~~~~~~~~~~ .. data:: OID_CPS_QUALIFIER Corresponds to the dotted string ``"1.3.6.1.5.5.7.2.1"``. .. data:: OID_CPS_USER_NOTICE Corresponds to the dotted string ``"1.3.6.1.5.5.7.2.2"``. .. _extension_oids: Extension OIDs ~~~~~~~~~~~~~~ .. data:: OID_BASIC_CONSTRAINTS Corresponds to the dotted string ``"2.5.29.19"``. The identifier for the :class:`BasicConstraints` extension type. .. data:: OID_KEY_USAGE Corresponds to the dotted string ``"2.5.29.15"``. The identifier for the :class:`KeyUsage` extension type. .. data:: OID_SUBJECT_ALTERNATIVE_NAME Corresponds to the dotted string ``"2.5.29.17"``. The identifier for the :class:`SubjectAlternativeName` extension type. .. data:: OID_SUBJECT_KEY_IDENTIFIER Corresponds to the dotted string ``"2.5.29.14"``. The identifier for the :class:`SubjectKeyIdentifier` extension type. .. data:: OID_CRL_DISTRIBUTION_POINTS Corresponds to the dotted string ``"2.5.29.31"``. The identifier for the :class:`CRLDistributionPoints` extension type. .. data:: OID_CERTIFICATE_POLICIES Corresponds to the dotted string ``"2.5.29.32"``. The identifier for the :class:`CertificatePolicies` extension type. .. data:: OID_AUTHORITY_KEY_IDENTIFIER Corresponds to the dotted string ``"2.5.29.35"``. The identifier for the :class:`AuthorityKeyIdentifier` extension type. .. data:: OID_EXTENDED_KEY_USAGE Corresponds to the dotted string ``"2.5.29.37"``. The identifier for the :class:`ExtendedKeyUsage` extension type. .. data:: OID_AUTHORITY_INFORMATION_ACCESS Corresponds to the dotted string ``"1.3.6.1.5.5.7.1.1"``. The identifier for the :class:`AuthorityInformationAccess` extension type. .. data:: OID_OCSP_NO_CHECK Corresponds to the dotted string ``"1.3.6.1.5.5.7.48.1.5"``. The identifier for the :class:`OCSPNoCheck` extension type. Exceptions ~~~~~~~~~~ .. 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. .. 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`_. .. _`public key infrastructure`: https://en.wikipedia.org/wiki/Public_key_infrastructure .. _`TLS`: https://en.wikipedia.org/wiki/Transport_Layer_Security .. _`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