X.509 ===== .. currentmodule:: cryptography.x509 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`. .. testsetup:: 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() .. 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 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 .. 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"``) X.509 Extensions ~~~~~~~~~~~~~~~~ .. class:: Extension .. versionadded:: 0.9 .. attribute:: oid :type: :class:`ObjectIdentifier` The attribute OID. .. attribute:: critical :type: bool Determines whether a given extension is critical or not. .. attribute:: value Returns an instance of the extension type corresponding to the OID. .. 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 that number defines the maximum length. 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. 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. Extension OIDs ~~~~~~~~~~~~~~ .. data:: OID_BASIC_CONSTRAINTS Corresponds to the dotted string ``"2.5.29.19"``. The identifier for the :class:`BasicConstraints` 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. .. _`public key infrastructure`: https://en.wikipedia.org/wiki/Public_key_infrastructure .. _`TLS`: https://en.wikipedia.org/wiki/Transport_Layer_Security