Source code for cryptography.x509.base

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

from __future__ import absolute_import, division, print_function

import abc
import datetime
import os
from enum import Enum

import six

from cryptography import utils
from cryptography.hazmat.primitives.asymmetric import (
    dsa, ec, ed25519, ed448, rsa
)
from cryptography.x509.extensions import Extension, ExtensionType
from cryptography.x509.name import Name


_EARLIEST_UTC_TIME = datetime.datetime(1950, 1, 1)


[docs]class AttributeNotFound(Exception): def __init__(self, msg, oid): super(AttributeNotFound, self).__init__(msg) self.oid = oid
def _reject_duplicate_extension(extension, extensions): # This is quadratic in the number of extensions for e in extensions: if e.oid == extension.oid: raise ValueError('This extension has already been set.') def _convert_to_naive_utc_time(time): """Normalizes a datetime to a naive datetime in UTC. time -- datetime to normalize. Assumed to be in UTC if not timezone aware. """ if time.tzinfo is not None: offset = time.utcoffset() offset = offset if offset else datetime.timedelta() return time.replace(tzinfo=None) - offset else: return time
[docs]class Version(Enum): v1 = 0 v3 = 2
[docs]def load_pem_x509_certificate(data, backend): return backend.load_pem_x509_certificate(data)
[docs]def load_der_x509_certificate(data, backend): return backend.load_der_x509_certificate(data)
[docs]def load_pem_x509_csr(data, backend): return backend.load_pem_x509_csr(data)
[docs]def load_der_x509_csr(data, backend): return backend.load_der_x509_csr(data)
[docs]def load_pem_x509_crl(data, backend): return backend.load_pem_x509_crl(data)
[docs]def load_der_x509_crl(data, backend): return backend.load_der_x509_crl(data)
[docs]class InvalidVersion(Exception): def __init__(self, msg, parsed_version): super(InvalidVersion, self).__init__(msg) self.parsed_version = parsed_version
[docs]@six.add_metaclass(abc.ABCMeta) class Certificate(object):
[docs] @abc.abstractmethod def fingerprint(self, algorithm): """ Returns bytes using digest passed. """
@abc.abstractproperty def serial_number(self): """ Returns certificate serial number """ @abc.abstractproperty def version(self): """ Returns the certificate version """
[docs] @abc.abstractmethod def public_key(self): """ Returns the public key """
@abc.abstractproperty def not_valid_before(self): """ Not before time (represented as UTC datetime) """ @abc.abstractproperty def not_valid_after(self): """ Not after time (represented as UTC datetime) """ @abc.abstractproperty def issuer(self): """ Returns the issuer name object. """ @abc.abstractproperty def subject(self): """ Returns the subject name object. """ @abc.abstractproperty def signature_hash_algorithm(self): """ Returns a HashAlgorithm corresponding to the type of the digest signed in the certificate. """ @abc.abstractproperty def signature_algorithm_oid(self): """ Returns the ObjectIdentifier of the signature algorithm. """ @abc.abstractproperty def extensions(self): """ Returns an Extensions object. """ @abc.abstractproperty def signature(self): """ Returns the signature bytes. """ @abc.abstractproperty def tbs_certificate_bytes(self): """ Returns the tbsCertificate payload bytes as defined in RFC 5280. """ @abc.abstractmethod def __eq__(self, other): """ Checks equality. """ @abc.abstractmethod def __ne__(self, other): """ Checks not equal. """ @abc.abstractmethod def __hash__(self): """ Computes a hash. """
[docs] @abc.abstractmethod def public_bytes(self, encoding): """ Serializes the certificate to PEM or DER format. """
[docs]@six.add_metaclass(abc.ABCMeta) class CertificateRevocationList(object):
[docs] @abc.abstractmethod def public_bytes(self, encoding): """ Serializes the CRL to PEM or DER format. """
[docs] @abc.abstractmethod def fingerprint(self, algorithm): """ Returns bytes using digest passed. """
[docs] @abc.abstractmethod def get_revoked_certificate_by_serial_number(self, serial_number): """ Returns an instance of RevokedCertificate or None if the serial_number is not in the CRL. """
@abc.abstractproperty def signature_hash_algorithm(self): """ Returns a HashAlgorithm corresponding to the type of the digest signed in the certificate. """ @abc.abstractproperty def signature_algorithm_oid(self): """ Returns the ObjectIdentifier of the signature algorithm. """ @abc.abstractproperty def issuer(self): """ Returns the X509Name with the issuer of this CRL. """ @abc.abstractproperty def next_update(self): """ Returns the date of next update for this CRL. """ @abc.abstractproperty def last_update(self): """ Returns the date of last update for this CRL. """ @abc.abstractproperty def extensions(self): """ Returns an Extensions object containing a list of CRL extensions. """ @abc.abstractproperty def signature(self): """ Returns the signature bytes. """ @abc.abstractproperty def tbs_certlist_bytes(self): """ Returns the tbsCertList payload bytes as defined in RFC 5280. """ @abc.abstractmethod def __eq__(self, other): """ Checks equality. """ @abc.abstractmethod def __ne__(self, other): """ Checks not equal. """ @abc.abstractmethod def __len__(self): """ Number of revoked certificates in the CRL. """ @abc.abstractmethod def __getitem__(self, idx): """ Returns a revoked certificate (or slice of revoked certificates). """ @abc.abstractmethod def __iter__(self): """ Iterator over the revoked certificates """
[docs] @abc.abstractmethod def is_signature_valid(self, public_key): """ Verifies signature of revocation list against given public key. """
[docs]@six.add_metaclass(abc.ABCMeta) class CertificateSigningRequest(object): @abc.abstractmethod def __eq__(self, other): """ Checks equality. """ @abc.abstractmethod def __ne__(self, other): """ Checks not equal. """ @abc.abstractmethod def __hash__(self): """ Computes a hash. """
[docs] @abc.abstractmethod def public_key(self): """ Returns the public key """
@abc.abstractproperty def subject(self): """ Returns the subject name object. """ @abc.abstractproperty def signature_hash_algorithm(self): """ Returns a HashAlgorithm corresponding to the type of the digest signed in the certificate. """ @abc.abstractproperty def signature_algorithm_oid(self): """ Returns the ObjectIdentifier of the signature algorithm. """ @abc.abstractproperty def extensions(self): """ Returns the extensions in the signing request. """
[docs] @abc.abstractmethod def public_bytes(self, encoding): """ Encodes the request to PEM or DER format. """
@abc.abstractproperty def signature(self): """ Returns the signature bytes. """ @abc.abstractproperty def tbs_certrequest_bytes(self): """ Returns the PKCS#10 CertificationRequestInfo bytes as defined in RFC 2986. """ @abc.abstractproperty def is_signature_valid(self): """ Verifies signature of signing request. """ @abc.abstractproperty def get_attribute_for_oid(self): """ Get the attribute value for a given OID. """
[docs]@six.add_metaclass(abc.ABCMeta) class RevokedCertificate(object): @abc.abstractproperty def serial_number(self): """ Returns the serial number of the revoked certificate. """ @abc.abstractproperty def revocation_date(self): """ Returns the date of when this certificate was revoked. """ @abc.abstractproperty def extensions(self): """ Returns an Extensions object containing a list of Revoked extensions. """
[docs]class CertificateSigningRequestBuilder(object): def __init__(self, subject_name=None, extensions=[]): """ Creates an empty X.509 certificate request (v1). """ self._subject_name = subject_name self._extensions = extensions
[docs] def subject_name(self, name): """ Sets the certificate requestor's distinguished name. """ if not isinstance(name, Name): raise TypeError('Expecting x509.Name object.') if self._subject_name is not None: raise ValueError('The subject name may only be set once.') return CertificateSigningRequestBuilder(name, self._extensions)
[docs] def add_extension(self, extension, critical): """ Adds an X.509 extension to the certificate request. """ if not isinstance(extension, ExtensionType): raise TypeError("extension must be an ExtensionType") extension = Extension(extension.oid, critical, extension) _reject_duplicate_extension(extension, self._extensions) return CertificateSigningRequestBuilder( self._subject_name, self._extensions + [extension] )
[docs] def sign(self, private_key, algorithm, backend): """ Signs the request using the requestor's private key. """ if self._subject_name is None: raise ValueError("A CertificateSigningRequest must have a subject") return backend.create_x509_csr(self, private_key, algorithm)
[docs]class CertificateBuilder(object): def __init__(self, issuer_name=None, subject_name=None, public_key=None, serial_number=None, not_valid_before=None, not_valid_after=None, extensions=[]): self._version = Version.v3 self._issuer_name = issuer_name self._subject_name = subject_name self._public_key = public_key self._serial_number = serial_number self._not_valid_before = not_valid_before self._not_valid_after = not_valid_after self._extensions = extensions
[docs] def issuer_name(self, name): """ Sets the CA's distinguished name. """ if not isinstance(name, Name): raise TypeError('Expecting x509.Name object.') if self._issuer_name is not None: raise ValueError('The issuer name may only be set once.') return CertificateBuilder( name, self._subject_name, self._public_key, self._serial_number, self._not_valid_before, self._not_valid_after, self._extensions )
[docs] def subject_name(self, name): """ Sets the requestor's distinguished name. """ if not isinstance(name, Name): raise TypeError('Expecting x509.Name object.') if self._subject_name is not None: raise ValueError('The subject name may only be set once.') return CertificateBuilder( self._issuer_name, name, self._public_key, self._serial_number, self._not_valid_before, self._not_valid_after, self._extensions )
[docs] def public_key(self, key): """ Sets the requestor's public key (as found in the signing request). """ if not isinstance(key, (dsa.DSAPublicKey, rsa.RSAPublicKey, ec.EllipticCurvePublicKey, ed25519.Ed25519PublicKey, ed448.Ed448PublicKey)): raise TypeError('Expecting one of DSAPublicKey, RSAPublicKey,' ' EllipticCurvePublicKey, Ed25519PublicKey or' ' Ed448PublicKey.') if self._public_key is not None: raise ValueError('The public key may only be set once.') return CertificateBuilder( self._issuer_name, self._subject_name, key, self._serial_number, self._not_valid_before, self._not_valid_after, self._extensions )
[docs] def serial_number(self, number): """ Sets the certificate serial number. """ if not isinstance(number, six.integer_types): raise TypeError('Serial number must be of integral type.') if self._serial_number is not None: raise ValueError('The serial number may only be set once.') if number <= 0: raise ValueError('The serial number should be positive.') # ASN.1 integers are always signed, so most significant bit must be # zero. if number.bit_length() >= 160: # As defined in RFC 5280 raise ValueError('The serial number should not be more than 159 ' 'bits.') return CertificateBuilder( self._issuer_name, self._subject_name, self._public_key, number, self._not_valid_before, self._not_valid_after, self._extensions )
[docs] def not_valid_before(self, time): """ Sets the certificate activation time. """ if not isinstance(time, datetime.datetime): raise TypeError('Expecting datetime object.') if self._not_valid_before is not None: raise ValueError('The not valid before may only be set once.') time = _convert_to_naive_utc_time(time) if time < _EARLIEST_UTC_TIME: raise ValueError('The not valid before date must be on or after' ' 1950 January 1).') if self._not_valid_after is not None and time > self._not_valid_after: raise ValueError( 'The not valid before date must be before the not valid after ' 'date.' ) return CertificateBuilder( self._issuer_name, self._subject_name, self._public_key, self._serial_number, time, self._not_valid_after, self._extensions )
[docs] def not_valid_after(self, time): """ Sets the certificate expiration time. """ if not isinstance(time, datetime.datetime): raise TypeError('Expecting datetime object.') if self._not_valid_after is not None: raise ValueError('The not valid after may only be set once.') time = _convert_to_naive_utc_time(time) if time < _EARLIEST_UTC_TIME: raise ValueError('The not valid after date must be on or after' ' 1950 January 1.') if (self._not_valid_before is not None and time < self._not_valid_before): raise ValueError( 'The not valid after date must be after the not valid before ' 'date.' ) return CertificateBuilder( self._issuer_name, self._subject_name, self._public_key, self._serial_number, self._not_valid_before, time, self._extensions )
[docs] def add_extension(self, extension, critical): """ Adds an X.509 extension to the certificate. """ if not isinstance(extension, ExtensionType): raise TypeError("extension must be an ExtensionType") extension = Extension(extension.oid, critical, extension) _reject_duplicate_extension(extension, self._extensions) return CertificateBuilder( self._issuer_name, self._subject_name, self._public_key, self._serial_number, self._not_valid_before, self._not_valid_after, self._extensions + [extension] )
[docs] def sign(self, private_key, algorithm, backend): """ Signs the certificate using the CA's private key. """ if self._subject_name is None: raise ValueError("A certificate must have a subject name") if self._issuer_name is None: raise ValueError("A certificate must have an issuer name") if self._serial_number is None: raise ValueError("A certificate must have a serial number") if self._not_valid_before is None: raise ValueError("A certificate must have a not valid before time") if self._not_valid_after is None: raise ValueError("A certificate must have a not valid after time") if self._public_key is None: raise ValueError("A certificate must have a public key") return backend.create_x509_certificate(self, private_key, algorithm)
[docs]class CertificateRevocationListBuilder(object): def __init__(self, issuer_name=None, last_update=None, next_update=None, extensions=[], revoked_certificates=[]): self._issuer_name = issuer_name self._last_update = last_update self._next_update = next_update self._extensions = extensions self._revoked_certificates = revoked_certificates
[docs] def issuer_name(self, issuer_name): if not isinstance(issuer_name, Name): raise TypeError('Expecting x509.Name object.') if self._issuer_name is not None: raise ValueError('The issuer name may only be set once.') return CertificateRevocationListBuilder( issuer_name, self._last_update, self._next_update, self._extensions, self._revoked_certificates )
[docs] def last_update(self, last_update): if not isinstance(last_update, datetime.datetime): raise TypeError('Expecting datetime object.') if self._last_update is not None: raise ValueError('Last update may only be set once.') last_update = _convert_to_naive_utc_time(last_update) if last_update < _EARLIEST_UTC_TIME: raise ValueError('The last update date must be on or after' ' 1950 January 1.') if self._next_update is not None and last_update > self._next_update: raise ValueError( 'The last update date must be before the next update date.' ) return CertificateRevocationListBuilder( self._issuer_name, last_update, self._next_update, self._extensions, self._revoked_certificates )
[docs] def next_update(self, next_update): if not isinstance(next_update, datetime.datetime): raise TypeError('Expecting datetime object.') if self._next_update is not None: raise ValueError('Last update may only be set once.') next_update = _convert_to_naive_utc_time(next_update) if next_update < _EARLIEST_UTC_TIME: raise ValueError('The last update date must be on or after' ' 1950 January 1.') if self._last_update is not None and next_update < self._last_update: raise ValueError( 'The next update date must be after the last update date.' ) return CertificateRevocationListBuilder( self._issuer_name, self._last_update, next_update, self._extensions, self._revoked_certificates )
[docs] def add_extension(self, extension, critical): """ Adds an X.509 extension to the certificate revocation list. """ if not isinstance(extension, ExtensionType): raise TypeError("extension must be an ExtensionType") extension = Extension(extension.oid, critical, extension) _reject_duplicate_extension(extension, self._extensions) return CertificateRevocationListBuilder( self._issuer_name, self._last_update, self._next_update, self._extensions + [extension], self._revoked_certificates )
[docs] def add_revoked_certificate(self, revoked_certificate): """ Adds a revoked certificate to the CRL. """ if not isinstance(revoked_certificate, RevokedCertificate): raise TypeError("Must be an instance of RevokedCertificate") return CertificateRevocationListBuilder( self._issuer_name, self._last_update, self._next_update, self._extensions, self._revoked_certificates + [revoked_certificate] )
[docs] def sign(self, private_key, algorithm, backend): if self._issuer_name is None: raise ValueError("A CRL must have an issuer name") if self._last_update is None: raise ValueError("A CRL must have a last update time") if self._next_update is None: raise ValueError("A CRL must have a next update time") return backend.create_x509_crl(self, private_key, algorithm)
[docs]class RevokedCertificateBuilder(object): def __init__(self, serial_number=None, revocation_date=None, extensions=[]): self._serial_number = serial_number self._revocation_date = revocation_date self._extensions = extensions
[docs] def serial_number(self, number): if not isinstance(number, six.integer_types): raise TypeError('Serial number must be of integral type.') if self._serial_number is not None: raise ValueError('The serial number may only be set once.') if number <= 0: raise ValueError('The serial number should be positive') # ASN.1 integers are always signed, so most significant bit must be # zero. if number.bit_length() >= 160: # As defined in RFC 5280 raise ValueError('The serial number should not be more than 159 ' 'bits.') return RevokedCertificateBuilder( number, self._revocation_date, self._extensions )
[docs] def revocation_date(self, time): if not isinstance(time, datetime.datetime): raise TypeError('Expecting datetime object.') if self._revocation_date is not None: raise ValueError('The revocation date may only be set once.') time = _convert_to_naive_utc_time(time) if time < _EARLIEST_UTC_TIME: raise ValueError('The revocation date must be on or after' ' 1950 January 1.') return RevokedCertificateBuilder( self._serial_number, time, self._extensions )
[docs] def add_extension(self, extension, critical): if not isinstance(extension, ExtensionType): raise TypeError("extension must be an ExtensionType") extension = Extension(extension.oid, critical, extension) _reject_duplicate_extension(extension, self._extensions) return RevokedCertificateBuilder( self._serial_number, self._revocation_date, self._extensions + [extension] )
[docs] def build(self, backend): if self._serial_number is None: raise ValueError("A revoked certificate must have a serial number") if self._revocation_date is None: raise ValueError( "A revoked certificate must have a revocation date" ) return backend.create_x509_revoked_certificate(self)
[docs]def random_serial_number(): return utils.int_from_bytes(os.urandom(20), "big") >> 1