Viewing file:  ocsp.py (18.1 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# 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 annotations
import abc
import datetime
import typing
from cryptography import utils, x509
from cryptography.hazmat.bindings._rust import ocsp
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric.types import (
CertificateIssuerPrivateKeyTypes,
)
from cryptography.x509.base import (
_EARLIEST_UTC_TIME,
_convert_to_naive_utc_time,
_reject_duplicate_extension,
)
class OCSPResponderEncoding(utils.Enum):
HASH = "By Hash"
NAME = "By Name"
class OCSPResponseStatus(utils.Enum):
SUCCESSFUL = 0
MALFORMED_REQUEST = 1
INTERNAL_ERROR = 2
TRY_LATER = 3
SIG_REQUIRED = 5
UNAUTHORIZED = 6
_ALLOWED_HASHES = (
hashes.SHA1,
hashes.SHA224,
hashes.SHA256,
hashes.SHA384,
hashes.SHA512,
)
def _verify_algorithm(algorithm: hashes.HashAlgorithm) -> None:
if not isinstance(algorithm, _ALLOWED_HASHES):
raise ValueError(
"Algorithm must be SHA1, SHA224, SHA256, SHA384, or SHA512"
)
class OCSPCertStatus(utils.Enum):
GOOD = 0
REVOKED = 1
UNKNOWN = 2
class _SingleResponse:
def __init__(
self,
cert: x509.Certificate,
issuer: x509.Certificate,
algorithm: hashes.HashAlgorithm,
cert_status: OCSPCertStatus,
this_update: datetime.datetime,
next_update: typing.Optional[datetime.datetime],
revocation_time: typing.Optional[datetime.datetime],
revocation_reason: typing.Optional[x509.ReasonFlags],
):
if not isinstance(cert, x509.Certificate) or not isinstance(
issuer, x509.Certificate
):
raise TypeError("cert and issuer must be a Certificate")
_verify_algorithm(algorithm)
if not isinstance(this_update, datetime.datetime):
raise TypeError("this_update must be a datetime object")
if next_update is not None and not isinstance(
next_update, datetime.datetime
):
raise TypeError("next_update must be a datetime object or None")
self._cert = cert
self._issuer = issuer
self._algorithm = algorithm
self._this_update = this_update
self._next_update = next_update
if not isinstance(cert_status, OCSPCertStatus):
raise TypeError(
"cert_status must be an item from the OCSPCertStatus enum"
)
if cert_status is not OCSPCertStatus.REVOKED:
if revocation_time is not None:
raise ValueError(
"revocation_time can only be provided if the certificate "
"is revoked"
)
if revocation_reason is not None:
raise ValueError(
"revocation_reason can only be provided if the certificate"
" is revoked"
)
else:
if not isinstance(revocation_time, datetime.datetime):
raise TypeError("revocation_time must be a datetime object")
revocation_time = _convert_to_naive_utc_time(revocation_time)
if revocation_time < _EARLIEST_UTC_TIME:
raise ValueError(
"The revocation_time must be on or after"
" 1950 January 1."
)
if revocation_reason is not None and not isinstance(
revocation_reason, x509.ReasonFlags
):
raise TypeError(
"revocation_reason must be an item from the ReasonFlags "
"enum or None"
)
self._cert_status = cert_status
self._revocation_time = revocation_time
self._revocation_reason = revocation_reason
class OCSPRequest(metaclass=abc.ABCMeta):
@property
@abc.abstractmethod
def issuer_key_hash(self) -> bytes:
"""
The hash of the issuer public key
"""
@property
@abc.abstractmethod
def issuer_name_hash(self) -> bytes:
"""
The hash of the issuer name
"""
@property
@abc.abstractmethod
def hash_algorithm(self) -> hashes.HashAlgorithm:
"""
The hash algorithm used in the issuer name and key hashes
"""
@property
@abc.abstractmethod
def serial_number(self) -> int:
"""
The serial number of the cert whose status is being checked
"""
@abc.abstractmethod
def public_bytes(self, encoding: serialization.Encoding) -> bytes:
"""
Serializes the request to DER
"""
@property
@abc.abstractmethod
def extensions(self) -> x509.Extensions:
"""
The list of request extensions. Not single request extensions.
"""
class OCSPSingleResponse(metaclass=abc.ABCMeta):
@property
@abc.abstractmethod
def certificate_status(self) -> OCSPCertStatus:
"""
The status of the certificate (an element from the OCSPCertStatus enum)
"""
@property
@abc.abstractmethod
def revocation_time(self) -> typing.Optional[datetime.datetime]:
"""
The date of when the certificate was revoked or None if not
revoked.
"""
@property
@abc.abstractmethod
def revocation_reason(self) -> typing.Optional[x509.ReasonFlags]:
"""
The reason the certificate was revoked or None if not specified or
not revoked.
"""
@property
@abc.abstractmethod
def this_update(self) -> datetime.datetime:
"""
The most recent time at which the status being indicated is known by
the responder to have been correct
"""
@property
@abc.abstractmethod
def next_update(self) -> typing.Optional[datetime.datetime]:
"""
The time when newer information will be available
"""
@property
@abc.abstractmethod
def issuer_key_hash(self) -> bytes:
"""
The hash of the issuer public key
"""
@property
@abc.abstractmethod
def issuer_name_hash(self) -> bytes:
"""
The hash of the issuer name
"""
@property
@abc.abstractmethod
def hash_algorithm(self) -> hashes.HashAlgorithm:
"""
The hash algorithm used in the issuer name and key hashes
"""
@property
@abc.abstractmethod
def serial_number(self) -> int:
"""
The serial number of the cert whose status is being checked
"""
class OCSPResponse(metaclass=abc.ABCMeta):
@property
@abc.abstractmethod
def responses(self) -> typing.Iterator[OCSPSingleResponse]:
"""
An iterator over the individual SINGLERESP structures in the
response
"""
@property
@abc.abstractmethod
def response_status(self) -> OCSPResponseStatus:
"""
The status of the response. This is a value from the OCSPResponseStatus
enumeration
"""
@property
@abc.abstractmethod
def signature_algorithm_oid(self) -> x509.ObjectIdentifier:
"""
The ObjectIdentifier of the signature algorithm
"""
@property
@abc.abstractmethod
def signature_hash_algorithm(
self,
) -> typing.Optional[hashes.HashAlgorithm]:
"""
Returns a HashAlgorithm corresponding to the type of the digest signed
"""
@property
@abc.abstractmethod
def signature(self) -> bytes:
"""
The signature bytes
"""
@property
@abc.abstractmethod
def tbs_response_bytes(self) -> bytes:
"""
The tbsResponseData bytes
"""
@property
@abc.abstractmethod
def certificates(self) -> typing.List[x509.Certificate]:
"""
A list of certificates used to help build a chain to verify the OCSP
response. This situation occurs when the OCSP responder uses a delegate
certificate.
"""
@property
@abc.abstractmethod
def responder_key_hash(self) -> typing.Optional[bytes]:
"""
The responder's key hash or None
"""
@property
@abc.abstractmethod
def responder_name(self) -> typing.Optional[x509.Name]:
"""
The responder's Name or None
"""
@property
@abc.abstractmethod
def produced_at(self) -> datetime.datetime:
"""
The time the response was produced
"""
@property
@abc.abstractmethod
def certificate_status(self) -> OCSPCertStatus:
"""
The status of the certificate (an element from the OCSPCertStatus enum)
"""
@property
@abc.abstractmethod
def revocation_time(self) -> typing.Optional[datetime.datetime]:
"""
The date of when the certificate was revoked or None if not
revoked.
"""
@property
@abc.abstractmethod
def revocation_reason(self) -> typing.Optional[x509.ReasonFlags]:
"""
The reason the certificate was revoked or None if not specified or
not revoked.
"""
@property
@abc.abstractmethod
def this_update(self) -> datetime.datetime:
"""
The most recent time at which the status being indicated is known by
the responder to have been correct
"""
@property
@abc.abstractmethod
def next_update(self) -> typing.Optional[datetime.datetime]:
"""
The time when newer information will be available
"""
@property
@abc.abstractmethod
def issuer_key_hash(self) -> bytes:
"""
The hash of the issuer public key
"""
@property
@abc.abstractmethod
def issuer_name_hash(self) -> bytes:
"""
The hash of the issuer name
"""
@property
@abc.abstractmethod
def hash_algorithm(self) -> hashes.HashAlgorithm:
"""
The hash algorithm used in the issuer name and key hashes
"""
@property
@abc.abstractmethod
def serial_number(self) -> int:
"""
The serial number of the cert whose status is being checked
"""
@property
@abc.abstractmethod
def extensions(self) -> x509.Extensions:
"""
The list of response extensions. Not single response extensions.
"""
@property
@abc.abstractmethod
def single_extensions(self) -> x509.Extensions:
"""
The list of single response extensions. Not response extensions.
"""
@abc.abstractmethod
def public_bytes(self, encoding: serialization.Encoding) -> bytes:
"""
Serializes the response to DER
"""
class OCSPRequestBuilder:
def __init__(
self,
request: typing.Optional[
typing.Tuple[
x509.Certificate, x509.Certificate, hashes.HashAlgorithm
]
] = None,
request_hash: typing.Optional[
typing.Tuple[bytes, bytes, int, hashes.HashAlgorithm]
] = None,
extensions: typing.List[x509.Extension[x509.ExtensionType]] = [],
) -> None:
self._request = request
self._request_hash = request_hash
self._extensions = extensions
def add_certificate(
self,
cert: x509.Certificate,
issuer: x509.Certificate,
algorithm: hashes.HashAlgorithm,
) -> OCSPRequestBuilder:
if self._request is not None or self._request_hash is not None:
raise ValueError("Only one certificate can be added to a request")
_verify_algorithm(algorithm)
if not isinstance(cert, x509.Certificate) or not isinstance(
issuer, x509.Certificate
):
raise TypeError("cert and issuer must be a Certificate")
return OCSPRequestBuilder(
(cert, issuer, algorithm), self._request_hash, self._extensions
)
def add_certificate_by_hash(
self,
issuer_name_hash: bytes,
issuer_key_hash: bytes,
serial_number: int,
algorithm: hashes.HashAlgorithm,
) -> OCSPRequestBuilder:
if self._request is not None or self._request_hash is not None:
raise ValueError("Only one certificate can be added to a request")
if not isinstance(serial_number, int):
raise TypeError("serial_number must be an integer")
_verify_algorithm(algorithm)
utils._check_bytes("issuer_name_hash", issuer_name_hash)
utils._check_bytes("issuer_key_hash", issuer_key_hash)
if algorithm.digest_size != len(
issuer_name_hash
) or algorithm.digest_size != len(issuer_key_hash):
raise ValueError(
"issuer_name_hash and issuer_key_hash must be the same length "
"as the digest size of the algorithm"
)
return OCSPRequestBuilder(
self._request,
(issuer_name_hash, issuer_key_hash, serial_number, algorithm),
self._extensions,
)
def add_extension(
self, extval: x509.ExtensionType, critical: bool
) -> OCSPRequestBuilder:
if not isinstance(extval, x509.ExtensionType):
raise TypeError("extension must be an ExtensionType")
extension = x509.Extension(extval.oid, critical, extval)
_reject_duplicate_extension(extension, self._extensions)
return OCSPRequestBuilder(
self._request, self._request_hash, self._extensions + [extension]
)
def build(self) -> OCSPRequest:
if self._request is None and self._request_hash is None:
raise ValueError("You must add a certificate before building")
return ocsp.create_ocsp_request(self)
class OCSPResponseBuilder:
def __init__(
self,
response: typing.Optional[_SingleResponse] = None,
responder_id: typing.Optional[
typing.Tuple[x509.Certificate, OCSPResponderEncoding]
] = None,
certs: typing.Optional[typing.List[x509.Certificate]] = None,
extensions: typing.List[x509.Extension[x509.ExtensionType]] = [],
):
self._response = response
self._responder_id = responder_id
self._certs = certs
self._extensions = extensions
def add_response(
self,
cert: x509.Certificate,
issuer: x509.Certificate,
algorithm: hashes.HashAlgorithm,
cert_status: OCSPCertStatus,
this_update: datetime.datetime,
next_update: typing.Optional[datetime.datetime],
revocation_time: typing.Optional[datetime.datetime],
revocation_reason: typing.Optional[x509.ReasonFlags],
) -> OCSPResponseBuilder:
if self._response is not None:
raise ValueError("Only one response per OCSPResponse.")
singleresp = _SingleResponse(
cert,
issuer,
algorithm,
cert_status,
this_update,
next_update,
revocation_time,
revocation_reason,
)
return OCSPResponseBuilder(
singleresp,
self._responder_id,
self._certs,
self._extensions,
)
def responder_id(
self, encoding: OCSPResponderEncoding, responder_cert: x509.Certificate
) -> OCSPResponseBuilder:
if self._responder_id is not None:
raise ValueError("responder_id can only be set once")
if not isinstance(responder_cert, x509.Certificate):
raise TypeError("responder_cert must be a Certificate")
if not isinstance(encoding, OCSPResponderEncoding):
raise TypeError(
"encoding must be an element from OCSPResponderEncoding"
)
return OCSPResponseBuilder(
self._response,
(responder_cert, encoding),
self._certs,
self._extensions,
)
def certificates(
self, certs: typing.Iterable[x509.Certificate]
) -> OCSPResponseBuilder:
if self._certs is not None:
raise ValueError("certificates may only be set once")
certs = list(certs)
if len(certs) == 0:
raise ValueError("certs must not be an empty list")
if not all(isinstance(x, x509.Certificate) for x in certs):
raise TypeError("certs must be a list of Certificates")
return OCSPResponseBuilder(
self._response,
self._responder_id,
certs,
self._extensions,
)
def add_extension(
self, extval: x509.ExtensionType, critical: bool
) -> OCSPResponseBuilder:
if not isinstance(extval, x509.ExtensionType):
raise TypeError("extension must be an ExtensionType")
extension = x509.Extension(extval.oid, critical, extval)
_reject_duplicate_extension(extension, self._extensions)
return OCSPResponseBuilder(
self._response,
self._responder_id,
self._certs,
self._extensions + [extension],
)
def sign(
self,
private_key: CertificateIssuerPrivateKeyTypes,
algorithm: typing.Optional[hashes.HashAlgorithm],
) -> OCSPResponse:
if self._response is None:
raise ValueError("You must add a response before signing")
if self._responder_id is None:
raise ValueError("You must add a responder_id before signing")
return ocsp.create_ocsp_response(
OCSPResponseStatus.SUCCESSFUL, self, private_key, algorithm
)
@classmethod
def build_unsuccessful(
cls, response_status: OCSPResponseStatus
) -> OCSPResponse:
if not isinstance(response_status, OCSPResponseStatus):
raise TypeError(
"response_status must be an item from OCSPResponseStatus"
)
if response_status is OCSPResponseStatus.SUCCESSFUL:
raise ValueError("response_status cannot be SUCCESSFUL")
return ocsp.create_ocsp_response(response_status, None, None, None)
def load_der_ocsp_request(data: bytes) -> OCSPRequest:
return ocsp.load_der_ocsp_request(data)
def load_der_ocsp_response(data: bytes) -> OCSPResponse:
return ocsp.load_der_ocsp_response(data)
|