Python cryptography.exceptions 模块，UnsupportedAlgorithm() 实例源码

def decrypt_pk(priv_key, ciphertext):
    """
    Decrypt a b64encoded ciphertext string with the RSA private key priv_key,
    using CryptoHash() as the OAEP/MGF1 padding hash.
    Returns the plaintext.
    Decryption failures result in an exception being raised.
    """
    try:
        plaintext = priv_key.decrypt(
            b64decode(ciphertext),
            padding.OAEP(
                mgf=padding.MGF1(algorithm=CryptoHash()),
                algorithm=CryptoHash(),
                label=None
                )
            )
    except UnsupportedAlgorithm as e:
        # a failure to dencrypt someone else's data is not typically a fatal
        # error, but in this particular case, the most likely cause of this
        # error is an old cryptography library
        logging.error("Fatal error: encryption hash {} unsupported, try upgrading to cryptography >= 1.4. Exception: {}".format(
                          CryptoHash, e))
        # re-raise the exception for the caller to handle
        raise e
    return plaintext

def _elliptic_curve_to_nid(self, curve):
        """
        Get the NID for a curve name.
        """

        curve_aliases = {
            "secp192r1": "prime192v1",
            "secp256r1": "prime256v1"
        }

        curve_name = curve_aliases.get(curve.name, curve.name)

        curve_nid = self._lib.OBJ_sn2nid(curve_name.encode())
        if curve_nid == self._lib.NID_undef:
            raise UnsupportedAlgorithm(
                "{0} is not a supported elliptic curve".format(curve.name),
                _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
            )
        return curve_nid

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm

        self._backend = backend

        if ctx is None:
            ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
            ctx = self._backend._ffi.gc(
                ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
            )
            evp_md = self._backend._lib.EVP_get_digestbyname(
                algorithm.name.encode("ascii"))
            if evp_md == self._backend._ffi.NULL:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            res = self._backend._lib.EVP_DigestInit_ex(ctx, evp_md,
                                                       self._backend._ffi.NULL)
            self._backend.openssl_assert(res != 0)

        self._ctx = ctx

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm

        self._backend = backend

        if ctx is None:
            ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
            ctx = self._backend._ffi.gc(
                ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
            )
            evp_md = self._backend._lib.EVP_get_digestbyname(
                algorithm.name.encode("ascii"))
            if evp_md == self._backend._ffi.NULL:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            res = self._backend._lib.EVP_DigestInit_ex(ctx, evp_md,
                                                       self._backend._ffi.NULL)
            self._backend.openssl_assert(res != 0)

        self._ctx = ctx

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm
        self._backend = backend

        if ctx is None:
            try:
                methods = self._backend._hash_mapping[self.algorithm.name]
            except KeyError:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            ctx = self._backend._ffi.new(methods.ctx)
            res = methods.hash_init(ctx)
            assert res == 1

        self._ctx = ctx

def _elliptic_curve_to_nid(self, curve):
        """
        Get the NID for a curve name.
        """

        curve_aliases = {
            "secp192r1": "prime192v1",
            "secp256r1": "prime256v1"
        }

        curve_name = curve_aliases.get(curve.name, curve.name)

        curve_nid = self._lib.OBJ_sn2nid(curve_name.encode())
        if curve_nid == self._lib.NID_undef:
            raise UnsupportedAlgorithm(
                "{0} is not a supported elliptic curve".format(curve.name),
                _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
            )
        return curve_nid

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm

        self._backend = backend

        if ctx is None:
            ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
            ctx = self._backend._ffi.gc(
                ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
            )
            name = self._backend._build_openssl_digest_name(algorithm)
            evp_md = self._backend._lib.EVP_get_digestbyname(name)
            if evp_md == self._backend._ffi.NULL:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        name),
                    _Reasons.UNSUPPORTED_HASH
                )
            res = self._backend._lib.EVP_DigestInit_ex(ctx, evp_md,
                                                       self._backend._ffi.NULL)
            self._backend.openssl_assert(res != 0)

        self._ctx = ctx

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm
        self._backend = backend

        if ctx is None:
            try:
                methods = self._backend._hash_mapping[self.algorithm.name]
            except KeyError:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            ctx = self._backend._ffi.new(methods.ctx)
            res = methods.hash_init(ctx)
            assert res == 1

        self._ctx = ctx

def _elliptic_curve_to_nid(self, curve):
        """
        Get the NID for a curve name.
        """

        curve_aliases = {
            "secp192r1": "prime192v1",
            "secp256r1": "prime256v1"
        }

        curve_name = curve_aliases.get(curve.name, curve.name)

        curve_nid = self._lib.OBJ_sn2nid(curve_name.encode())
        if curve_nid == self._lib.NID_undef:
            raise UnsupportedAlgorithm(
                "{0} is not a supported elliptic curve".format(curve.name),
                _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
            )
        return curve_nid

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm

        self._backend = backend

        if ctx is None:
            ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
            ctx = self._backend._ffi.gc(
                ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
            )
            evp_md = self._backend._lib.EVP_get_digestbyname(
                algorithm.name.encode("ascii"))
            if evp_md == self._backend._ffi.NULL:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            res = self._backend._lib.EVP_DigestInit_ex(ctx, evp_md,
                                                       self._backend._ffi.NULL)
            self._backend.openssl_assert(res != 0)

        self._ctx = ctx

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm

        self._backend = backend

        if ctx is None:
            ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
            ctx = self._backend._ffi.gc(
                ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
            )
            evp_md = self._backend._lib.EVP_get_digestbyname(
                algorithm.name.encode("ascii"))
            if evp_md == self._backend._ffi.NULL:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            res = self._backend._lib.EVP_DigestInit_ex(ctx, evp_md,
                                                       self._backend._ffi.NULL)
            self._backend.openssl_assert(res != 0)

        self._ctx = ctx

def __init__(self, backend, algorithm, ctx=None):
        self._algorithm = algorithm
        self._backend = backend

        if ctx is None:
            try:
                methods = self._backend._hash_mapping[self.algorithm.name]
            except KeyError:
                raise UnsupportedAlgorithm(
                    "{0} is not a supported hash on this backend.".format(
                        algorithm.name),
                    _Reasons.UNSUPPORTED_HASH
                )
            ctx = self._backend._ffi.new(methods.ctx)
            res = methods.hash_init(ctx)
            assert res == 1

        self._ctx = ctx

def encrypt_pk(pub_key, plaintext):
    """
    Encrypt plaintext with the RSA public key pub_key, using CryptoHash()
    as the OAEP/MGF1 padding hash.
    plaintext is limited to the size of the RSA key, minus the padding, or a
    few hundred bytes.
    Returns a b64encoded ciphertext string.
    Encryption failures result in an exception being raised.
    """
    try:
        ciphertext = pub_key.encrypt(
            plaintext,
            padding.OAEP(
                mgf=padding.MGF1(algorithm=CryptoHash()),
                algorithm=CryptoHash(),
                label=None
                )
            )
    except UnsupportedAlgorithm as e:
        # a failure to encrypt our own data is a fatal error
        # the most likely cause of this error is an old cryptography library
        # although some newer binary cryptography libraries are linked with
        # old OpenSSL versions, to fix, check 'openssl version' >= 1.0.2, then:
        # pip install -I --no-binary cryptography cryptography
        logging.error("Fatal error: encryption hash {} unsupported, try upgrading to cryptography >= 1.4 compiled with OpenSSL >= 1.0.2. Exception: {}".format(
                          CryptoHash, e))
        # re-raise the exception for the caller to handle
        raise e
    return b64encode(ciphertext)

def signature_hash_algorithm(self):
        alg = self._backend._ffi.new("X509_ALGOR **")
        self._backend._lib.X509_get0_signature(
            self._backend._ffi.NULL, alg, self._x509
        )
        self._backend.openssl_assert(alg[0] != self._backend._ffi.NULL)
        oid = _obj2txt(self._backend, alg[0].algorithm)
        try:
            return x509._SIG_OIDS_TO_HASH[oid]
        except KeyError:
            raise UnsupportedAlgorithm(
                "Signature algorithm OID:{0} not recognized".format(oid)
            )

def signature_hash_algorithm(self):
        alg = self._backend._ffi.new("X509_ALGOR **")
        self._backend._lib.X509_CRL_get0_signature(
            self._backend._ffi.NULL, alg, self._x509_crl
        )
        self._backend.openssl_assert(alg[0] != self._backend._ffi.NULL)
        oid = _obj2txt(self._backend, alg[0].algorithm)
        try:
            return x509._SIG_OIDS_TO_HASH[oid]
        except KeyError:
            raise UnsupportedAlgorithm(
                "Signature algorithm OID:{0} not recognized".format(oid)
            )

def signature_hash_algorithm(self):
        alg = self._backend._ffi.new("X509_ALGOR **")
        self._backend._lib.X509_REQ_get0_signature(
            self._backend._ffi.NULL, alg, self._x509_req
        )
        self._backend.openssl_assert(alg[0] != self._backend._ffi.NULL)
        oid = _obj2txt(self._backend, alg[0].algorithm)
        try:
            return x509._SIG_OIDS_TO_HASH[oid]
        except KeyError:
            raise UnsupportedAlgorithm(
                "Signature algorithm OID:{0} not recognized".format(oid)
            )

def derive_pbkdf2_hmac(self, algorithm, length, salt, iterations,
                           key_material):
        buf = self._ffi.new("char[]", length)
        if self._lib.Cryptography_HAS_PBKDF2_HMAC:
            evp_md = self._lib.EVP_get_digestbyname(
                algorithm.name.encode("ascii"))
            self.openssl_assert(evp_md != self._ffi.NULL)
            res = self._lib.PKCS5_PBKDF2_HMAC(
                key_material,
                len(key_material),
                salt,
                len(salt),
                iterations,
                evp_md,
                length,
                buf
            )
            self.openssl_assert(res == 1)
        else:
            if not isinstance(algorithm, hashes.SHA1):
                raise UnsupportedAlgorithm(
                    "This version of OpenSSL only supports PBKDF2HMAC with "
                    "SHA1.",
                    _Reasons.UNSUPPORTED_HASH
                )
            res = self._lib.PKCS5_PBKDF2_HMAC_SHA1(
                key_material,
                len(key_material),
                salt,
                len(salt),
                iterations,
                length,
                buf
            )
            self.openssl_assert(res == 1)

        return self._ffi.buffer(buf)[:]

def _evp_pkey_to_private_key(self, evp_pkey):
        """
        Return the appropriate type of PrivateKey given an evp_pkey cdata
        pointer.
        """

        key_type = self._lib.Cryptography_EVP_PKEY_id(evp_pkey)

        if key_type == self._lib.EVP_PKEY_RSA:
            rsa_cdata = self._lib.EVP_PKEY_get1_RSA(evp_pkey)
            self.openssl_assert(rsa_cdata != self._ffi.NULL)
            rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
            return _RSAPrivateKey(self, rsa_cdata, evp_pkey)
        elif key_type == self._lib.EVP_PKEY_DSA:
            dsa_cdata = self._lib.EVP_PKEY_get1_DSA(evp_pkey)
            self.openssl_assert(dsa_cdata != self._ffi.NULL)
            dsa_cdata = self._ffi.gc(dsa_cdata, self._lib.DSA_free)
            return _DSAPrivateKey(self, dsa_cdata, evp_pkey)
        elif (self._lib.Cryptography_HAS_EC == 1 and
              key_type == self._lib.EVP_PKEY_EC):
            ec_cdata = self._lib.EVP_PKEY_get1_EC_KEY(evp_pkey)
            self.openssl_assert(ec_cdata != self._ffi.NULL)
            ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)
            return _EllipticCurvePrivateKey(self, ec_cdata, evp_pkey)
        else:
            raise UnsupportedAlgorithm("Unsupported key type.")

def elliptic_curve_supported(self, curve):
        if self._lib.Cryptography_HAS_EC != 1:
            return False

        try:
            curve_nid = self._elliptic_curve_to_nid(curve)
        except UnsupportedAlgorithm:
            curve_nid = self._lib.NID_undef

        ctx = self._lib.EC_GROUP_new_by_curve_name(curve_nid)

        if ctx == self._ffi.NULL:
            errors = self._consume_errors()
            self.openssl_assert(
                curve_nid == self._lib.NID_undef or
                errors[0][1:] == (
                    self._lib.ERR_LIB_EC,
                    self._lib.EC_F_EC_GROUP_NEW_BY_CURVE_NAME,
                    self._lib.EC_R_UNKNOWN_GROUP
                )
            )
            return False
        else:
            self.openssl_assert(curve_nid != self._lib.NID_undef)
            self._lib.EC_GROUP_free(ctx)
            return True

def generate_elliptic_curve_private_key(self, curve):
        """
        Generate a new private key on the named curve.
        """

        if self.elliptic_curve_supported(curve):
            curve_nid = self._elliptic_curve_to_nid(curve)

            ec_cdata = self._lib.EC_KEY_new_by_curve_name(curve_nid)
            self.openssl_assert(ec_cdata != self._ffi.NULL)
            ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)

            res = self._lib.EC_KEY_generate_key(ec_cdata)
            self.openssl_assert(res == 1)

            res = self._lib.EC_KEY_check_key(ec_cdata)
            self.openssl_assert(res == 1)

            evp_pkey = self._ec_cdata_to_evp_pkey(ec_cdata)

            return _EllipticCurvePrivateKey(self, ec_cdata, evp_pkey)
        else:
            raise UnsupportedAlgorithm(
                "Backend object does not support {0}.".format(curve.name),
                _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
            )

def create_symmetric_encryption_ctx(self, cipher, mode):
        for b in self._filtered_backends(CipherBackend):
            try:
                return b.create_symmetric_encryption_ctx(cipher, mode)
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm(
            "cipher {0} in {1} mode is not supported by this backend.".format(
                cipher.name, mode.name if mode else mode),
            _Reasons.UNSUPPORTED_CIPHER
        )

def create_symmetric_decryption_ctx(self, cipher, mode):
        for b in self._filtered_backends(CipherBackend):
            try:
                return b.create_symmetric_decryption_ctx(cipher, mode)
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm(
            "cipher {0} in {1} mode is not supported by this backend.".format(
                cipher.name, mode.name if mode else mode),
            _Reasons.UNSUPPORTED_CIPHER
        )

def create_hash_ctx(self, algorithm):
        for b in self._filtered_backends(HashBackend):
            try:
                return b.create_hash_ctx(algorithm)
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm(
            "{0} is not a supported hash on this backend.".format(
                algorithm.name),
            _Reasons.UNSUPPORTED_HASH
        )

def create_hmac_ctx(self, key, algorithm):
        for b in self._filtered_backends(HMACBackend):
            try:
                return b.create_hmac_ctx(key, algorithm)
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm(
            "{0} is not a supported hash on this backend.".format(
                algorithm.name),
            _Reasons.UNSUPPORTED_HASH
        )

def derive_pbkdf2_hmac(self, algorithm, length, salt, iterations,
                           key_material):
        for b in self._filtered_backends(PBKDF2HMACBackend):
            try:
                return b.derive_pbkdf2_hmac(
                    algorithm, length, salt, iterations, key_material
                )
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm(
            "{0} is not a supported hash on this backend.".format(
                algorithm.name),
            _Reasons.UNSUPPORTED_HASH
        )

def generate_rsa_parameters_supported(self, public_exponent, key_size):
        for b in self._filtered_backends(RSABackend):
            return b.generate_rsa_parameters_supported(
                public_exponent, key_size
            )
        raise UnsupportedAlgorithm("RSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def rsa_padding_supported(self, padding):
        for b in self._filtered_backends(RSABackend):
            return b.rsa_padding_supported(padding)
        raise UnsupportedAlgorithm("RSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def load_rsa_private_numbers(self, numbers):
        for b in self._filtered_backends(RSABackend):
            return b.load_rsa_private_numbers(numbers)

        raise UnsupportedAlgorithm("RSA is not supported by the backend",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def load_rsa_public_numbers(self, numbers):
        for b in self._filtered_backends(RSABackend):
            return b.load_rsa_public_numbers(numbers)

        raise UnsupportedAlgorithm("RSA is not supported by the backend",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def generate_dsa_parameters(self, key_size):
        for b in self._filtered_backends(DSABackend):
            return b.generate_dsa_parameters(key_size)
        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def generate_dsa_private_key_and_parameters(self, key_size):
        for b in self._filtered_backends(DSABackend):
            return b.generate_dsa_private_key_and_parameters(key_size)
        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def dsa_hash_supported(self, algorithm):
        for b in self._filtered_backends(DSABackend):
            return b.dsa_hash_supported(algorithm)
        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def dsa_parameters_supported(self, p, q, g):
        for b in self._filtered_backends(DSABackend):
            return b.dsa_parameters_supported(p, q, g)
        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def load_dsa_public_numbers(self, numbers):
        for b in self._filtered_backends(DSABackend):
            return b.load_dsa_public_numbers(numbers)
        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def load_dsa_private_numbers(self, numbers):
        for b in self._filtered_backends(DSABackend):
            return b.load_dsa_private_numbers(numbers)
        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)

def create_cmac_ctx(self, algorithm):
        for b in self._filtered_backends(CMACBackend):
            try:
                return b.create_cmac_ctx(algorithm)
            except UnsupportedAlgorithm:
                pass
        raise UnsupportedAlgorithm("This backend does not support CMAC.",
                                   _Reasons.UNSUPPORTED_CIPHER)

def generate_elliptic_curve_private_key(self, curve):
        for b in self._filtered_backends(EllipticCurveBackend):
            try:
                return b.generate_elliptic_curve_private_key(curve)
            except UnsupportedAlgorithm:
                continue

        raise UnsupportedAlgorithm(
            "This backend does not support this elliptic curve.",
            _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
        )

def load_elliptic_curve_private_numbers(self, numbers):
        for b in self._filtered_backends(EllipticCurveBackend):
            try:
                return b.load_elliptic_curve_private_numbers(numbers)
            except UnsupportedAlgorithm:
                continue

        raise UnsupportedAlgorithm(
            "This backend does not support this elliptic curve.",
            _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
        )

def load_elliptic_curve_public_numbers(self, numbers):
        for b in self._filtered_backends(EllipticCurveBackend):
            try:
                return b.load_elliptic_curve_public_numbers(numbers)
            except UnsupportedAlgorithm:
                continue

        raise UnsupportedAlgorithm(
            "This backend does not support this elliptic curve.",
            _Reasons.UNSUPPORTED_ELLIPTIC_CURVE
        )

def load_pem_private_key(self, data, password):
        for b in self._filtered_backends(PEMSerializationBackend):
            return b.load_pem_private_key(data, password)

        raise UnsupportedAlgorithm(
            "This backend does not support this key serialization.",
            _Reasons.UNSUPPORTED_SERIALIZATION
        )

def load_der_private_key(self, data, password):
        for b in self._filtered_backends(DERSerializationBackend):
            return b.load_der_private_key(data, password)

        raise UnsupportedAlgorithm(
            "This backend does not support this key serialization.",
            _Reasons.UNSUPPORTED_SERIALIZATION
        )

def load_der_public_key(self, data):
        for b in self._filtered_backends(DERSerializationBackend):
            return b.load_der_public_key(data)

        raise UnsupportedAlgorithm(
            "This backend does not support this key serialization.",
            _Reasons.UNSUPPORTED_SERIALIZATION
        )

def load_pem_x509_certificate(self, data):
        for b in self._filtered_backends(X509Backend):
            return b.load_pem_x509_certificate(data)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def load_der_x509_certificate(self, data):
        for b in self._filtered_backends(X509Backend):
            return b.load_der_x509_certificate(data)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def load_pem_x509_crl(self, data):
        for b in self._filtered_backends(X509Backend):
            return b.load_pem_x509_crl(data)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def load_der_x509_csr(self, data):
        for b in self._filtered_backends(X509Backend):
            return b.load_der_x509_csr(data)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def load_pem_x509_csr(self, data):
        for b in self._filtered_backends(X509Backend):
            return b.load_pem_x509_csr(data)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def create_x509_csr(self, builder, private_key, algorithm):
        for b in self._filtered_backends(X509Backend):
            return b.create_x509_csr(builder, private_key, algorithm)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def create_x509_certificate(self, builder, private_key, algorithm):
        for b in self._filtered_backends(X509Backend):
            return b.create_x509_certificate(builder, private_key, algorithm)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )

def create_x509_crl(self, builder, private_key, algorithm):
        for b in self._filtered_backends(X509Backend):
            return b.create_x509_crl(builder, private_key, algorithm)

        raise UnsupportedAlgorithm(
            "This backend does not support X.509.",
            _Reasons.UNSUPPORTED_X509
        )