Method __init__

jose/backends/cryptography_backend.py:212–257

(self, key, algorithm, cryptography_backend=default_backend)

    RSA_OAEP_256 = padding.OAEP(padding.MGF1(hashes.SHA256()), hashes.SHA256(), None)

    def __init__(self, key, algorithm, cryptography_backend=default_backend):
        if algorithm not in ALGORITHMS.RSA:
            raise JWKError("hash_alg: %s is not a valid hash algorithm" % algorithm)

        self.hash_alg = {
            ALGORITHMS.RS256: self.SHA256,
            ALGORITHMS.RS384: self.SHA384,
            ALGORITHMS.RS512: self.SHA512,
        }.get(algorithm)
        self._algorithm = algorithm

        self.padding = {
            ALGORITHMS.RSA1_5: self.RSA1_5,
            ALGORITHMS.RSA_OAEP: self.RSA_OAEP,
            ALGORITHMS.RSA_OAEP_256: self.RSA_OAEP_256,
        }.get(algorithm)

        self.cryptography_backend = cryptography_backend

        # if it conforms to RSAPublicKey or RSAPrivateKey interface
        if (hasattr(key, "public_bytes") and hasattr(key, "public_numbers")) or hasattr(key, "private_bytes"):
            self.prepared_key = key
            return

        if isinstance(key, dict):
            self.prepared_key = self._process_jwk(key)
            return

        if isinstance(key, str):
            key = key.encode("utf-8")

        if isinstance(key, bytes):
            try:
                if key.startswith(b"-----BEGIN CERTIFICATE-----"):
                    self._process_cert(key)
                    return

                try:
                    self.prepared_key = load_pem_public_key(key, self.cryptography_backend())
                except ValueError:
                    self.prepared_key = load_pem_private_key(key, password=None, backend=self.cryptography_backend())
            except Exception as e:
                raise JWKError(e)
            return

        raise JWKError("Unable to parse an RSA_JWK from key: %s" % key)

    def _process_jwk(self, jwk_dict):
        if not jwk_dict.get("kty") == "RSA":