Python cryptography.hazmat.primitives.asymmetric.ec.ECDSA Examples

def load_pem_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.PEM_read_bio_PUBKEY(
            mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
        )
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.PEM_read_bio_RSAPublicKey(
                mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_pem_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.PEM_read_bio_PUBKEY(
            mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
        )
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.PEM_read_bio_RSAPublicKey(
                mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def verify(self, byts, sign):
        '''
        Verify the signature for the given bytes using the ECC
        public key.

        Args:
            byts (bytes): The data bytes.
            sign (bytes): The signature bytes.

        Returns:
            bool: True if the data was verified, False otherwise.
        '''
        try:
            chosen_hash = c_hashes.SHA256()
            hasher = c_hashes.Hash(chosen_hash, default_backend())
            hasher.update(byts)
            digest = hasher.finalize()
            self.publ.verify(sign,
                             digest,
                             c_ec.ECDSA(c_utils.Prehashed(chosen_hash))
                             )
            return True
        except InvalidSignature:
            logger.exception('Error in publ.verify')
            return False 

def sign(self, byts):
        '''
        Compute the ECC signature for the given bytestream.

        Args:
            byts (bytes): The bytes to sign.

        Returns:
            bytes: The RSA Signature bytes.
        '''
        chosen_hash = c_hashes.SHA256()
        hasher = c_hashes.Hash(chosen_hash, default_backend())
        hasher.update(byts)
        digest = hasher.finalize()
        return self.priv.sign(digest,
                              c_ec.ECDSA(c_utils.Prehashed(chosen_hash))
                              ) 

def load_der_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.d2i_PUBKEY_bio(mem_bio.bio, self._ffi.NULL)
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.d2i_RSAPublicKey_bio(
                mem_bio.bio, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_pem_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.PEM_read_bio_PUBKEY(
            mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
        )
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.PEM_read_bio_RSAPublicKey(
                mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_der_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.d2i_PUBKEY_bio(mem_bio.bio, self._ffi.NULL)
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.d2i_RSAPublicKey_bio(
                mem_bio.bio, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def generate_signature(self, pri_key: str, msg: bytes) -> str:
        if self.__scheme == SignatureScheme.SHA224withECDSA:
            private_key = ec.derive_private_key(int(pri_key, 16), ec.SECP224R1(), default_backend())
            signature = private_key.sign(
                msg,
                ec.ECDSA(hashes.SHA224())
            )
        elif self.__scheme == SignatureScheme.SHA256withECDSA:
            private_key = ec.derive_private_key(int(pri_key, 16), ec.SECP256R1(), default_backend())
            signature = private_key.sign(
                msg,
                ec.ECDSA(hashes.SHA256())
            )
        elif self.__scheme == SignatureScheme.SHA384withECDSA:
            private_key = ec.derive_private_key(int(pri_key, 16), ec.SECP384R1(), default_backend())
            signature = private_key.sign(
                msg,
                ec.ECDSA(hashes.SHA384())
            )
        else:
            raise SDKException(ErrorCode.other_error('Invalid signature scheme.'))
        sign = SignatureHandler.dsa_der_to_plain(signature)
        return sign 

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

        # We only support ECDSA right now.
        if not isinstance(signature_algorithm, ec.ECDSA):
            return False

        # Before 0.9.8m OpenSSL can't cope with digests longer than the curve.
        if (
            self._lib.OPENSSL_VERSION_NUMBER < 0x009080df and
            curve.key_size < signature_algorithm.algorithm.digest_size * 8
        ):
            return False

        return self.elliptic_curve_supported(curve) 

def _fromString_PUBLIC_OPENSSH(cls, data):
        """
        Return a public key object corresponding to this OpenSSH public key
        string.  The format of an OpenSSH public key string is::
            <key type> <base64-encoded public key blob>

        @type data: L{bytes}
        @param data: The key data.

        @return: A new key.
        @rtype: L{twisted.conch.ssh.keys.Key}
        @raises BadKeyError: if the blob type is unknown.
        """
        # ECDSA keys don't need base64 decoding which is required
        # for RSA or DSA key.
        if data.startswith(b'ecdsa-sha2'):
            return cls(load_ssh_public_key(data, default_backend()))
        blob = decodebytes(data.split()[1])
        return cls._fromString_BLOB(blob) 

def validate(self, authenticator_data, rp_id_hash, client_data_hash):
        # See https://www.w3.org/TR/webauthn/#fido-u2f-attestation, "Verification procedure"
        credential = authenticator_data.credential
        public_key_u2f = b'\x04' + credential.public_key.x + credential.public_key.y
        verification_data = b'\x00' + rp_id_hash + client_data_hash + credential.id + public_key_u2f
        assert len(credential.public_key.x) == 32
        assert len(credential.public_key.y) == 32
        self.cert_public_key.verify(self.signature, verification_data, ec.ECDSA(hashes.SHA256()))
        key_id = x509.SubjectKeyIdentifier.from_public_key(self.cert_public_key).digest.hex()
        att_root_cert_chain = self.metadata_for_key_id(key_id)["attestationRootCertificates"]

        # TODO: implement full cert chain validation
        # See https://cryptography.io/en/latest/x509/reference/#cryptography.x509.Certificate.tbs_certificate_bytes
        # See https://github.com/pyca/cryptography/issues/2381
        # See https://github.com/wbond/certvalidator
        assert len(att_root_cert_chain) == 1
        att_root_cert = x509.load_der_x509_certificate(att_root_cert_chain[0].encode(),
                                                       cryptography.hazmat.backends.default_backend())
        att_root_cert.public_key().verify(self.att_cert.signature,
                                          self.att_cert.tbs_certificate_bytes,
                                          padding.PKCS1v15(),
                                          self.att_cert.signature_hash_algorithm)
        return self.validated_attestation(type="Basic", trust_path="x5c", credential=credential) 

def load_pem_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.PEM_read_bio_PUBKEY(
            mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
        )
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.PEM_read_bio_RSAPublicKey(
                mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_der_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.d2i_PUBKEY_bio(mem_bio.bio, self._ffi.NULL)
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.d2i_RSAPublicKey_bio(
                mem_bio.bio, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_der_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.d2i_PUBKEY_bio(mem_bio.bio, self._ffi.NULL)
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.d2i_RSAPublicKey_bio(
                mem_bio.bio, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_der_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.d2i_PUBKEY_bio(mem_bio.bio, self._ffi.NULL)
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.d2i_RSAPublicKey_bio(
                mem_bio.bio, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def load_pem_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.PEM_read_bio_PUBKEY(
            mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
        )
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.PEM_read_bio_RSAPublicKey(
                mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def generate(cls, curve=ec.SECP256R1(), progress_func=None, bits=None):
        """
        Generate a new private ECDSA key.  This factory function can be used to
        generate a new host key or authentication key.

        :param function progress_func: Not used for this type of key.
        :returns: A new private key (`.ECDSAKey`) object
        """
        if bits is not None:
            curve = cls._ECDSA_CURVES.get_by_key_length(bits)
            if curve is None:
                raise ValueError("Unsupported key length: %d"%(bits))
            curve = curve.curve_class()

        private_key = ec.generate_private_key(curve, backend=default_backend())
        return ECDSAKey(vals=(private_key, private_key.public_key()))

    ###  internals... 

def load_der_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.d2i_PUBKEY_bio(mem_bio.bio, self._ffi.NULL)
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.d2i_RSAPublicKey_bio(
                mem_bio.bio, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def verify_ssh_sig(self, data, msg):
        if msg.get_text() != self.ecdsa_curve.key_format_identifier:
            return False
        sig = msg.get_binary()
        sigR, sigS = self._sigdecode(sig)
        signature = encode_dss_signature(sigR, sigS)

        verifier = self.verifying_key.verifier(
            signature, ec.ECDSA(self.ecdsa_curve.hash_object())
        )
        verifier.update(data)
        try:
            verifier.verify()
        except InvalidSignature:
            return False
        else:
            return True 

def verify(self, public_key, message, signature):
        """ECDSA verify signature.

        :param public_key: Signing public key
        :param message: Origin message
        :param signature: Signature of message
        :return: verify result boolean, True means valid
        """
        if not (self._check_malleability(signature)):
            return False
        try:
            public_key.verify(signature, message,
                              ec.ECDSA(self.sign_hash_algorithm))
        except InvalidSignature:
            return False
        except Exception as e:
            raise e
        return True 

def sign_digest(hash_hex, privkey_hex, hashfunc=hashlib.sha256):
    """
    Given a digest and a private key, sign it.
    Return the base64-encoded signature
    """
    if not isinstance(hash_hex, (str, unicode)):
        raise ValueError("hash hex is not a string")

    hash_hex = str(hash_hex)

    pk_i = decode_privkey_hex(privkey_hex)
    privk = ec.derive_private_key(pk_i, ec.SECP256K1(), default_backend())

    sig = privk.sign(hash_hex.decode('hex'), ec.ECDSA(utils.Prehashed(hashes.SHA256())))

    sig_r, sig_s = decode_dss_signature(sig)
    sigb64 = encode_signature(sig_r, sig_s)
    return sigb64 

def verify_digest(hash_hex, pubkey_hex, sigb64, hashfunc=hashlib.sha256):
    """
    Given a digest, public key (as hex), and a base64 signature,
    verify that the public key signed the digest.
    Return True if so
    Return False if not
    """
    if not isinstance(hash_hex, (str, unicode)):
        raise ValueError("hash hex is not a string")

    hash_hex = str(hash_hex)
    pubk_uncompressed_hex = keylib.key_formatting.decompress(pubkey_hex)
    sig_r, sig_s = decode_signature(sigb64)

    pubk = ec.EllipticCurvePublicNumbers.from_encoded_point(ec.SECP256K1(), pubk_uncompressed_hex.decode('hex')).public_key(default_backend())
    signature = encode_dss_signature(sig_r, sig_s)

    try:
        pubk.verify(signature, hash_hex.decode('hex'), ec.ECDSA(utils.Prehashed(hashes.SHA256())))
        return True
    except InvalidSignature:
        return False 

def load_pem_public_key(self, data):
        mem_bio = self._bytes_to_bio(data)
        evp_pkey = self._lib.PEM_read_bio_PUBKEY(
            mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
        )
        if evp_pkey != self._ffi.NULL:
            evp_pkey = self._ffi.gc(evp_pkey, self._lib.EVP_PKEY_free)
            return self._evp_pkey_to_public_key(evp_pkey)
        else:
            # It's not a (RSA/DSA/ECDSA) subjectPublicKeyInfo, but we still
            # need to check to see if it is a pure PKCS1 RSA public key (not
            # embedded in a subjectPublicKeyInfo)
            self._consume_errors()
            res = self._lib.BIO_reset(mem_bio.bio)
            self.openssl_assert(res == 1)
            rsa_cdata = self._lib.PEM_read_bio_RSAPublicKey(
                mem_bio.bio, self._ffi.NULL, self._ffi.NULL, self._ffi.NULL
            )
            if rsa_cdata != self._ffi.NULL:
                rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
                evp_pkey = self._rsa_cdata_to_evp_pkey(rsa_cdata)
                return _RSAPublicKey(self, rsa_cdata, evp_pkey)
            else:
                self._handle_key_loading_error() 

def _fromString_PUBLIC_OPENSSH(cls, data):
        """
        Return a public key object corresponding to this OpenSSH public key
        string.  The format of an OpenSSH public key string is::
            <key type> <base64-encoded public key blob>

        @type data: L{bytes}
        @param data: The key data.

        @return: A new key.
        @rtype: L{twisted.conch.ssh.keys.Key}
        @raises BadKeyError: if the blob type is unknown.
        """
        # ECDSA keys don't need base64 decoding which is required
        # for RSA or DSA key.
        if data.startswith(b'ecdsa-sha2'):
            return cls(load_ssh_public_key(data, default_backend()))
        blob = decodebytes(data.split()[1])
        return cls._fromString_BLOB(blob) 

def verify(self, message: bytes,
               verifying_key: UmbralPublicKey,
               is_prehashed: bool = False) -> bool:
        """
        Verifies that a message's signature was valid.

        :param message: The message to verify
        :param verifying_key: UmbralPublicKey of the signer
        :param is_prehashed: True if the message has been prehashed previously
        :return: True if valid, False if invalid
        """
        cryptography_pub_key = verifying_key.to_cryptography_pubkey()
        if is_prehashed:
            signature_algorithm = ECDSA(utils.Prehashed(self.hash_algorithm()))
        else:
            signature_algorithm = ECDSA(self.hash_algorithm())

        # TODO: Raise error instead of returning boolean
        try:
            cryptography_pub_key.verify(
                signature=self._der_encoded_bytes(),
                data=message,
                signature_algorithm=signature_algorithm
            )
        except InvalidSignature:
            return False
        return True 

def sign_data(self, data):
        from OpenSSL import crypto
        from cryptography.hazmat.backends import default_backend
        from cryptography.hazmat.primitives import hashes
        from cryptography.hazmat.primitives.asymmetric import dsa, rsa
        from cryptography.hazmat.primitives.asymmetric import ec
        from cryptography.hazmat.primitives.serialization import load_pem_private_key
        private_key_str = self.get_private_key()
#       The pyOpenSSL sign operation seems broken and corrupts memory, atleast for EC, so let's use
#       the cryptography package instead
#        try:
#            private_key = OpenSSL.crypto.load_privatekey(OpenSSL.crypto.FILETYPE_PEM,
#                                                        private_key_str, '')
#            signature = OpenSSL.crypto.sign(private_key,
#                                            data,
#                                            "sha256")
#        except Exception as err:
#            _log.error("Failed to sign data, err={}".format(err))
#            raise
        try:
            private_key = load_pem_private_key(private_key_str, password=None, backend=default_backend())
            if isinstance(private_key, ec.EllipticCurvePrivateKey):
                signature = private_key.sign(data, ec.ECDSA(hashes.SHA256()))
            elif isinstance(private_key, rsa.RSAPrivateKey):
                signature = sign_with_rsa_key(private_key, message)
            elif isinstance(private_key, dsa.DSAPrivateKey):
                signature = sign_with_dsa_key(private_key, message)
            else:
                raise TypeError
        except Exception as err:
            _log.error("Failed to sign data, err={}".format(err))
            raise
        return signature 

def is_signature_valid(encoded_signature, signature_digest, public_key_bytes):
        try:
            public_key = load_der_public_key(public_key_bytes, default_backend())
            public_key.verify(encoded_signature, signature_digest, ec.ECDSA(Prehashed(hashes.SHA256())))
            return True
        except (ValueError, InvalidSignature):
            pass
        return False 

def sign(self, private_key, message):
        """ECDSA sign message.

        :param private_key: private key
        :param message: message to sign
        :return: signature
        """
        signer = private_key.sign(message, ec.ECDSA(self.sign_hash_algorithm))
        return self._prevent_malleability(signer) 

def elliptic_curve_signature_algorithm_supported(
        self, signature_algorithm, curve
    ):
        # We only support ECDSA right now.
        if not isinstance(signature_algorithm, ec.ECDSA):
            return False

        return self.elliptic_curve_supported(curve) 

def verify(self, msg, key, sig):
            try:
                der_sig = raw_to_der_signature(sig, key.curve)
            except ValueError:
                return False

            verifier = key.verifier(der_sig, ec.ECDSA(self.hash_alg()))

            verifier.update(msg)

            try:
                verifier.verify()
                return True
            except InvalidSignature:
                return False