# 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 cryptography.hazmat.backends.openssl.utils import _evp_pkey_derive from cryptography.hazmat.primitives import serialization from cryptography.hazmat.primitives.asymmetric.x448 import ( X448PrivateKey, X448PublicKey, ) _X448_KEY_SIZE = 56 class _X448PublicKey(X448PublicKey): def __init__(self, backend, evp_pkey): self._backend = backend self._evp_pkey = evp_pkey def public_bytes( self, encoding: serialization.Encoding, format: serialization.PublicFormat, ) -> bytes: if ( encoding is serialization.Encoding.Raw or format is serialization.PublicFormat.Raw ): if ( encoding is not serialization.Encoding.Raw or format is not serialization.PublicFormat.Raw ): raise ValueError( "When using Raw both encoding and format must be Raw" ) return self._raw_public_bytes() return self._backend._public_key_bytes( encoding, format, self, self._evp_pkey, None ) def _raw_public_bytes(self) -> bytes: buf = self._backend._ffi.new("unsigned char []", _X448_KEY_SIZE) buflen = self._backend._ffi.new("size_t *", _X448_KEY_SIZE) res = self._backend._lib.EVP_PKEY_get_raw_public_key( self._evp_pkey, buf, buflen ) self._backend.openssl_assert(res == 1) self._backend.openssl_assert(buflen[0] == _X448_KEY_SIZE) return self._backend._ffi.buffer(buf, _X448_KEY_SIZE)[:] class _X448PrivateKey(X448PrivateKey): def __init__(self, backend, evp_pkey): self._backend = backend self._evp_pkey = evp_pkey def public_key(self) -> X448PublicKey: buf = self._backend._ffi.new("unsigned char []", _X448_KEY_SIZE) buflen = self._backend._ffi.new("size_t *", _X448_KEY_SIZE) res = self._backend._lib.EVP_PKEY_get_raw_public_key( self._evp_pkey, buf, buflen ) self._backend.openssl_assert(res == 1) self._backend.openssl_assert(buflen[0] == _X448_KEY_SIZE) return self._backend.x448_load_public_bytes(buf) def exchange(self, peer_public_key: X448PublicKey) -> bytes: if not isinstance(peer_public_key, X448PublicKey): raise TypeError("peer_public_key must be X448PublicKey.") return _evp_pkey_derive(self._backend, self._evp_pkey, peer_public_key) def private_bytes( self, encoding: serialization.Encoding, format: serialization.PrivateFormat, encryption_algorithm: serialization.KeySerializationEncryption, ) -> bytes: if ( encoding is serialization.Encoding.Raw or format is serialization.PublicFormat.Raw ): if ( format is not serialization.PrivateFormat.Raw or encoding is not serialization.Encoding.Raw or not isinstance( encryption_algorithm, serialization.NoEncryption ) ): raise ValueError( "When using Raw both encoding and format must be Raw " "and encryption_algorithm must be NoEncryption()" ) return self._raw_private_bytes() return self._backend._private_key_bytes( encoding, format, encryption_algorithm, self, self._evp_pkey, None ) def _raw_private_bytes(self) -> bytes: buf = self._backend._ffi.new("unsigned char []", _X448_KEY_SIZE) buflen = self._backend._ffi.new("size_t *", _X448_KEY_SIZE) res = self._backend._lib.EVP_PKEY_get_raw_private_key( self._evp_pkey, buf, buflen ) self._backend.openssl_assert(res == 1) self._backend.openssl_assert(buflen[0] == _X448_KEY_SIZE) return self._backend._ffi.buffer(buf, _X448_KEY_SIZE)[:]