diff options
Diffstat (limited to 'src/cryptography/hazmat/backends/openssl/aead.py')
| -rw-r--r-- | src/cryptography/hazmat/backends/openssl/aead.py | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/cryptography/hazmat/backends/openssl/aead.py b/src/cryptography/hazmat/backends/openssl/aead.py index 5eb2e997..53b10e99 100644 --- a/src/cryptography/hazmat/backends/openssl/aead.py +++ b/src/cryptography/hazmat/backends/openssl/aead.py @@ -11,6 +11,15 @@ _ENCRYPT = 1 _DECRYPT = 0 +def _aead_cipher_name(cls, key_length): + from cryptography.hazmat.primitives.ciphers.aead import ( + ChaCha20Poly1305 + ) + assert cls is ChaCha20Poly1305 + assert key_length == 32 or key_length is None + return b"chacha20-poly1305" + + def _aead_setup(backend, cipher_name, key, nonce, tag, tag_len, operation): evp_cipher = backend._lib.EVP_get_cipherbyname(cipher_name) backend.openssl_assert(evp_cipher != backend._ffi.NULL) @@ -69,8 +78,9 @@ def _process_data(backend, ctx, data): return backend._ffi.buffer(buf, outlen[0])[:] -def _encrypt(backend, cipher_name, key, nonce, data, associated_data, +def _encrypt(backend, cipher_cls, key, nonce, data, associated_data, tag_length): + cipher_name = _aead_cipher_name(cipher_cls, len(key)) ctx = _aead_setup( backend, cipher_name, key, nonce, None, tag_length, _ENCRYPT ) @@ -91,12 +101,13 @@ def _encrypt(backend, cipher_name, key, nonce, data, associated_data, return processed_data + tag -def _decrypt(backend, cipher_name, key, nonce, data, associated_data, +def _decrypt(backend, cipher_cls, key, nonce, data, associated_data, tag_length): if len(data) < tag_length: raise InvalidTag tag = data[-tag_length:] data = data[:-tag_length] + cipher_name = _aead_cipher_name(cipher_cls, len(key)) ctx = _aead_setup( backend, cipher_name, key, nonce, tag, tag_length, _DECRYPT ) |