diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/olm/cipher.h | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/include/olm/cipher.h b/include/olm/cipher.h index 5f7185c..b26f8ba 100644 --- a/include/olm/cipher.h +++ b/include/olm/cipher.h @@ -102,28 +102,33 @@ struct _olm_cipher { struct _olm_cipher_aes_sha_256 { struct _olm_cipher base_cipher; + /** context string for the HKDF used for deriving the AES256 key, HMAC key, + * and AES IV, from the key material passed to encrypt/decrypt. + */ uint8_t const * kdf_info; + + /** length of context string kdf_info */ size_t kdf_info_length; }; +extern const struct _olm_cipher_ops _olm_cipher_aes_sha_256_ops; /** - * initialises a cipher type which uses AES256 for encryption and SHA256 for - * authentication. - * - * cipher: structure to be initialised + * get an initializer for an instance of struct _olm_cipher_aes_sha_256. * - * kdf_info: context string for the HKDF used for deriving the AES256 key, HMAC - * key, and AES IV, from the key material passed to encrypt/decrypt. Note that - * this is NOT copied so must have a lifetime at least as long as the cipher - * instance. + * To use it, declare: * - * kdf_info_length: length of context string kdf_info + * struct _olm_cipher_aes_sha_256 MY_CIPHER = + * OLM_CIPHER_INIT_AES_SHA_256("MY_KDF"); + * struct _olm_cipher *cipher = OLM_CIPHER_BASE(&MY_CIPHER); */ -struct _olm_cipher *_olm_cipher_aes_sha_256_init( - struct _olm_cipher_aes_sha_256 *cipher, - uint8_t const * kdf_info, - size_t kdf_info_length); +#define OLM_CIPHER_INIT_AES_SHA_256(KDF_INFO) { \ + .base_cipher = { &_olm_cipher_aes_sha_256_ops },\ + .kdf_info = (uint8_t *)(KDF_INFO), \ + .kdf_info_length = sizeof(KDF_INFO) - 1 \ +} +#define OLM_CIPHER_BASE(CIPHER) \ + (&((CIPHER)->base_cipher)) #ifdef __cplusplus |