/**
* @brief Derive an authentication key
* @param key authentication key
* @param rkey root key
* @param salt salt
* @param salt_len size of the salt
* @param argp pair of void * & size_t for context chunks, terminated by NULL
*/
void
GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key,
const struct GNUNET_CRYPTO_AesSessionKey *rkey,
const void *salt, size_t salt_len,
va_list argp)
{
GNUNET_CRYPTO_kdf_v (key->key, sizeof (key->key), salt, salt_len, rkey->key,
sizeof (rkey->key), argp);
}
/**
* @brief Derive an IV
*
* @param iv initialization vector
* @param skey session key
* @param salt salt for the derivation
* @param salt_len size of the salt
* @param argp pairs of void * & size_t for context chunks, terminated by NULL
*/
void
GNUNET_CRYPTO_symmetric_derive_iv_v (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
const void *salt, size_t salt_len, va_list argp)
{
char aes_salt[salt_len + 4];
char twofish_salt[salt_len + 4];
memcpy (aes_salt, salt, salt_len);
memcpy (&aes_salt[salt_len], "AES!", 4);
memcpy (twofish_salt, salt, salt_len);
memcpy (&twofish_salt[salt_len], "FISH", 4);
GNUNET_CRYPTO_kdf_v (iv->aes_iv, sizeof (iv->aes_iv),
aes_salt, salt_len + 4,
skey->aes_key, sizeof (skey->aes_key),
argp);
GNUNET_CRYPTO_kdf_v (iv->twofish_iv, sizeof (iv->twofish_iv),
twofish_salt, salt_len + 4,
skey->twofish_key, sizeof (skey->twofish_key),
argp);
}
