#include "gnunet_crypto_lib.h"
#include <gcrypt.h>
+#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+
/**
* Create a new SessionKey (for AES-256).
+ *
+ * @param key session key to initialize
*/
void
GNUNET_CRYPTO_aes_create_session_key (struct GNUNET_CRYPTO_AesSessionKey *key)
{
gcry_randomize (&key->key[0], GNUNET_CRYPTO_AES_KEY_LENGTH,
GCRY_STRONG_RANDOM);
- key->crc32 =
- htonl (GNUNET_CRYPTO_crc32_n (key, GNUNET_CRYPTO_AES_KEY_LENGTH));
}
+
/**
- * Check that a new session key is well-formed.
+ * Initialize AES cipher.
*
- * @return GNUNET_OK if the key is valid
+ * @param handle handle to initialize
+ * @param sessionkey session key to use
+ * @param iv initialization vector to use
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
*/
-int
-GNUNET_CRYPTO_aes_check_session_key (const struct GNUNET_CRYPTO_AesSessionKey
- *key)
+static int
+setup_cipher (gcry_cipher_hd_t *handle,
+ const struct GNUNET_CRYPTO_AesSessionKey *
+ sessionkey,
+ const struct GNUNET_CRYPTO_AesInitializationVector *
+ iv)
{
- uint32_t crc;
+ int rc;
- crc = GNUNET_CRYPTO_crc32_n (key, GNUNET_CRYPTO_AES_KEY_LENGTH);
- if (ntohl (key->crc32) == crc)
- return GNUNET_OK;
- GNUNET_break (0);
- return GNUNET_SYSERR;
+ GNUNET_assert (0 ==
+ gcry_cipher_open (handle, GCRY_CIPHER_AES256,
+ GCRY_CIPHER_MODE_CFB, 0));
+ rc = gcry_cipher_setkey (*handle, sessionkey, GNUNET_CRYPTO_AES_KEY_LENGTH);
+ GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
+ rc = gcry_cipher_setiv (*handle, iv,
+ sizeof (struct
+ GNUNET_CRYPTO_AesInitializationVector));
+ GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
+ return GNUNET_OK;
}
/**
* Encrypt a block with the public key of another
* host that uses the same cyper.
+ *
* @param block the block to encrypt
* @param len the size of the block
* @param sessionkey the key used to encrypt
* @returns the size of the encrypted block, -1 for errors
*/
ssize_t
-GNUNET_CRYPTO_aes_encrypt (const void *block,
- size_t len,
- const struct GNUNET_CRYPTO_AesSessionKey
- *sessionkey,
- const struct GNUNET_CRYPTO_AesInitializationVector
- *iv, void *result)
+GNUNET_CRYPTO_aes_encrypt (const void *block, size_t len,
+ const struct GNUNET_CRYPTO_AesSessionKey *
+ sessionkey,
+ const struct GNUNET_CRYPTO_AesInitializationVector *
+ iv, void *result)
{
gcry_cipher_hd_t handle;
- int rc;
- if (sessionkey->crc32 !=
- htonl (GNUNET_CRYPTO_crc32_n
- (sessionkey, GNUNET_CRYPTO_AES_KEY_LENGTH)))
- {
- GNUNET_break (0);
- return -1;
- }
- GNUNET_assert (0 == gcry_cipher_open (&handle,
- GCRY_CIPHER_AES256,
- GCRY_CIPHER_MODE_CFB, 0));
- rc = gcry_cipher_setkey (handle, sessionkey, GNUNET_CRYPTO_AES_KEY_LENGTH);
- GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
- rc =
- gcry_cipher_setiv (handle, iv,
- sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
- GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
+ if (GNUNET_OK != setup_cipher (&handle, sessionkey, iv))
+ return -1;
GNUNET_assert (0 == gcry_cipher_encrypt (handle, result, len, block, len));
gcry_cipher_close (handle);
return len;
}
+
/**
* Decrypt a given block with the sessionkey.
*
* @return -1 on failure, size of decrypted block on success
*/
ssize_t
-GNUNET_CRYPTO_aes_decrypt (const void *block,
- size_t size,
- const struct GNUNET_CRYPTO_AesSessionKey
- *sessionkey,
- const struct GNUNET_CRYPTO_AesInitializationVector
- *iv, void *result)
+GNUNET_CRYPTO_aes_decrypt (const void *block, size_t size,
+ const struct GNUNET_CRYPTO_AesSessionKey *
+ sessionkey,
+ const struct GNUNET_CRYPTO_AesInitializationVector *
+ iv, void *result)
{
gcry_cipher_hd_t handle;
- int rc;
- if (sessionkey->crc32 !=
- htonl (GNUNET_CRYPTO_crc32_n
- (sessionkey, GNUNET_CRYPTO_AES_KEY_LENGTH)))
- {
- GNUNET_break (0);
- return -1;
- }
- GNUNET_assert (0 == gcry_cipher_open (&handle,
- GCRY_CIPHER_AES256,
- GCRY_CIPHER_MODE_CFB, 0));
- rc = gcry_cipher_setkey (handle, sessionkey, GNUNET_CRYPTO_AES_KEY_LENGTH);
- GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
- rc =
- gcry_cipher_setiv (handle, iv,
- sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
- GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
- GNUNET_assert (0 ==
- gcry_cipher_decrypt (handle, result, size, block, size));
+ if (GNUNET_OK != setup_cipher (&handle, sessionkey, iv))
+ return -1;
+ GNUNET_assert (0 == gcry_cipher_decrypt (handle, result, size, block, size));
gcry_cipher_close (handle);
return size;
}
+
+/**
+ * @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 ... pairs of void * & size_t for context chunks, terminated by NULL
+ */
+void
+GNUNET_CRYPTO_aes_derive_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
+ const struct GNUNET_CRYPTO_AesSessionKey *skey,
+ const void *salt, size_t salt_len, ...)
+{
+ va_list argp;
+
+ va_start (argp, salt_len);
+ GNUNET_CRYPTO_aes_derive_iv_v (iv, skey, salt, salt_len, argp);
+ va_end (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_aes_derive_iv_v (struct GNUNET_CRYPTO_AesInitializationVector *iv,
+ const struct GNUNET_CRYPTO_AesSessionKey *skey,
+ const void *salt, size_t salt_len, va_list argp)
+{
+ GNUNET_CRYPTO_kdf_v (iv->iv, sizeof (iv->iv), salt, salt_len, skey->key,
+ sizeof (skey->key), argp);
+}
+
/* end of crypto_aes.c */