Link libgnunetblockgroup to libgnunetblock
[oweals/gnunet.git] / src / util / crypto_symmetric.c
index 3cc54665232f6ca8fa76b18d0ce5ea2a562c88d6..e25e2f1dd502b042c6dbc22458035f336cce056b 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2001, 2002, 2003, 2004, 2005, 2006, 2013 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2013 GNUnet e.V.
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -14,8 +14,8 @@
 
      You should have received a copy of the GNU General Public License
      along with GNUnet; see the file COPYING.  If not, write to the
-     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-     Boston, MA 02111-1307, USA.
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
 */
 
 /**
  */
 
 #include "platform.h"
-#include "gnunet_util_lib.h"
+#include "gnunet_crypto_lib.h"
 #include <gcrypt.h>
 
-#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+#define LOG(kind,...) GNUNET_log_from (kind, "util-crypto-symmetric", __VA_ARGS__)
 
 /**
  * Create a new SessionKey (for symmetric encryption).
 void
 GNUNET_CRYPTO_symmetric_create_session_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
 {
-  gcry_randomize (key->aes_key, 
+  gcry_randomize (key->aes_key,
                   GNUNET_CRYPTO_AES_KEY_LENGTH,
                   GCRY_STRONG_RANDOM);
-  gcry_randomize (key->twofish_key, 
+  gcry_randomize (key->twofish_key,
                   GNUNET_CRYPTO_AES_KEY_LENGTH,
                   GCRY_STRONG_RANDOM);
 }
@@ -66,12 +66,12 @@ setup_cipher_aes (gcry_cipher_hd_t *handle,
   GNUNET_assert (0 ==
                  gcry_cipher_open (handle, GCRY_CIPHER_AES256,
                                    GCRY_CIPHER_MODE_CFB, 0));
-  rc = gcry_cipher_setkey (*handle, 
-                           sessionkey->aes_key, 
+  rc = gcry_cipher_setkey (*handle,
+                           sessionkey->aes_key,
                            sizeof (sessionkey->aes_key));
   GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
-  rc = gcry_cipher_setiv (*handle, 
-                          iv->aes_iv, 
+  rc = gcry_cipher_setiv (*handle,
+                          iv->aes_iv,
                           sizeof (iv->aes_iv));
   GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
   return GNUNET_OK;
@@ -94,13 +94,13 @@ setup_cipher_twofish (gcry_cipher_hd_t *handle,
   int rc;
 
   GNUNET_assert (0 ==
-                 gcry_cipher_open (handle, GCRY_CIPHER_TWOFISH, 
+                 gcry_cipher_open (handle, GCRY_CIPHER_TWOFISH,
                                    GCRY_CIPHER_MODE_CFB, 0));
-  rc = gcry_cipher_setkey (*handle, 
-                           sessionkey->twofish_key, 
+  rc = gcry_cipher_setkey (*handle,
+                           sessionkey->twofish_key,
                            sizeof (sessionkey->twofish_key));
   GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
-  rc = gcry_cipher_setiv (*handle, 
+  rc = gcry_cipher_setiv (*handle,
                           iv->twofish_iv,
                           sizeof (iv->twofish_iv));
   GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
@@ -109,56 +109,60 @@ setup_cipher_twofish (gcry_cipher_hd_t *handle,
 
 
 /**
- * Encrypt a block with the public key of another
- * host that uses the same cyper.
+ * Encrypt a block with a symmetric session key.
  *
  * @param block the block to encrypt
- * @param len the size of the @a block
+ * @param size the size of the @a block
  * @param sessionkey the key used to encrypt
- * @param iv the initialization vector to use, use INITVALUE
- *        for streams.
+ * @param iv the initialization vector to use, use INITVALUE for streams
  * @param result the output parameter in which to store the encrypted result
- * @returns the size of the encrypted block, -1 for errors
+ *               can be the same or overlap with @c block
+ * @returns the size of the encrypted block, -1 for errors.
+ *          Due to the use of CFB and therefore an effective stream cipher,
+ *          this size should be the same as @c len.
  */
 ssize_t
-GNUNET_CRYPTO_symmetric_encrypt (const void *block, size_t len,
-                           const struct GNUNET_CRYPTO_SymmetricSessionKey *
-                           sessionkey,
-                           const struct GNUNET_CRYPTO_SymmetricInitializationVector *
-                           iv, void *result)
+GNUNET_CRYPTO_symmetric_encrypt (const void *block,
+                                 size_t size,
+                                 const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
+                                 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
+                                 void *result)
 {
   gcry_cipher_hd_t handle;
-  char tmp[len];
+  char tmp[size];
 
   if (GNUNET_OK != setup_cipher_aes (&handle, sessionkey, iv))
     return -1;
-  GNUNET_assert (0 == gcry_cipher_encrypt (handle, tmp, len, block, len));
+  GNUNET_assert (0 == gcry_cipher_encrypt (handle, tmp, size, block, size));
   gcry_cipher_close (handle);
   if (GNUNET_OK != setup_cipher_twofish (&handle, sessionkey, iv))
     return -1;
-  GNUNET_assert (0 == gcry_cipher_encrypt (handle, result, len, tmp, len));
+  GNUNET_assert (0 == gcry_cipher_encrypt (handle, result, size, tmp, size));
   gcry_cipher_close (handle);
   memset (tmp, 0, sizeof (tmp));
-  return len;
+  return size;
 }
 
 
 /**
- * Decrypt a given block with the sessionkey.
+ * Decrypt a given block with the session key.
  *
  * @param block the data to decrypt, encoded as returned by encrypt
  * @param size the size of the @a block to decrypt
  * @param sessionkey the key used to decrypt
- * @param iv the initialization vector to use, use INITVALUE
- *        for streams.
+ * @param iv the initialization vector to use, use INITVALUE for streams
  * @param result address to store the result at
- * @return -1 on failure, size of decrypted block on success
+ *               can be the same or overlap with @c block
+ * @return -1 on failure, size of decrypted block on success.
+ *         Due to the use of CFB and therefore an effective stream cipher,
+ *         this size should be the same as @c size.
  */
 ssize_t
-GNUNET_CRYPTO_symmetric_decrypt (const void *block, size_t size,
-                           const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
-                           const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, 
-                           void *result)
+GNUNET_CRYPTO_symmetric_decrypt (const void *block,
+                                 size_t size,
+                                 const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
+                                 const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
+                                 void *result)
 {
   gcry_cipher_hd_t handle;
   char tmp[size];
@@ -187,8 +191,10 @@ GNUNET_CRYPTO_symmetric_decrypt (const void *block, size_t size,
  */
 void
 GNUNET_CRYPTO_symmetric_derive_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
-                             const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
-                             const void *salt, size_t salt_len, ...)
+                                   const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
+                                   const void *salt,
+                                   size_t salt_len,
+                                   ...)
 {
   va_list argp;
 
@@ -209,24 +215,32 @@ GNUNET_CRYPTO_symmetric_derive_iv (struct GNUNET_CRYPTO_SymmetricInitializationV
  */
 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)
+                                     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), 
+  GNUNET_memcpy (aes_salt, salt, salt_len);
+  GNUNET_memcpy (&aes_salt[salt_len], "AES!", 4);
+  GNUNET_memcpy (twofish_salt, salt, salt_len);
+  GNUNET_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), 
+  GNUNET_CRYPTO_kdf_v (iv->twofish_iv,
+                       sizeof (iv->twofish_iv),
+                       twofish_salt,
+                       salt_len + 4,
+                       skey->twofish_key,
+                       sizeof (skey->twofish_key),
                        argp);
 }
 
-/* end of crypto_aes.c */
+/* end of crypto_symmetric.c */