add out-of-order pref

[oweals/gnunet.git] / src / util / crypto_crc.c

diff --git a/src/util/crypto_crc.c b/src/util/crypto_crc.c
index 386f161385d20b64c9a98bbc005b43f21029b8b5..3d8e23e24db0cb8e53b769e06780deb104311b96 100644 (file)
--- a/src/util/crypto_crc.c
+++ b/src/util/crypto_crc.c
@@ -1,21 +1,21 @@
 /*
      This file is part of GNUnet.
-     (C) 2001, 2002, 2003, 2004, 2006 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2001, 2002, 2003, 2004, 2006 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
-     by the Free Software Foundation; either version 3, or (at your
-     option) any later version.
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
 
      GNUnet is distributed in the hope that it will be useful, but
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-     General Public License for more details.
+     Affero General Public License for more details.
+    
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-     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.
+     SPDX-License-Identifier: AGPL3.0-or-later
 
      For the actual CRC-32 code:
      Copyright abandoned; this code is in the public domain.
@@ -28,9 +28,9 @@
  * @author Christian Grothoff
  */
 #include "platform.h"
-#include "gnunet_util_lib.h"
+#include "gnunet_crypto_lib.h"
 
-#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+#define LOG(kind,...) GNUNET_log_from (kind, "util-crypto-crc", __VA_ARGS__)
 
 /* Avoid wasting space on 8-byte longs. */
 #if UINT_MAX >= 0xffffffff
@@ -165,5 +165,35 @@ GNUNET_CRYPTO_crc16_n (const void *buf, size_t len)
 }
 
 
+/**
+ * @ingroup hash
+ * Calculate the checksum of a buffer in one step.
+ *
+ * @param buf buffer to calculate CRC over
+ * @param len number of bytes in @a buf
+ * @return crc8 value
+ */
+uint8_t
+GNUNET_CRYPTO_crc8_n (const void *buf,
+                      size_t len)
+{
+  const uint8_t *data = buf;
+  unsigned int crc = 0;
+  int i;
+  int j;
+
+  for (j = len; 0 != j; j--)
+  {
+    crc ^= (*data++ << 8);
+    for (i = 8; 0 != i; i--)
+    {
+      if (0 != (crc & 0x8000))
+        crc ^= (0x1070 << 3);
+      crc <<= 1;
+    }
+  }
+  return (uint8_t) (crc >> 8);
+}
+
 
 /* end of crypto_crc.c */