release/src/router/nettle/sha1.c

   1 /* sha1.c
   2  *
   3  * The sha1 hash function.
   4  * Defined by http://www.itl.nist.gov/fipspubs/fip180-1.htm.
   5  */
   6
   7 /* nettle, low-level cryptographics library
   8  *
   9  * Copyright (C) 2001 Peter Gutmann, Andrew Kuchling, Niels Möller
  10  *
  11  * The nettle library is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 of the License, or (at your
  14  * option) any later version.
  15  *
  16  * The nettle library is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  18  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  19  * License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  23  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  24  * MA 02111-1301, USA.
  25  */
  26
  27 /* Here's the first paragraph of Peter Gutmann's posting,
  28  * <30ajo5$oe8@ccu2.auckland.ac.nz>:
  29  *
  30  * The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
  31  * SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
  32  * what's changed in the new version.  The fix is a simple change which involves
  33  * adding a single rotate in the initial expansion function.  It is unknown
  34  * whether this is an optimal solution to the problem which was discovered in the
  35  * SHA or whether it's simply a bandaid which fixes the problem with a minimum of
  36  * effort (for example the reengineering of a great many Capstone chips).
  37  */
  38
  39 #if HAVE_CONFIG_H
  40 # include "config.h"
  41 #endif
  42
  43 #include <assert.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 #include "sha1.h"
  48
  49 #include "macros.h"
  50 #include "nettle-write.h"
  51
  52 /* Initialize the SHA values */
  53 void
  54 sha1_init(struct sha1_ctx *ctx)
  55 {
  56   /* FIXME: Put the buffer last in the struct, and arrange so that we
  57      can initialize with a single memcpy. */
  58   static const uint32_t iv[_SHA1_DIGEST_LENGTH] =
  59     {
  60       /* SHA initial values */
  61       0x67452301L,
  62       0xEFCDAB89L,
  63       0x98BADCFEL,
  64       0x10325476L,
  65       0xC3D2E1F0L,
  66     };
  67
  68   memcpy(ctx->state, iv, sizeof(ctx->state));
  69   ctx->count_low = ctx->count_high = 0;
  70
  71   /* Initialize buffer */
  72   ctx->index = 0;
  73 }
  74
  75 #define COMPRESS(ctx, data) (_nettle_sha1_compress((ctx)->state, data))
  76
  77 void
  78 sha1_update(struct sha1_ctx *ctx,
  79             unsigned length, const uint8_t *data)
  80 {
  81   MD_UPDATE (ctx, length, data, COMPRESS, MD_INCR(ctx));
  82 }
  83
  84 void
  85 sha1_digest(struct sha1_ctx *ctx,
  86             unsigned length,
  87             uint8_t *digest)
  88 {
  89   uint32_t high, low;
  90
  91   assert(length <= SHA1_DIGEST_SIZE);
  92
  93   MD_PAD(ctx, 8, COMPRESS);
  94
  95   /* There are 512 = 2^9 bits in one block */
  96   high = (ctx->count_high << 9) | (ctx->count_low >> 23);
  97   low = (ctx->count_low << 9) | (ctx->index << 3);
  98
  99   /* append the 64 bit count */
 100   WRITE_UINT32(ctx->block + (SHA1_DATA_SIZE - 8), high);
 101   WRITE_UINT32(ctx->block + (SHA1_DATA_SIZE - 4), low);
 102   _nettle_sha1_compress(ctx->state, ctx->block);
 103
 104   _nettle_write_be32(length, digest, ctx->state);
 105   sha1_init(ctx);
 106 }