sha512.c 7.27 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
/* sha512.c
 *
 * The sha512 hash function FIXME: Add the SHA384 variant.
 *
 * See http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2001, 2010 Niels Mller
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 *
 * The nettle library 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 Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/* Modelled after the sha1.c code by Peter Gutmann. */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "sha.h"

#include "macros.h"

/* Generated by the gp script

     {
       print("obase=16");
       for (i = 1,80,
         root = prime(i)^(1/3);
         fraction = root - floor(root);
         print(floor(2^64 * fraction));
       );
       quit();
     }

   piped through

     |grep -v '^[' | bc \
       |awk '{printf("0x%sULL,%s", $1, NR%3 == 0 ? "\n" : "");}'

   to convert it to hex.
*/

static const uint64_t
K[80] =
{
  0x428A2F98D728AE22ULL,0x7137449123EF65CDULL,
  0xB5C0FBCFEC4D3B2FULL,0xE9B5DBA58189DBBCULL,
  0x3956C25BF348B538ULL,0x59F111F1B605D019ULL,
  0x923F82A4AF194F9BULL,0xAB1C5ED5DA6D8118ULL,
  0xD807AA98A3030242ULL,0x12835B0145706FBEULL,
  0x243185BE4EE4B28CULL,0x550C7DC3D5FFB4E2ULL,
  0x72BE5D74F27B896FULL,0x80DEB1FE3B1696B1ULL,
  0x9BDC06A725C71235ULL,0xC19BF174CF692694ULL,
  0xE49B69C19EF14AD2ULL,0xEFBE4786384F25E3ULL,
  0xFC19DC68B8CD5B5ULL,0x240CA1CC77AC9C65ULL,
  0x2DE92C6F592B0275ULL,0x4A7484AA6EA6E483ULL,
  0x5CB0A9DCBD41FBD4ULL,0x76F988DA831153B5ULL,
  0x983E5152EE66DFABULL,0xA831C66D2DB43210ULL,
  0xB00327C898FB213FULL,0xBF597FC7BEEF0EE4ULL,
  0xC6E00BF33DA88FC2ULL,0xD5A79147930AA725ULL,
  0x6CA6351E003826FULL,0x142929670A0E6E70ULL,
  0x27B70A8546D22FFCULL,0x2E1B21385C26C926ULL,
  0x4D2C6DFC5AC42AEDULL,0x53380D139D95B3DFULL,
  0x650A73548BAF63DEULL,0x766A0ABB3C77B2A8ULL,
  0x81C2C92E47EDAEE6ULL,0x92722C851482353BULL,
  0xA2BFE8A14CF10364ULL,0xA81A664BBC423001ULL,
  0xC24B8B70D0F89791ULL,0xC76C51A30654BE30ULL,
  0xD192E819D6EF5218ULL,0xD69906245565A910ULL,
  0xF40E35855771202AULL,0x106AA07032BBD1B8ULL,
  0x19A4C116B8D2D0C8ULL,0x1E376C085141AB53ULL,
  0x2748774CDF8EEB99ULL,0x34B0BCB5E19B48A8ULL,
  0x391C0CB3C5C95A63ULL,0x4ED8AA4AE3418ACBULL,
  0x5B9CCA4F7763E373ULL,0x682E6FF3D6B2B8A3ULL,
  0x748F82EE5DEFB2FCULL,0x78A5636F43172F60ULL,
  0x84C87814A1F0AB72ULL,0x8CC702081A6439ECULL,
  0x90BEFFFA23631E28ULL,0xA4506CEBDE82BDE9ULL,
  0xBEF9A3F7B2C67915ULL,0xC67178F2E372532BULL,
  0xCA273ECEEA26619CULL,0xD186B8C721C0C207ULL,
  0xEADA7DD6CDE0EB1EULL,0xF57D4F7FEE6ED178ULL,
  0x6F067AA72176FBAULL,0xA637DC5A2C898A6ULL,
  0x113F9804BEF90DAEULL,0x1B710B35131C471BULL,
  0x28DB77F523047D84ULL,0x32CAAB7B40C72493ULL,
  0x3C9EBE0A15C9BEBCULL,0x431D67C49C100D4CULL,
  0x4CC5D4BECB3E42B6ULL,0x597F299CFC657E2AULL,
  0x5FCB6FAB3AD6FAECULL,0x6C44198C4A475817ULL,
};

void
sha512_init(struct sha512_ctx *ctx)
{
  /* Initial values, generated by the gp script
       {
         for (i = 1,8,
	   root = prime(i)^(1/2);
	   fraction = root - floor(root);
	   print(floor(2^64 * fraction));
	 );
       }
. */
  static const uint64_t H0[_SHA512_DIGEST_LENGTH] =
  {
    0x6A09E667F3BCC908ULL,0xBB67AE8584CAA73BULL,
    0x3C6EF372FE94F82BULL,0xA54FF53A5F1D36F1ULL,
    0x510E527FADE682D1ULL,0x9B05688C2B3E6C1FULL,
    0x1F83D9ABFB41BD6BULL,0x5BE0CD19137E2179ULL,
  };

  memcpy(ctx->state, H0, sizeof(H0));

  /* Initialize bit count */
  ctx->count_low = ctx->count_high = 0;
  
  /* Initialize buffer */
  ctx->index = 0;
}

136
#define SHA512_INCR(ctx) ((ctx)->count_high += !++(ctx)->count_low)
137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153

void
sha512_update(struct sha512_ctx *ctx,
	      unsigned length, const uint8_t *buffer)
{
  if (ctx->index)
    { /* Try to fill partial block */
      unsigned left = SHA512_DATA_SIZE - ctx->index;
      if (length < left)
	{
	  memcpy(ctx->block + ctx->index, buffer, length);
	  ctx->index += length;
	  return; /* Finished */
	}
      else
	{
	  memcpy(ctx->block + ctx->index, buffer, left);
154 155 156 157

	  _nettle_sha512_compress(ctx->state, ctx->block, K);
	  SHA512_INCR(ctx);

158 159 160 161 162 163
	  buffer += left;
	  length -= left;
	}
    }
  while (length >= SHA512_DATA_SIZE)
    {
164 165 166
      _nettle_sha512_compress(ctx->state, buffer, K);
      SHA512_INCR(ctx);

167 168 169 170 171 172 173 174 175 176 177 178 179 180 181
      buffer += SHA512_DATA_SIZE;
      length -= SHA512_DATA_SIZE;
    }

  /* Buffer leftovers */
  memcpy(ctx->block, buffer, length);
  ctx->index = length;
}

/* Final wrapup - pad to SHA1_DATA_SIZE-byte boundary with the bit pattern
   1 0* (64-bit count of bits processed, MSB-first) */

static void
sha512_final(struct sha512_ctx *ctx)
{
182 183
  uint64_t bitcount_high;
  uint64_t bitcount_low;
184 185 186 187 188 189 190 191 192 193
  int i;

  i = ctx->index;
  
  /* Set the first char of padding to 0x80.  This is safe since there is
     always at least one byte free */

  assert(i < SHA512_DATA_SIZE);
  ctx->block[i++] = 0x80;

194
  if (i > (SHA512_DATA_SIZE-16))
195 196
    { /* No room for length in this block. Process it and
       * pad with another one */
197 198 199 200
      memset(ctx->block + i, 0, SHA512_DATA_SIZE - i);
      _nettle_sha512_compress(ctx->state, ctx->block, K);

      i = 0;
201
    }
202 203 204

  if (i < (SHA512_DATA_SIZE - 16))
    memset(ctx->block + i, 0, (SHA512_DATA_SIZE - 16) - i);
205 206

  /* There are 1024 = 2^10 bits in one block */
207 208 209 210 211 212 213 214 215 216
  bitcount_high = (ctx->count_high << 10) | (ctx->count_low >> 54);
  bitcount_low = (ctx->count_low << 10) | (ctx->index << 3);

  /* This is slightly inefficient, as the numbers are converted to
     big-endian format, and will be converted back by the compression
     function. It's probably not worth the effort to fix this. */
  WRITE_UINT64(ctx->block + (SHA512_DATA_SIZE - 16), bitcount_high);
  WRITE_UINT64(ctx->block + (SHA512_DATA_SIZE - 8), bitcount_low);

  _nettle_sha512_compress(ctx->state, ctx->block, K);
217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273
}

void
sha512_digest(struct sha512_ctx *ctx,
	      unsigned length,
	      uint8_t *digest)
{
  unsigned i;
  unsigned words;
  unsigned leftover;
  
  assert(length <= SHA512_DIGEST_SIZE);

  sha512_final(ctx);
  
  words = length / 8;
  leftover = length % 8;

  for (i = 0; i < words; i++, digest += 8)
    WRITE_UINT64(digest, ctx->state[i]);

  if (leftover)
    {
      uint64_t word;
      unsigned j = leftover;
      
      assert(i < _SHA512_DIGEST_LENGTH);
      
      word = ctx->state[i];
      
      switch (leftover)
	{
	default:
	  abort();
	case 7:
	  digest[--j] = (word >> 8) & 0xff;
	  /* Fall through */
	case 6:
	  digest[--j] = (word >> 16) & 0xff;
	  /* Fall through */
	case 5:
	  digest[--j] = (word >> 24) & 0xff;
	  /* Fall through */
	case 4:
	  digest[--j] = (word >> 32) & 0xff;
	case 3:
	  digest[--j] = (word >> 40) & 0xff;
	  /* Fall through */
	case 2:
	  digest[--j] = (word >> 48) & 0xff;
	  /* Fall through */
	case 1:
	  digest[--j] = (word >> 56) & 0xff;
	}
    }
  sha512_init(ctx);
}