crypt/sha512.c

   1 /* Functions to compute SHA512 message digest of files or memory blocks.
   2    according to the definition of SHA512 in FIPS 180-2.
   3    Copyright (C) 2007-2012 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 /* Written by Ulrich Drepper <drepper@redhat.com>, 2007.  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <endian.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30
  31 #include "sha512.h"
  32
  33 #if __BYTE_ORDER == __LITTLE_ENDIAN
  34 # ifdef _LIBC
  35 #  include <byteswap.h>
  36 #  define SWAP(n) bswap_64 (n)
  37 # else
  38 #  define SWAP(n) \
  39   (((n) << 56)                                  \
  40    | (((n) & 0xff00) << 40)                     \
  41    | (((n) & 0xff0000) << 24)                   \
  42    | (((n) & 0xff000000) << 8)                  \
  43    | (((n) >> 8) & 0xff000000)                  \
  44    | (((n) >> 24) & 0xff0000)                   \
  45    | (((n) >> 40) & 0xff00)                     \
  46    | ((n) >> 56))
  47 # endif
  48 #else
  49 # define SWAP(n) (n)
  50 #endif
  51
  52
  53 /* This array contains the bytes used to pad the buffer to the next
  54    64-byte boundary.  (FIPS 180-2:5.1.2)  */
  55 static const unsigned char fillbuf[128] = { 0x80, 0 /* , 0, 0, ...  */ };
  56
  57
  58 /* Constants for SHA512 from FIPS 180-2:4.2.3.  */
  59 static const uint64_t K[80] =
  60   {
  61     UINT64_C (0x428a2f98d728ae22), UINT64_C (0x7137449123ef65cd),
  62     UINT64_C (0xb5c0fbcfec4d3b2f), UINT64_C (0xe9b5dba58189dbbc),
  63     UINT64_C (0x3956c25bf348b538), UINT64_C (0x59f111f1b605d019),
  64     UINT64_C (0x923f82a4af194f9b), UINT64_C (0xab1c5ed5da6d8118),
  65     UINT64_C (0xd807aa98a3030242), UINT64_C (0x12835b0145706fbe),
  66     UINT64_C (0x243185be4ee4b28c), UINT64_C (0x550c7dc3d5ffb4e2),
  67     UINT64_C (0x72be5d74f27b896f), UINT64_C (0x80deb1fe3b1696b1),
  68     UINT64_C (0x9bdc06a725c71235), UINT64_C (0xc19bf174cf692694),
  69     UINT64_C (0xe49b69c19ef14ad2), UINT64_C (0xefbe4786384f25e3),
  70     UINT64_C (0x0fc19dc68b8cd5b5), UINT64_C (0x240ca1cc77ac9c65),
  71     UINT64_C (0x2de92c6f592b0275), UINT64_C (0x4a7484aa6ea6e483),
  72     UINT64_C (0x5cb0a9dcbd41fbd4), UINT64_C (0x76f988da831153b5),
  73     UINT64_C (0x983e5152ee66dfab), UINT64_C (0xa831c66d2db43210),
  74     UINT64_C (0xb00327c898fb213f), UINT64_C (0xbf597fc7beef0ee4),
  75     UINT64_C (0xc6e00bf33da88fc2), UINT64_C (0xd5a79147930aa725),
  76     UINT64_C (0x06ca6351e003826f), UINT64_C (0x142929670a0e6e70),
  77     UINT64_C (0x27b70a8546d22ffc), UINT64_C (0x2e1b21385c26c926),
  78     UINT64_C (0x4d2c6dfc5ac42aed), UINT64_C (0x53380d139d95b3df),
  79     UINT64_C (0x650a73548baf63de), UINT64_C (0x766a0abb3c77b2a8),
  80     UINT64_C (0x81c2c92e47edaee6), UINT64_C (0x92722c851482353b),
  81     UINT64_C (0xa2bfe8a14cf10364), UINT64_C (0xa81a664bbc423001),
  82     UINT64_C (0xc24b8b70d0f89791), UINT64_C (0xc76c51a30654be30),
  83     UINT64_C (0xd192e819d6ef5218), UINT64_C (0xd69906245565a910),
  84     UINT64_C (0xf40e35855771202a), UINT64_C (0x106aa07032bbd1b8),
  85     UINT64_C (0x19a4c116b8d2d0c8), UINT64_C (0x1e376c085141ab53),
  86     UINT64_C (0x2748774cdf8eeb99), UINT64_C (0x34b0bcb5e19b48a8),
  87     UINT64_C (0x391c0cb3c5c95a63), UINT64_C (0x4ed8aa4ae3418acb),
  88     UINT64_C (0x5b9cca4f7763e373), UINT64_C (0x682e6ff3d6b2b8a3),
  89     UINT64_C (0x748f82ee5defb2fc), UINT64_C (0x78a5636f43172f60),
  90     UINT64_C (0x84c87814a1f0ab72), UINT64_C (0x8cc702081a6439ec),
  91     UINT64_C (0x90befffa23631e28), UINT64_C (0xa4506cebde82bde9),
  92     UINT64_C (0xbef9a3f7b2c67915), UINT64_C (0xc67178f2e372532b),
  93     UINT64_C (0xca273eceea26619c), UINT64_C (0xd186b8c721c0c207),
  94     UINT64_C (0xeada7dd6cde0eb1e), UINT64_C (0xf57d4f7fee6ed178),
  95     UINT64_C (0x06f067aa72176fba), UINT64_C (0x0a637dc5a2c898a6),
  96     UINT64_C (0x113f9804bef90dae), UINT64_C (0x1b710b35131c471b),
  97     UINT64_C (0x28db77f523047d84), UINT64_C (0x32caab7b40c72493),
  98     UINT64_C (0x3c9ebe0a15c9bebc), UINT64_C (0x431d67c49c100d4c),
  99     UINT64_C (0x4cc5d4becb3e42b6), UINT64_C (0x597f299cfc657e2a),
 100     UINT64_C (0x5fcb6fab3ad6faec), UINT64_C (0x6c44198c4a475817)
 101   };
 102
 103
 104 /* Process LEN bytes of BUFFER, accumulating context into CTX.
 105    It is assumed that LEN % 128 == 0.  */
 106 static void
 107 sha512_process_block (const void *buffer, size_t len, struct sha512_ctx *ctx)
 108 {
 109   const uint64_t *words = buffer;
 110   size_t nwords = len / sizeof (uint64_t);
 111   uint64_t a = ctx->H[0];
 112   uint64_t b = ctx->H[1];
 113   uint64_t c = ctx->H[2];
 114   uint64_t d = ctx->H[3];
 115   uint64_t e = ctx->H[4];
 116   uint64_t f = ctx->H[5];
 117   uint64_t g = ctx->H[6];
 118   uint64_t h = ctx->H[7];
 119
 120   /* First increment the byte count.  FIPS 180-2 specifies the possible
 121      length of the file up to 2^128 bits.  Here we only compute the
 122      number of bytes.  Do a double word increment.  */
 123 #ifdef USE_TOTAL128
 124   ctx->total128 += len;
 125 #else
 126   uint64_t lolen = len;
 127   ctx->total[TOTAL128_low] += lolen;
 128   ctx->total[TOTAL128_high] += ((len >> 31 >> 31 >> 2)
 129                                 + (ctx->total[TOTAL128_low] < lolen));
 130 #endif
 131
 132   /* Process all bytes in the buffer with 128 bytes in each round of
 133      the loop.  */
 134   while (nwords > 0)
 135     {
 136       uint64_t W[80];
 137       uint64_t a_save = a;
 138       uint64_t b_save = b;
 139       uint64_t c_save = c;
 140       uint64_t d_save = d;
 141       uint64_t e_save = e;
 142       uint64_t f_save = f;
 143       uint64_t g_save = g;
 144       uint64_t h_save = h;
 145
 146       /* Operators defined in FIPS 180-2:4.1.2.  */
 147 #define Ch(x, y, z) ((x & y) ^ (~x & z))
 148 #define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
 149 #define S0(x) (CYCLIC (x, 28) ^ CYCLIC (x, 34) ^ CYCLIC (x, 39))
 150 #define S1(x) (CYCLIC (x, 14) ^ CYCLIC (x, 18) ^ CYCLIC (x, 41))
 151 #define R0(x) (CYCLIC (x, 1) ^ CYCLIC (x, 8) ^ (x >> 7))
 152 #define R1(x) (CYCLIC (x, 19) ^ CYCLIC (x, 61) ^ (x >> 6))
 153
 154       /* It is unfortunate that C does not provide an operator for
 155          cyclic rotation.  Hope the C compiler is smart enough.  */
 156 #define CYCLIC(w, s) ((w >> s) | (w << (64 - s)))
 157
 158       /* Compute the message schedule according to FIPS 180-2:6.3.2 step 2.  */
 159       for (unsigned int t = 0; t < 16; ++t)
 160         {
 161           W[t] = SWAP (*words);
 162           ++words;
 163         }
 164       for (unsigned int t = 16; t < 80; ++t)
 165         W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
 166
 167       /* The actual computation according to FIPS 180-2:6.3.2 step 3.  */
 168       for (unsigned int t = 0; t < 80; ++t)
 169         {
 170           uint64_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
 171           uint64_t T2 = S0 (a) + Maj (a, b, c);
 172           h = g;
 173           g = f;
 174           f = e;
 175           e = d + T1;
 176           d = c;
 177           c = b;
 178           b = a;
 179           a = T1 + T2;
 180         }
 181
 182       /* Add the starting values of the context according to FIPS 180-2:6.3.2
 183          step 4.  */
 184       a += a_save;
 185       b += b_save;
 186       c += c_save;
 187       d += d_save;
 188       e += e_save;
 189       f += f_save;
 190       g += g_save;
 191       h += h_save;
 192
 193       /* Prepare for the next round.  */
 194       nwords -= 16;
 195     }
 196
 197   /* Put checksum in context given as argument.  */
 198   ctx->H[0] = a;
 199   ctx->H[1] = b;
 200   ctx->H[2] = c;
 201   ctx->H[3] = d;
 202   ctx->H[4] = e;
 203   ctx->H[5] = f;
 204   ctx->H[6] = g;
 205   ctx->H[7] = h;
 206 }
 207
 208
 209 /* Initialize structure containing state of computation.
 210    (FIPS 180-2:5.3.3)  */
 211 void
 212 __sha512_init_ctx (ctx)
 213      struct sha512_ctx *ctx;
 214 {
 215   ctx->H[0] = UINT64_C (0x6a09e667f3bcc908);
 216   ctx->H[1] = UINT64_C (0xbb67ae8584caa73b);
 217   ctx->H[2] = UINT64_C (0x3c6ef372fe94f82b);
 218   ctx->H[3] = UINT64_C (0xa54ff53a5f1d36f1);
 219   ctx->H[4] = UINT64_C (0x510e527fade682d1);
 220   ctx->H[5] = UINT64_C (0x9b05688c2b3e6c1f);
 221   ctx->H[6] = UINT64_C (0x1f83d9abfb41bd6b);
 222   ctx->H[7] = UINT64_C (0x5be0cd19137e2179);
 223
 224   ctx->total[0] = ctx->total[1] = 0;
 225   ctx->buflen = 0;
 226 }
 227
 228
 229 /* Process the remaining bytes in the internal buffer and the usual
 230    prolog according to the standard and write the result to RESBUF.
 231
 232    IMPORTANT: On some systems it is required that RESBUF is correctly
 233    aligned for a 32 bits value.  */
 234 void *
 235 __sha512_finish_ctx (ctx, resbuf)
 236      struct sha512_ctx *ctx;
 237      void *resbuf;
 238 {
 239   /* Take yet unprocessed bytes into account.  */
 240   uint64_t bytes = ctx->buflen;
 241   size_t pad;
 242
 243   /* Now count remaining bytes.  */
 244 #ifdef USE_TOTAL128
 245   ctx->total128 += bytes;
 246 #else
 247   ctx->total[TOTAL128_low] += bytes;
 248   if (ctx->total[TOTAL128_low] < bytes)
 249     ++ctx->total[TOTAL128_high];
 250 #endif
 251
 252   pad = bytes >= 112 ? 128 + 112 - bytes : 112 - bytes;
 253   memcpy (&ctx->buffer[bytes], fillbuf, pad);
 254
 255   /* Put the 128-bit file length in *bits* at the end of the buffer.  */
 256   ctx->buffer64[(bytes + pad + 8) / 8] = SWAP (ctx->total[TOTAL128_low] << 3);
 257   ctx->buffer64[(bytes + pad) / 8] = SWAP ((ctx->total[TOTAL128_high] << 3) |
 258                                            (ctx->total[TOTAL128_low] >> 61));
 259
 260   /* Process last bytes.  */
 261   sha512_process_block (ctx->buffer, bytes + pad + 16, ctx);
 262
 263   /* Put result from CTX in first 64 bytes following RESBUF.  */
 264   for (unsigned int i = 0; i < 8; ++i)
 265     ((uint64_t *) resbuf)[i] = SWAP (ctx->H[i]);
 266
 267   return resbuf;
 268 }
 269
 270
 271 void
 272 __sha512_process_bytes (buffer, len, ctx)
 273      const void *buffer;
 274      size_t len;
 275      struct sha512_ctx *ctx;
 276 {
 277   /* When we already have some bits in our internal buffer concatenate
 278      both inputs first.  */
 279   if (ctx->buflen != 0)
 280     {
 281       size_t left_over = ctx->buflen;
 282       size_t add = 256 - left_over > len ? len : 256 - left_over;
 283
 284       memcpy (&ctx->buffer[left_over], buffer, add);
 285       ctx->buflen += add;
 286
 287       if (ctx->buflen > 128)
 288         {
 289           sha512_process_block (ctx->buffer, ctx->buflen & ~127, ctx);
 290
 291           ctx->buflen &= 127;
 292           /* The regions in the following copy operation cannot overlap.  */
 293           memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~127],
 294                   ctx->buflen);
 295         }
 296
 297       buffer = (const char *) buffer + add;
 298       len -= add;
 299     }
 300
 301   /* Process available complete blocks.  */
 302   if (len >= 128)
 303     {
 304 #if !_STRING_ARCH_unaligned
 305 /* To check alignment gcc has an appropriate operator.  Other
 306    compilers don't.  */
 307 # if __GNUC__ >= 2
 308 #  define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint64_t) != 0)
 309 # else
 310 #  define UNALIGNED_P(p) (((uintptr_t) p) % sizeof (uint64_t) != 0)
 311 # endif
 312       if (UNALIGNED_P (buffer))
 313         while (len > 128)
 314           {
 315             sha512_process_block (memcpy (ctx->buffer, buffer, 128), 128,
 316                                     ctx);
 317             buffer = (const char *) buffer + 128;
 318             len -= 128;
 319           }
 320       else
 321 #endif
 322         {
 323           sha512_process_block (buffer, len & ~127, ctx);
 324           buffer = (const char *) buffer + (len & ~127);
 325           len &= 127;
 326         }
 327     }
 328
 329   /* Move remaining bytes into internal buffer.  */
 330   if (len > 0)
 331     {
 332       size_t left_over = ctx->buflen;
 333
 334       memcpy (&ctx->buffer[left_over], buffer, len);
 335       left_over += len;
 336       if (left_over >= 128)
 337         {
 338           sha512_process_block (ctx->buffer, 128, ctx);
 339           left_over -= 128;
 340           memcpy (ctx->buffer, &ctx->buffer[128], left_over);
 341         }
 342       ctx->buflen = left_over;
 343     }
 344 }