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 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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 /* Written by Ulrich Drepper <drepper@redhat.com>, 2007.  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 #include <endian.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <sys/types.h>
  31
  32 #include "sha512.h"
  33
  34 #if __BYTE_ORDER == __LITTLE_ENDIAN
  35 # ifdef _LIBC
  36 #  include <byteswap.h>
  37 #  define SWAP(n) bswap_64 (n)
  38 # else
  39 #  define SWAP(n) \
  40   (((n) << 56)                                  \
  41    | (((n) & 0xff00) << 40)                     \
  42    | (((n) & 0xff0000) << 24)                   \
  43    | (((n) & 0xff000000) << 8)                  \
  44    | (((n) >> 8) & 0xff000000)                  \
  45    | (((n) >> 24) & 0xff0000)                   \
  46    | (((n) >> 40) & 0xff00)                     \
  47    | ((n) >> 56))
  48 # endif
  49 #else
  50 # define SWAP(n) (n)
  51 #endif
  52
  53
  54 /* This array contains the bytes used to pad the buffer to the next
  55    64-byte boundary.  (FIPS 180-2:5.1.2)  */
  56 static const unsigned char fillbuf[128] = { 0x80, 0 /* , 0, 0, ...  */ };
  57
  58
  59 /* Constants for SHA512 from FIPS 180-2:4.2.3.  */
  60 static const uint64_t K[80] =
  61   {
  62     UINT64_C (0x428a2f98d728ae22), UINT64_C (0x7137449123ef65cd),
  63     UINT64_C (0xb5c0fbcfec4d3b2f), UINT64_C (0xe9b5dba58189dbbc),
  64     UINT64_C (0x3956c25bf348b538), UINT64_C (0x59f111f1b605d019),
  65     UINT64_C (0x923f82a4af194f9b), UINT64_C (0xab1c5ed5da6d8118),
  66     UINT64_C (0xd807aa98a3030242), UINT64_C (0x12835b0145706fbe),
  67     UINT64_C (0x243185be4ee4b28c), UINT64_C (0x550c7dc3d5ffb4e2),
  68     UINT64_C (0x72be5d74f27b896f), UINT64_C (0x80deb1fe3b1696b1),
  69     UINT64_C (0x9bdc06a725c71235), UINT64_C (0xc19bf174cf692694),
  70     UINT64_C (0xe49b69c19ef14ad2), UINT64_C (0xefbe4786384f25e3),
  71     UINT64_C (0x0fc19dc68b8cd5b5), UINT64_C (0x240ca1cc77ac9c65),
  72     UINT64_C (0x2de92c6f592b0275), UINT64_C (0x4a7484aa6ea6e483),
  73     UINT64_C (0x5cb0a9dcbd41fbd4), UINT64_C (0x76f988da831153b5),
  74     UINT64_C (0x983e5152ee66dfab), UINT64_C (0xa831c66d2db43210),
  75     UINT64_C (0xb00327c898fb213f), UINT64_C (0xbf597fc7beef0ee4),
  76     UINT64_C (0xc6e00bf33da88fc2), UINT64_C (0xd5a79147930aa725),
  77     UINT64_C (0x06ca6351e003826f), UINT64_C (0x142929670a0e6e70),
  78     UINT64_C (0x27b70a8546d22ffc), UINT64_C (0x2e1b21385c26c926),
  79     UINT64_C (0x4d2c6dfc5ac42aed), UINT64_C (0x53380d139d95b3df),
  80     UINT64_C (0x650a73548baf63de), UINT64_C (0x766a0abb3c77b2a8),
  81     UINT64_C (0x81c2c92e47edaee6), UINT64_C (0x92722c851482353b),
  82     UINT64_C (0xa2bfe8a14cf10364), UINT64_C (0xa81a664bbc423001),
  83     UINT64_C (0xc24b8b70d0f89791), UINT64_C (0xc76c51a30654be30),
  84     UINT64_C (0xd192e819d6ef5218), UINT64_C (0xd69906245565a910),
  85     UINT64_C (0xf40e35855771202a), UINT64_C (0x106aa07032bbd1b8),
  86     UINT64_C (0x19a4c116b8d2d0c8), UINT64_C (0x1e376c085141ab53),
  87     UINT64_C (0x2748774cdf8eeb99), UINT64_C (0x34b0bcb5e19b48a8),
  88     UINT64_C (0x391c0cb3c5c95a63), UINT64_C (0x4ed8aa4ae3418acb),
  89     UINT64_C (0x5b9cca4f7763e373), UINT64_C (0x682e6ff3d6b2b8a3),
  90     UINT64_C (0x748f82ee5defb2fc), UINT64_C (0x78a5636f43172f60),
  91     UINT64_C (0x84c87814a1f0ab72), UINT64_C (0x8cc702081a6439ec),
  92     UINT64_C (0x90befffa23631e28), UINT64_C (0xa4506cebde82bde9),
  93     UINT64_C (0xbef9a3f7b2c67915), UINT64_C (0xc67178f2e372532b),
  94     UINT64_C (0xca273eceea26619c), UINT64_C (0xd186b8c721c0c207),
  95     UINT64_C (0xeada7dd6cde0eb1e), UINT64_C (0xf57d4f7fee6ed178),
  96     UINT64_C (0x06f067aa72176fba), UINT64_C (0x0a637dc5a2c898a6),
  97     UINT64_C (0x113f9804bef90dae), UINT64_C (0x1b710b35131c471b),
  98     UINT64_C (0x28db77f523047d84), UINT64_C (0x32caab7b40c72493),
  99     UINT64_C (0x3c9ebe0a15c9bebc), UINT64_C (0x431d67c49c100d4c),
 100     UINT64_C (0x4cc5d4becb3e42b6), UINT64_C (0x597f299cfc657e2a),
 101     UINT64_C (0x5fcb6fab3ad6faec), UINT64_C (0x6c44198c4a475817)
 102   };
 103
 104
 105 /* Process LEN bytes of BUFFER, accumulating context into CTX.
 106    It is assumed that LEN % 128 == 0.  */
 107 static void
 108 sha512_process_block (const void *buffer, size_t len, struct sha512_ctx *ctx)
 109 {
 110   const uint64_t *words = buffer;
 111   size_t nwords = len / sizeof (uint64_t);
 112   uint64_t a = ctx->H[0];
 113   uint64_t b = ctx->H[1];
 114   uint64_t c = ctx->H[2];
 115   uint64_t d = ctx->H[3];
 116   uint64_t e = ctx->H[4];
 117   uint64_t f = ctx->H[5];
 118   uint64_t g = ctx->H[6];
 119   uint64_t h = ctx->H[7];
 120
 121   /* First increment the byte count.  FIPS 180-2 specifies the possible
 122      length of the file up to 2^128 bits.  Here we only compute the
 123      number of bytes.  Do a double word increment.  */
 124   ctx->total[0] += len;
 125   if (ctx->total[0] < len)
 126     ++ctx->total[1];
 127
 128   /* Process all bytes in the buffer with 128 bytes in each round of
 129      the loop.  */
 130   while (nwords > 0)
 131     {
 132       uint64_t W[80];
 133       uint64_t a_save = a;
 134       uint64_t b_save = b;
 135       uint64_t c_save = c;
 136       uint64_t d_save = d;
 137       uint64_t e_save = e;
 138       uint64_t f_save = f;
 139       uint64_t g_save = g;
 140       uint64_t h_save = h;
 141
 142       /* Operators defined in FIPS 180-2:4.1.2.  */
 143 #define Ch(x, y, z) ((x & y) ^ (~x & z))
 144 #define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
 145 #define S0(x) (CYCLIC (x, 28) ^ CYCLIC (x, 34) ^ CYCLIC (x, 39))
 146 #define S1(x) (CYCLIC (x, 14) ^ CYCLIC (x, 18) ^ CYCLIC (x, 41))
 147 #define R0(x) (CYCLIC (x, 1) ^ CYCLIC (x, 8) ^ (x >> 7))
 148 #define R1(x) (CYCLIC (x, 19) ^ CYCLIC (x, 61) ^ (x >> 6))
 149
 150       /* It is unfortunate that C does not provide an operator for
 151          cyclic rotation.  Hope the C compiler is smart enough.  */
 152 #define CYCLIC(w, s) ((w >> s) | (w << (64 - s)))
 153
 154       /* Compute the message schedule according to FIPS 180-2:6.3.2 step 2.  */
 155       for (unsigned int t = 0; t < 16; ++t)
 156         {
 157           W[t] = SWAP (*words);
 158           ++words;
 159         }
 160       for (unsigned int t = 16; t < 80; ++t)
 161         W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
 162
 163       /* The actual computation according to FIPS 180-2:6.3.2 step 3.  */
 164       for (unsigned int t = 0; t < 80; ++t)
 165         {
 166           uint64_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
 167           uint64_t T2 = S0 (a) + Maj (a, b, c);
 168           h = g;
 169           g = f;
 170           f = e;
 171           e = d + T1;
 172           d = c;
 173           c = b;
 174           b = a;
 175           a = T1 + T2;
 176         }
 177
 178       /* Add the starting values of the context according to FIPS 180-2:6.3.2
 179          step 4.  */
 180       a += a_save;
 181       b += b_save;
 182       c += c_save;
 183       d += d_save;
 184       e += e_save;
 185       f += f_save;
 186       g += g_save;
 187       h += h_save;
 188
 189       /* Prepare for the next round.  */
 190       nwords -= 16;
 191     }
 192
 193   /* Put checksum in context given as argument.  */
 194   ctx->H[0] = a;
 195   ctx->H[1] = b;
 196   ctx->H[2] = c;
 197   ctx->H[3] = d;
 198   ctx->H[4] = e;
 199   ctx->H[5] = f;
 200   ctx->H[6] = g;
 201   ctx->H[7] = h;
 202 }
 203
 204
 205 /* Initialize structure containing state of computation.
 206    (FIPS 180-2:5.3.3)  */
 207 void
 208 __sha512_init_ctx (ctx)
 209      struct sha512_ctx *ctx;
 210 {
 211   ctx->H[0] = UINT64_C (0x6a09e667f3bcc908);
 212   ctx->H[1] = UINT64_C (0xbb67ae8584caa73b);
 213   ctx->H[2] = UINT64_C (0x3c6ef372fe94f82b);
 214   ctx->H[3] = UINT64_C (0xa54ff53a5f1d36f1);
 215   ctx->H[4] = UINT64_C (0x510e527fade682d1);
 216   ctx->H[5] = UINT64_C (0x9b05688c2b3e6c1f);
 217   ctx->H[6] = UINT64_C (0x1f83d9abfb41bd6b);
 218   ctx->H[7] = UINT64_C (0x5be0cd19137e2179);
 219
 220   ctx->total[0] = ctx->total[1] = 0;
 221   ctx->buflen = 0;
 222 }
 223
 224
 225 /* Process the remaining bytes in the internal buffer and the usual
 226    prolog according to the standard and write the result to RESBUF.
 227
 228    IMPORTANT: On some systems it is required that RESBUF is correctly
 229    aligned for a 32 bits value.  */
 230 void *
 231 __sha512_finish_ctx (ctx, resbuf)
 232      struct sha512_ctx *ctx;
 233      void *resbuf;
 234 {
 235   /* Take yet unprocessed bytes into account.  */
 236   uint64_t bytes = ctx->buflen;
 237   size_t pad;
 238
 239   /* Now count remaining bytes.  */
 240   ctx->total[0] += bytes;
 241   if (ctx->total[0] < bytes)
 242     ++ctx->total[1];
 243
 244   pad = bytes >= 112 ? 128 + 112 - bytes : 112 - bytes;
 245   memcpy (&ctx->buffer[bytes], fillbuf, pad);
 246
 247   /* Put the 128-bit file length in *bits* at the end of the buffer.  */
 248   *(uint64_t *) &ctx->buffer[bytes + pad + 8] = SWAP (ctx->total[0] << 3);
 249   *(uint64_t *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
 250                                                   (ctx->total[0] >> 61));
 251
 252   /* Process last bytes.  */
 253   sha512_process_block (ctx->buffer, bytes + pad + 16, ctx);
 254
 255   /* Put result from CTX in first 64 bytes following RESBUF.  */
 256   for (unsigned int i = 0; i < 8; ++i)
 257     ((uint64_t *) resbuf)[i] = SWAP (ctx->H[i]);
 258
 259   return resbuf;
 260 }
 261
 262
 263 void
 264 __sha512_process_bytes (buffer, len, ctx)
 265      const void *buffer;
 266      size_t len;
 267      struct sha512_ctx *ctx;
 268 {
 269   /* When we already have some bits in our internal buffer concatenate
 270      both inputs first.  */
 271   if (ctx->buflen != 0)
 272     {
 273       size_t left_over = ctx->buflen;
 274       size_t add = 256 - left_over > len ? len : 256 - left_over;
 275
 276       memcpy (&ctx->buffer[left_over], buffer, add);
 277       ctx->buflen += add;
 278
 279       if (ctx->buflen > 128)
 280         {
 281           sha512_process_block (ctx->buffer, ctx->buflen & ~127, ctx);
 282
 283           ctx->buflen &= 127;
 284           /* The regions in the following copy operation cannot overlap.  */
 285           memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~127],
 286                   ctx->buflen);
 287         }
 288
 289       buffer = (const char *) buffer + add;
 290       len -= add;
 291     }
 292
 293   /* Process available complete blocks.  */
 294   if (len >= 128)
 295     {
 296 #if !_STRING_ARCH_unaligned
 297 /* To check alignment gcc has an appropriate operator.  Other
 298    compilers don't.  */
 299 # if __GNUC__ >= 2
 300 #  define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint64_t) != 0)
 301 # else
 302 #  define UNALIGNED_P(p) (((uintptr_t) p) % sizeof (uint64_t) != 0)
 303 # endif
 304       if (UNALIGNED_P (buffer))
 305         while (len > 128)
 306           {
 307             sha512_process_block (memcpy (ctx->buffer, buffer, 128), 128,
 308                                     ctx);
 309             buffer = (const char *) buffer + 128;
 310             len -= 128;
 311           }
 312       else
 313 #endif
 314         {
 315           sha512_process_block (buffer, len & ~127, ctx);
 316           buffer = (const char *) buffer + (len & ~127);
 317           len &= 127;
 318         }
 319     }
 320
 321   /* Move remaining bytes into internal buffer.  */
 322   if (len > 0)
 323     {
 324       size_t left_over = ctx->buflen;
 325
 326       memcpy (&ctx->buffer[left_over], buffer, len);
 327       left_over += len;
 328       if (left_over >= 128)
 329         {
 330           sha512_process_block (ctx->buffer, 128, ctx);
 331           left_over -= 128;
 332           memcpy (ctx->buffer, &ctx->buffer[128], left_over);
 333         }
 334       ctx->buflen = left_over;
 335     }
 336 }