libcrypt/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, 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   ctx->total[0] += len;
 124   if (ctx->total[0] < len)
 125     ++ctx->total[1];
 126
 127   /* Process all bytes in the buffer with 128 bytes in each round of
 128      the loop.  */
 129   while (nwords > 0)
 130     {
 131       uint64_t W[80];
 132       uint64_t a_save = a;
 133       uint64_t b_save = b;
 134       uint64_t c_save = c;
 135       uint64_t d_save = d;
 136       uint64_t e_save = e;
 137       uint64_t f_save = f;
 138       uint64_t g_save = g;
 139       uint64_t h_save = h;
 140
 141       /* Operators defined in FIPS 180-2:4.1.2.  */
 142 #define _Ch(x, y, z) ((x & y) ^ (~x & z))
 143 #define _Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
 144 #define _S0(x) (CYCLIC (x, 28) ^ CYCLIC (x, 34) ^ CYCLIC (x, 39))
 145 #define _S1(x) (CYCLIC (x, 14) ^ CYCLIC (x, 18) ^ CYCLIC (x, 41))
 146 #define _R0(x) (CYCLIC (x, 1) ^ CYCLIC (x, 8) ^ (x >> 7))
 147 #define _R1(x) (CYCLIC (x, 19) ^ CYCLIC (x, 61) ^ (x >> 6))
 148
 149       /* It is unfortunate that C does not provide an operator for
 150          cyclic rotation.  Hope the C compiler is smart enough.  */
 151 #define CYCLIC(w, s) ((w >> s) | (w << (64 - s)))
 152
 153       /* Compute the message schedule according to FIPS 180-2:6.3.2 step 2.  */
 154       for (unsigned int t = 0; t < 16; ++t)
 155         {
 156           W[t] = SWAP (*words);
 157           ++words;
 158         }
 159       for (unsigned int t = 16; t < 80; ++t)
 160         W[t] = _R1 (W[t - 2]) + W[t - 7] + _R0 (W[t - 15]) + W[t - 16];
 161
 162       /* The actual computation according to FIPS 180-2:6.3.2 step 3.  */
 163       for (unsigned int t = 0; t < 80; ++t)
 164         {
 165           uint64_t T1 = h + _S1 (e) + _Ch (e, f, g) + K[t] + W[t];
 166           uint64_t T2 = _S0 (a) + _Maj (a, b, c);
 167           h = g;
 168           g = f;
 169           f = e;
 170           e = d + T1;
 171           d = c;
 172           c = b;
 173           b = a;
 174           a = T1 + T2;
 175         }
 176
 177       /* Add the starting values of the context according to FIPS 180-2:6.3.2
 178          step 4.  */
 179       a += a_save;
 180       b += b_save;
 181       c += c_save;
 182       d += d_save;
 183       e += e_save;
 184       f += f_save;
 185       g += g_save;
 186       h += h_save;
 187
 188       /* Prepare for the next round.  */
 189       nwords -= 16;
 190     }
 191
 192   /* Put checksum in context given as argument.  */
 193   ctx->H[0] = a;
 194   ctx->H[1] = b;
 195   ctx->H[2] = c;
 196   ctx->H[3] = d;
 197   ctx->H[4] = e;
 198   ctx->H[5] = f;
 199   ctx->H[6] = g;
 200   ctx->H[7] = h;
 201 }
 202
 203
 204 /* Initialize structure containing state of computation.
 205    (FIPS 180-2:5.3.3)  */
 206 void
 207 __sha512_init_ctx (struct sha512_ctx *ctx)
 208 {
 209   ctx->H[0] = UINT64_C (0x6a09e667f3bcc908);
 210   ctx->H[1] = UINT64_C (0xbb67ae8584caa73b);
 211   ctx->H[2] = UINT64_C (0x3c6ef372fe94f82b);
 212   ctx->H[3] = UINT64_C (0xa54ff53a5f1d36f1);
 213   ctx->H[4] = UINT64_C (0x510e527fade682d1);
 214   ctx->H[5] = UINT64_C (0x9b05688c2b3e6c1f);
 215   ctx->H[6] = UINT64_C (0x1f83d9abfb41bd6b);
 216   ctx->H[7] = UINT64_C (0x5be0cd19137e2179);
 217
 218   ctx->total[0] = ctx->total[1] = 0;
 219   ctx->buflen = 0;
 220 }
 221
 222
 223 /* Process the remaining bytes in the internal buffer and the usual
 224    prolog according to the standard and write the result to RESBUF.
 225
 226    IMPORTANT: On some systems it is required that RESBUF is correctly
 227    aligned for a 32 bits value.  */
 228 void *
 229 __sha512_finish_ctx (struct sha512_ctx *ctx, void *resbuf)
 230 {
 231   /* Take yet unprocessed bytes into account.  */
 232   uint64_t bytes = ctx->buflen;
 233   size_t pad;
 234
 235   /* Now count remaining bytes.  */
 236   ctx->total[0] += bytes;
 237   if (ctx->total[0] < bytes)
 238     ++ctx->total[1];
 239
 240   pad = bytes >= 112 ? 128 + 112 - bytes : 112 - bytes;
 241   memcpy (&ctx->buffer[bytes], fillbuf, pad);
 242
 243   /* Put the 128-bit file length in *bits* at the end of the buffer.  */
 244   *(uint64_t *) &ctx->buffer[bytes + pad + 8] = SWAP (ctx->total[0] << 3);
 245   *(uint64_t *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
 246                                                   (ctx->total[0] >> 61));
 247
 248   /* Process last bytes.  */
 249   sha512_process_block (ctx->buffer, bytes + pad + 16, ctx);
 250
 251   /* Put result from CTX in first 64 bytes following RESBUF.  */
 252   for (unsigned int i = 0; i < 8; ++i)
 253     ((uint64_t *) resbuf)[i] = SWAP (ctx->H[i]);
 254
 255   return resbuf;
 256 }
 257
 258
 259 void
 260 __sha512_process_bytes (const void *buffer, size_t len, struct sha512_ctx *ctx)
 261 {
 262   /* When we already have some bits in our internal buffer concatenate
 263      both inputs first.  */
 264   if (ctx->buflen != 0)
 265     {
 266       size_t left_over = ctx->buflen;
 267       size_t add = 256 - left_over > len ? len : 256 - left_over;
 268
 269       memcpy (&ctx->buffer[left_over], buffer, add);
 270       ctx->buflen += add;
 271
 272       if (ctx->buflen > 128)
 273         {
 274           sha512_process_block (ctx->buffer, ctx->buflen & ~127, ctx);
 275
 276           ctx->buflen &= 127;
 277           /* The regions in the following copy operation cannot overlap.  */
 278           memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~127],
 279                   ctx->buflen);
 280         }
 281
 282       buffer = (const char *) buffer + add;
 283       len -= add;
 284     }
 285
 286   /* Process available complete blocks.  */
 287   if (len >= 128)
 288     {
 289 #if __GNUC__ >= 2
 290 # define UNALIGNED_P(p) (((uintptr_t) p) % __alignof__ (uint64_t) != 0)
 291 #else
 292 # define UNALIGNED_P(p) (((uintptr_t) p) % sizeof (uint64_t) != 0)
 293 #endif
 294       if (UNALIGNED_P (buffer))
 295         while (len > 128)
 296           {
 297             sha512_process_block (memcpy (ctx->buffer, buffer, 128), 128,
 298                                     ctx);
 299             buffer = (const char *) buffer + 128;
 300             len -= 128;
 301           }
 302       else
 303         {
 304           sha512_process_block (buffer, len & ~127, ctx);
 305           buffer = (const char *) buffer + (len & ~127);
 306           len &= 127;
 307         }
 308     }
 309
 310   /* Move remaining bytes into internal buffer.  */
 311   if (len > 0)
 312     {
 313       size_t left_over = ctx->buflen;
 314
 315       memcpy (&ctx->buffer[left_over], buffer, len);
 316       left_over += len;
 317       if (left_over >= 128)
 318         {
 319           sha512_process_block (ctx->buffer, 128, ctx);
 320           left_over -= 128;
 321           memcpy (ctx->buffer, &ctx->buffer[128], left_over);
 322         }
 323       ctx->buflen = left_over;
 324     }
 325 }