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   1 /* -*-c-*-
   2  *
   3  * $Id: sha256.c,v 1.2 2004/03/21 22:43:34 mdw Exp $
   4  *
   5  * Implementation of the SHA-256 hash function
   6  *
   7  * (c) 2000 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: sha256.c,v $
  33  * Revision 1.2  2004/03/21 22:43:34  mdw
  34  * New hash variant SHA224.
  35  *
  36  * Revision 1.1  2000/10/15 17:48:14  mdw
  37  * New SHA variants with longer outputs.
  38  *
  39  */
  40
  41 /*----- Header files ------------------------------------------------------*/
  42
  43 #include <mLib/bits.h>
  44
  45 #include "ghash.h"
  46 #include "ghash-def.h"
  47 #include "hash.h"
  48 #include "sha256.h"
  49
  50 /*----- Main code ---------------------------------------------------------*/
  51
  52 /* --- @sha256_compress@, @sha224_compress@ --- *
  53  *
  54  * Arguments:   @sha256_ctx *ctx@ = pointer to context block
  55  *              @const void *sbuf@ = pointer to buffer of appropriate size
  56  *
  57  * Returns:     ---
  58  *
  59  * Use:         SHA-256 compression function.
  60  */
  61
  62 void sha256_compress(sha256_ctx *ctx, const void *sbuf)
  63 {
  64   uint32 a, b, c, d, e, f, g, h;
  65   uint32 buf[64];
  66
  67   /* --- Fetch the chaining variables --- */
  68
  69   a = ctx->a;
  70   b = ctx->b;
  71   c = ctx->c;
  72   d = ctx->d;
  73   e = ctx->e;
  74   f = ctx->f;
  75   g = ctx->g;
  76   h = ctx->h;
  77
  78   /* --- Definitions for round functions --- */
  79
  80 #define CH(x, y, z) (((x) & (y)) | (~(x) & (z)))
  81 #define MAJ(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
  82
  83 #define S0(x) (ROR32((x),  2) ^ ROR32((x), 13) ^ ROR32((x), 22))
  84 #define S1(x) (ROR32((x),  6) ^ ROR32((x), 11) ^ ROR32((x), 25))
  85 #define s0(x) (ROR32((x),  7) ^ ROR32((x), 18) ^ LSR32((x),  3))
  86 #define s1(x) (ROR32((x), 17) ^ ROR32((x), 19) ^ LSR32((x), 10))
  87
  88 #define T(a, b, c, d, e, f, g, h, i, k) do {                            \
  89   uint32 t1 = h + S1(e) + CH(e, f, g) + k + buf[i];                     \
  90   uint32 t2 = S0(a) + MAJ(a, b, c);                                     \
  91   d += t1; h = t1 + t2;                                                 \
  92 } while (0)
  93
  94   /* --- Fetch and expand the buffer contents --- */
  95
  96   {
  97     int i;
  98     const octet *p;
  99
 100     for (i = 0, p = sbuf; i < 16; i++, p += 4)
 101       buf[i] = LOAD32(p);
 102     for (i = 16; i < 64; i++)
 103       buf[i] = s1(buf[i - 2]) + buf[i - 7] + s0(buf[i - 15]) + buf[i - 16];
 104   }
 105
 106   /* --- The main compression function --- */
 107
 108   T(a, b, c, d, e, f, g, h,  0, 0x428a2f98);
 109   T(h, a, b, c, d, e, f, g,  1, 0x71374491);
 110   T(g, h, a, b, c, d, e, f,  2, 0xb5c0fbcf);
 111   T(f, g, h, a, b, c, d, e,  3, 0xe9b5dba5);
 112   T(e, f, g, h, a, b, c, d,  4, 0x3956c25b);
 113   T(d, e, f, g, h, a, b, c,  5, 0x59f111f1);
 114   T(c, d, e, f, g, h, a, b,  6, 0x923f82a4);
 115   T(b, c, d, e, f, g, h, a,  7, 0xab1c5ed5);
 116   T(a, b, c, d, e, f, g, h,  8, 0xd807aa98);
 117   T(h, a, b, c, d, e, f, g,  9, 0x12835b01);
 118   T(g, h, a, b, c, d, e, f, 10, 0x243185be);
 119   T(f, g, h, a, b, c, d, e, 11, 0x550c7dc3);
 120   T(e, f, g, h, a, b, c, d, 12, 0x72be5d74);
 121   T(d, e, f, g, h, a, b, c, 13, 0x80deb1fe);
 122   T(c, d, e, f, g, h, a, b, 14, 0x9bdc06a7);
 123   T(b, c, d, e, f, g, h, a, 15, 0xc19bf174);
 124   T(a, b, c, d, e, f, g, h, 16, 0xe49b69c1);
 125   T(h, a, b, c, d, e, f, g, 17, 0xefbe4786);
 126   T(g, h, a, b, c, d, e, f, 18, 0x0fc19dc6);
 127   T(f, g, h, a, b, c, d, e, 19, 0x240ca1cc);
 128   T(e, f, g, h, a, b, c, d, 20, 0x2de92c6f);
 129   T(d, e, f, g, h, a, b, c, 21, 0x4a7484aa);
 130   T(c, d, e, f, g, h, a, b, 22, 0x5cb0a9dc);
 131   T(b, c, d, e, f, g, h, a, 23, 0x76f988da);
 132   T(a, b, c, d, e, f, g, h, 24, 0x983e5152);
 133   T(h, a, b, c, d, e, f, g, 25, 0xa831c66d);
 134   T(g, h, a, b, c, d, e, f, 26, 0xb00327c8);
 135   T(f, g, h, a, b, c, d, e, 27, 0xbf597fc7);
 136   T(e, f, g, h, a, b, c, d, 28, 0xc6e00bf3);
 137   T(d, e, f, g, h, a, b, c, 29, 0xd5a79147);
 138   T(c, d, e, f, g, h, a, b, 30, 0x06ca6351);
 139   T(b, c, d, e, f, g, h, a, 31, 0x14292967);
 140   T(a, b, c, d, e, f, g, h, 32, 0x27b70a85);
 141   T(h, a, b, c, d, e, f, g, 33, 0x2e1b2138);
 142   T(g, h, a, b, c, d, e, f, 34, 0x4d2c6dfc);
 143   T(f, g, h, a, b, c, d, e, 35, 0x53380d13);
 144   T(e, f, g, h, a, b, c, d, 36, 0x650a7354);
 145   T(d, e, f, g, h, a, b, c, 37, 0x766a0abb);
 146   T(c, d, e, f, g, h, a, b, 38, 0x81c2c92e);
 147   T(b, c, d, e, f, g, h, a, 39, 0x92722c85);
 148   T(a, b, c, d, e, f, g, h, 40, 0xa2bfe8a1);
 149   T(h, a, b, c, d, e, f, g, 41, 0xa81a664b);
 150   T(g, h, a, b, c, d, e, f, 42, 0xc24b8b70);
 151   T(f, g, h, a, b, c, d, e, 43, 0xc76c51a3);
 152   T(e, f, g, h, a, b, c, d, 44, 0xd192e819);
 153   T(d, e, f, g, h, a, b, c, 45, 0xd6990624);
 154   T(c, d, e, f, g, h, a, b, 46, 0xf40e3585);
 155   T(b, c, d, e, f, g, h, a, 47, 0x106aa070);
 156   T(a, b, c, d, e, f, g, h, 48, 0x19a4c116);
 157   T(h, a, b, c, d, e, f, g, 49, 0x1e376c08);
 158   T(g, h, a, b, c, d, e, f, 50, 0x2748774c);
 159   T(f, g, h, a, b, c, d, e, 51, 0x34b0bcb5);
 160   T(e, f, g, h, a, b, c, d, 52, 0x391c0cb3);
 161   T(d, e, f, g, h, a, b, c, 53, 0x4ed8aa4a);
 162   T(c, d, e, f, g, h, a, b, 54, 0x5b9cca4f);
 163   T(b, c, d, e, f, g, h, a, 55, 0x682e6ff3);
 164   T(a, b, c, d, e, f, g, h, 56, 0x748f82ee);
 165   T(h, a, b, c, d, e, f, g, 57, 0x78a5636f);
 166   T(g, h, a, b, c, d, e, f, 58, 0x84c87814);
 167   T(f, g, h, a, b, c, d, e, 59, 0x8cc70208);
 168   T(e, f, g, h, a, b, c, d, 60, 0x90befffa);
 169   T(d, e, f, g, h, a, b, c, 61, 0xa4506ceb);
 170   T(c, d, e, f, g, h, a, b, 62, 0xbef9a3f7);
 171   T(b, c, d, e, f, g, h, a, 63, 0xc67178f2);
 172
 173   /* --- Update the chaining variables --- */
 174
 175   ctx->a += a;
 176   ctx->b += b;
 177   ctx->c += c;
 178   ctx->d += d;
 179   ctx->e += e;
 180   ctx->f += f;
 181   ctx->g += g;
 182   ctx->h += h;
 183 }
 184
 185 /* --- @sha256_init@, @sha224_init@ --- *
 186  *
 187  * Arguments:   @sha256_ctx *ctx@ = pointer to context block to initialize
 188  *
 189  * Returns:     ---
 190  *
 191  * Use:         Initializes a context block ready for hashing.
 192  */
 193
 194 void sha256_init(sha256_ctx *ctx)
 195 {
 196   ctx->a = 0x6a09e667;
 197   ctx->b = 0xbb67ae85;
 198   ctx->c = 0x3c6ef372;
 199   ctx->d = 0xa54ff53a;
 200   ctx->e = 0x510e527f;
 201   ctx->f = 0x9b05688c;
 202   ctx->g = 0x1f83d9ab;
 203   ctx->h = 0x5be0cd19;
 204   ctx->off = 0;
 205   ctx->nl = ctx->nh = 0;
 206 }
 207
 208 void sha224_init(sha256_ctx *ctx)
 209 {
 210   ctx->a = 0xc1059ed8;
 211   ctx->b = 0x367cd507;
 212   ctx->c = 0x3070dd17;
 213   ctx->d = 0xf70e5939;
 214   ctx->e = 0xffc00b31;
 215   ctx->f = 0x68581511;
 216   ctx->g = 0x64f98fa7;
 217   ctx->h = 0xbefa4fa4;
 218   ctx->off = 0;
 219   ctx->nl = ctx->nh = 0;
 220 }
 221
 222 /* --- @sha256_set@, @sha224_set@ --- *
 223  *
 224  * Arguments:   @sha256_ctx *ctx@ = pointer to context block
 225  *              @const void *buf@ = pointer to state buffer
 226  *              @unsigned long count@ = current count of bytes processed
 227  *
 228  * Returns:     ---
 229  *
 230  * Use:         Initializes a context block from a given state.  This is
 231  *              useful in cases where the initial hash state is meant to be
 232  *              secret, e.g., for NMAC and HMAC support.
 233  */
 234
 235 void sha256_set(sha256_ctx *ctx, const void *buf, unsigned long count)
 236 {
 237   const octet *p = buf;
 238   ctx->a = LOAD32(p +  0);
 239   ctx->b = LOAD32(p +  4);
 240   ctx->c = LOAD32(p +  8);
 241   ctx->d = LOAD32(p + 12);
 242   ctx->e = LOAD32(p + 16);
 243   ctx->f = LOAD32(p + 20);
 244   ctx->g = LOAD32(p + 24);
 245   ctx->h = LOAD32(p + 28);
 246   ctx->off = 0;
 247   ctx->nl = U32(count);
 248   ctx->nh = U32(((count & ~MASK32) >> 16) >> 16);
 249 }
 250
 251 /* --- @sha256_hash@, @sha224_hash@ --- *
 252  *
 253  * Arguments:   @sha256_ctx *ctx@ = pointer to context block
 254  *              @const void *buf@ = buffer of data to hash
 255  *              @size_t sz@ = size of buffer to hash
 256  *
 257  * Returns:     ---
 258  *
 259  * Use:         Hashes a buffer of data.  The buffer may be of any size and
 260  *              alignment.
 261  */
 262
 263 void sha256_hash(sha256_ctx *ctx, const void *buf, size_t sz)
 264 {
 265   HASH_BUFFER(SHA256, sha256, ctx, buf, sz);
 266 }
 267
 268 /* --- @sha256_done, @sha224_done@ --- *
 269  *
 270  * Arguments:   @sha256_ctx *ctx@ = pointer to context block
 271  *              @void *hash@ = pointer to output buffer
 272  *
 273  * Returns:     ---
 274  *
 275  * Use:         Returns the hash of the data read so far.
 276  */
 277
 278 static void final(sha256_ctx *ctx)
 279 {
 280   HASH_PAD(SHA256, sha256, ctx, 0x80, 0, 8);
 281   STORE32(ctx->buf + SHA256_BUFSZ - 8, (ctx->nl >> 29) | (ctx->nh << 3));
 282   STORE32(ctx->buf + SHA256_BUFSZ - 4, ctx->nl << 3);
 283   sha256_compress(ctx, ctx->buf);
 284 }
 285
 286 void sha256_done(sha256_ctx *ctx, void *hash)
 287 {
 288   octet *p = hash;
 289   final(ctx);
 290   STORE32(p +  0, ctx->a);
 291   STORE32(p +  4, ctx->b);
 292   STORE32(p +  8, ctx->c);
 293   STORE32(p + 12, ctx->d);
 294   STORE32(p + 16, ctx->e);
 295   STORE32(p + 20, ctx->f);
 296   STORE32(p + 24, ctx->g);
 297   STORE32(p + 28, ctx->h);
 298 }
 299
 300 void sha224_done(sha224_ctx *ctx, void *hash)
 301 {
 302   octet *p = hash;
 303   final(ctx);
 304   STORE32(p +  0, ctx->a);
 305   STORE32(p +  4, ctx->b);
 306   STORE32(p +  8, ctx->c);
 307   STORE32(p + 12, ctx->d);
 308   STORE32(p + 16, ctx->e);
 309   STORE32(p + 20, ctx->f);
 310   STORE32(p + 24, ctx->g);
 311 }
 312
 313 /* --- @sha256_state@, @sha224_state@ --- *
 314  *
 315  * Arguments:   @sha256_ctx *ctx@ = pointer to context
 316  *              @void *state@ = pointer to buffer for current state
 317  *
 318  * Returns:     Number of bytes written to the hash function so far.
 319  *
 320  * Use:         Returns the current state of the hash function such that
 321  *              it can be passed to @sha256_set@.
 322  */
 323
 324 unsigned long sha256_state(sha256_ctx *ctx, void *state)
 325 {
 326   octet *p = state;
 327   STORE32(p +  0, ctx->a);
 328   STORE32(p +  4, ctx->b);
 329   STORE32(p +  8, ctx->c);
 330   STORE32(p + 12, ctx->d);
 331   STORE32(p + 16, ctx->e);
 332   STORE32(p + 20, ctx->f);
 333   STORE32(p + 24, ctx->g);
 334   STORE32(p + 28, ctx->h);
 335   return (ctx->nl | ((ctx->nh << 16) << 16));
 336 }
 337
 338 /* --- Generic interface --- */
 339
 340 GHASH_DEF(SHA256, sha256)
 341
 342 /* --- Test code --- */
 343
 344 HASH_TEST(SHA256, sha256)
 345
 346 /*----- That's all, folks -------------------------------------------------*/