lib/sha1.c

   1 /* sha1.c - Functions to compute SHA1 message digest of files or
   2    memory blocks according to the NIST specification FIPS-180-1.
   3
   4    Copyright (C) 2000-2001, 2003-2006, 2008-2024 Free Software Foundation, Inc.
   5
   6    This file is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU Lesser General Public License as
   8    published by the Free Software Foundation; either version 2.1 of the
   9    License, or (at your option) any later version.
  10
  11    This file 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
  14    GNU Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public License
  17    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  18
  19 /* Written by Scott G. Miller
  20    Credits:
  21       Robert Klep <robert@ilse.nl>  -- Expansion function fix
  22 */
  23
  24 #include <config.h>
  25
  26 /* Specification.  */
  27 #if HAVE_OPENSSL_SHA1
  28 # define GL_OPENSSL_INLINE _GL_EXTERN_INLINE
  29 #endif
  30 #include "sha1.h"
  31
  32 #include <stdint.h>
  33 #include <string.h>
  34
  35 #include <byteswap.h>
  36 #ifdef WORDS_BIGENDIAN
  37 # define SWAP(n) (n)
  38 #else
  39 # define SWAP(n) bswap_32 (n)
  40 #endif
  41
  42 #if ! HAVE_OPENSSL_SHA1
  43
  44 /* This array contains the bytes used to pad the buffer to the next
  45    64-byte boundary.  (RFC 1321, 3.1: Step 1)  */
  46 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ...  */ };
  47
  48
  49 /* Take a pointer to a 160 bit block of data (five 32 bit ints) and
  50    initialize it to the start constants of the SHA1 algorithm.  This
  51    must be called before using hash in the call to sha1_hash.  */
  52 void
  53 sha1_init_ctx (struct sha1_ctx *ctx)
  54 {
  55   ctx->A = 0x67452301;
  56   ctx->B = 0xefcdab89;
  57   ctx->C = 0x98badcfe;
  58   ctx->D = 0x10325476;
  59   ctx->E = 0xc3d2e1f0;
  60
  61   ctx->total[0] = ctx->total[1] = 0;
  62   ctx->buflen = 0;
  63 }
  64
  65 /* Copy the 4 byte value from v into the memory location pointed to by *cp,
  66    If your architecture allows unaligned access this is equivalent to
  67    * (uint32_t *) cp = v  */
  68 static void
  69 set_uint32 (char *cp, uint32_t v)
  70 {
  71   memcpy (cp, &v, sizeof v);
  72 }
  73
  74 /* Put result from CTX in first 20 bytes following RESBUF.  The result
  75    must be in little endian byte order.  */
  76 void *
  77 sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
  78 {
  79   char *r = resbuf;
  80   set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A));
  81   set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B));
  82   set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C));
  83   set_uint32 (r + 3 * sizeof ctx->D, SWAP (ctx->D));
  84   set_uint32 (r + 4 * sizeof ctx->E, SWAP (ctx->E));
  85
  86   return resbuf;
  87 }
  88
  89 /* Process the remaining bytes in the internal buffer and the usual
  90    prolog according to the standard and write the result to RESBUF.  */
  91 void *
  92 sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
  93 {
  94   /* Take yet unprocessed bytes into account.  */
  95   uint32_t bytes = ctx->buflen;
  96   size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
  97
  98   /* Now count remaining bytes.  */
  99   ctx->total[0] += bytes;
 100   if (ctx->total[0] < bytes)
 101     ++ctx->total[1];
 102
 103   /* Put the 64-bit file length in *bits* at the end of the buffer.  */
 104   ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
 105   ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
 106
 107   memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
 108
 109   /* Process last bytes.  */
 110   sha1_process_block (ctx->buffer, size * 4, ctx);
 111
 112   return sha1_read_ctx (ctx, resbuf);
 113 }
 114
 115 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER.  The
 116    result is always in little endian byte order, so that a byte-wise
 117    output yields to the wanted ASCII representation of the message
 118    digest.  */
 119 void *
 120 sha1_buffer (const char *buffer, size_t len, void *resblock)
 121 {
 122   struct sha1_ctx ctx;
 123
 124   /* Initialize the computation context.  */
 125   sha1_init_ctx (&ctx);
 126
 127   /* Process whole buffer but last len % 64 bytes.  */
 128   sha1_process_bytes (buffer, len, &ctx);
 129
 130   /* Put result in desired memory area.  */
 131   return sha1_finish_ctx (&ctx, resblock);
 132 }
 133
 134 void
 135 sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx)
 136 {
 137   /* When we already have some bits in our internal buffer concatenate
 138      both inputs first.  */
 139   if (ctx->buflen != 0)
 140     {
 141       size_t left_over = ctx->buflen;
 142       size_t add = 128 - left_over > len ? len : 128 - left_over;
 143
 144       memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
 145       ctx->buflen += add;
 146
 147       if (ctx->buflen > 64)
 148         {
 149           sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
 150
 151           ctx->buflen &= 63;
 152           /* The regions in the following copy operation cannot overlap,
 153              because ctx->buflen < 64 ≤ (left_over + add) & ~63.  */
 154           memcpy (ctx->buffer,
 155                   &((char *) ctx->buffer)[(left_over + add) & ~63],
 156                   ctx->buflen);
 157         }
 158
 159       buffer = (const char *) buffer + add;
 160       len -= add;
 161     }
 162
 163   /* Process available complete blocks.  */
 164   if (len >= 64)
 165     {
 166 #if !(_STRING_ARCH_unaligned || _STRING_INLINE_unaligned)
 167 # define UNALIGNED_P(p) ((uintptr_t) (p) % alignof (uint32_t) != 0)
 168       if (UNALIGNED_P (buffer))
 169         while (len > 64)
 170           {
 171             sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
 172             buffer = (const char *) buffer + 64;
 173             len -= 64;
 174           }
 175       else
 176 #endif
 177         {
 178           sha1_process_block (buffer, len & ~63, ctx);
 179           buffer = (const char *) buffer + (len & ~63);
 180           len &= 63;
 181         }
 182     }
 183
 184   /* Move remaining bytes in internal buffer.  */
 185   if (len > 0)
 186     {
 187       size_t left_over = ctx->buflen;
 188
 189       memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
 190       left_over += len;
 191       if (left_over >= 64)
 192         {
 193           sha1_process_block (ctx->buffer, 64, ctx);
 194           left_over -= 64;
 195           /* The regions in the following copy operation cannot overlap,
 196              because left_over ≤ 64.  */
 197           memcpy (ctx->buffer, &ctx->buffer[16], left_over);
 198         }
 199       ctx->buflen = left_over;
 200     }
 201 }
 202
 203 /* --- Code below is the primary difference between md5.c and sha1.c --- */
 204
 205 /* SHA1 round constants */
 206 #define K1 0x5a827999
 207 #define K2 0x6ed9eba1
 208 #define K3 0x8f1bbcdc
 209 #define K4 0xca62c1d6
 210
 211 /* Round functions.  Note that F2 is the same as F4.  */
 212 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) )
 213 #define F2(B,C,D) (B ^ C ^ D)
 214 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) )
 215 #define F4(B,C,D) (B ^ C ^ D)
 216
 217 /* Process LEN bytes of BUFFER, accumulating context into CTX.
 218    It is assumed that LEN % 64 == 0.
 219    Most of this code comes from GnuPG's cipher/sha1.c.  */
 220
 221 void
 222 sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx)
 223 {
 224   const uint32_t *words = buffer;
 225   size_t nwords = len / sizeof (uint32_t);
 226   const uint32_t *endp = words + nwords;
 227   uint32_t x[16];
 228   uint32_t a = ctx->A;
 229   uint32_t b = ctx->B;
 230   uint32_t c = ctx->C;
 231   uint32_t d = ctx->D;
 232   uint32_t e = ctx->E;
 233   uint32_t lolen = len;
 234
 235   /* First increment the byte count.  RFC 1321 specifies the possible
 236      length of the file up to 2^64 bits.  Here we only compute the
 237      number of bytes.  Do a double word increment.  */
 238   ctx->total[0] += lolen;
 239   ctx->total[1] += (len >> 31 >> 1) + (ctx->total[0] < lolen);
 240
 241 #define rol(x, n) (((x) << (n)) | ((uint32_t) (x) >> (32 - (n))))
 242
 243 #define M(I) ( tm =   x[I&0x0f] ^ x[(I-14)&0x0f] \
 244                     ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \
 245                , (x[I&0x0f] = rol(tm, 1)) )
 246
 247 #define R(A,B,C,D,E,F,K,M)  do { E += rol( A, 5 )     \
 248                                       + F( B, C, D )  \
 249                                       + K             \
 250                                       + M;            \
 251                                  B = rol( B, 30 );    \
 252                                } while(0)
 253
 254   while (words < endp)
 255     {
 256       uint32_t tm;
 257       int t;
 258       for (t = 0; t < 16; t++)
 259         {
 260           x[t] = SWAP (*words);
 261           words++;
 262         }
 263
 264       R( a, b, c, d, e, F1, K1, x[ 0] );
 265       R( e, a, b, c, d, F1, K1, x[ 1] );
 266       R( d, e, a, b, c, F1, K1, x[ 2] );
 267       R( c, d, e, a, b, F1, K1, x[ 3] );
 268       R( b, c, d, e, a, F1, K1, x[ 4] );
 269       R( a, b, c, d, e, F1, K1, x[ 5] );
 270       R( e, a, b, c, d, F1, K1, x[ 6] );
 271       R( d, e, a, b, c, F1, K1, x[ 7] );
 272       R( c, d, e, a, b, F1, K1, x[ 8] );
 273       R( b, c, d, e, a, F1, K1, x[ 9] );
 274       R( a, b, c, d, e, F1, K1, x[10] );
 275       R( e, a, b, c, d, F1, K1, x[11] );
 276       R( d, e, a, b, c, F1, K1, x[12] );
 277       R( c, d, e, a, b, F1, K1, x[13] );
 278       R( b, c, d, e, a, F1, K1, x[14] );
 279       R( a, b, c, d, e, F1, K1, x[15] );
 280       R( e, a, b, c, d, F1, K1, M(16) );
 281       R( d, e, a, b, c, F1, K1, M(17) );
 282       R( c, d, e, a, b, F1, K1, M(18) );
 283       R( b, c, d, e, a, F1, K1, M(19) );
 284       R( a, b, c, d, e, F2, K2, M(20) );
 285       R( e, a, b, c, d, F2, K2, M(21) );
 286       R( d, e, a, b, c, F2, K2, M(22) );
 287       R( c, d, e, a, b, F2, K2, M(23) );
 288       R( b, c, d, e, a, F2, K2, M(24) );
 289       R( a, b, c, d, e, F2, K2, M(25) );
 290       R( e, a, b, c, d, F2, K2, M(26) );
 291       R( d, e, a, b, c, F2, K2, M(27) );
 292       R( c, d, e, a, b, F2, K2, M(28) );
 293       R( b, c, d, e, a, F2, K2, M(29) );
 294       R( a, b, c, d, e, F2, K2, M(30) );
 295       R( e, a, b, c, d, F2, K2, M(31) );
 296       R( d, e, a, b, c, F2, K2, M(32) );
 297       R( c, d, e, a, b, F2, K2, M(33) );
 298       R( b, c, d, e, a, F2, K2, M(34) );
 299       R( a, b, c, d, e, F2, K2, M(35) );
 300       R( e, a, b, c, d, F2, K2, M(36) );
 301       R( d, e, a, b, c, F2, K2, M(37) );
 302       R( c, d, e, a, b, F2, K2, M(38) );
 303       R( b, c, d, e, a, F2, K2, M(39) );
 304       R( a, b, c, d, e, F3, K3, M(40) );
 305       R( e, a, b, c, d, F3, K3, M(41) );
 306       R( d, e, a, b, c, F3, K3, M(42) );
 307       R( c, d, e, a, b, F3, K3, M(43) );
 308       R( b, c, d, e, a, F3, K3, M(44) );
 309       R( a, b, c, d, e, F3, K3, M(45) );
 310       R( e, a, b, c, d, F3, K3, M(46) );
 311       R( d, e, a, b, c, F3, K3, M(47) );
 312       R( c, d, e, a, b, F3, K3, M(48) );
 313       R( b, c, d, e, a, F3, K3, M(49) );
 314       R( a, b, c, d, e, F3, K3, M(50) );
 315       R( e, a, b, c, d, F3, K3, M(51) );
 316       R( d, e, a, b, c, F3, K3, M(52) );
 317       R( c, d, e, a, b, F3, K3, M(53) );
 318       R( b, c, d, e, a, F3, K3, M(54) );
 319       R( a, b, c, d, e, F3, K3, M(55) );
 320       R( e, a, b, c, d, F3, K3, M(56) );
 321       R( d, e, a, b, c, F3, K3, M(57) );
 322       R( c, d, e, a, b, F3, K3, M(58) );
 323       R( b, c, d, e, a, F3, K3, M(59) );
 324       R( a, b, c, d, e, F4, K4, M(60) );
 325       R( e, a, b, c, d, F4, K4, M(61) );
 326       R( d, e, a, b, c, F4, K4, M(62) );
 327       R( c, d, e, a, b, F4, K4, M(63) );
 328       R( b, c, d, e, a, F4, K4, M(64) );
 329       R( a, b, c, d, e, F4, K4, M(65) );
 330       R( e, a, b, c, d, F4, K4, M(66) );
 331       R( d, e, a, b, c, F4, K4, M(67) );
 332       R( c, d, e, a, b, F4, K4, M(68) );
 333       R( b, c, d, e, a, F4, K4, M(69) );
 334       R( a, b, c, d, e, F4, K4, M(70) );
 335       R( e, a, b, c, d, F4, K4, M(71) );
 336       R( d, e, a, b, c, F4, K4, M(72) );
 337       R( c, d, e, a, b, F4, K4, M(73) );
 338       R( b, c, d, e, a, F4, K4, M(74) );
 339       R( a, b, c, d, e, F4, K4, M(75) );
 340       R( e, a, b, c, d, F4, K4, M(76) );
 341       R( d, e, a, b, c, F4, K4, M(77) );
 342       R( c, d, e, a, b, F4, K4, M(78) );
 343       R( b, c, d, e, a, F4, K4, M(79) );
 344
 345       a = ctx->A += a;
 346       b = ctx->B += b;
 347       c = ctx->C += c;
 348       d = ctx->D += d;
 349       e = ctx->E += e;
 350     }
 351 }
 352
 353 #endif
 354
 355 /*
 356  * Hey Emacs!
 357  * Local Variables:
 358  * coding: utf-8
 359  * End:
 360  */