chiark - git - mdw - catacomb/blob - symm/hash.h

   1 /* -*-c-*-
   2  *
   3  * Generic handling for message digest functions
   4  *
   5  * (c) 1998 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 #ifndef CATACOMB_HASH_H
  29 #define CATACOMB_HASH_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <string.h>
  38
  39 #include <mLib/bits.h>
  40
  41 #ifndef CATACOMB_RSVR_H
  42 #  include "rsvr.h"
  43 #endif
  44
  45 /*----- Macros ------------------------------------------------------------*/
  46
  47 /* --- @HASH_BUFFER@ --- *
  48  *
  49  * Arguments:   @PRE@, @pre@ = prefixes for hash-specific definitions
  50  *              @ictx@ = pointer to context block for the hash
  51  *              @ibuf@ = pointer to input data to hash
  52  *              @isz@ = size of buffer
  53  *
  54  * Use:         Handles buffering of input data to a hash function.  The
  55  *              hash's compression function is called when the buffer is
  56  *              full.  Note that the compression function can be called on
  57  *              data which is at odd alignments; it is expected to cope
  58  *              gracefully with this (possibly by copying the data into its
  59  *              internal buffer before starting).
  60  */
  61
  62 #define HASH_BUFFER(PRE, pre, ictx, ibuf, isz) do {                     \
  63   pre##_ctx *_bctx = (ictx);                                            \
  64   size_t _bsz = (isz);                                                  \
  65   const octet *_bbuf = (octet *)(ibuf), *_p;                            \
  66   static const rsvr_policy _pol = { 0, PRE##_BUFSZ, PRE##_BUFSZ };      \
  67   uint32 _l, _h;                                                        \
  68   rsvr_state _st;                                                       \
  69                                                                         \
  70   /* --- Add on the size done so far --- *                              \
  71    *                                                                    \
  72    * Messy, because trapping overflow is difficult when you don't know  \
  73    * how many bits you've actually got.                                 \
  74    */                                                                   \
  75                                                                         \
  76   _l = U32(_bsz); _h = ((_bsz & ~(size_t)MASK32) >> 16) >> 16;          \
  77   _bctx->nl += _l; if (_bctx->nl < _l || _bctx->nl & ~(uint32)MASK32) _h++; \
  78   _bctx->nh += _h;                                                      \
  79                                                                         \
  80   /* --- Accumulate the input data --- */                               \
  81                                                                         \
  82   rsvr_setup(&_st, &_pol, _bctx->buf, &_bctx->off, _bbuf, _bsz);        \
  83   RSVR_DO(&_st) while ((_p = RSVR_NEXT(&_st, PRE##_BUFSZ)) != 0)        \
  84     pre##_compress(_bctx, _p);                                          \
  85 } while (0)
  86
  87 /* --- @HASH_PAD@ --- *
  88  *
  89  * Arguments:   @PRE@, @pre@ = prefixes for hash-specific definitions
  90  *              @ictx@ = pointer to context block for the hash
  91  *              @term@ = terminator character to write following the data
  92  *              @pad@ = pad character to fill with
  93  *              @diff@ = size of space to leave at the end of the last block
  94  *
  95  * Use:         Does padding for message digest functions.
  96  */
  97
  98 #define HASH_PAD(PRE, pre, ictx, term, pad, diff) do {                  \
  99   pre##_ctx *_pctx = (ictx);                                            \
 100                                                                         \
 101   _pctx->buf[_pctx->off] = term;                                        \
 102   _pctx->off++;                                                         \
 103   if (_pctx->off > PRE##_BUFSZ - diff) {                                \
 104     if (_pctx->off < PRE##_BUFSZ)                                       \
 105       memset(_pctx->buf + _pctx->off, pad, PRE##_BUFSZ - _pctx->off);   \
 106     pre##_compress(_pctx, _pctx->buf);                                  \
 107     memset(_pctx->buf, pad, PRE##_BUFSZ - diff);                        \
 108   } else                                                                \
 109     memset(_pctx->buf + _pctx->off, pad,                                \
 110            PRE##_BUFSZ - _pctx->off - diff);                            \
 111 } while (0)
 112
 113 /* --- @HASH_MD5STRENGTH@ --- *
 114  *
 115  * Arguments:   @PRE@, @pre@ = prefixes for hash-specific definitions
 116  *              @ictx@ = pointer to context block for the hash
 117  *
 118  * Use:         Does MD5-style MD strengthening.  The data is terminated
 119  *              by a single set bit, padded with zero bits, and then a 64-
 120  *              bit length is written, little-end first.
 121  */
 122
 123 #define HASH_MD5STRENGTH(PRE, pre, ictx) do {                           \
 124   pre##_ctx *_mctx = (ictx);                                            \
 125   HASH_PAD(PRE, pre, _mctx, 0x80u, 0, 8);                               \
 126   STORE32_L(_mctx->buf + PRE##_BUFSZ - 8, _mctx->nl << 3);              \
 127   STORE32_L(_mctx->buf + PRE##_BUFSZ - 4,                               \
 128             (_mctx->nl >> 29) | (_mctx->nh << 3));                      \
 129   pre##_compress(_mctx, _mctx->buf);                                    \
 130 } while (0)
 131
 132 /* --- @HASH_TEST@ --- *
 133  *
 134  * Arguments:   @PRE@, @pre@ = prefixes for hash-specfic definitions
 135  *
 136  * Use:         Standard test rig for hash functions.
 137  */
 138
 139 #ifdef TEST_RIG
 140
 141 #include <mLib/quis.h>
 142 #include <mLib/testrig.h>
 143
 144 #define HASH_BUFLEN 100000
 145
 146 #define HASH_VERIFY(PRE, pre) HASH_VERIFYX(PRE, pre, #pre)
 147
 148 #define HASH_VERIFYX(PRE, pre, name)                                    \
 149                                                                         \
 150 static int vrf_##pre(dstr *v, const test_type *msgty)                   \
 151 {                                                                       \
 152   pre##_ctx ctx;                                                        \
 153   int ok = 1;                                                           \
 154   int i;                                                                \
 155   octet *p;                                                             \
 156   int szs[] = { 1, 7, 192, -1, 0 }, *ip;                                \
 157   size_t sz;                                                            \
 158   dstr d;                                                               \
 159                                                                         \
 160   dstr_create(&d);                                                      \
 161   dstr_ensure(&d, PRE##_HASHSZ);                                        \
 162   d.len = PRE##_HASHSZ;                                                 \
 163                                                                         \
 164   for (ip = szs; *ip; ip++) {                                           \
 165     i = *ip;                                                            \
 166     sz = v[0].len;                                                      \
 167     if (i == -1)                                                        \
 168       i = sz;                                                           \
 169     if (i > sz)                                                         \
 170       continue;                                                         \
 171     p = (octet *)v[0].buf;                                              \
 172     pre##_init(&ctx);                                                   \
 173     while (sz) {                                                        \
 174       if (i > sz)                                                       \
 175         i = sz;                                                         \
 176       pre##_hash(&ctx, p, i);                                           \
 177       p += i;                                                           \
 178       sz -= i;                                                          \
 179     }                                                                   \
 180     pre##_done(&ctx, d.buf);                                            \
 181     if (memcmp(d.buf, v[1].buf, PRE##_HASHSZ) != 0) {                   \
 182       printf("\nfail:\n\tstep = %i\n\tinput = ", *ip);                  \
 183       msgty->dump(&v[0], stdout);                                       \
 184       printf("\n\texpected = ");                                        \
 185       type_hex.dump(&v[1], stdout);                                     \
 186       fputs("\n\tcomputed = ", stdout);                                 \
 187       type_hex.dump(&d, stdout);                                        \
 188       putchar('\n');                                                    \
 189       ok = 0;                                                           \
 190     }                                                                   \
 191   }                                                                     \
 192                                                                         \
 193   dstr_destroy(&d);                                                     \
 194   return (ok);                                                          \
 195 }                                                                       \
 196                                                                         \
 197 static int vrf_##pre##_hex(dstr *v)                                     \
 198   { return vrf_##pre(v, &type_hex); }                                   \
 199 static int vrf_##pre##_lit(dstr *v)                                     \
 200   { return vrf_##pre(v, &type_string); }                                \
 201                                                                         \
 202 static int vrf_##pre##_rep(dstr *v)                                     \
 203 {                                                                       \
 204   pre##_ctx ctx;                                                        \
 205   size_t len = v[0].len;                                                \
 206   int n = *(int *)v[1].buf;                                             \
 207   int nd = 0;                                                           \
 208   int nn = len;                                                         \
 209   int ok = 1;                                                           \
 210   octet *p, *q;                                                         \
 211   dstr d = DSTR_INIT;                                                   \
 212                                                                         \
 213   while (nn < HASH_BUFLEN && (n & 1) == 0) { nd++; nn <<= 1; n >>= 1; } \
 214   p = xmalloc(nn);                                                      \
 215   memcpy(p, v[0].buf, len);                                             \
 216   q = p + len;                                                          \
 217   while (nd--) { memcpy(q, p, len); q += len; len <<= 1; }              \
 218                                                                         \
 219   dstr_ensure(&d, PRE##_HASHSZ);                                        \
 220   d.len = PRE##_HASHSZ;                                                 \
 221   pre##_init(&ctx);                                                     \
 222   while (n--) pre##_hash(&ctx, p, len);                                 \
 223   pre##_done(&ctx, d.buf);                                              \
 224                                                                         \
 225   if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) {                     \
 226     printf("\nfail:\n\tinput = `%s'\n\treps = `%i'\n\texpected = ",     \
 227              v[0].buf, *(int *)v[1].buf);                               \
 228     type_hex.dump(&v[2], stdout);                                       \
 229     fputs("\n\tcomputed = ", stdout);                                   \
 230     type_hex.dump(&d, stdout);                                          \
 231     putchar('\n');                                                      \
 232     ok = 0;                                                             \
 233   }                                                                     \
 234   xfree(p);                                                             \
 235   dstr_destroy(&d);                                                     \
 236   return (ok);                                                          \
 237 }
 238
 239 #define HASH_TESTDEFS(PRE, pre) HASH_TESTDEFSX(PRE, pre, #pre)
 240
 241 #define HASH_TESTDEFSX(PRE, pre, name)                                  \
 242   { name, vrf_##pre##_lit, { &type_string, &type_hex, 0 } },            \
 243   { name "-hex", vrf_##pre##_hex, { &type_hex, &type_hex, 0 } },        \
 244   { name "-rep", vrf_##pre##_rep,                                       \
 245     { &type_string, &type_int, &type_hex, 0 } },
 246
 247 #define HASH_TESTX(PRE, pre, name, fname)                               \
 248                                                                         \
 249 HASH_VERIFYX(PRE, pre, name)                                            \
 250                                                                         \
 251 static test_chunk defs[] = {                                            \
 252   HASH_TESTDEFSX(PRE, pre, name)                                        \
 253   { 0, 0, { 0 } }                                                       \
 254 };                                                                      \
 255                                                                         \
 256 int main(int argc, char *argv[])                                        \
 257 {                                                                       \
 258   ego(argv[0]);                                                         \
 259   test_run(argc, argv, defs, SRCDIR"/t/" fname);                        \
 260   return (0);                                                           \
 261 }
 262
 263 #else
 264 #  define HASH_TESTX(PRE, pre, name, fname)
 265 #endif
 266
 267 #define HASH_TEST(PRE, pre) HASH_TESTX(PRE, pre, #pre, #pre)
 268
 269 /*----- That's all, folks -------------------------------------------------*/
 270
 271 #ifdef __cplusplus
 272   }
 273 #endif
 274
 275 #endif