chiark - git - mdw - catacomb/blob - symm/hmac-def.h

   1 /* -*-c-*-
   2  *
   3  * Definitions for HMAC and NMAC
   4  *
   5  * (c) 1999 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_HMAC_DEF_H
  29 #define CATACOMB_HMAC_DEF_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <assert.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include <mLib/bits.h>
  42 #include <mLib/sub.h>
  43
  44 #ifndef CATACOMB_ARENA_H
  45 #  include "arena.h"
  46 #endif
  47
  48 #ifndef CATACOMB_GMAC_H
  49 #  include "gmac.h"
  50 #endif
  51
  52 #ifndef CATACOMB_PARANOIA_H
  53 #  include "paranoia.h"
  54 #endif
  55
  56 /*----- Macros ------------------------------------------------------------*/
  57
  58 /* --- @HMAC_DEF@ --- *
  59  *
  60  * Arguments:   @PRE@, @pre@ = prefixes for the underlying hash function
  61  *
  62  * Use:         Creates implementations for the HMAC and NMAC functions.
  63  */
  64
  65 #define HMAC_DEF(PRE, pre) HMAC_DEFX(PRE, pre, #pre, #pre)
  66 #define HMAC_DEFX(PRE, pre, name, fname)                                \
  67                                                                         \
  68 /* --- Useful constants --- */                                          \
  69                                                                         \
  70 const octet pre##_hmackeysz[] =                                         \
  71   { KSZ_ANY | KSZ_16BIT, PRE##_STATESZ/256, PRE##_STATESZ%256 };        \
  72 const octet pre##_sslmackeysz[] =                                       \
  73   { KSZ_ANY | KSZ_16BIT, PRE##_STATESZ/256, PRE##_STATESZ%256 };        \
  74 const octet pre##_nmackeysz[] =                                         \
  75   { KSZ_SET | KSZ_16BIT,                                                \
  76     2*PRE##_STATESZ/256, 2*PRE##_STATESZ%256, 0, 0 };                   \
  77                                                                         \
  78 /* --- @pre_nmacinit@ --- *                                             \
  79  *                                                                      \
  80  * Arguments:   @pre_macctx *key@ = pointer to a MAC key object         \
  81  *              @const void *ok@ = pointer to outer hash init vector    \
  82  *              @const void *ik@ = pointer to inner hash init vector    \
  83  *                                                                      \
  84  * Returns:     ---                                                     \
  85  *                                                                      \
  86  * Use:         Initializes a MAC key for doing NMAC hashing.           \
  87  */                                                                     \
  88                                                                         \
  89 void pre##_nmacinit(pre##_mackey *key, const void *ok, const void *ik)  \
  90 {                                                                       \
  91   memcpy(key->ochain, ok, PRE##_STATESZ);                               \
  92   memcpy(key->ichain, ik, PRE##_STATESZ);                               \
  93   key->ocount = key->icount = 0;                                        \
  94 }                                                                       \
  95                                                                         \
  96 /* --- @pre_hmacinit@ --- *                                             \
  97  *                                                                      \
  98  * Arguments:   @pre_mackey *key@ = pointer to MAC key object           \
  99  *              @const void *k@ = pointer to key to use                 \
 100  *              @size_t sz@ = size of key data                          \
 101  *                                                                      \
 102  * Returns:     ---                                                     \
 103  *                                                                      \
 104  * Use:         Initializes a MAC key for doing HMAC hashing.  Keys     \
 105  *              longer than the hash function's output size aren't very \
 106  *              useful, but are accepted.  Keys longer than the hash's  \
 107  *              block size are also accepted; they are hashed before    \
 108  *              use, as specified in RFC2104.                           \
 109  */                                                                     \
 110                                                                         \
 111 void pre##_hmacinit(pre##_mackey *key, const void *k, size_t sz)        \
 112 {                                                                       \
 113   int i;                                                                \
 114   const octet *kbuf = k;                                                \
 115   pre##_ctx ctx;                                                        \
 116   octet hbuf[PRE##_HASHSZ], buf[PRE##_BUFSZ];                           \
 117                                                                         \
 118   if (sz > PRE##_BUFSZ) {                                               \
 119     pre##_init(&ctx);                                                   \
 120     pre##_hash(&ctx, k, sz);                                            \
 121     pre##_done(&ctx, hbuf);                                             \
 122     kbuf = hbuf;                                                        \
 123     sz = PRE##_HASHSZ;                                                  \
 124   }                                                                     \
 125                                                                         \
 126   pre##_init(&ctx);                                                     \
 127   memset(buf, 0x5c, PRE##_BUFSZ);                                       \
 128   for (i = 0; i < sz; i++) buf[i] ^= kbuf[i];                           \
 129   pre##_hash(&ctx, buf, PRE##_BUFSZ);                                   \
 130   key->ocount = pre##_state(&ctx, key->ochain);                         \
 131                                                                         \
 132   pre##_init(&ctx);                                                     \
 133   memset(buf, 0x36, PRE##_BUFSZ);                                       \
 134   for (i = 0; i < sz; i++) buf[i] ^= kbuf[i];                           \
 135   pre##_hash(&ctx, buf, PRE##_BUFSZ);                                   \
 136   key->icount = pre##_state(&ctx, key->ichain);                         \
 137                                                                         \
 138   BURN(ctx);                                                            \
 139 }                                                                       \
 140                                                                         \
 141 /* --- @pre_sslmacinit@ --- *                                           \
 142  *                                                                      \
 143  * Arguments:   @pre_mackey *key@ = pointer to MAC key object           \
 144  *              @const void *k@ = pointer to key to use                 \
 145  *              @size_t sz@ = size of key data                          \
 146  *                                                                      \
 147  * Returns:     ---                                                     \
 148  *                                                                      \
 149  * Use:         Initializes a MAC key for doing hasing using the SSL3   \
 150  *              variant of HMAC.                                        \
 151  */                                                                     \
 152                                                                         \
 153 void pre##_sslmacinit(pre##_mackey *key, const void *k, size_t sz)      \
 154 {                                                                       \
 155   const octet *kbuf = k;                                                \
 156   pre##_ctx ctx;                                                        \
 157   octet hbuf[PRE##_HASHSZ], buf[PRE##_BUFSZ];                           \
 158                                                                         \
 159   if (sz > PRE##_BUFSZ) {                                               \
 160     pre##_init(&ctx);                                                   \
 161     pre##_hash(&ctx, k, sz);                                            \
 162     pre##_done(&ctx, hbuf);                                             \
 163     kbuf = hbuf;                                                        \
 164     sz = PRE##_HASHSZ;                                                  \
 165   }                                                                     \
 166                                                                         \
 167   pre##_init(&ctx);                                                     \
 168   memcpy(buf, kbuf, sz);                                                \
 169   memset(buf + sz, 0x5c, PRE##_BUFSZ - sz);                             \
 170   pre##_hash(&ctx, buf, PRE##_BUFSZ);                                   \
 171   key->ocount = pre##_state(&ctx, key->ochain);                         \
 172                                                                         \
 173   pre##_init(&ctx);                                                     \
 174   memcpy(buf, kbuf, sz);                                                \
 175   memset(buf + sz, 0x36, PRE##_BUFSZ - sz);                             \
 176   pre##_hash(&ctx, buf, PRE##_BUFSZ);                                   \
 177   key->icount = pre##_state(&ctx, key->ichain);                         \
 178                                                                         \
 179   BURN(ctx);                                                            \
 180 }                                                                       \
 181                                                                         \
 182 /* --- @pre_macinit@ --- *                                              \
 183  *                                                                      \
 184  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 185  *              @const pre_mackey *key@ = pointer to MAC key block      \
 186  *                                                                      \
 187  * Returns:     ---                                                     \
 188  *                                                                      \
 189  * Use:         Instantiates a MAC context from a key block.            \
 190  */                                                                     \
 191                                                                         \
 192 void pre##_macinit(pre##_macctx *ctx, const pre##_mackey *key)          \
 193 {                                                                       \
 194   memcpy(ctx->chain, key->ochain, PRE##_STATESZ);                       \
 195   ctx->count = key->ocount;                                             \
 196   pre##_set(&ctx->ctx, key->ichain, key->icount);                       \
 197 }                                                                       \
 198                                                                         \
 199 /* --- @pre_machash@ --- *                                              \
 200  *                                                                      \
 201  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 202  *              @const void *buf@ = pointer to buffer                   \
 203  *              @size_t sz@ = size of the buffer                        \
 204  *                                                                      \
 205  * Returns:     ---                                                     \
 206  *                                                                      \
 207  * Use:         Hashes a buffer.                                        \
 208  */                                                                     \
 209                                                                         \
 210 void pre##_machash(pre##_macctx *ctx, const void *buf, size_t sz)       \
 211 {                                                                       \
 212   pre##_hash(&ctx->ctx, buf, sz);                                       \
 213 }                                                                       \
 214                                                                         \
 215 /* --- @pre_macdone@ --- *                                              \
 216  *                                                                      \
 217  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 218  *              @void *mac@ = pointer to buffer to receive MAC          \
 219  *                                                                      \
 220  * Returns:     ---                                                     \
 221  *                                                                      \
 222  * Use:         Returns the result of a MAC computation.                \
 223  */                                                                     \
 224                                                                         \
 225 void pre##_macdone(pre##_macctx *ctx, void *mac)                        \
 226 {                                                                       \
 227   pre##_done(&ctx->ctx, mac);                                           \
 228   pre##_set(&ctx->ctx, ctx->chain, ctx->count);                         \
 229   pre##_hash(&ctx->ctx, mac, PRE##_HASHSZ);                             \
 230   pre##_done(&ctx->ctx, mac);                                           \
 231 }                                                                       \
 232                                                                         \
 233 /* --- Generic MAC interface --- */                                     \
 234                                                                         \
 235 static const gmac_ops gkops, gnkops, gsslkops;                          \
 236 static const ghash_ops gops, gnops, gsslops;                            \
 237                                                                         \
 238 typedef struct gkctx {                                                  \
 239   gmac m;                                                               \
 240   const ghash_ops *gops;                                                \
 241   pre##_mackey k;                                                       \
 242 } gkctx;                                                                \
 243                                                                         \
 244 typedef struct gctx {                                                   \
 245   ghash h;                                                              \
 246   pre##_macctx c;                                                       \
 247   octet buf[PRE##_HASHSZ];                                              \
 248 } gctx;                                                                 \
 249                                                                         \
 250 static ghash *gkinit(gmac *m)                                           \
 251 {                                                                       \
 252   gkctx *gk = (gkctx *)m;                                               \
 253   gctx *g = S_CREATE(gctx);                                             \
 254   g->h.ops = gk->gops;                                                  \
 255   pre##_macinit(&g->c, &gk->k);                                         \
 256   return (&g->h);                                                       \
 257 }                                                                       \
 258                                                                         \
 259 static gmac *gkey(const void *k, size_t sz)                             \
 260 {                                                                       \
 261   gkctx *gk = S_CREATE(gkctx);                                          \
 262   gk->m.ops = &gkops;                                                   \
 263   gk->gops = &gops;                                                     \
 264   pre##_hmacinit(&gk->k, k, sz);                                        \
 265   return (&gk->m);                                                      \
 266 }                                                                       \
 267                                                                         \
 268 static gmac *gnkey(const void *k, size_t sz)                            \
 269 {                                                                       \
 270   gkctx *gk = S_CREATE(gkctx);                                          \
 271   const octet *kk = k;                                                  \
 272   assert(keysz(sz, pre##_nmackeysz) == sz);                             \
 273   gk->m.ops = &gnkops;                                                  \
 274   gk->gops = &gnops;                                                    \
 275   pre##_nmacinit(&gk->k, kk, kk + PRE##_STATESZ);                       \
 276   return (&gk->m);                                                      \
 277 }                                                                       \
 278                                                                         \
 279 static gmac *gsslkey(const void *k, size_t sz)                          \
 280 {                                                                       \
 281   gkctx *gk = S_CREATE(gkctx);                                          \
 282   gk->m.ops = &gsslkops;                                                \
 283   gk->gops = &gsslops;                                                  \
 284   pre##_sslmacinit(&gk->k, k, sz);                                      \
 285   return (&gk->m);                                                      \
 286 }                                                                       \
 287                                                                         \
 288 static void ghhash(ghash *h, const void *p, size_t sz)                  \
 289 {                                                                       \
 290   gctx *g = (gctx *)h;                                                  \
 291   pre##_machash(&g->c, p, sz);                                          \
 292 }                                                                       \
 293                                                                         \
 294 static octet *ghdone(ghash *h, void *buf)                               \
 295 {                                                                       \
 296   gctx *g = (gctx *)h;                                                  \
 297   if (!buf)                                                             \
 298     buf = g->buf;                                                       \
 299   pre##_macdone(&g->c, buf);                                            \
 300   return (buf);                                                         \
 301 }                                                                       \
 302                                                                         \
 303 static ghash *ghcopy(ghash *h)                                          \
 304 {                                                                       \
 305   gctx *g = (gctx *)h;                                                  \
 306   gctx *gg = S_CREATE(gctx);                                            \
 307   memcpy(gg, g, sizeof(gctx));                                          \
 308   return (&gg->h);                                                      \
 309 }                                                                       \
 310                                                                         \
 311 static void ghdestroy(ghash *h)                                         \
 312 {                                                                       \
 313   gctx *g = (gctx *)h;                                                  \
 314   BURN(*g);                                                             \
 315   S_DESTROY(g);                                                         \
 316 }                                                                       \
 317                                                                         \
 318 static void gkdestroy(gmac *m)                                          \
 319 {                                                                       \
 320   gkctx *gk = (gkctx *)m;                                               \
 321   BURN(*gk);                                                            \
 322   S_DESTROY(gk);                                                        \
 323 }                                                                       \
 324                                                                         \
 325 static ghash *ghinit(void)                                              \
 326 {                                                                       \
 327   assert(((void)"Attempt to instantiate an unkeyed MAC", 0));           \
 328   return (0);                                                           \
 329 }                                                                       \
 330                                                                         \
 331 const gcmac pre##_nmac =                                                \
 332   { name "-nmac", PRE##_HASHSZ, pre##_nmackeysz, gnkey };               \
 333 const gcmac pre##_hmac =                                                \
 334   { name "-hmac", PRE##_HASHSZ, pre##_hmackeysz, gkey };                \
 335 const gcmac pre##_sslmac =                                              \
 336   { name "-sslmac", PRE##_HASHSZ, pre##_sslmackeysz, gsslkey };         \
 337 static const gmac_ops gkops = { &pre##_hmac, gkinit, gkdestroy };       \
 338 static const gmac_ops gnkops = { &pre##_nmac, gkinit, gkdestroy };      \
 339 static const gmac_ops gsslkops = { &pre##_sslmac, gkinit, gkdestroy };  \
 340 static const gchash gch = { name "-hmac", PRE##_HASHSZ, ghinit };       \
 341 static const ghash_ops gops =                                           \
 342   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 343 static const gchash gnch = { name "-nmac", PRE##_HASHSZ, ghinit };      \
 344 static const ghash_ops gnops =                                          \
 345   { &gnch, ghhash, ghdone, ghdestroy, ghcopy };                         \
 346 static const gchash gsslch = { name "-sslmac", PRE##_HASHSZ, ghinit };  \
 347 static const ghash_ops gsslops =                                        \
 348   { &gsslch, ghhash, ghdone, ghdestroy, ghcopy };                       \
 349                                                                         \
 350 HMAC_TESTX(PRE, pre, name, fname)
 351
 352 #define HMAC_TEST(PRE, pre) HMAC_TESTX(PRE, pre, #pre, #pre)
 353
 354 /* --- @HMAC_TEST@ --- *
 355  *
 356  * Arguments:   @PRE@, @pre@ = prefixes for hash-specfic definitions
 357  *
 358  * Use:         Standard test rig for MAC functions.
 359  */
 360
 361 #ifdef TEST_RIG
 362
 363 #include <stdio.h>
 364
 365 #include <mLib/dstr.h>
 366 #include <mLib/quis.h>
 367 #include <mLib/testrig.h>
 368
 369 #define HMAC_TESTX(PRE, pre, name, fname)                               \
 370                                                                         \
 371 static int macverify(dstr *v)                                           \
 372 {                                                                       \
 373   pre##_macctx cctx;                                                    \
 374   pre##_mackey ckey;                                                    \
 375   int ok = 1;                                                           \
 376   int i;                                                                \
 377   octet *p;                                                             \
 378   int szs[] = { 1, 7, 192, -1, 0 }, *ip;                                \
 379   size_t csz;                                                           \
 380   dstr d;                                                               \
 381                                                                         \
 382   dstr_create(&d);                                                      \
 383   dstr_ensure(&d, PRE##_HASHSZ);                                        \
 384   d.len = PRE##_HASHSZ;                                                 \
 385                                                                         \
 386   pre##_hmacinit(&ckey, v[1].buf, v[1].len);                            \
 387                                                                         \
 388   for (ip = szs; *ip; ip++) {                                           \
 389     i = *ip;                                                            \
 390     csz = v[0].len;                                                     \
 391     if (i == -1)                                                        \
 392       i = csz;                                                          \
 393     if (i > csz)                                                        \
 394       continue;                                                         \
 395     p = (octet *)v[0].buf;                                              \
 396     pre##_macinit(&cctx, &ckey);                                        \
 397     while (csz) {                                                       \
 398       if (i > csz)                                                      \
 399         i = csz;                                                        \
 400       pre##_machash(&cctx, p, i);                                       \
 401       p += i;                                                           \
 402       csz -= i;                                                         \
 403     }                                                                   \
 404     pre##_macdone(&cctx, d.buf);                                        \
 405     if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) {                   \
 406       printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\tkey = ",          \
 407              *ip, v[0].buf);                                            \
 408       type_hex.dump(&v[1], stdout);                                     \
 409       fputs("\n\texpected = ", stdout);                                 \
 410       type_hex.dump(&v[2], stdout);                                     \
 411       fputs("\n\tcomputed = ", stdout);                                 \
 412       type_hex.dump(&d, stdout);                                        \
 413       putchar('\n');                                                    \
 414       ok = 0;                                                           \
 415     }                                                                   \
 416   }                                                                     \
 417                                                                         \
 418   dstr_destroy(&d);                                                     \
 419   return (ok);                                                          \
 420 }                                                                       \
 421                                                                         \
 422 static test_chunk macdefs[] = {                                         \
 423   { name "-hmac", macverify,                                            \
 424     { &type_string, &type_hex, &type_hex, 0 } },                        \
 425   { 0, 0, { 0 } }                                                       \
 426 };                                                                      \
 427                                                                         \
 428 int main(int argc, char *argv[])                                        \
 429 {                                                                       \
 430   ego(argv[0]);                                                         \
 431   test_run(argc, argv, macdefs, SRCDIR"/t/" fname);                     \
 432   return (0);                                                           \
 433 }
 434
 435 #else
 436 #  define HMAC_TESTX(PRE, pre, name, fname)
 437 #endif
 438
 439 /*----- That's all, folks -------------------------------------------------*/
 440
 441 #ifdef __cplusplus
 442   }
 443 #endif
 444
 445 #endif