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   1 /* -*-c-*-
   2  *
   3  * $Id: hmac-def.h,v 1.8 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Definitions for HMAC and NMAC
   6  *
   7  * (c) 1999 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 #ifndef CATACOMB_HMAC_DEF_H
  31 #define CATACOMB_HMAC_DEF_H
  32
  33 #ifdef __cplusplus
  34   extern "C" {
  35 #endif
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include <assert.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include <mLib/bits.h>
  44 #include <mLib/sub.h>
  45
  46 #ifndef CATACOMB_ARENA_H
  47 #  include "arena.h"
  48 #endif
  49
  50 #ifndef CATACOMB_GMAC_H
  51 #  include "gmac.h"
  52 #endif
  53
  54 #ifndef CATACOMB_PARANOIA_H
  55 #  include "paranoia.h"
  56 #endif
  57
  58 /*----- Macros ------------------------------------------------------------*/
  59
  60 /* --- @HMAC_DEF@ --- *
  61  *
  62  * Arguments:   @PRE@, @pre@ = prefixes for the underlying hash function
  63  *
  64  * Use:         Creates implementations for the HMAC and NMAC functions.
  65  */
  66
  67 #define HMAC_DEF(PRE, pre)                                              \
  68                                                                         \
  69 /* --- Useful constants --- */                                          \
  70                                                                         \
  71 const octet pre##_hmackeysz[] = { KSZ_ANY, PRE##_STATESZ };             \
  72 const octet pre##_sslmackeysz[] = { KSZ_ANY, PRE##_STATESZ };           \
  73 const octet pre##_nmackeysz[] = { KSZ_SET, 2 * PRE##_STATESZ, 0 };      \
  74                                                                         \
  75 /* --- @pre_nmacinit@ --- *                                             \
  76  *                                                                      \
  77  * Arguments:   @pre_macctx *key@ = pointer to a MAC key object         \
  78  *              @const void *ok@ = pointer to outer hash init vector    \
  79  *              @const void *ik@ = pointer to inner hash init vector    \
  80  *                                                                      \
  81  * Returns:     ---                                                     \
  82  *                                                                      \
  83  * Use:         Initializes a MAC key for doing NMAC hashing.           \
  84  */                                                                     \
  85                                                                         \
  86 void pre##_nmacinit(pre##_mackey *key, const void *ok, const void *ik)  \
  87 {                                                                       \
  88   memcpy(key->ochain, ok, PRE##_STATESZ);                               \
  89   memcpy(key->ichain, ik, PRE##_STATESZ);                               \
  90   key->ocount = key->icount = 0;                                        \
  91 }                                                                       \
  92                                                                         \
  93 /* --- @pre_hmacinit@ --- *                                             \
  94  *                                                                      \
  95  * Arguments:   @pre_mackey *key@ = pointer to MAC key object           \
  96  *              @const void *k@ = pointer to key to use                 \
  97  *              @size_t sz@ = size of key data                          \
  98  *                                                                      \
  99  * Returns:     ---                                                     \
 100  *                                                                      \
 101  * Use:         Initializes a MAC key for doing HMAC hashing.  Keys     \
 102  *              longer than the hash function's output size aren't very \
 103  *              useful, but are accepted.  Keys longer than the hash's  \
 104  *              block size are also accepted; they are hashed before    \
 105  *              use, as specified in RFC2104.                           \
 106  */                                                                     \
 107                                                                         \
 108 void pre##_hmacinit(pre##_mackey *key, const void *k, size_t sz)        \
 109 {                                                                       \
 110   int i;                                                                \
 111   const octet *kbuf = k;                                                \
 112   pre##_ctx ctx;                                                        \
 113   octet buf[PRE##_HASHSZ];                                              \
 114                                                                         \
 115   if (sz > PRE##_BUFSZ) {                                               \
 116     pre##_init(&ctx);                                                   \
 117     pre##_hash(&ctx, k, sz);                                            \
 118     pre##_done(&ctx, buf);                                              \
 119     kbuf = buf;                                                         \
 120     sz = PRE##_HASHSZ;                                                  \
 121   }                                                                     \
 122                                                                         \
 123   pre##_init(&ctx);                                                     \
 124   memset(ctx.buf, 0x5c, PRE##_BUFSZ);                                   \
 125   for (i = 0; i < sz; i++)                                              \
 126     ctx.buf[i] ^= kbuf[i];                                              \
 127   pre##_compress(&ctx, ctx.buf);                                        \
 128   pre##_state(&ctx, key->ochain);                                       \
 129                                                                         \
 130   pre##_init(&ctx);                                                     \
 131   memset(ctx.buf, 0x36, PRE##_BUFSZ);                                   \
 132   for (i = 0; i < sz; i++)                                              \
 133     ctx.buf[i] ^= kbuf[i];                                              \
 134   pre##_compress(&ctx, ctx.buf);                                        \
 135   pre##_state(&ctx, key->ichain);                                       \
 136                                                                         \
 137   key->ocount = key->icount = PRE##_BUFSZ;                              \
 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 buf[PRE##_HASHSZ];                                              \
 158                                                                         \
 159   if (sz > PRE##_BUFSZ) {                                               \
 160     pre##_init(&ctx);                                                   \
 161     pre##_hash(&ctx, k, sz);                                            \
 162     pre##_done(&ctx, buf);                                              \
 163     kbuf = buf;                                                         \
 164     sz = PRE##_HASHSZ;                                                  \
 165   }                                                                     \
 166                                                                         \
 167   pre##_init(&ctx);                                                     \
 168   memcpy(ctx.buf, kbuf, sz);                                            \
 169   memset(ctx.buf + sz, 0x5c, PRE##_BUFSZ - sz);                         \
 170   pre##_compress(&ctx, ctx.buf);                                        \
 171   pre##_state(&ctx, key->ochain);                                       \
 172                                                                         \
 173   pre##_init(&ctx);                                                     \
 174   memcpy(ctx.buf, kbuf, sz);                                            \
 175   memset(ctx.buf + sz, 0x36, PRE##_BUFSZ - sz);                         \
 176   pre##_compress(&ctx, ctx.buf);                                        \
 177   pre##_state(&ctx, key->ichain);                                       \
 178                                                                         \
 179   key->ocount = key->icount = PRE##_BUFSZ;                              \
 180   BURN(ctx);                                                            \
 181 }                                                                       \
 182                                                                         \
 183 /* --- @pre_macinit@ --- *                                              \
 184  *                                                                      \
 185  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 186  *              @const pre_mackey *key@ = pointer to MAC key block      \
 187  *                                                                      \
 188  * Returns:     ---                                                     \
 189  *                                                                      \
 190  * Use:         Instantiates a MAC context from a key block.            \
 191  */                                                                     \
 192                                                                         \
 193 void pre##_macinit(pre##_macctx *ctx, const pre##_mackey *key)          \
 194 {                                                                       \
 195   memcpy(ctx->chain, key->ochain, PRE##_STATESZ);                       \
 196   ctx->count = key->ocount;                                             \
 197   pre##_set(&ctx->ctx, key->ichain, key->icount);                       \
 198 }                                                                       \
 199                                                                         \
 200 /* --- @pre_machash@ --- *                                              \
 201  *                                                                      \
 202  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 203  *              @const void *buf@ = pointer to buffer                   \
 204  *              @size_t sz@ = size of the buffer                        \
 205  *                                                                      \
 206  * Returns:     ---                                                     \
 207  *                                                                      \
 208  * Use:         Hashes a buffer.                                        \
 209  */                                                                     \
 210                                                                         \
 211 void pre##_machash(pre##_macctx *ctx, const void *buf, size_t sz)       \
 212 {                                                                       \
 213   pre##_hash(&ctx->ctx, buf, sz);                                       \
 214 }                                                                       \
 215                                                                         \
 216 /* --- @pre_macdone@ --- *                                              \
 217  *                                                                      \
 218  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 219  *              @void *mac@ = pointer to buffer to receive MAC          \
 220  *                                                                      \
 221  * Returns:     ---                                                     \
 222  *                                                                      \
 223  * Use:         Returns the result of a MAC computation.                \
 224  */                                                                     \
 225                                                                         \
 226 void pre##_macdone(pre##_macctx *ctx, void *mac)                        \
 227 {                                                                       \
 228   pre##_done(&ctx->ctx, mac);                                           \
 229   pre##_set(&ctx->ctx, ctx->chain, ctx->count);                         \
 230   pre##_hash(&ctx->ctx, mac, PRE##_HASHSZ);                             \
 231   pre##_done(&ctx->ctx, mac);                                           \
 232 }                                                                       \
 233                                                                         \
 234 /* --- Generic MAC interface --- */                                     \
 235                                                                         \
 236 static const gmac_ops gkops;                                            \
 237 static const ghash_ops gops, gnops, gsslops;                            \
 238                                                                         \
 239 typedef struct gkctx {                                                  \
 240   gmac m;                                                               \
 241   const ghash_ops *gops;                                                \
 242   pre##_mackey k;                                                       \
 243 } gkctx;                                                                \
 244                                                                         \
 245 typedef struct gctx {                                                   \
 246   ghash h;                                                              \
 247   pre##_macctx c;                                                       \
 248   octet buf[PRE##_HASHSZ];                                              \
 249 } gctx;                                                                 \
 250                                                                         \
 251 static ghash *gkinit(gmac *m)                                           \
 252 {                                                                       \
 253   gkctx *gk = (gkctx *)m;                                               \
 254   gctx *g = S_CREATE(gctx);                                             \
 255   g->h.ops = gk->gops;                                                  \
 256   pre##_macinit(&g->c, &gk->k);                                         \
 257   return (&g->h);                                                       \
 258 }                                                                       \
 259                                                                         \
 260 static gmac *gkey(const void *k, size_t sz)                             \
 261 {                                                                       \
 262   gkctx *gk = S_CREATE(gkctx);                                          \
 263   gk->m.ops = &gkops;                                                   \
 264   gk->gops = &gops;                                                     \
 265   pre##_hmacinit(&gk->k, k, sz);                                        \
 266   return (&gk->m);                                                      \
 267 }                                                                       \
 268                                                                         \
 269 static gmac *gnkey(const void *k, size_t sz)                            \
 270 {                                                                       \
 271   gkctx *gk = S_CREATE(gkctx);                                          \
 272   const octet *kk = k;                                                  \
 273   assert(keysz(sz, pre##_nmackeysz) == sz);                             \
 274   gk->m.ops = &gkops;                                                   \
 275   gk->gops = &gnops;                                                    \
 276   pre##_nmacinit(&gk->k, kk, kk + PRE##_STATESZ);                       \
 277   return (&gk->m);                                                      \
 278 }                                                                       \
 279                                                                         \
 280 static gmac *gsslkey(const void *k, size_t sz)                          \
 281 {                                                                       \
 282   gkctx *gk = S_CREATE(gkctx);                                          \
 283   gk->m.ops = &gkops;                                                   \
 284   gk->gops = &gsslops;                                                  \
 285   pre##_sslmacinit(&gk->k, k, sz);                                      \
 286   return (&gk->m);                                                      \
 287 }                                                                       \
 288                                                                         \
 289 static void ghhash(ghash *h, const void *p, size_t sz)                  \
 290 {                                                                       \
 291   gctx *g = (gctx *)h;                                                  \
 292   pre##_machash(&g->c, p, sz);                                          \
 293 }                                                                       \
 294                                                                         \
 295 static octet *ghdone(ghash *h, void *buf)                               \
 296 {                                                                       \
 297   gctx *g = (gctx *)h;                                                  \
 298   if (!buf)                                                             \
 299     buf = g->buf;                                                       \
 300   pre##_macdone(&g->c, buf);                                            \
 301   return (buf);                                                         \
 302 }                                                                       \
 303                                                                         \
 304 static ghash *ghcopy(ghash *h)                                          \
 305 {                                                                       \
 306   gctx *g = (gctx *)h;                                                  \
 307   gctx *gg = S_CREATE(gctx);                                            \
 308   memcpy(gg, g, sizeof(gctx));                                          \
 309   return (&gg->h);                                                      \
 310 }                                                                       \
 311                                                                         \
 312 static void ghdestroy(ghash *h)                                         \
 313 {                                                                       \
 314   gctx *g = (gctx *)h;                                                  \
 315   BURN(*g);                                                             \
 316   S_DESTROY(g);                                                         \
 317 }                                                                       \
 318                                                                         \
 319 static void gkdestroy(gmac *m)                                          \
 320 {                                                                       \
 321   gkctx *gk = (gkctx *)m;                                               \
 322   BURN(*gk);                                                            \
 323   S_DESTROY(gk);                                                        \
 324 }                                                                       \
 325                                                                         \
 326 static ghash *ghinit(void)                                              \
 327 {                                                                       \
 328   assert(((void)"Attempt to instantiate an unkeyed MAC", 0));           \
 329   return (0);                                                           \
 330 }                                                                       \
 331                                                                         \
 332 const gcmac pre##_nmac =                                                \
 333   { #pre "-nmac", PRE##_HASHSZ, pre##_nmackeysz, gnkey };               \
 334 const gcmac pre##_hmac =                                                \
 335   { #pre "-hmac", PRE##_HASHSZ, pre##_hmackeysz, gkey };                \
 336 const gcmac pre##_sslmac =                                              \
 337   { #pre "-sslmac", PRE##_HASHSZ, pre##_sslmackeysz, gsslkey };         \
 338 static const gmac_ops gkops = { &pre##_hmac, gkinit, gkdestroy };       \
 339 static const gmac_ops gnkops = { &pre##_nmac, gkinit, gkdestroy };      \
 340 static const gmac_ops gsslkops = { &pre##_sslmac, gkinit, gkdestroy };  \
 341 static const gchash gch = { #pre "-hmac", PRE##_HASHSZ, ghinit };       \
 342 static const ghash_ops gops =                                           \
 343   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 344 static const gchash gnch = { #pre "-nmac", PRE##_HASHSZ, ghinit };      \
 345 static const ghash_ops gnops =                                          \
 346   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 347 static const gchash gsslch = { #pre "-sslmac", PRE##_HASHSZ, ghinit };  \
 348 static const ghash_ops gsslops =                                        \
 349   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 350                                                                         \
 351 HMAC_TEST(PRE, pre)
 352
 353 /* --- @HMAC_TEST@ --- *
 354  *
 355  * Arguments:   @PRE@, @pre@ = prefixes for hash-specfic definitions
 356  *
 357  * Use:         Standard test rig for MAC functions.
 358  */
 359
 360 #ifdef TEST_RIG
 361
 362 #include <stdio.h>
 363
 364 #include <mLib/dstr.h>
 365 #include <mLib/quis.h>
 366 #include <mLib/testrig.h>
 367
 368 #define HMAC_TEST(PRE, pre)                                             \
 369                                                                         \
 370 static int macverify(dstr *v)                                           \
 371 {                                                                       \
 372   pre##_macctx cctx;                                                    \
 373   pre##_mackey ckey;                                                    \
 374   int ok = 1;                                                           \
 375   int i;                                                                \
 376   octet *p;                                                             \
 377   int szs[] = { 1, 7, 192, -1, 0 }, *ip;                                \
 378   size_t csz;                                                           \
 379   dstr d;                                                               \
 380                                                                         \
 381   dstr_create(&d);                                                      \
 382   dstr_ensure(&d, PRE##_HASHSZ);                                        \
 383   d.len = PRE##_HASHSZ;                                                 \
 384                                                                         \
 385   pre##_hmacinit(&ckey, v[1].buf, v[1].len);                            \
 386                                                                         \
 387   for (ip = szs; *ip; ip++) {                                           \
 388     i = *ip;                                                            \
 389     csz = v[0].len;                                                     \
 390     if (i == -1)                                                        \
 391       i = csz;                                                          \
 392     if (i > csz)                                                        \
 393       continue;                                                         \
 394     p = (octet *)v[0].buf;                                              \
 395     pre##_macinit(&cctx, &ckey);                                        \
 396     while (csz) {                                                       \
 397       if (i > csz)                                                      \
 398         i = csz;                                                        \
 399       pre##_machash(&cctx, p, i);                                       \
 400       p += i;                                                           \
 401       csz -= i;                                                         \
 402     }                                                                   \
 403     pre##_macdone(&cctx, d.buf);                                        \
 404     if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) {                   \
 405       printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\tkey = ",          \
 406              *ip, v[0].buf);                                            \
 407       type_hex.dump(&v[1], stdout);                                     \
 408       fputs("\n\texpected = ", stdout);                                 \
 409       type_hex.dump(&v[2], stdout);                                     \
 410       fputs("\n\tcomputed = ", stdout);                                 \
 411       type_hex.dump(&d, stdout);                                        \
 412       putchar('\n');                                                    \
 413       ok = 0;                                                           \
 414     }                                                                   \
 415   }                                                                     \
 416                                                                         \
 417   dstr_destroy(&d);                                                     \
 418   return (ok);                                                          \
 419 }                                                                       \
 420                                                                         \
 421 static test_chunk macdefs[] = {                                         \
 422   { #pre "-hmac", macverify,                                            \
 423     { &type_string, &type_hex, &type_hex, 0 } },                        \
 424   { 0, 0, { 0 } }                                                       \
 425 };                                                                      \
 426                                                                         \
 427 int main(int argc, char *argv[])                                        \
 428 {                                                                       \
 429   ego(argv[0]);                                                         \
 430   test_run(argc, argv, macdefs, SRCDIR"/tests/" #pre);                  \
 431   return (0);                                                           \
 432 }
 433
 434 #else
 435 #  define HMAC_TEST(PRE, pre)
 436 #endif
 437
 438 /*----- That's all, folks -------------------------------------------------*/
 439
 440 #ifdef __cplusplus
 441   }
 442 #endif
 443
 444 #endif