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   1 /* -*-c-*-
   2  *
   3  * $Id: hmac-def.h,v 1.6 2001/04/03 19:35:45 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 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: hmac-def.h,v $
  33  * Revision 1.6  2001/04/03 19:35:45  mdw
  34  * Support the SSL HMAC variant (untested).
  35  *
  36  * Revision 1.5  2000/10/15 19:09:20  mdw
  37  * Support HMAC mode for hash functions which need to store more state than
  38  * the hash output size.
  39  *
  40  * Revision 1.4  2000/07/15 10:00:58  mdw
  41  * New generic hash operation for copying hash contexts.
  42  *
  43  * Revision 1.3  2000/07/02 18:27:42  mdw
  44  * (ghash->ops->done): Interface change.  Passing in a null buffer pointer
  45  * uses a buffer internal to the ghash object.  The operation returns the
  46  * address of the buffer it used.  Clients of generic hashes no longer need
  47  * to use dynamically allocated memory for hash results.
  48  *
  49  * Revision 1.2  2000/06/17 11:23:44  mdw
  50  * Use secure arena for memory allocation.  Minor changes in the generic
  51  * hash interface.
  52  *
  53  * Revision 1.1  1999/12/10 23:16:40  mdw
  54  * Split mode macros into interface and implementation.
  55  *
  56  */
  57
  58 #ifndef CATACOMB_HMAC_DEF_H
  59 #define CATACOMB_HMAC_DEF_H
  60
  61 #ifdef __cplusplus
  62   extern "C" {
  63 #endif
  64
  65 /*----- Header files ------------------------------------------------------*/
  66
  67 #include <assert.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70
  71 #include <mLib/bits.h>
  72 #include <mLib/sub.h>
  73
  74 #ifndef CATACOMB_ARENA_H
  75 #  include "arena.h"
  76 #endif
  77
  78 #ifndef CATACOMB_GMAC_H
  79 #  include "gmac.h"
  80 #endif
  81
  82 #ifndef CATACOMB_PARANOIA_H
  83 #  include "paranoia.h"
  84 #endif
  85
  86 /*----- Macros ------------------------------------------------------------*/
  87
  88 /* --- @HMAC_DEF@ --- *
  89  *
  90  * Arguments:   @PRE@, @pre@ = prefixes for the underlying hash function
  91  *
  92  * Use:         Creates implementations for the HMAC and NMAC functions.
  93  */
  94
  95 #define HMAC_DEF(PRE, pre)                                              \
  96                                                                         \
  97 /* --- Useful constants --- */                                          \
  98                                                                         \
  99 const octet pre##_mackeysz[] = { KSZ_ANY, PRE##_STATESZ };              \
 100                                                                         \
 101 /* --- @pre_nmacinit@ --- *                                             \
 102  *                                                                      \
 103  * Arguments:   @pre_macctx *key@ = pointer to a MAC key object         \
 104  *              @const void *ok@ = pointer to outer hash init vector    \
 105  *              @const void *ik@ = pointer to inner hash init vector    \
 106  *                                                                      \
 107  * Returns:     ---                                                     \
 108  *                                                                      \
 109  * Use:         Initializes a MAC key for doing NMAC hashing.           \
 110  */                                                                     \
 111                                                                         \
 112 void pre##_nmacinit(pre##_mackey *key, const void *ok, const void *ik)  \
 113 {                                                                       \
 114   memcpy(key->ochain, ok, PRE##_STATESZ);                               \
 115   memcpy(key->ichain, ik, PRE##_STATESZ);                               \
 116   key->ocount = key->icount = 0;                                        \
 117 }                                                                       \
 118                                                                         \
 119 /* --- @pre_hmacinit@ --- *                                             \
 120  *                                                                      \
 121  * Arguments:   @pre_mackey *key@ = pointer to MAC key object           \
 122  *              @const void *k@ = pointer to key to use                 \
 123  *              @size_t sz@ = size of key data                          \
 124  *                                                                      \
 125  * Returns:     ---                                                     \
 126  *                                                                      \
 127  * Use:         Initializes a MAC key for doing HMAC hashing.  Keys     \
 128  *              longer than the hash function's output size aren't very \
 129  *              useful, but are accepted.  Keys longer than the hash's  \
 130  *              block size are also accepted; they are hashed before    \
 131  *              use, as specified in RFC2104.                           \
 132  */                                                                     \
 133                                                                         \
 134 void pre##_hmacinit(pre##_mackey *key, const void *k, size_t sz)        \
 135 {                                                                       \
 136   int i;                                                                \
 137   const octet *kbuf = k;                                                \
 138   pre##_ctx ctx;                                                        \
 139   octet buf[PRE##_HASHSZ];                                              \
 140                                                                         \
 141   if (sz > PRE##_BUFSZ) {                                               \
 142     pre##_init(&ctx);                                                   \
 143     pre##_hash(&ctx, k, sz);                                            \
 144     pre##_done(&ctx, buf);                                              \
 145     kbuf = buf;                                                         \
 146     sz = PRE##_HASHSZ;                                                  \
 147   }                                                                     \
 148                                                                         \
 149   pre##_init(&ctx);                                                     \
 150   memset(ctx.buf, 0x5c, PRE##_BUFSZ);                                   \
 151   for (i = 0; i < sz; i++)                                              \
 152     ctx.buf[i] ^= kbuf[i];                                              \
 153   pre##_compress(&ctx, ctx.buf);                                        \
 154   pre##_state(&ctx, key->ochain);                                       \
 155                                                                         \
 156   pre##_init(&ctx);                                                     \
 157   memset(ctx.buf, 0x36, PRE##_BUFSZ);                                   \
 158   for (i = 0; i < sz; i++)                                              \
 159     ctx.buf[i] ^= kbuf[i];                                              \
 160   pre##_compress(&ctx, ctx.buf);                                        \
 161   pre##_state(&ctx, key->ichain);                                       \
 162                                                                         \
 163   key->ocount = key->icount = PRE##_BUFSZ;                              \
 164   BURN(ctx);                                                            \
 165 }                                                                       \
 166                                                                         \
 167 /* --- @pre_sslmacinit@ --- *                                           \
 168  *                                                                      \
 169  * Arguments:   @pre_mackey *key@ = pointer to MAC key object           \
 170  *              @const void *k@ = pointer to key to use                 \
 171  *              @size_t sz@ = size of key data                          \
 172  *                                                                      \
 173  * Returns:     ---                                                     \
 174  *                                                                      \
 175  * Use:         Initializes a MAC key for doing hasing using the SSL3   \
 176  *              variant of HMAC.                                        \
 177  */                                                                     \
 178                                                                         \
 179 void pre##_sslmacinit(pre##_mackey *key, const void *k, size_t sz)      \
 180 {                                                                       \
 181   int i;                                                                \
 182   const octet *kbuf = k;                                                \
 183   pre##_ctx ctx;                                                        \
 184   octet buf[PRE##_HASHSZ];                                              \
 185                                                                         \
 186   if (sz > PRE##_BUFSZ) {                                               \
 187     pre##_init(&ctx);                                                   \
 188     pre##_hash(&ctx, k, sz);                                            \
 189     pre##_done(&ctx, buf);                                              \
 190     kbuf = buf;                                                         \
 191     sz = PRE##_HASHSZ;                                                  \
 192   }                                                                     \
 193                                                                         \
 194   pre##_init(&ctx);                                                     \
 195   memcpy(ctx.buf, kbuf, sz);                                            \
 196   memset(ctx.buf + sz, 0x5c, PRE##_BUFSZ - sz);                         \
 197   pre##_compress(&ctx, ctx.buf);                                        \
 198   pre##_state(&ctx, key->ochain);                                       \
 199                                                                         \
 200   pre##_init(&ctx);                                                     \
 201   memcpy(ctx.buf, kbuf, sz);                                            \
 202   memset(ctx.buf + sz, 0x36, PRE##_BUFSZ - sz);                         \
 203   pre##_compress(&ctx, ctx.buf);                                        \
 204   pre##_state(&ctx, key->ichain);                                       \
 205                                                                         \
 206   key->ocount = key->icount = PRE##_BUFSZ;                              \
 207   BURN(ctx);                                                            \
 208 }                                                                       \
 209                                                                         \
 210 /* --- @pre_macinit@ --- *                                              \
 211  *                                                                      \
 212  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 213  *              @const pre_mackey *key@ = pointer to MAC key block      \
 214  *                                                                      \
 215  * Returns:     ---                                                     \
 216  *                                                                      \
 217  * Use:         Instantiates a MAC context from a key block.            \
 218  */                                                                     \
 219                                                                         \
 220 void pre##_macinit(pre##_macctx *ctx, const pre##_mackey *key)          \
 221 {                                                                       \
 222   memcpy(ctx->chain, key->ochain, PRE##_STATESZ);                       \
 223   ctx->count = key->ocount;                                             \
 224   pre##_set(&ctx->ctx, key->ichain, key->icount);                       \
 225 }                                                                       \
 226                                                                         \
 227 /* --- @pre_machash@ --- *                                              \
 228  *                                                                      \
 229  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 230  *              @const void *buf@ = pointer to buffer                   \
 231  *              @size_t sz@ = size of the buffer                        \
 232  *                                                                      \
 233  * Returns:     ---                                                     \
 234  *                                                                      \
 235  * Use:         Hashes a buffer.                                        \
 236  */                                                                     \
 237                                                                         \
 238 void pre##_machash(pre##_macctx *ctx, const void *buf, size_t sz)       \
 239 {                                                                       \
 240   pre##_hash(&ctx->ctx, buf, sz);                                       \
 241 }                                                                       \
 242                                                                         \
 243 /* --- @pre_macdone@ --- *                                              \
 244  *                                                                      \
 245  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 246  *              @void *mac@ = pointer to buffer to receive MAC          \
 247  *                                                                      \
 248  * Returns:     ---                                                     \
 249  *                                                                      \
 250  * Use:         Returns the result of a MAC computation.                \
 251  */                                                                     \
 252                                                                         \
 253 void pre##_macdone(pre##_macctx *ctx, void *mac)                        \
 254 {                                                                       \
 255   pre##_done(&ctx->ctx, mac);                                           \
 256   pre##_set(&ctx->ctx, ctx->chain, ctx->count);                         \
 257   pre##_hash(&ctx->ctx, mac, PRE##_HASHSZ);                             \
 258   pre##_done(&ctx->ctx, mac);                                           \
 259 }                                                                       \
 260                                                                         \
 261 /* --- Generic MAC interface --- */                                     \
 262                                                                         \
 263 static const gmac_ops gkops;                                            \
 264 static const ghash_ops gops;                                            \
 265                                                                         \
 266 typedef struct gkctx {                                                  \
 267   gmac m;                                                               \
 268   pre##_mackey k;                                                       \
 269 } gkctx;                                                                \
 270                                                                         \
 271 typedef struct gctx {                                                   \
 272   ghash h;                                                              \
 273   pre##_macctx c;                                                       \
 274   octet buf[PRE##_HASHSZ];                                              \
 275 } gctx;                                                                 \
 276                                                                         \
 277 static ghash *gkinit(gmac *m)                                           \
 278 {                                                                       \
 279   gkctx *gk = (gkctx *)m;                                               \
 280   gctx *g = S_CREATE(gctx);                                             \
 281   g->h.ops = &gops;                                                     \
 282   pre##_macinit(&g->c, &gk->k);                                         \
 283   return (&g->h);                                                       \
 284 }                                                                       \
 285                                                                         \
 286 static gmac *gkey(const void *k, size_t sz)                             \
 287 {                                                                       \
 288   gkctx *gk = S_CREATE(gkctx);                                          \
 289   gk->m.ops = &gkops;                                                   \
 290   pre##_hmacinit(&gk->k, k, sz);                                        \
 291   return (&gk->m);                                                      \
 292 }                                                                       \
 293                                                                         \
 294 static gmac *gsslkey(const void *k, size_t sz)                          \
 295 {                                                                       \
 296   gkctx *gk = S_CREATE(gkctx);                                          \
 297   gk->m.ops = &gkops;                                                   \
 298   pre##_sslmacinit(&gk->k, k, sz);                                      \
 299   return (&gk->m);                                                      \
 300 }                                                                       \
 301                                                                         \
 302 static void ghhash(ghash *h, const void *p, size_t sz)                  \
 303 {                                                                       \
 304   gctx *g = (gctx *)h;                                                  \
 305   pre##_machash(&g->c, p, sz);                                          \
 306 }                                                                       \
 307                                                                         \
 308 static octet *ghdone(ghash *h, void *buf)                               \
 309 {                                                                       \
 310   gctx *g = (gctx *)h;                                                  \
 311   if (!buf)                                                             \
 312     buf = g->buf;                                                       \
 313   pre##_macdone(&g->c, buf);                                            \
 314   return (buf);                                                         \
 315 }                                                                       \
 316                                                                         \
 317 static ghash *ghcopy(ghash *h)                                          \
 318 {                                                                       \
 319   gctx *g = (gctx *)h;                                                  \
 320   gctx *gg = S_CREATE(gctx);                                            \
 321   memcpy(gg, g, sizeof(gctx));                                          \
 322   return (&gg->h);                                                      \
 323 }                                                                       \
 324                                                                         \
 325 static void ghdestroy(ghash *h)                                         \
 326 {                                                                       \
 327   gctx *g = (gctx *)h;                                                  \
 328   BURN(*g);                                                             \
 329   S_DESTROY(g);                                                         \
 330 }                                                                       \
 331                                                                         \
 332 static void gkdestroy(gmac *m)                                          \
 333 {                                                                       \
 334   gkctx *gk = (gkctx *)m;                                               \
 335   BURN(*gk);                                                            \
 336   S_DESTROY(gk);                                                        \
 337 }                                                                       \
 338                                                                         \
 339 static ghash *ghinit(void)                                              \
 340 {                                                                       \
 341   assert(((void)"Attempt to instantiate an unkeyed MAC", 0));           \
 342   return (0);                                                           \
 343 }                                                                       \
 344                                                                         \
 345 const gcmac pre##_hmac =                                                \
 346   { #pre "-hmac", PRE##_HASHSZ, pre##_mackeysz, gkey };                 \
 347 const gcmac pre##_sslmac =                                              \
 348   { #pre "-sslmac", PRE##_HASHSZ, pre##_mackeysz, gsslkey };            \
 349 static const gmac_ops gkops = { &pre##_hmac, gkinit, gkdestroy };       \
 350 static const gchash gch = { #pre "-hmac", PRE##_HASHSZ, ghinit };       \
 351 static const ghash_ops gops =                                           \
 352   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 353                                                                         \
 354 HMAC_TEST(PRE, pre)
 355
 356 /* --- @HMAC_TEST@ --- *
 357  *
 358  * Arguments:   @PRE@, @pre@ = prefixes for hash-specfic definitions
 359  *
 360  * Use:         Standard test rig for MAC functions.
 361  */
 362
 363 #ifdef TEST_RIG
 364
 365 #include <stdio.h>
 366
 367 #include <mLib/dstr.h>
 368 #include <mLib/quis.h>
 369 #include <mLib/testrig.h>
 370
 371 #define HMAC_TEST(PRE, pre)                                             \
 372                                                                         \
 373 static int macverify(dstr *v)                                           \
 374 {                                                                       \
 375   pre##_macctx cctx;                                                    \
 376   pre##_mackey ckey;                                                    \
 377   int ok = 1;                                                           \
 378   int i;                                                                \
 379   octet *p;                                                             \
 380   int szs[] = { 1, 7, 192, -1, 0 }, *ip;                                \
 381   size_t csz;                                                           \
 382   dstr d;                                                               \
 383                                                                         \
 384   dstr_create(&d);                                                      \
 385   dstr_ensure(&d, PRE##_HASHSZ);                                        \
 386   d.len = PRE##_HASHSZ;                                                 \
 387                                                                         \
 388   pre##_hmacinit(&ckey, v[1].buf, v[1].len);                            \
 389                                                                         \
 390   for (ip = szs; *ip; ip++) {                                           \
 391     i = *ip;                                                            \
 392     csz = v[0].len;                                                     \
 393     if (i == -1)                                                        \
 394       i = csz;                                                          \
 395     if (i > csz)                                                        \
 396       continue;                                                         \
 397     p = (octet *)v[0].buf;                                              \
 398     pre##_macinit(&cctx, &ckey);                                        \
 399     while (csz) {                                                       \
 400       if (i > csz)                                                      \
 401         i = csz;                                                        \
 402       pre##_machash(&cctx, p, i);                                       \
 403       p += i;                                                           \
 404       csz -= i;                                                         \
 405     }                                                                   \
 406     pre##_macdone(&cctx, d.buf);                                        \
 407     if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) {                   \
 408       printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\tkey = ",          \
 409              *ip, v[0].buf);                                            \
 410       type_hex.dump(&v[1], stdout);                                     \
 411       fputs("\n\texpected = ", stdout);                                 \
 412       type_hex.dump(&v[2], stdout);                                     \
 413       fputs("\n\tcomputed = ", stdout);                                 \
 414       type_hex.dump(&d, stdout);                                        \
 415       putchar('\n');                                                    \
 416       ok = 0;                                                           \
 417     }                                                                   \
 418   }                                                                     \
 419                                                                         \
 420   dstr_destroy(&d);                                                     \
 421   return (ok);                                                          \
 422 }                                                                       \
 423                                                                         \
 424 static test_chunk macdefs[] = {                                         \
 425   { #pre "-hmac", macverify,                                            \
 426     { &type_string, &type_hex, &type_hex, 0 } },                        \
 427   { 0, 0, { 0 } }                                                       \
 428 };                                                                      \
 429                                                                         \
 430 int main(int argc, char *argv[])                                        \
 431 {                                                                       \
 432   ego(argv[0]);                                                         \
 433   test_run(argc, argv, macdefs, SRCDIR"/tests/" #pre);                  \
 434   return (0);                                                           \
 435 }
 436
 437 #else
 438 #  define HMAC_TEST(PRE, pre)
 439 #endif
 440
 441 /*----- That's all, folks -------------------------------------------------*/
 442
 443 #ifdef __cplusplus
 444   }
 445 #endif
 446
 447 #endif