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