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 buf[PRE##_HASHSZ];                                              \
 117                                                                         \
 118   if (sz > PRE##_BUFSZ) {                                               \
 119     pre##_init(&ctx);                                                   \
 120     pre##_hash(&ctx, k, sz);                                            \
 121     pre##_done(&ctx, buf);                                              \
 122     kbuf = buf;                                                         \
 123     sz = PRE##_HASHSZ;                                                  \
 124   }                                                                     \
 125                                                                         \
 126   pre##_init(&ctx);                                                     \
 127   memset(ctx.buf, 0x5c, PRE##_BUFSZ);                                   \
 128   for (i = 0; i < sz; i++)                                              \
 129     ctx.buf[i] ^= kbuf[i];                                              \
 130   pre##_compress(&ctx, ctx.buf);                                        \
 131   pre##_state(&ctx, key->ochain);                                       \
 132                                                                         \
 133   pre##_init(&ctx);                                                     \
 134   memset(ctx.buf, 0x36, PRE##_BUFSZ);                                   \
 135   for (i = 0; i < sz; i++)                                              \
 136     ctx.buf[i] ^= kbuf[i];                                              \
 137   pre##_compress(&ctx, ctx.buf);                                        \
 138   pre##_state(&ctx, key->ichain);                                       \
 139                                                                         \
 140   key->ocount = key->icount = PRE##_BUFSZ;                              \
 141   BURN(ctx);                                                            \
 142 }                                                                       \
 143                                                                         \
 144 /* --- @pre_sslmacinit@ --- *                                           \
 145  *                                                                      \
 146  * Arguments:   @pre_mackey *key@ = pointer to MAC key object           \
 147  *              @const void *k@ = pointer to key to use                 \
 148  *              @size_t sz@ = size of key data                          \
 149  *                                                                      \
 150  * Returns:     ---                                                     \
 151  *                                                                      \
 152  * Use:         Initializes a MAC key for doing hasing using the SSL3   \
 153  *              variant of HMAC.                                        \
 154  */                                                                     \
 155                                                                         \
 156 void pre##_sslmacinit(pre##_mackey *key, const void *k, size_t sz)      \
 157 {                                                                       \
 158   const octet *kbuf = k;                                                \
 159   pre##_ctx ctx;                                                        \
 160   octet buf[PRE##_HASHSZ];                                              \
 161                                                                         \
 162   if (sz > PRE##_BUFSZ) {                                               \
 163     pre##_init(&ctx);                                                   \
 164     pre##_hash(&ctx, k, sz);                                            \
 165     pre##_done(&ctx, buf);                                              \
 166     kbuf = buf;                                                         \
 167     sz = PRE##_HASHSZ;                                                  \
 168   }                                                                     \
 169                                                                         \
 170   pre##_init(&ctx);                                                     \
 171   memcpy(ctx.buf, kbuf, sz);                                            \
 172   memset(ctx.buf + sz, 0x5c, PRE##_BUFSZ - sz);                         \
 173   pre##_compress(&ctx, ctx.buf);                                        \
 174   pre##_state(&ctx, key->ochain);                                       \
 175                                                                         \
 176   pre##_init(&ctx);                                                     \
 177   memcpy(ctx.buf, kbuf, sz);                                            \
 178   memset(ctx.buf + sz, 0x36, PRE##_BUFSZ - sz);                         \
 179   pre##_compress(&ctx, ctx.buf);                                        \
 180   pre##_state(&ctx, key->ichain);                                       \
 181                                                                         \
 182   key->ocount = key->icount = PRE##_BUFSZ;                              \
 183   BURN(ctx);                                                            \
 184 }                                                                       \
 185                                                                         \
 186 /* --- @pre_macinit@ --- *                                              \
 187  *                                                                      \
 188  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 189  *              @const pre_mackey *key@ = pointer to MAC key block      \
 190  *                                                                      \
 191  * Returns:     ---                                                     \
 192  *                                                                      \
 193  * Use:         Instantiates a MAC context from a key block.            \
 194  */                                                                     \
 195                                                                         \
 196 void pre##_macinit(pre##_macctx *ctx, const pre##_mackey *key)          \
 197 {                                                                       \
 198   memcpy(ctx->chain, key->ochain, PRE##_STATESZ);                       \
 199   ctx->count = key->ocount;                                             \
 200   pre##_set(&ctx->ctx, key->ichain, key->icount);                       \
 201 }                                                                       \
 202                                                                         \
 203 /* --- @pre_machash@ --- *                                              \
 204  *                                                                      \
 205  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 206  *              @const void *buf@ = pointer to buffer                   \
 207  *              @size_t sz@ = size of the buffer                        \
 208  *                                                                      \
 209  * Returns:     ---                                                     \
 210  *                                                                      \
 211  * Use:         Hashes a buffer.                                        \
 212  */                                                                     \
 213                                                                         \
 214 void pre##_machash(pre##_macctx *ctx, const void *buf, size_t sz)       \
 215 {                                                                       \
 216   pre##_hash(&ctx->ctx, buf, sz);                                       \
 217 }                                                                       \
 218                                                                         \
 219 /* --- @pre_macdone@ --- *                                              \
 220  *                                                                      \
 221  * Arguments:   @pre_macctx *ctx@ = pointer to MAC context block        \
 222  *              @void *mac@ = pointer to buffer to receive MAC          \
 223  *                                                                      \
 224  * Returns:     ---                                                     \
 225  *                                                                      \
 226  * Use:         Returns the result of a MAC computation.                \
 227  */                                                                     \
 228                                                                         \
 229 void pre##_macdone(pre##_macctx *ctx, void *mac)                        \
 230 {                                                                       \
 231   pre##_done(&ctx->ctx, mac);                                           \
 232   pre##_set(&ctx->ctx, ctx->chain, ctx->count);                         \
 233   pre##_hash(&ctx->ctx, mac, PRE##_HASHSZ);                             \
 234   pre##_done(&ctx->ctx, mac);                                           \
 235 }                                                                       \
 236                                                                         \
 237 /* --- Generic MAC interface --- */                                     \
 238                                                                         \
 239 static const gmac_ops gkops;                                            \
 240 static const ghash_ops gops, gnops, gsslops;                            \
 241                                                                         \
 242 typedef struct gkctx {                                                  \
 243   gmac m;                                                               \
 244   const ghash_ops *gops;                                                \
 245   pre##_mackey k;                                                       \
 246 } gkctx;                                                                \
 247                                                                         \
 248 typedef struct gctx {                                                   \
 249   ghash h;                                                              \
 250   pre##_macctx c;                                                       \
 251   octet buf[PRE##_HASHSZ];                                              \
 252 } gctx;                                                                 \
 253                                                                         \
 254 static ghash *gkinit(gmac *m)                                           \
 255 {                                                                       \
 256   gkctx *gk = (gkctx *)m;                                               \
 257   gctx *g = S_CREATE(gctx);                                             \
 258   g->h.ops = gk->gops;                                                  \
 259   pre##_macinit(&g->c, &gk->k);                                         \
 260   return (&g->h);                                                       \
 261 }                                                                       \
 262                                                                         \
 263 static gmac *gkey(const void *k, size_t sz)                             \
 264 {                                                                       \
 265   gkctx *gk = S_CREATE(gkctx);                                          \
 266   gk->m.ops = &gkops;                                                   \
 267   gk->gops = &gops;                                                     \
 268   pre##_hmacinit(&gk->k, k, sz);                                        \
 269   return (&gk->m);                                                      \
 270 }                                                                       \
 271                                                                         \
 272 static gmac *gnkey(const void *k, size_t sz)                            \
 273 {                                                                       \
 274   gkctx *gk = S_CREATE(gkctx);                                          \
 275   const octet *kk = k;                                                  \
 276   assert(keysz(sz, pre##_nmackeysz) == sz);                             \
 277   gk->m.ops = &gkops;                                                   \
 278   gk->gops = &gnops;                                                    \
 279   pre##_nmacinit(&gk->k, kk, kk + PRE##_STATESZ);                       \
 280   return (&gk->m);                                                      \
 281 }                                                                       \
 282                                                                         \
 283 static gmac *gsslkey(const void *k, size_t sz)                          \
 284 {                                                                       \
 285   gkctx *gk = S_CREATE(gkctx);                                          \
 286   gk->m.ops = &gkops;                                                   \
 287   gk->gops = &gsslops;                                                  \
 288   pre##_sslmacinit(&gk->k, k, sz);                                      \
 289   return (&gk->m);                                                      \
 290 }                                                                       \
 291                                                                         \
 292 static void ghhash(ghash *h, const void *p, size_t sz)                  \
 293 {                                                                       \
 294   gctx *g = (gctx *)h;                                                  \
 295   pre##_machash(&g->c, p, sz);                                          \
 296 }                                                                       \
 297                                                                         \
 298 static octet *ghdone(ghash *h, void *buf)                               \
 299 {                                                                       \
 300   gctx *g = (gctx *)h;                                                  \
 301   if (!buf)                                                             \
 302     buf = g->buf;                                                       \
 303   pre##_macdone(&g->c, buf);                                            \
 304   return (buf);                                                         \
 305 }                                                                       \
 306                                                                         \
 307 static ghash *ghcopy(ghash *h)                                          \
 308 {                                                                       \
 309   gctx *g = (gctx *)h;                                                  \
 310   gctx *gg = S_CREATE(gctx);                                            \
 311   memcpy(gg, g, sizeof(gctx));                                          \
 312   return (&gg->h);                                                      \
 313 }                                                                       \
 314                                                                         \
 315 static void ghdestroy(ghash *h)                                         \
 316 {                                                                       \
 317   gctx *g = (gctx *)h;                                                  \
 318   BURN(*g);                                                             \
 319   S_DESTROY(g);                                                         \
 320 }                                                                       \
 321                                                                         \
 322 static void gkdestroy(gmac *m)                                          \
 323 {                                                                       \
 324   gkctx *gk = (gkctx *)m;                                               \
 325   BURN(*gk);                                                            \
 326   S_DESTROY(gk);                                                        \
 327 }                                                                       \
 328                                                                         \
 329 static ghash *ghinit(void)                                              \
 330 {                                                                       \
 331   assert(((void)"Attempt to instantiate an unkeyed MAC", 0));           \
 332   return (0);                                                           \
 333 }                                                                       \
 334                                                                         \
 335 const gcmac pre##_nmac =                                                \
 336   { name "-nmac", PRE##_HASHSZ, pre##_nmackeysz, gnkey };               \
 337 const gcmac pre##_hmac =                                                \
 338   { name "-hmac", PRE##_HASHSZ, pre##_hmackeysz, gkey };                \
 339 const gcmac pre##_sslmac =                                              \
 340   { name "-sslmac", PRE##_HASHSZ, pre##_sslmackeysz, gsslkey };         \
 341 static const gmac_ops gkops = { &pre##_hmac, gkinit, gkdestroy };       \
 342 static const gmac_ops gnkops = { &pre##_nmac, gkinit, gkdestroy };      \
 343 static const gmac_ops gsslkops = { &pre##_sslmac, gkinit, gkdestroy };  \
 344 static const gchash gch = { name "-hmac", PRE##_HASHSZ, ghinit };       \
 345 static const ghash_ops gops =                                           \
 346   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 347 static const gchash gnch = { name "-nmac", PRE##_HASHSZ, ghinit };      \
 348 static const ghash_ops gnops =                                          \
 349   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 350 static const gchash gsslch = { name "-sslmac", PRE##_HASHSZ, ghinit };  \
 351 static const ghash_ops gsslops =                                        \
 352   { &gch, ghhash, ghdone, ghdestroy, ghcopy };                          \
 353                                                                         \
 354 HMAC_TESTX(PRE, pre, name, fname)
 355
 356 #define HMAC_TEST(PRE, pre) HMAC_TESTX(PRE, pre, #pre, #pre)
 357
 358 /* --- @HMAC_TEST@ --- *
 359  *
 360  * Arguments:   @PRE@, @pre@ = prefixes for hash-specfic definitions
 361  *
 362  * Use:         Standard test rig for MAC functions.
 363  */
 364
 365 #ifdef TEST_RIG
 366
 367 #include <stdio.h>
 368
 369 #include <mLib/dstr.h>
 370 #include <mLib/quis.h>
 371 #include <mLib/testrig.h>
 372
 373 #define HMAC_TESTX(PRE, pre, name, fname)                               \
 374                                                                         \
 375 static int macverify(dstr *v)                                           \
 376 {                                                                       \
 377   pre##_macctx cctx;                                                    \
 378   pre##_mackey ckey;                                                    \
 379   int ok = 1;                                                           \
 380   int i;                                                                \
 381   octet *p;                                                             \
 382   int szs[] = { 1, 7, 192, -1, 0 }, *ip;                                \
 383   size_t csz;                                                           \
 384   dstr d;                                                               \
 385                                                                         \
 386   dstr_create(&d);                                                      \
 387   dstr_ensure(&d, PRE##_HASHSZ);                                        \
 388   d.len = PRE##_HASHSZ;                                                 \
 389                                                                         \
 390   pre##_hmacinit(&ckey, v[1].buf, v[1].len);                            \
 391                                                                         \
 392   for (ip = szs; *ip; ip++) {                                           \
 393     i = *ip;                                                            \
 394     csz = v[0].len;                                                     \
 395     if (i == -1)                                                        \
 396       i = csz;                                                          \
 397     if (i > csz)                                                        \
 398       continue;                                                         \
 399     p = (octet *)v[0].buf;                                              \
 400     pre##_macinit(&cctx, &ckey);                                        \
 401     while (csz) {                                                       \
 402       if (i > csz)                                                      \
 403         i = csz;                                                        \
 404       pre##_machash(&cctx, p, i);                                       \
 405       p += i;                                                           \
 406       csz -= i;                                                         \
 407     }                                                                   \
 408     pre##_macdone(&cctx, d.buf);                                        \
 409     if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) {                   \
 410       printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\tkey = ",          \
 411              *ip, v[0].buf);                                            \
 412       type_hex.dump(&v[1], stdout);                                     \
 413       fputs("\n\texpected = ", stdout);                                 \
 414       type_hex.dump(&v[2], stdout);                                     \
 415       fputs("\n\tcomputed = ", stdout);                                 \
 416       type_hex.dump(&d, stdout);                                        \
 417       putchar('\n');                                                    \
 418       ok = 0;                                                           \
 419     }                                                                   \
 420   }                                                                     \
 421                                                                         \
 422   dstr_destroy(&d);                                                     \
 423   return (ok);                                                          \
 424 }                                                                       \
 425                                                                         \
 426 static test_chunk macdefs[] = {                                         \
 427   { name "-hmac", macverify,                                            \
 428     { &type_string, &type_hex, &type_hex, 0 } },                        \
 429   { 0, 0, { 0 } }                                                       \
 430 };                                                                      \
 431                                                                         \
 432 int main(int argc, char *argv[])                                        \
 433 {                                                                       \
 434   ego(argv[0]);                                                         \
 435   test_run(argc, argv, macdefs, SRCDIR"/t/" fname);                     \
 436   return (0);                                                           \
 437 }
 438
 439 #else
 440 #  define HMAC_TESTX(PRE, pre, name, fname)
 441 #endif
 442
 443 /*----- That's all, folks -------------------------------------------------*/
 444
 445 #ifdef __cplusplus
 446   }
 447 #endif
 448
 449 #endif