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

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