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