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