| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: hmac.h,v 1.1 1999/09/03 08:41:12 mdw Exp $ |
| 4 | * |
| 5 | * Generic code for HMAC and NMAC |
| 6 | * |
| 7 | * (c) 1998 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.h,v $ |
| 33 | * Revision 1.1 1999/09/03 08:41:12 mdw |
| 34 | * Initial import. |
| 35 | * |
| 36 | */ |
| 37 | |
| 38 | /*----- Notes on the HMAC and NMAC constructions --------------------------* |
| 39 | * |
| 40 | * Designed by Mihir Bellare, Ran Canetti and Hugo Krawczyk, NMAC is a |
| 41 | * method for constructing keyed message authentication algorithms from |
| 42 | * unkeyed hash functions. HMAC is an alternative formulation which doesn't |
| 43 | * require low-level access to the hash function's implementation. NMAC was |
| 44 | * designed to allow MD5 has a suitable underlying hash function, even though |
| 45 | * doubts were already being raised about its collision resistance. |
| 46 | */ |
| 47 | |
| 48 | #ifndef HMAC_H |
| 49 | #define HMAC_H |
| 50 | |
| 51 | #ifdef __cplusplus |
| 52 | extern "C" { |
| 53 | #endif |
| 54 | |
| 55 | /*----- Header files ------------------------------------------------------*/ |
| 56 | |
| 57 | #include <stdlib.h> |
| 58 | #include <string.h> |
| 59 | |
| 60 | #include <mLib/bits.h> |
| 61 | |
| 62 | #ifndef PARANOIA_H |
| 63 | # include "paranoia.h" |
| 64 | #endif |
| 65 | |
| 66 | /*----- Macros ------------------------------------------------------------*/ |
| 67 | |
| 68 | /* --- @HMAC_DECL@ --- * |
| 69 | * |
| 70 | * Arguments: @PRE@, @pre@ = prefixes for the underlying hash function |
| 71 | * |
| 72 | * Use: Creates declarations for the HMAC and NMAC functions. |
| 73 | */ |
| 74 | |
| 75 | #define HMAC_DECL(PRE, pre) \ |
| 76 | \ |
| 77 | typedef struct pre##_mackey { \ |
| 78 | octet ochain[PRE##_HASHSZ]; /* Chaining for outer hash */ \ |
| 79 | unsigned long ocount; /* Byte count for outer hash */ \ |
| 80 | octet ichain[PRE##_HASHSZ]; /* Chaining for inner hash */ \ |
| 81 | unsigned long icount; /* Byte count for inner hash */ \ |
| 82 | } pre##_mackey; \ |
| 83 | \ |
| 84 | typedef struct pre##_macctx { \ |
| 85 | pre##_ctx ctx; /* Context for main hashing */ \ |
| 86 | octet chain[PRE##_HASHSZ]; /* Chaining for outer hash */ \ |
| 87 | unsigned long count; /* Byte count for outer hash */ \ |
| 88 | } pre##_macctx; \ |
| 89 | \ |
| 90 | extern void pre##_nmac(pre##_mackey */*key*/, \ |
| 91 | const void */*ok*/, const void */*ik*/); \ |
| 92 | \ |
| 93 | extern void pre##_hmac(pre##_mackey */*key*/, \ |
| 94 | const void */*k*/, size_t /*sz*/); \ |
| 95 | \ |
| 96 | extern void pre##_macinit(pre##_macctx */*ctx*/, \ |
| 97 | const pre##_mackey */*key*/); \ |
| 98 | \ |
| 99 | extern void pre##_mac(pre##_macctx */*ctx*/, \ |
| 100 | const void */*buf*/, size_t /*sz*/); \ |
| 101 | \ |
| 102 | extern void pre##_macdone(pre##_macctx */*ctx*/, void */*mac*/); |
| 103 | |
| 104 | /* --- @HMAC_DEF@ --- * |
| 105 | * |
| 106 | * Arguments: @PRE@, @pre@ = prefixes for the underlying hash function |
| 107 | * |
| 108 | * Use: Creates implementations for the HMAC and NMAC functions. |
| 109 | */ |
| 110 | |
| 111 | #define HMAC_DEF(PRE, pre) \ |
| 112 | \ |
| 113 | /* --- @pre_nmac@ --- * \ |
| 114 | * \ |
| 115 | * Arguments: @pre_macctx *key@ = pointer to a MAC key object \ |
| 116 | * @const void *ok@ = pointer to outer hash init vector \ |
| 117 | * @const void *ik@ = pointer to inner hash init vector \ |
| 118 | * \ |
| 119 | * Returns: --- \ |
| 120 | * \ |
| 121 | * Use: Initializes a MAC key for doing NMAC hashing. \ |
| 122 | */ \ |
| 123 | \ |
| 124 | void pre##_nmac(pre##_mackey *key, const void *ok, const void *ik) \ |
| 125 | { \ |
| 126 | memcpy(key->ochain, ok, PRE##_HASHSZ); \ |
| 127 | memcpy(key->ichain, ik, PRE##_HASHSZ); \ |
| 128 | key->ocount = key->icount = 0; \ |
| 129 | } \ |
| 130 | \ |
| 131 | /* --- @pre_hmac@ --- * \ |
| 132 | * \ |
| 133 | * Arguments: @pre_mackey *key@ = pointer to MAC key object \ |
| 134 | * @const void *k@ = pointer to key to use \ |
| 135 | * @size_t sz@ = size of key data \ |
| 136 | * \ |
| 137 | * Returns: --- \ |
| 138 | * \ |
| 139 | * Use: Initializes a MAC key for doing HMAC hashing. Keys \ |
| 140 | * longer than the hash function's output size aren't very \ |
| 141 | * useful, but are accepted. Keys longer than the hash's \ |
| 142 | * block size are also accepted; they are hashed before \ |
| 143 | * use, as specified in RFC2104. \ |
| 144 | */ \ |
| 145 | \ |
| 146 | void pre##_hmac(pre##_mackey *key, const void *k, size_t sz) \ |
| 147 | { \ |
| 148 | int i; \ |
| 149 | const octet *kbuf = k; \ |
| 150 | pre##_ctx ctx; \ |
| 151 | octet buf[PRE##_HASHSZ]; \ |
| 152 | \ |
| 153 | if (sz > PRE##_BUFSZ) { \ |
| 154 | pre##_init(&ctx); \ |
| 155 | pre##_hash(&ctx, k, sz); \ |
| 156 | pre##_done(&ctx, buf); \ |
| 157 | kbuf = buf; \ |
| 158 | sz = PRE##_HASHSZ; \ |
| 159 | } \ |
| 160 | \ |
| 161 | pre##_init(&ctx); \ |
| 162 | memset(ctx.buf, 0x5c, PRE##_BUFSZ); \ |
| 163 | for (i = 0; i < sz; i++) \ |
| 164 | ctx.buf[i] ^= kbuf[i]; \ |
| 165 | pre##_compress(&ctx, ctx.buf); \ |
| 166 | pre##_state(&ctx, key->ochain); \ |
| 167 | \ |
| 168 | pre##_init(&ctx); \ |
| 169 | memset(ctx.buf, 0x36, PRE##_BUFSZ); \ |
| 170 | for (i = 0; i < sz; i++) \ |
| 171 | ctx.buf[i] ^= kbuf[i]; \ |
| 172 | pre##_compress(&ctx, ctx.buf); \ |
| 173 | pre##_state(&ctx, key->ichain); \ |
| 174 | \ |
| 175 | key->ocount = key->icount = PRE##_BUFSZ; \ |
| 176 | BURN(ctx); \ |
| 177 | } \ |
| 178 | \ |
| 179 | /* --- @pre_macinit@ --- * \ |
| 180 | * \ |
| 181 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
| 182 | * @const pre_mackey *key@ = pointer to MAC key block \ |
| 183 | * \ |
| 184 | * Returns: --- \ |
| 185 | * \ |
| 186 | * Use: Instantiates a MAC context from a key block. \ |
| 187 | */ \ |
| 188 | \ |
| 189 | void pre##_macinit(pre##_macctx *ctx, const pre##_mackey *key) \ |
| 190 | { \ |
| 191 | memcpy(ctx->chain, key->ochain, PRE##_HASHSZ); \ |
| 192 | ctx->count = key->ocount; \ |
| 193 | pre##_set(&ctx->ctx, key->ichain, key->icount); \ |
| 194 | } \ |
| 195 | \ |
| 196 | /* --- @pre_mac@ --- * \ |
| 197 | * \ |
| 198 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
| 199 | * @const void *buf@ = pointer to buffer \ |
| 200 | * @size_t sz@ = size of the buffer \ |
| 201 | * \ |
| 202 | * Returns: --- \ |
| 203 | * \ |
| 204 | * Use: Hashes a buffer. \ |
| 205 | */ \ |
| 206 | \ |
| 207 | void pre##_mac(pre##_macctx *ctx, const void *buf, size_t sz) \ |
| 208 | { \ |
| 209 | pre##_hash(&ctx->ctx, buf, sz); \ |
| 210 | } \ |
| 211 | \ |
| 212 | /* --- @pre_macdone@ --- * \ |
| 213 | * \ |
| 214 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
| 215 | * @void *mac@ = pointer to buffer to receive MAC \ |
| 216 | * \ |
| 217 | * Returns: --- \ |
| 218 | * \ |
| 219 | * Use: Returns the result of a MAC computation. \ |
| 220 | */ \ |
| 221 | \ |
| 222 | void pre##_macdone(pre##_macctx *ctx, void *mac) \ |
| 223 | { \ |
| 224 | pre##_done(&ctx->ctx, mac); \ |
| 225 | pre##_set(&ctx->ctx, ctx->chain, ctx->count); \ |
| 226 | pre##_hash(&ctx->ctx, mac, PRE##_HASHSZ); \ |
| 227 | pre##_done(&ctx->ctx, mac); \ |
| 228 | } \ |
| 229 | \ |
| 230 | HMAC_TEST(PRE, pre) \ |
| 231 | |
| 232 | /* --- @HMAC_TEST@ --- * |
| 233 | * |
| 234 | * Arguments: @PRE@, @pre@ = prefixes for hash-specfic definitions |
| 235 | * |
| 236 | * Use: Standard test rig for MAC functions. |
| 237 | */ |
| 238 | |
| 239 | #ifdef TEST_RIG |
| 240 | |
| 241 | #include <mLib/dstr.h> |
| 242 | #include <mLib/quis.h> |
| 243 | #include <mLib/testrig.h> |
| 244 | |
| 245 | #define HMAC_TEST(PRE, pre) \ |
| 246 | \ |
| 247 | static int macverify(dstr *v) \ |
| 248 | { \ |
| 249 | pre##_macctx cctx; \ |
| 250 | pre##_mackey ckey; \ |
| 251 | int ok = 1; \ |
| 252 | int i; \ |
| 253 | octet *p; \ |
| 254 | int szs[] = { 1, 7, 192, -1, 0 }, *ip; \ |
| 255 | size_t csz; \ |
| 256 | dstr d; \ |
| 257 | \ |
| 258 | dstr_create(&d); \ |
| 259 | dstr_ensure(&d, PRE##_HASHSZ); \ |
| 260 | d.len = PRE##_HASHSZ; \ |
| 261 | \ |
| 262 | pre##_hmac(&ckey, v[1].buf, v[1].len); \ |
| 263 | \ |
| 264 | for (ip = szs; *ip; ip++) { \ |
| 265 | i = *ip; \ |
| 266 | csz = v[0].len; \ |
| 267 | if (i == -1) \ |
| 268 | i = csz; \ |
| 269 | if (i > csz) \ |
| 270 | continue; \ |
| 271 | p = (octet *)v[0].buf; \ |
| 272 | pre##_macinit(&cctx, &ckey); \ |
| 273 | while (csz) { \ |
| 274 | if (i > csz) \ |
| 275 | i = csz; \ |
| 276 | pre##_mac(&cctx, p, i); \ |
| 277 | p += i; \ |
| 278 | csz -= i; \ |
| 279 | } \ |
| 280 | pre##_macdone(&cctx, d.buf); \ |
| 281 | if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) { \ |
| 282 | printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\tkey = ", \ |
| 283 | *ip, v[0].buf); \ |
| 284 | type_hex.dump(&v[1], stdout); \ |
| 285 | fputs("\n\texpected = ", stdout); \ |
| 286 | type_hex.dump(&v[2], stdout); \ |
| 287 | fputs("\n\tcomputed = ", stdout); \ |
| 288 | type_hex.dump(&d, stdout); \ |
| 289 | putchar('\n'); \ |
| 290 | ok = 0; \ |
| 291 | } \ |
| 292 | } \ |
| 293 | \ |
| 294 | dstr_destroy(&d); \ |
| 295 | return (ok); \ |
| 296 | } \ |
| 297 | \ |
| 298 | static test_chunk macdefs[] = { \ |
| 299 | { #pre "-hmac", macverify, \ |
| 300 | { &type_string, &type_hex, &type_hex, 0 } }, \ |
| 301 | { 0, 0, { 0 } } \ |
| 302 | }; \ |
| 303 | \ |
| 304 | int main(int argc, char *argv[]) \ |
| 305 | { \ |
| 306 | ego(argv[0]); \ |
| 307 | test_run(argc, argv, macdefs, SRCDIR"/tests/" #pre); \ |
| 308 | return (0); \ |
| 309 | } |
| 310 | |
| 311 | #else |
| 312 | # define HMAC_TEST(PRE, pre) |
| 313 | #endif |
| 314 | |
| 315 | /*----- That's all, folks -------------------------------------------------*/ |
| 316 | |
| 317 | #ifdef __cplusplus |
| 318 | } |
| 319 | #endif |
| 320 | |
| 321 | #endif |