Ashley Mills / tinydtls_0_4_0

mbed port of tinydtls

hmac.c@1:bc8a649bad13, 2013-10-11 (annotated)

Committer:
ashleymills
Date:
Fri Oct 11 08:46:21 2013 +0000
Revision:
1:bc8a649bad13
Parent:
0:04990d454f45 
Cleaned up all the debug stuff I added finding the hash table bug.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ashleymills 0:04990d454f45 1 /* dtls -- a very basic DTLS implementation
ashleymills 0:04990d454f45 2 *
ashleymills 0:04990d454f45 3 * Copyright (C) 2011--2012 Olaf Bergmann <bergmann@tzi.org>
ashleymills 0:04990d454f45 4 *
ashleymills 0:04990d454f45 5 * Permission is hereby granted, free of charge, to any person
ashleymills 0:04990d454f45 6 * obtaining a copy of this software and associated documentation
ashleymills 0:04990d454f45 7 * files (the "Software"), to deal in the Software without
ashleymills 0:04990d454f45 8 * restriction, including without limitation the rights to use, copy,
ashleymills 0:04990d454f45 9 * modify, merge, publish, distribute, sublicense, and/or sell copies
ashleymills 0:04990d454f45 10 * of the Software, and to permit persons to whom the Software is
ashleymills 0:04990d454f45 11 * furnished to do so, subject to the following conditions:
ashleymills 0:04990d454f45 12 *
ashleymills 0:04990d454f45 13 * The above copyright notice and this permission notice shall be
ashleymills 0:04990d454f45 14 * included in all copies or substantial portions of the Software.
ashleymills 0:04990d454f45 15 *
ashleymills 0:04990d454f45 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
ashleymills 0:04990d454f45 17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
ashleymills 0:04990d454f45 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
ashleymills 0:04990d454f45 19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
ashleymills 0:04990d454f45 20 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ashleymills 0:04990d454f45 21 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
ashleymills 0:04990d454f45 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
ashleymills 0:04990d454f45 23 * SOFTWARE.
ashleymills 0:04990d454f45 24 */
ashleymills 0:04990d454f45 25
ashleymills 0:04990d454f45 26 #include <stdio.h>
ashleymills 0:04990d454f45 27 #include <stdlib.h>
ashleymills 0:04990d454f45 28 #include <string.h>
ashleymills 0:04990d454f45 29 #ifdef HAVE_ASSERT_H
ashleymills 0:04990d454f45 30 #include <assert.h>
ashleymills 0:04990d454f45 31 #endif
ashleymills 0:04990d454f45 32
ashleymills 0:04990d454f45 33 #include "debug.h"
ashleymills 0:04990d454f45 34 #include "hmac.h"
ashleymills 0:04990d454f45 35 /* use malloc()/free() on platforms other than Contiki */
ashleymills 0:04990d454f45 36 #ifndef WITH_CONTIKI
ashleymills 0:04990d454f45 37 #include <stdlib.h>
ashleymills 0:04990d454f45 38
ashleymills 0:04990d454f45 39 static inline dtls_hmac_context_t *
ashleymills 0:04990d454f45 40 dtls_hmac_context_new() {
ashleymills 0:04990d454f45 41 return (dtls_hmac_context_t *)malloc(sizeof(dtls_hmac_context_t));
ashleymills 0:04990d454f45 42 }
ashleymills 0:04990d454f45 43
ashleymills 0:04990d454f45 44 static inline void
ashleymills 0:04990d454f45 45 dtls_hmac_context_free(dtls_hmac_context_t *ctx) {
ashleymills 0:04990d454f45 46 free(ctx);
ashleymills 0:04990d454f45 47 }
ashleymills 0:04990d454f45 48
ashleymills 0:04990d454f45 49 #else /* WITH_CONTIKI */
ashleymills 0:04990d454f45 50 #include "memb.h"
ashleymills 0:04990d454f45 51 MEMB(hmac_context_storage, dtls_hmac_context_t, DTLS_HASH_MAX);
ashleymills 0:04990d454f45 52
ashleymills 0:04990d454f45 53 static inline dtls_hmac_context_t *
ashleymills 0:04990d454f45 54 dtls_hmac_context_new() {
ashleymills 0:04990d454f45 55 return (dtls_hmac_context_t *)memb_alloc(&hmac_context_storage);
ashleymills 0:04990d454f45 56 }
ashleymills 0:04990d454f45 57
ashleymills 0:04990d454f45 58 static inline void
ashleymills 0:04990d454f45 59 dtls_hmac_context_free(dtls_hmac_context_t *ctx) {
ashleymills 0:04990d454f45 60 memb_free(&hmac_context_storage, ctx);
ashleymills 0:04990d454f45 61 }
ashleymills 0:04990d454f45 62 #endif /* WITH_CONTIKI */
ashleymills 0:04990d454f45 63
ashleymills 0:04990d454f45 64 void
ashleymills 0:04990d454f45 65 dtls_hmac_storage_init() {
ashleymills 0:04990d454f45 66 #ifdef WITH_CONTIKI
ashleymills 0:04990d454f45 67 memb_init(&hmac_context_storage);
ashleymills 0:04990d454f45 68 #endif /* WITH_CONTIKI */
ashleymills 0:04990d454f45 69 }
ashleymills 0:04990d454f45 70
ashleymills 0:04990d454f45 71 void
ashleymills 0:04990d454f45 72 dtls_hmac_update(dtls_hmac_context_t *ctx,
ashleymills 0:04990d454f45 73 const unsigned char *input, size_t ilen) {
ashleymills 0:04990d454f45 74 assert(ctx);
ashleymills 0:04990d454f45 75 dtls_hash_update(&ctx->data, input, ilen);
ashleymills 0:04990d454f45 76 }
ashleymills 0:04990d454f45 77
ashleymills 0:04990d454f45 78 dtls_hmac_context_t *
ashleymills 0:04990d454f45 79 dtls_hmac_new(const unsigned char *key, size_t klen) {
ashleymills 0:04990d454f45 80 dtls_hmac_context_t *ctx;
ashleymills 0:04990d454f45 81
ashleymills 0:04990d454f45 82 ctx = dtls_hmac_context_new();
ashleymills 0:04990d454f45 83 if (ctx)
ashleymills 0:04990d454f45 84 dtls_hmac_init(ctx, key, klen);
ashleymills 0:04990d454f45 85
ashleymills 0:04990d454f45 86 return ctx;
ashleymills 0:04990d454f45 87 }
ashleymills 0:04990d454f45 88
ashleymills 0:04990d454f45 89 void
ashleymills 0:04990d454f45 90 dtls_hmac_init(dtls_hmac_context_t *ctx, const unsigned char *key, size_t klen) {
ashleymills 0:04990d454f45 91 int i;
ashleymills 0:04990d454f45 92
ashleymills 0:04990d454f45 93 assert(ctx);
ashleymills 0:04990d454f45 94
ashleymills 0:04990d454f45 95 memset(ctx, 0, sizeof(dtls_hmac_context_t));
ashleymills 0:04990d454f45 96
ashleymills 0:04990d454f45 97 if (klen > DTLS_HMAC_BLOCKSIZE) {
ashleymills 0:04990d454f45 98 dtls_hash_init(&ctx->data);
ashleymills 0:04990d454f45 99 dtls_hash_update(&ctx->data, key, klen);
ashleymills 0:04990d454f45 100 dtls_hash_finalize(ctx->pad, &ctx->data);
ashleymills 0:04990d454f45 101 } else
ashleymills 0:04990d454f45 102 memcpy(ctx->pad, key, klen);
ashleymills 0:04990d454f45 103
ashleymills 0:04990d454f45 104 /* create ipad: */
ashleymills 0:04990d454f45 105 for (i=0; i < DTLS_HMAC_BLOCKSIZE; ++i)
ashleymills 0:04990d454f45 106 ctx->pad[i] ^= 0x36;
ashleymills 0:04990d454f45 107
ashleymills 0:04990d454f45 108 dtls_hash_init(&ctx->data);
ashleymills 0:04990d454f45 109 dtls_hmac_update(ctx, ctx->pad, DTLS_HMAC_BLOCKSIZE);
ashleymills 0:04990d454f45 110
ashleymills 0:04990d454f45 111 /* create opad by xor-ing pad[i] with 0x36 ^ 0x5C: */
ashleymills 0:04990d454f45 112 for (i=0; i < DTLS_HMAC_BLOCKSIZE; ++i)
ashleymills 0:04990d454f45 113 ctx->pad[i] ^= 0x6A;
ashleymills 0:04990d454f45 114 }
ashleymills 0:04990d454f45 115
ashleymills 0:04990d454f45 116 void
ashleymills 0:04990d454f45 117 dtls_hmac_free(dtls_hmac_context_t *ctx) {
ashleymills 0:04990d454f45 118 if (ctx)
ashleymills 0:04990d454f45 119 dtls_hmac_context_free(ctx);
ashleymills 0:04990d454f45 120 }
ashleymills 0:04990d454f45 121
ashleymills 0:04990d454f45 122 int
ashleymills 0:04990d454f45 123 dtls_hmac_finalize(dtls_hmac_context_t *ctx, unsigned char *result) {
ashleymills 0:04990d454f45 124 unsigned char buf[DTLS_HMAC_DIGEST_SIZE];
ashleymills 0:04990d454f45 125 size_t len;
ashleymills 0:04990d454f45 126
ashleymills 0:04990d454f45 127 assert(ctx);
ashleymills 0:04990d454f45 128 assert(result);
ashleymills 0:04990d454f45 129
ashleymills 0:04990d454f45 130 len = dtls_hash_finalize(buf, &ctx->data);
ashleymills 0:04990d454f45 131
ashleymills 0:04990d454f45 132 dtls_hash_init(&ctx->data);
ashleymills 0:04990d454f45 133 dtls_hash_update(&ctx->data, ctx->pad, DTLS_HMAC_BLOCKSIZE);
ashleymills 0:04990d454f45 134 dtls_hash_update(&ctx->data, buf, len);
ashleymills 0:04990d454f45 135
ashleymills 0:04990d454f45 136 len = dtls_hash_finalize(result, &ctx->data);
ashleymills 0:04990d454f45 137
ashleymills 0:04990d454f45 138 return len;
ashleymills 0:04990d454f45 139 }
ashleymills 0:04990d454f45 140
ashleymills 0:04990d454f45 141 #ifdef HMAC_TEST
ashleymills 0:04990d454f45 142 #include <stdio.h>
ashleymills 0:04990d454f45 143
ashleymills 0:04990d454f45 144 int main(int argc, char **argv) {
ashleymills 0:04990d454f45 145 static unsigned char buf[DTLS_HMAC_DIGEST_SIZE];
ashleymills 0:04990d454f45 146 size_t len, i;
ashleymills 0:04990d454f45 147 dtls_hmac_context_t *ctx;
ashleymills 0:04990d454f45 148
ashleymills 0:04990d454f45 149 if (argc < 3) {
ashleymills 0:04990d454f45 150 fprintf(stderr, "usage: %s key text", argv[0]);
ashleymills 0:04990d454f45 151 return -1;
ashleymills 0:04990d454f45 152 }
ashleymills 0:04990d454f45 153
ashleymills 0:04990d454f45 154 dtls_hmac_storage_init();
ashleymills 0:04990d454f45 155 ctx = dtls_hmac_new(argv[1], strlen(argv[1]));
ashleymills 0:04990d454f45 156 assert(ctx);
ashleymills 0:04990d454f45 157 dtls_hmac_update(ctx, argv[2], strlen(argv[2]));
ashleymills 0:04990d454f45 158
ashleymills 0:04990d454f45 159 len = dtls_hmac_finalize(ctx, buf);
ashleymills 0:04990d454f45 160
ashleymills 0:04990d454f45 161 for(i = 0; i < len; i++)
ashleymills 0:04990d454f45 162 printf("%02x", buf[i]);
ashleymills 0:04990d454f45 163 printf("\n");
ashleymills 0:04990d454f45 164
ashleymills 0:04990d454f45 165 dtls_hmac_free(ctx);
ashleymills 0:04990d454f45 166
ashleymills 0:04990d454f45 167 return 0;
ashleymills 0:04990d454f45 168 }
ashleymills 0:04990d454f45 169 #endif