/* $NetBSD: hmac.c,v 1.3 2011/05/16 10:39:12 drochner Exp $ */ /* * Copyright (c) 2004, Juniper Networks, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Implement HMAC as described in RFC 2104 * * You need to define the following before including this file. * * HMAC_FUNC the name of the function (hmac_sha1 or hmac_md5 etc) * HASH_LENGTH the size of the digest (20 for SHA1, 16 for MD5) * HASH_CTX the name of the HASH CTX * HASH_Init * HASH_Update * Hash_Final */ #include #if !defined(lint) __RCSID("$NetBSD: hmac.c,v 1.3 2011/05/16 10:39:12 drochner Exp $"); #endif /* not lint */ #include #include /* Don't change these */ #define HMAC_IPAD 0x36 #define HMAC_OPAD 0x5c /* Nor this */ #ifndef HMAC_BLOCKSZ # define HMAC_BLOCKSZ 64 #endif /* * The logic here is lifted straight from RFC 2104 except that * rather than filling the pads with 0, copying in the key and then * XOR with the pad byte, we just fill with the pad byte and * XOR with the key. */ void HMAC_FUNC (const unsigned char *text, size_t text_len, const unsigned char *key, size_t key_len, unsigned char *digest) { HASH_CTX context; /* Inner padding key XOR'd with ipad */ unsigned char k_ipad[HMAC_BLOCKSZ]; /* Outer padding key XOR'd with opad */ unsigned char k_opad[HMAC_BLOCKSZ]; /* HASH(key) if needed */ unsigned char tk[HASH_LENGTH]; size_t i; /* * If key is longer than HMAC_BLOCKSZ bytes * reset it to key=HASH(key) */ if (key_len > HMAC_BLOCKSZ) { HASH_CTX tctx; HASH_Init(&tctx); HASH_Update(&tctx, key, key_len); HASH_Final(tk, &tctx); key = tk; key_len = HASH_LENGTH; } /* * The HMAC_ transform looks like: * * HASH(K XOR opad, HASH(K XOR ipad, text)) * * where K is an n byte key * ipad is the byte HMAC_IPAD repeated HMAC_BLOCKSZ times * opad is the byte HMAC_OPAD repeated HMAC_BLOCKSZ times * and text is the data being protected */ /* * Fill the pads and XOR in the key */ memset( k_ipad, HMAC_IPAD, sizeof k_ipad); memset( k_opad, HMAC_OPAD, sizeof k_opad); for (i = 0; i < key_len; i++) { k_ipad[i] ^= key[i]; k_opad[i] ^= key[i]; } /* * Perform inner HASH. * Start with inner pad, * then the text. */ HASH_Init(&context); HASH_Update(&context, k_ipad, HMAC_BLOCKSZ); HASH_Update(&context, text, text_len); HASH_Final(digest, &context); /* * Perform outer HASH. * Start with the outer pad, * then the result of the inner hash. */ HASH_Init(&context); HASH_Update(&context, k_opad, HMAC_BLOCKSZ); HASH_Update(&context, digest, HASH_LENGTH); HASH_Final(digest, &context); } #if defined(MAIN) || defined(UNIT_TEST) #include static char * b2x(char *buf, int bufsz, unsigned char *data, int nbytes) { int i; if (bufsz <= (nbytes * 2)) return NULL; buf[0] = '\0'; for (i = 0; i < nbytes; i++) { (void) sprintf(&buf[i*2], "%02x", data[i]); } return buf; } #if defined(UNIT_TEST) static int x2b(unsigned char *buf, int bufsz, char *data, int nbytes) { int i; int c; if (nbytes < 0) nbytes = strlen(data); nbytes /= 2; if (bufsz <= nbytes) return 0; for (i = 0; i < nbytes; i++) { if (sscanf(&data[i*2], "%02x", &c) < 1) break; buf[i] = c; } buf[i] = 0; return i; } #ifndef HMAC_KAT # define HMAC_KAT hmac_kat #endif /* * If a test key or data starts with 0x we'll convert to binary. */ #define X2B(v, b) do { \ if (strncmp(v, "0x", 2) == 0) { \ v += 2; \ x2b(b, sizeof(b), v, strlen(v)); \ v = b; \ } \ } while (0) /* * Run some of the known answer tests from RFC 2202 * We assume that HASH_LENGTH==20 means SHA1 else MD5. */ static int HMAC_KAT (FILE *fp) { struct test_s { unsigned char *key; unsigned char *data; unsigned char *expect; } tests[] = { { #if HASH_LENGTH == 20 "0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b", "Hi There", "0xb617318655057264e28bc0b6fb378c8ef146be00", #else "0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b", "Hi There", "0x9294727a3638bb1c13f48ef8158bfc9d", #endif }, { "Jefe", "what do ya want for nothing?", #if HASH_LENGTH == 20 "0xeffcdf6ae5eb2fa2d27416d5f184df9c259a7c79", #else "0x750c783e6ab0b503eaa86e310a5db738", #endif }, { #if HASH_LENGTH == 20 "0x0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c", "Test With Truncation", "0x4c1a03424b55e07fe7f27be1d58bb9324a9a5a04", #else "0x0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c", "Test With Truncation", "0x56461ef2342edc00f9bab995690efd4c", #endif }, { "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "Test Using Larger Than Block-Size Key - Hash Key First", #if HASH_LENGTH == 20 "0xaa4ae5e15272d00e95705637ce8a3b55ed402112", #else "0x6b1ab7fe4bd7bf8f0b62e6ce61b9d0cd", #endif }, { 0, 0, 0, }, }; struct test_s *test = tests; unsigned char digest[HASH_LENGTH]; unsigned char kbuf[BUFSIZ]; unsigned char dbuf[BUFSIZ]; unsigned char *key; unsigned char *data; char *result; int n = 0; for (test = tests; test->key; test++) { key = test->key; X2B(key, kbuf); data = test->data; X2B(data, dbuf); HMAC_FUNC(data, strlen(data), key, strlen(key), digest); strcpy(dbuf, "0x"); b2x(&dbuf[2], (sizeof dbuf) - 2, digest, HASH_LENGTH); if (strcmp(dbuf, test->expect) == 0) result = "Ok"; else { n++; result = test->expect; } if (fp) fprintf(fp, "key=%s, data=%s, result=%s: %s\n", test->key, test->data, dbuf, result); } return n; } #endif int main (int argc, char *argv[]) { char buf[BUFSIZ]; unsigned char *key; unsigned char *data; int key_len; int data_len; int i; unsigned char digest[HASH_LENGTH]; #ifdef UNIT_TEST if (argc == 1) exit(HMAC_KAT(stdout)); #endif if (argc < 3) { fprintf(stderr, "Usage:\n\t%s key data\n", argv[0]); exit(1); } key = argv[1]; data = argv[2]; key_len = strlen(key); data_len = strlen(data); HMAC_FUNC(data, data_len, key, key_len, digest); printf("0x%s\n", b2x(buf, sizeof buf, digest, HASH_LENGTH)); exit(0); } #endif