NetBSD/lib/libcrypt/hmac.c

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/* $NetBSD: hmac.c,v 1.1 2006/10/27 18:22:56 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 <sys/cdefs.h>
#if !defined(lint)
__RCSID("$NetBSD: hmac.c,v 1.1 2006/10/27 18:22:56 drochner Exp $");
#endif /* not lint */
#include <stdlib.h>
#include <string.h>
/* 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 + 1];
/* Outer padding key XOR'd with opad */
unsigned char k_opad[HMAC_BLOCKSZ + 1];
/* HASH(key) if needed */
unsigned char tk[HASH_LENGTH];
int 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 <stdio.h>
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