|
- /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
- *
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * 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 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.] */
-
- #include <openssl/hmac.h>
-
- #include <assert.h>
- #include <string.h>
-
- #include <openssl/mem.h>
-
-
- uint8_t *HMAC(const EVP_MD *evp_md, const void *key, size_t key_len,
- const uint8_t *data, size_t data_len, uint8_t *out,
- unsigned int *out_len) {
- HMAC_CTX ctx;
- static uint8_t static_out_buffer[EVP_MAX_MD_SIZE];
-
- /* OpenSSL has traditionally supported using a static buffer if |out| is
- * NULL. We maintain that but don't document it. This behaviour should be
- * considered to be deprecated. */
- if (out == NULL) {
- out = static_out_buffer;
- }
-
- HMAC_CTX_init(&ctx);
- if (!HMAC_Init_ex(&ctx, key, key_len, evp_md, NULL) ||
- !HMAC_Update(&ctx, data, data_len) ||
- !HMAC_Final(&ctx, out, out_len)) {
- out = NULL;
- }
-
- HMAC_CTX_cleanup(&ctx);
- return out;
- }
-
- void HMAC_CTX_init(HMAC_CTX *ctx) {
- ctx->md = NULL;
- EVP_MD_CTX_init(&ctx->i_ctx);
- EVP_MD_CTX_init(&ctx->o_ctx);
- EVP_MD_CTX_init(&ctx->md_ctx);
- }
-
- void HMAC_CTX_cleanup(HMAC_CTX *ctx) {
- EVP_MD_CTX_cleanup(&ctx->i_ctx);
- EVP_MD_CTX_cleanup(&ctx->o_ctx);
- EVP_MD_CTX_cleanup(&ctx->md_ctx);
- OPENSSL_cleanse(ctx, sizeof(HMAC_CTX));
- }
-
- int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, size_t key_len,
- const EVP_MD *md, ENGINE *impl) {
- if (md == NULL) {
- md = ctx->md;
- }
-
- /* If either |key| is non-NULL or |md| has changed, initialize with a new key
- * rather than rewinding the previous one.
- *
- * TODO(davidben,eroman): Passing the previous |md| with a NULL |key| is
- * ambiguous between using the empty key and reusing the previous key. There
- * exist callers which intend the latter, but the former is an awkward edge
- * case. Fix to API to avoid this. */
- if (md != ctx->md || key != NULL) {
- size_t i;
- uint8_t pad[HMAC_MAX_MD_CBLOCK];
- uint8_t key_block[HMAC_MAX_MD_CBLOCK];
- unsigned key_block_len;
-
- size_t block_size = EVP_MD_block_size(md);
- assert(block_size <= sizeof(key_block));
- if (block_size < key_len) {
- /* Long keys are hashed. */
- if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl) ||
- !EVP_DigestUpdate(&ctx->md_ctx, key, key_len) ||
- !EVP_DigestFinal_ex(&ctx->md_ctx, key_block, &key_block_len)) {
- return 0;
- }
- } else {
- assert(key_len >= 0 && key_len <= sizeof(key_block));
- memcpy(key_block, key, key_len);
- key_block_len = (unsigned)key_len;
- }
- /* Keys are then padded with zeros. */
- if (key_block_len != HMAC_MAX_MD_CBLOCK) {
- memset(&key_block[key_block_len], 0, sizeof(key_block) - key_block_len);
- }
-
- for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++) {
- pad[i] = 0x36 ^ key_block[i];
- }
- if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl) ||
- !EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md))) {
- return 0;
- }
-
- for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++) {
- pad[i] = 0x5c ^ key_block[i];
- }
- if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl) ||
- !EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md))) {
- return 0;
- }
-
- ctx->md = md;
- }
-
- if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx)) {
- return 0;
- }
-
- return 1;
- }
-
- int HMAC_Update(HMAC_CTX *ctx, const uint8_t *data, size_t data_len) {
- return EVP_DigestUpdate(&ctx->md_ctx, data, data_len);
- }
-
- int HMAC_Final(HMAC_CTX *ctx, uint8_t *out, unsigned int *out_len) {
- unsigned int i;
- uint8_t buf[EVP_MAX_MD_SIZE];
-
- /* TODO(davidben): The only thing that can officially fail here is
- * |EVP_MD_CTX_copy_ex|, but even that should be impossible in this case. */
- if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i) ||
- !EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx) ||
- !EVP_DigestUpdate(&ctx->md_ctx, buf, i) ||
- !EVP_DigestFinal_ex(&ctx->md_ctx, out, out_len)) {
- *out_len = 0;
- return 0;
- }
-
- return 1;
- }
-
- size_t HMAC_size(const HMAC_CTX *ctx) {
- return EVP_MD_size(ctx->md);
- }
-
- int HMAC_CTX_copy_ex(HMAC_CTX *dest, const HMAC_CTX *src) {
- if (!EVP_MD_CTX_copy_ex(&dest->i_ctx, &src->i_ctx) ||
- !EVP_MD_CTX_copy_ex(&dest->o_ctx, &src->o_ctx) ||
- !EVP_MD_CTX_copy_ex(&dest->md_ctx, &src->md_ctx)) {
- return 0;
- }
-
- dest->md = src->md;
- return 1;
- }
-
- int HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len, const EVP_MD *md) {
- if (key && md) {
- HMAC_CTX_init(ctx);
- }
- return HMAC_Init_ex(ctx, key, key_len, md, NULL);
- }
-
- int HMAC_CTX_copy(HMAC_CTX *dest, const HMAC_CTX *src) {
- HMAC_CTX_init(dest);
- return HMAC_CTX_copy_ex(dest, src);
- }
|