| /* 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); |
| } |