| /* |
| * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the OpenSSL license (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include "internal/cryptlib.h" |
| #include <openssl/hmac.h> |
| #include <openssl/opensslconf.h> |
| #include "hmac_local.h" |
| |
| int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, |
| const EVP_MD *md, ENGINE *impl) |
| { |
| int rv = 0, reset = 0; |
| int i, j; |
| unsigned char pad[HMAC_MAX_MD_CBLOCK_SIZE]; |
| unsigned int keytmp_length; |
| unsigned char keytmp[HMAC_MAX_MD_CBLOCK_SIZE]; |
| |
| /* If we are changing MD then we must have a key */ |
| if (md != NULL && md != ctx->md && (key == NULL || len < 0)) |
| return 0; |
| |
| if (md != NULL) { |
| ctx->md = md; |
| } else if (ctx->md) { |
| md = ctx->md; |
| } else { |
| return 0; |
| } |
| |
| /* |
| * The HMAC construction is not allowed to be used with the |
| * extendable-output functions (XOF) shake128 and shake256. |
| */ |
| if ((EVP_MD_meth_get_flags(md) & EVP_MD_FLAG_XOF) != 0) |
| return 0; |
| |
| if (key != NULL) { |
| reset = 1; |
| |
| j = EVP_MD_block_size(md); |
| if (!ossl_assert(j <= (int)sizeof(keytmp))) |
| return 0; |
| if (j < len) { |
| if (!EVP_DigestInit_ex(ctx->md_ctx, md, impl) |
| || !EVP_DigestUpdate(ctx->md_ctx, key, len) |
| || !EVP_DigestFinal_ex(ctx->md_ctx, keytmp, |
| &keytmp_length)) |
| return 0; |
| } else { |
| if (len < 0 || len > (int)sizeof(keytmp)) |
| return 0; |
| memcpy(keytmp, key, len); |
| keytmp_length = len; |
| } |
| if (keytmp_length != HMAC_MAX_MD_CBLOCK_SIZE) |
| memset(&keytmp[keytmp_length], 0, |
| HMAC_MAX_MD_CBLOCK_SIZE - keytmp_length); |
| |
| for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++) |
| pad[i] = 0x36 ^ keytmp[i]; |
| if (!EVP_DigestInit_ex(ctx->i_ctx, md, impl) |
| || !EVP_DigestUpdate(ctx->i_ctx, pad, EVP_MD_block_size(md))) |
| goto err; |
| |
| for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++) |
| pad[i] = 0x5c ^ keytmp[i]; |
| if (!EVP_DigestInit_ex(ctx->o_ctx, md, impl) |
| || !EVP_DigestUpdate(ctx->o_ctx, pad, EVP_MD_block_size(md))) |
| goto err; |
| } |
| if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->i_ctx)) |
| goto err; |
| rv = 1; |
| err: |
| if (reset) { |
| OPENSSL_cleanse(keytmp, sizeof(keytmp)); |
| OPENSSL_cleanse(pad, sizeof(pad)); |
| } |
| return rv; |
| } |
| |
| #if OPENSSL_API_COMPAT < 0x10100000L |
| int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md) |
| { |
| if (key && md) |
| HMAC_CTX_reset(ctx); |
| return HMAC_Init_ex(ctx, key, len, md, NULL); |
| } |
| #endif |
| |
| int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len) |
| { |
| if (!ctx->md) |
| return 0; |
| return EVP_DigestUpdate(ctx->md_ctx, data, len); |
| } |
| |
| int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len) |
| { |
| unsigned int i; |
| unsigned char buf[EVP_MAX_MD_SIZE]; |
| |
| if (!ctx->md) |
| goto err; |
| |
| if (!EVP_DigestFinal_ex(ctx->md_ctx, buf, &i)) |
| goto err; |
| if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->o_ctx)) |
| goto err; |
| if (!EVP_DigestUpdate(ctx->md_ctx, buf, i)) |
| goto err; |
| if (!EVP_DigestFinal_ex(ctx->md_ctx, md, len)) |
| goto err; |
| return 1; |
| err: |
| return 0; |
| } |
| |
| size_t HMAC_size(const HMAC_CTX *ctx) |
| { |
| int size = EVP_MD_size((ctx)->md); |
| |
| return (size < 0) ? 0 : size; |
| } |
| |
| HMAC_CTX *HMAC_CTX_new(void) |
| { |
| HMAC_CTX *ctx = OPENSSL_zalloc(sizeof(HMAC_CTX)); |
| |
| if (ctx != NULL) { |
| if (!HMAC_CTX_reset(ctx)) { |
| HMAC_CTX_free(ctx); |
| return NULL; |
| } |
| } |
| return ctx; |
| } |
| |
| static void hmac_ctx_cleanup(HMAC_CTX *ctx) |
| { |
| EVP_MD_CTX_reset(ctx->i_ctx); |
| EVP_MD_CTX_reset(ctx->o_ctx); |
| EVP_MD_CTX_reset(ctx->md_ctx); |
| ctx->md = NULL; |
| } |
| |
| void HMAC_CTX_free(HMAC_CTX *ctx) |
| { |
| if (ctx != NULL) { |
| hmac_ctx_cleanup(ctx); |
| EVP_MD_CTX_free(ctx->i_ctx); |
| EVP_MD_CTX_free(ctx->o_ctx); |
| EVP_MD_CTX_free(ctx->md_ctx); |
| OPENSSL_free(ctx); |
| } |
| } |
| |
| static int hmac_ctx_alloc_mds(HMAC_CTX *ctx) |
| { |
| if (ctx->i_ctx == NULL) |
| ctx->i_ctx = EVP_MD_CTX_new(); |
| if (ctx->i_ctx == NULL) |
| return 0; |
| if (ctx->o_ctx == NULL) |
| ctx->o_ctx = EVP_MD_CTX_new(); |
| if (ctx->o_ctx == NULL) |
| return 0; |
| if (ctx->md_ctx == NULL) |
| ctx->md_ctx = EVP_MD_CTX_new(); |
| if (ctx->md_ctx == NULL) |
| return 0; |
| return 1; |
| } |
| |
| int HMAC_CTX_reset(HMAC_CTX *ctx) |
| { |
| hmac_ctx_cleanup(ctx); |
| if (!hmac_ctx_alloc_mds(ctx)) { |
| hmac_ctx_cleanup(ctx); |
| return 0; |
| } |
| return 1; |
| } |
| |
| int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx) |
| { |
| if (!hmac_ctx_alloc_mds(dctx)) |
| goto err; |
| if (!EVP_MD_CTX_copy_ex(dctx->i_ctx, sctx->i_ctx)) |
| goto err; |
| if (!EVP_MD_CTX_copy_ex(dctx->o_ctx, sctx->o_ctx)) |
| goto err; |
| if (!EVP_MD_CTX_copy_ex(dctx->md_ctx, sctx->md_ctx)) |
| goto err; |
| dctx->md = sctx->md; |
| return 1; |
| err: |
| hmac_ctx_cleanup(dctx); |
| return 0; |
| } |
| |
| unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len, |
| const unsigned char *d, size_t n, unsigned char *md, |
| unsigned int *md_len) |
| { |
| HMAC_CTX *c = NULL; |
| static unsigned char m[EVP_MAX_MD_SIZE]; |
| static const unsigned char dummy_key[1] = {'\0'}; |
| |
| if (md == NULL) |
| md = m; |
| if ((c = HMAC_CTX_new()) == NULL) |
| goto err; |
| |
| /* For HMAC_Init_ex, NULL key signals reuse. */ |
| if (key == NULL && key_len == 0) { |
| key = dummy_key; |
| } |
| |
| if (!HMAC_Init_ex(c, key, key_len, evp_md, NULL)) |
| goto err; |
| if (!HMAC_Update(c, d, n)) |
| goto err; |
| if (!HMAC_Final(c, md, md_len)) |
| goto err; |
| HMAC_CTX_free(c); |
| return md; |
| err: |
| HMAC_CTX_free(c); |
| return NULL; |
| } |
| |
| void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags) |
| { |
| EVP_MD_CTX_set_flags(ctx->i_ctx, flags); |
| EVP_MD_CTX_set_flags(ctx->o_ctx, flags); |
| EVP_MD_CTX_set_flags(ctx->md_ctx, flags); |
| } |
| |
| const EVP_MD *HMAC_CTX_get_md(const HMAC_CTX *ctx) |
| { |
| return ctx->md; |
| } |