2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 * HMAC low level APIs are deprecated for public use, but still ok for internal
14 #include "internal/deprecated.h"
19 #include "internal/cryptlib.h"
20 #include <openssl/opensslconf.h>
21 #include <openssl/hmac.h>
22 #include <openssl/core_names.h>
23 #include "hmac_local.h"
25 int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
26 const EVP_MD *md, ENGINE *impl)
28 int rv = 0, reset = 0;
30 unsigned char pad[HMAC_MAX_MD_CBLOCK_SIZE];
31 unsigned int keytmp_length;
32 unsigned char keytmp[HMAC_MAX_MD_CBLOCK_SIZE];
34 /* If we are changing MD then we must have a key */
35 if (md != NULL && md != ctx->md && (key == NULL || len < 0))
40 else if (ctx->md != NULL)
46 * The HMAC construction is not allowed to be used with the
47 * extendable-output functions (XOF) shake128 and shake256.
49 if ((EVP_MD_get_flags(md) & EVP_MD_FLAG_XOF) != 0)
55 j = EVP_MD_get_block_size(md);
56 if (!ossl_assert(j <= (int)sizeof(keytmp)))
61 if (!EVP_DigestInit_ex(ctx->md_ctx, md, impl)
62 || !EVP_DigestUpdate(ctx->md_ctx, key, len)
63 || !EVP_DigestFinal_ex(ctx->md_ctx, keytmp,
67 if (len < 0 || len > (int)sizeof(keytmp))
69 memcpy(keytmp, key, len);
72 if (keytmp_length != HMAC_MAX_MD_CBLOCK_SIZE)
73 memset(&keytmp[keytmp_length], 0,
74 HMAC_MAX_MD_CBLOCK_SIZE - keytmp_length);
76 for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++)
77 pad[i] = 0x36 ^ keytmp[i];
78 if (!EVP_DigestInit_ex(ctx->i_ctx, md, impl)
79 || !EVP_DigestUpdate(ctx->i_ctx, pad,
80 EVP_MD_get_block_size(md)))
83 for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++)
84 pad[i] = 0x5c ^ keytmp[i];
85 if (!EVP_DigestInit_ex(ctx->o_ctx, md, impl)
86 || !EVP_DigestUpdate(ctx->o_ctx, pad,
87 EVP_MD_get_block_size(md)))
90 if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->i_ctx))
95 OPENSSL_cleanse(keytmp, sizeof(keytmp));
96 OPENSSL_cleanse(pad, sizeof(pad));
101 #ifndef OPENSSL_NO_DEPRECATED_1_1_0
102 int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
106 return HMAC_Init_ex(ctx, key, len, md, NULL);
110 int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
114 return EVP_DigestUpdate(ctx->md_ctx, data, len);
117 int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
120 unsigned char buf[EVP_MAX_MD_SIZE];
125 if (!EVP_DigestFinal_ex(ctx->md_ctx, buf, &i))
127 if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->o_ctx))
129 if (!EVP_DigestUpdate(ctx->md_ctx, buf, i))
131 if (!EVP_DigestFinal_ex(ctx->md_ctx, md, len))
138 size_t HMAC_size(const HMAC_CTX *ctx)
140 int size = EVP_MD_get_size((ctx)->md);
142 return (size < 0) ? 0 : size;
145 HMAC_CTX *HMAC_CTX_new(void)
147 HMAC_CTX *ctx = OPENSSL_zalloc(sizeof(HMAC_CTX));
150 if (!HMAC_CTX_reset(ctx)) {
158 static void hmac_ctx_cleanup(HMAC_CTX *ctx)
160 EVP_MD_CTX_reset(ctx->i_ctx);
161 EVP_MD_CTX_reset(ctx->o_ctx);
162 EVP_MD_CTX_reset(ctx->md_ctx);
166 void HMAC_CTX_free(HMAC_CTX *ctx)
169 hmac_ctx_cleanup(ctx);
170 EVP_MD_CTX_free(ctx->i_ctx);
171 EVP_MD_CTX_free(ctx->o_ctx);
172 EVP_MD_CTX_free(ctx->md_ctx);
177 static int hmac_ctx_alloc_mds(HMAC_CTX *ctx)
179 if (ctx->i_ctx == NULL)
180 ctx->i_ctx = EVP_MD_CTX_new();
181 if (ctx->i_ctx == NULL)
183 if (ctx->o_ctx == NULL)
184 ctx->o_ctx = EVP_MD_CTX_new();
185 if (ctx->o_ctx == NULL)
187 if (ctx->md_ctx == NULL)
188 ctx->md_ctx = EVP_MD_CTX_new();
189 if (ctx->md_ctx == NULL)
194 int HMAC_CTX_reset(HMAC_CTX *ctx)
196 hmac_ctx_cleanup(ctx);
197 if (!hmac_ctx_alloc_mds(ctx)) {
198 hmac_ctx_cleanup(ctx);
204 int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
206 if (!hmac_ctx_alloc_mds(dctx))
208 if (!EVP_MD_CTX_copy_ex(dctx->i_ctx, sctx->i_ctx))
210 if (!EVP_MD_CTX_copy_ex(dctx->o_ctx, sctx->o_ctx))
212 if (!EVP_MD_CTX_copy_ex(dctx->md_ctx, sctx->md_ctx))
217 hmac_ctx_cleanup(dctx);
221 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
222 const unsigned char *data, size_t data_len,
223 unsigned char *md, unsigned int *md_len)
225 static unsigned char static_md[EVP_MAX_MD_SIZE];
226 int size = EVP_MD_get_size(evp_md);
227 size_t temp_md_len = 0;
228 unsigned char *ret = NULL;
231 ret = EVP_Q_mac(NULL, "HMAC", NULL, EVP_MD_get0_name(evp_md), NULL,
232 key, key_len, data, data_len,
233 md == NULL ? static_md : md, size, &temp_md_len);
235 *md_len = (unsigned int)temp_md_len;
240 void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
242 EVP_MD_CTX_set_flags(ctx->i_ctx, flags);
243 EVP_MD_CTX_set_flags(ctx->o_ctx, flags);
244 EVP_MD_CTX_set_flags(ctx->md_ctx, flags);
247 const EVP_MD *HMAC_CTX_get_md(const HMAC_CTX *ctx)