2 * Copyright 1995-2020 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/hmac.h>
21 #include <openssl/opensslconf.h>
22 #include "hmac_local.h"
24 int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
25 const EVP_MD *md, ENGINE *impl)
27 int rv = 0, reset = 0;
29 unsigned char pad[HMAC_MAX_MD_CBLOCK_SIZE];
30 unsigned int keytmp_length;
31 unsigned char keytmp[HMAC_MAX_MD_CBLOCK_SIZE];
33 /* If we are changing MD then we must have a key */
34 if (md != NULL && md != ctx->md && (key == NULL || len < 0))
46 * The HMAC construction is not allowed to be used with the
47 * extendable-output functions (XOF) shake128 and shake256.
49 if ((EVP_MD_flags(md) & EVP_MD_FLAG_XOF) != 0)
55 j = EVP_MD_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, EVP_MD_block_size(md)))
82 for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++)
83 pad[i] = 0x5c ^ keytmp[i];
84 if (!EVP_DigestInit_ex(ctx->o_ctx, md, impl)
85 || !EVP_DigestUpdate(ctx->o_ctx, pad, EVP_MD_block_size(md)))
88 if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->i_ctx))
93 OPENSSL_cleanse(keytmp, sizeof(keytmp));
94 OPENSSL_cleanse(pad, sizeof(pad));
99 #ifndef OPENSSL_NO_DEPRECATED_1_1_0
100 int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
104 return HMAC_Init_ex(ctx, key, len, md, NULL);
108 int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
112 return EVP_DigestUpdate(ctx->md_ctx, data, len);
115 int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
118 unsigned char buf[EVP_MAX_MD_SIZE];
123 if (!EVP_DigestFinal_ex(ctx->md_ctx, buf, &i))
125 if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->o_ctx))
127 if (!EVP_DigestUpdate(ctx->md_ctx, buf, i))
129 if (!EVP_DigestFinal_ex(ctx->md_ctx, md, len))
136 size_t HMAC_size(const HMAC_CTX *ctx)
138 int size = EVP_MD_size((ctx)->md);
140 return (size < 0) ? 0 : size;
143 HMAC_CTX *HMAC_CTX_new(void)
145 HMAC_CTX *ctx = OPENSSL_zalloc(sizeof(HMAC_CTX));
148 if (!HMAC_CTX_reset(ctx)) {
156 static void hmac_ctx_cleanup(HMAC_CTX *ctx)
158 EVP_MD_CTX_reset(ctx->i_ctx);
159 EVP_MD_CTX_reset(ctx->o_ctx);
160 EVP_MD_CTX_reset(ctx->md_ctx);
164 void HMAC_CTX_free(HMAC_CTX *ctx)
167 hmac_ctx_cleanup(ctx);
168 EVP_MD_CTX_free(ctx->i_ctx);
169 EVP_MD_CTX_free(ctx->o_ctx);
170 EVP_MD_CTX_free(ctx->md_ctx);
175 static int hmac_ctx_alloc_mds(HMAC_CTX *ctx)
177 if (ctx->i_ctx == NULL)
178 ctx->i_ctx = EVP_MD_CTX_new();
179 if (ctx->i_ctx == NULL)
181 if (ctx->o_ctx == NULL)
182 ctx->o_ctx = EVP_MD_CTX_new();
183 if (ctx->o_ctx == NULL)
185 if (ctx->md_ctx == NULL)
186 ctx->md_ctx = EVP_MD_CTX_new();
187 if (ctx->md_ctx == NULL)
192 int HMAC_CTX_reset(HMAC_CTX *ctx)
194 hmac_ctx_cleanup(ctx);
195 if (!hmac_ctx_alloc_mds(ctx)) {
196 hmac_ctx_cleanup(ctx);
202 int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
204 if (!hmac_ctx_alloc_mds(dctx))
206 if (!EVP_MD_CTX_copy_ex(dctx->i_ctx, sctx->i_ctx))
208 if (!EVP_MD_CTX_copy_ex(dctx->o_ctx, sctx->o_ctx))
210 if (!EVP_MD_CTX_copy_ex(dctx->md_ctx, sctx->md_ctx))
215 hmac_ctx_cleanup(dctx);
219 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
220 const unsigned char *d, size_t n, unsigned char *md,
221 unsigned int *md_len)
224 static unsigned char m[EVP_MAX_MD_SIZE];
225 static const unsigned char dummy_key[1] = {'\0'};
229 if ((c = HMAC_CTX_new()) == NULL)
232 /* For HMAC_Init_ex, NULL key signals reuse. */
233 if (key == NULL && key_len == 0) {
237 if (!HMAC_Init_ex(c, key, key_len, evp_md, NULL))
239 if (!HMAC_Update(c, d, n))
241 if (!HMAC_Final(c, md, md_len))
250 void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
252 EVP_MD_CTX_set_flags(ctx->i_ctx, flags);
253 EVP_MD_CTX_set_flags(ctx->o_ctx, flags);
254 EVP_MD_CTX_set_flags(ctx->md_ctx, flags);
257 const EVP_MD *HMAC_CTX_get_md(const HMAC_CTX *ctx)