aboutsummaryrefslogtreecommitdiffstats
path: root/crypto/hmac/hmac.c
blob: 213504e85fee582ac8848d869b9f74d6e4d1895c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/* crypto/hmac/hmac.c */
/* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cryptlib.h"
#include <openssl/hmac.h>

#ifdef OPENSSL_FIPS
# include <openssl/fips.h>
#endif

int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
                 const EVP_MD *md, ENGINE *impl)
{
    int i, j, reset = 0;
    unsigned char pad[HMAC_MAX_MD_CBLOCK];

#ifdef OPENSSL_FIPS
    /* If FIPS mode switch to approved implementation if possible */
    if (FIPS_mode()) {
        const EVP_MD *fipsmd;
        if (md) {
            fipsmd = FIPS_get_digestbynid(EVP_MD_type(md));
            if (fipsmd)
                md = fipsmd;
        }
    }

    if (FIPS_mode()) {
        /* If we have an ENGINE need to allow non FIPS */
        if ((impl || ctx->i_ctx.engine)
            && !(ctx->i_ctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) {
            EVPerr(EVP_F_HMAC_INIT_EX, EVP_R_DISABLED_FOR_FIPS);
            return 0;
        }
        /*
         * Other algorithm blocking will be done in FIPS_cmac_init, via
         * FIPS_hmac_init_ex().
         */
        if (!impl && !ctx->i_ctx.engine)
            return FIPS_hmac_init_ex(ctx, key, len, md, NULL);
    }
#endif
    /* 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) {
        reset = 1;
        ctx->md = md;
    } else if (ctx->md) {
        md = ctx->md;
    } else {
        return 0;
    }

    if (key != NULL) {
        reset = 1;
        j = EVP_MD_block_size(md);
        OPENSSL_assert(j <= (int)sizeof(ctx->key));
        if (j < len) {
            if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
                goto err;
            if (!EVP_DigestUpdate(&ctx->md_ctx, key, len))
                goto err;
            if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key,
                                    &ctx->key_length))
                goto err;
        } else {
            if (len < 0 || len > (int)sizeof(ctx->key))
                return 0;
            memcpy(ctx->key, key, len);
            ctx->key_length = len;
        }
        if (ctx->key_length != HMAC_MAX_MD_CBLOCK)
            memset(&ctx->key[ctx->key_length], 0,
                   HMAC_MAX_MD_CBLOCK - ctx->key_length);
    }

    if (reset) {
        for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
            pad[i] = 0x36 ^ ctx->key[i];
        if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl))
            goto err;
        if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
            goto err;

        for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
            pad[i] = 0x5c ^ ctx->key[i];
        if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl))
            goto err;
        if (!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;
    return 1;
 err:
    return 0;
}

int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
{
    if (key && md)
        HMAC_CTX_init(ctx);
    return HMAC_Init_ex(ctx, key, len, md, NULL);
}

int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
{
#ifdef OPENSSL_FIPS
    if (FIPS_mode() && !ctx->i_ctx.engine)
        return FIPS_hmac_update(ctx, data, len);
#endif
    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];
#ifdef OPENSSL_FIPS
    if (FIPS_mode() && !ctx->i_ctx.engine)
        return FIPS_hmac_final(ctx, md, len);
#endif

    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;
}

void HMAC_CTX_init(HMAC_CTX *ctx)
{
    EVP_MD_CTX_init(&ctx->i_ctx);
    EVP_MD_CTX_init(&ctx->o_ctx);
    EVP_MD_CTX_init(&ctx->md_ctx);
    ctx->md = NULL;
}

int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
{
    if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
        goto err;
    if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
        goto err;
    if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
        goto err;
    memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
    dctx->key_length = sctx->key_length;
    dctx->md = sctx->md;
    return 1;
 err:
    return 0;
}

void HMAC_CTX_cleanup(HMAC_CTX *ctx)
{
#ifdef OPENSSL_FIPS
    if (FIPS_mode() && !ctx->i_ctx.engine) {
        FIPS_hmac_ctx_cleanup(ctx);
        return;
    }
#endif
    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 *ctx);
}

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;
    static unsigned char m[EVP_MAX_MD_SIZE];

    if (md == NULL)
        md = m;
    HMAC_CTX_init(&c);
    if (!HMAC_Init(&c, key, key_len, evp_md))
        goto err;
    if (!HMAC_Update(&c, d, n))
        goto err;
    if (!HMAC_Final(&c, md, md_len))
        goto err;
    HMAC_CTX_cleanup(&c);
    return md;
 err:
    HMAC_CTX_cleanup(&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);
}