/src/openssl/crypto/hmac/hmac.c

Source (jump to first uncovered line)
/*
 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (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
 */

/*
 * HMAC low level APIs are deprecated for public use, but still ok for internal
 * use.
 */
#include "internal/deprecated.h"

#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_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 < 0)
            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;
}

#ifndef OPENSSL_NO_DEPRECATED_1_1_0
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;
}

Coverage Report

Created: 2020-08-14 21:15

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3		*
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
8		*/
9
10		/*
11		* HMAC low level APIs are deprecated for public use, but still ok for internal
12		* use.
13		*/
14		#include "internal/deprecated.h"
15
16		#include <stdio.h>
17		#include <stdlib.h>
18		#include <string.h>
19		#include "internal/cryptlib.h"
20		#include <openssl/hmac.h>
21		#include <openssl/opensslconf.h>
22		#include "hmac_local.h"
23
24		int HMAC_Init_ex(HMAC_CTX ctx, const void key, int len,
25		const EVP_MD md, ENGINE impl)
26	0	{
27	0	int rv = 0, reset = 0;
28	0	int i, j;
29	0	unsigned char pad[HMAC_MAX_MD_CBLOCK_SIZE];
30	0	unsigned int keytmp_length;
31	0	unsigned char keytmp[HMAC_MAX_MD_CBLOCK_SIZE];
32	0
33	0	/* If we are changing MD then we must have a key */
34	0	if (md != NULL && md != ctx->md && (key == NULL \|\| len < 0))
35	0	return 0;
36	0
37	0	if (md != NULL) {
38	0	ctx->md = md;
39	0	} else if (ctx->md) {
40	0	md = ctx->md;
41	0	} else {
42	0	return 0;
43	0	}
44	0
45	0	/*
46	0	* The HMAC construction is not allowed to be used with the
47	0	* extendable-output functions (XOF) shake128 and shake256.
48	0	*/
49	0	if ((EVP_MD_flags(md) & EVP_MD_FLAG_XOF) != 0)
50	0	return 0;
51	0
52	0	if (key != NULL) {
53	0	reset = 1;
54	0
55	0	j = EVP_MD_block_size(md);
56	0	if (!ossl_assert(j <= (int)sizeof(keytmp)))
57	0	return 0;
58	0	if (j < 0)
59	0	return 0;
60	0	if (j < len) {
61	0	if (!EVP_DigestInit_ex(ctx->md_ctx, md, impl)
62	0	\|\| !EVP_DigestUpdate(ctx->md_ctx, key, len)
63	0	\|\| !EVP_DigestFinal_ex(ctx->md_ctx, keytmp,
64	0	&keytmp_length))
65	0	return 0;
66	0	} else {
67	0	if (len < 0 \|\| len > (int)sizeof(keytmp))
68	0	return 0;
69	0	memcpy(keytmp, key, len);
70	0	keytmp_length = len;
71	0	}
72	0	if (keytmp_length != HMAC_MAX_MD_CBLOCK_SIZE)
73	0	memset(&keytmp[keytmp_length], 0,
74	0	HMAC_MAX_MD_CBLOCK_SIZE - keytmp_length);
75	0
76	0	for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++)
77	0	pad[i] = 0x36 ^ keytmp[i];
78	0	if (!EVP_DigestInit_ex(ctx->i_ctx, md, impl)
79	0	\|\| !EVP_DigestUpdate(ctx->i_ctx, pad, EVP_MD_block_size(md)))
80	0	goto err;
81	0
82	0	for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++)
83	0	pad[i] = 0x5c ^ keytmp[i];
84	0	if (!EVP_DigestInit_ex(ctx->o_ctx, md, impl)
85	0	\|\| !EVP_DigestUpdate(ctx->o_ctx, pad, EVP_MD_block_size(md)))
86	0	goto err;
87	0	}
88	0	if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->i_ctx))
89	0	goto err;
90	0	rv = 1;
91	0	err:
92	0	if (reset) {
93	0	OPENSSL_cleanse(keytmp, sizeof(keytmp));
94	0	OPENSSL_cleanse(pad, sizeof(pad));
95	0	}
96		return rv;
97		}
98
99	0	#ifndef OPENSSL_NO_DEPRECATED_1_1_0
100	0	int HMAC_Init(HMAC_CTX ctx, const void key, int len, const EVP_MD *md)
101	0	{
102	0	if (key && md)
103	0	HMAC_CTX_reset(ctx);
104		return HMAC_Init_ex(ctx, key, len, md, NULL);
105		}
106		#endif
107	0
108	0	int HMAC_Update(HMAC_CTX ctx, const unsigned char data, size_t len)
109	0	{
110	0	if (!ctx->md)
111	0	return 0;
112		return EVP_DigestUpdate(ctx->md_ctx, data, len);
113		}
114	0
115	0	int HMAC_Final(HMAC_CTX ctx, unsigned char md, unsigned int *len)
116	0	{
117	0	unsigned int i;
118	0	unsigned char buf[EVP_MAX_MD_SIZE];
119	0
120	0	if (!ctx->md)
121	0	goto err;
122	0
123	0	if (!EVP_DigestFinal_ex(ctx->md_ctx, buf, &i))
124	0	goto err;
125	0	if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->o_ctx))
126	0	goto err;
127	0	if (!EVP_DigestUpdate(ctx->md_ctx, buf, i))
128	0	goto err;
129	0	if (!EVP_DigestFinal_ex(ctx->md_ctx, md, len))
130	0	goto err;
131	0	return 1;
132	0	err:
133		return 0;
134		}
135	0
136	0	size_t HMAC_size(const HMAC_CTX *ctx)
137	0	{
138	0	int size = EVP_MD_size((ctx)->md);
139	0
140		return (size < 0) ? 0 : size;
141		}
142	0
143	0	HMAC_CTX *HMAC_CTX_new(void)
144	0	{
145	0	HMAC_CTX *ctx = OPENSSL_zalloc(sizeof(HMAC_CTX));
146	0
147	0	if (ctx != NULL) {
148	0	if (!HMAC_CTX_reset(ctx)) {
149	0	HMAC_CTX_free(ctx);
150	0	return NULL;
151	0	}
152	0	}
153		return ctx;
154		}
155	0
156	0	static void hmac_ctx_cleanup(HMAC_CTX *ctx)
157	0	{
158	0	EVP_MD_CTX_reset(ctx->i_ctx);
159	0	EVP_MD_CTX_reset(ctx->o_ctx);
160	0	EVP_MD_CTX_reset(ctx->md_ctx);
161		ctx->md = NULL;
162		}
163	0
164	0	void HMAC_CTX_free(HMAC_CTX *ctx)
165	0	{
166	0	if (ctx != NULL) {
167	0	hmac_ctx_cleanup(ctx);
168	0	EVP_MD_CTX_free(ctx->i_ctx);
169	0	EVP_MD_CTX_free(ctx->o_ctx);
170	0	EVP_MD_CTX_free(ctx->md_ctx);
171	0	OPENSSL_free(ctx);
172		}
173		}
174	0
175	0	static int hmac_ctx_alloc_mds(HMAC_CTX *ctx)
176	0	{
177	0	if (ctx->i_ctx == NULL)
178	0	ctx->i_ctx = EVP_MD_CTX_new();
179	0	if (ctx->i_ctx == NULL)
180	0	return 0;
181	0	if (ctx->o_ctx == NULL)
182	0	ctx->o_ctx = EVP_MD_CTX_new();
183	0	if (ctx->o_ctx == NULL)
184	0	return 0;
185	0	if (ctx->md_ctx == NULL)
186	0	ctx->md_ctx = EVP_MD_CTX_new();
187	0	if (ctx->md_ctx == NULL)
188	0	return 0;
189		return 1;
190		}
191	0
192	0	int HMAC_CTX_reset(HMAC_CTX *ctx)
193	0	{
194	0	hmac_ctx_cleanup(ctx);
195	0	if (!hmac_ctx_alloc_mds(ctx)) {
196	0	hmac_ctx_cleanup(ctx);
197	0	return 0;
198	0	}
199		return 1;
200		}
201	0
202	0	int HMAC_CTX_copy(HMAC_CTX dctx, HMAC_CTX sctx)
203	0	{
204	0	if (!hmac_ctx_alloc_mds(dctx))
205	0	goto err;
206	0	if (!EVP_MD_CTX_copy_ex(dctx->i_ctx, sctx->i_ctx))
207	0	goto err;
208	0	if (!EVP_MD_CTX_copy_ex(dctx->o_ctx, sctx->o_ctx))
209	0	goto err;
210	0	if (!EVP_MD_CTX_copy_ex(dctx->md_ctx, sctx->md_ctx))
211	0	goto err;
212	0	dctx->md = sctx->md;
213	0	return 1;
214	0	err:
215	0	hmac_ctx_cleanup(dctx);
216		return 0;
217		}
218
219		unsigned char HMAC(const EVP_MD evp_md, const void *key, int key_len,
220	0	const unsigned char d, size_t n, unsigned char md,
221	0	unsigned int *md_len)
222	0	{
223	0	HMAC_CTX *c = NULL;
224	0	static unsigned char m[EVP_MAX_MD_SIZE];
225	0	static const unsigned char dummy_key[1] = {'\0'};
226	0
227	0	if (md == NULL)
228	0	md = m;
229	0	if ((c = HMAC_CTX_new()) == NULL)
230	0	goto err;
231	0
232	0	/* For HMAC_Init_ex, NULL key signals reuse. */
233	0	if (key == NULL && key_len == 0) {
234	0	key = dummy_key;
235	0	}
236	0
237	0	if (!HMAC_Init_ex(c, key, key_len, evp_md, NULL))
238	0	goto err;
239	0	if (!HMAC_Update(c, d, n))
240	0	goto err;
241	0	if (!HMAC_Final(c, md, md_len))
242	0	goto err;
243	0	HMAC_CTX_free(c);
244	0	return md;
245	0	err:
246	0	HMAC_CTX_free(c);
247		return NULL;
248		}
249	0
250	0	void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
251	0	{
252	0	EVP_MD_CTX_set_flags(ctx->i_ctx, flags);
253	0	EVP_MD_CTX_set_flags(ctx->o_ctx, flags);
254		EVP_MD_CTX_set_flags(ctx->md_ctx, flags);
255		}
256	0
257	0	const EVP_MD HMAC_CTX_get_md(const HMAC_CTX ctx)
258	0	{
259		return ctx->md;
260		}