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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libcrypto/cmac/cmac.c	Lines:	82	117	70.1 %
Date:	2017-11-07	Branches:	40	74	54.1 %


/* $OpenBSD: cmac.c,v 1.10 2015/09/10 15:56:25 jsing Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project.
 */
/* ====================================================================
 * Copyright (c) 2010 The OpenSSL Project.  All rights reserved.
 *
 * 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 above 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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/cmac.h>

struct CMAC_CTX_st {
	/* Cipher context to use */
	EVP_CIPHER_CTX cctx;
	/* Keys k1 and k2 */
	unsigned char k1[EVP_MAX_BLOCK_LENGTH];
	unsigned char k2[EVP_MAX_BLOCK_LENGTH];
	/* Temporary block */
	unsigned char tbl[EVP_MAX_BLOCK_LENGTH];
	/* Last (possibly partial) block */
	unsigned char last_block[EVP_MAX_BLOCK_LENGTH];
	/* Number of bytes in last block: -1 means context not initialised */
	int nlast_block;
};


/* Make temporary keys K1 and K2 */

static void
make_kn(unsigned char *k1, unsigned char *l, int bl)
{
	int i;

	/* Shift block to left, including carry */
	for (i = 0; i < bl; i++) {
		k1[i] = l[i] << 1;
		if (i < bl - 1 && l[i + 1] & 0x80)
			k1[i] |= 1;
	}
	/* If MSB set fixup with R */
	if (l[0] & 0x80)
		k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b;
}

CMAC_CTX *
CMAC_CTX_new(void)
{
	CMAC_CTX *ctx;

	ctx = malloc(sizeof(CMAC_CTX));
	if (!ctx)
		return NULL;
	EVP_CIPHER_CTX_init(&ctx->cctx);
	ctx->nlast_block = -1;
	return ctx;
}

void
CMAC_CTX_cleanup(CMAC_CTX *ctx)
{
	EVP_CIPHER_CTX_cleanup(&ctx->cctx);
	explicit_bzero(ctx->tbl, EVP_MAX_BLOCK_LENGTH);
	explicit_bzero(ctx->k1, EVP_MAX_BLOCK_LENGTH);
	explicit_bzero(ctx->k2, EVP_MAX_BLOCK_LENGTH);
	explicit_bzero(ctx->last_block, EVP_MAX_BLOCK_LENGTH);
	ctx->nlast_block = -1;
}

EVP_CIPHER_CTX *
CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx)
{
	return &ctx->cctx;
}

void
CMAC_CTX_free(CMAC_CTX *ctx)
{
	if (ctx == NULL)
		return;

	CMAC_CTX_cleanup(ctx);
	free(ctx);
}

int
CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in)
{
	int bl;

	if (in->nlast_block == -1)
		return 0;
	if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx))
		return 0;
	bl = EVP_CIPHER_CTX_block_size(&in->cctx);
	memcpy(out->k1, in->k1, bl);
	memcpy(out->k2, in->k2, bl);
	memcpy(out->tbl, in->tbl, bl);
	memcpy(out->last_block, in->last_block, bl);
	out->nlast_block = in->nlast_block;
	return 1;
}

int
CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,
    const EVP_CIPHER *cipher, ENGINE *impl)
{
	static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];

	/* All zeros means restart */
	if (!key && !cipher && !impl && keylen == 0) {
		/* Not initialised */
		if (ctx->nlast_block == -1)
			return 0;
		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
			return 0;
		memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx));
		ctx->nlast_block = 0;
		return 1;
	}
	/* Initialiase context */
	if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL))
		return 0;
	/* Non-NULL key means initialisation complete */
	if (key) {
		int bl;

		if (!EVP_CIPHER_CTX_cipher(&ctx->cctx))
			return 0;
		if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen))
			return 0;
		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv))
			return 0;
		bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl))
			return 0;
		make_kn(ctx->k1, ctx->tbl, bl);
		make_kn(ctx->k2, ctx->k1, bl);
		explicit_bzero(ctx->tbl, bl);
		/* Reset context again ready for first data block */
		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
			return 0;
		/* Zero tbl so resume works */
		memset(ctx->tbl, 0, bl);
		ctx->nlast_block = 0;
	}
	return 1;
}

int
CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen)
{
	const unsigned char *data = in;
	size_t bl;

	if (ctx->nlast_block == -1)
		return 0;
	if (dlen == 0)
		return 1;
	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
	/* Copy into partial block if we need to */
	if (ctx->nlast_block > 0) {
		size_t nleft;

		nleft = bl - ctx->nlast_block;
		if (dlen < nleft)
			nleft = dlen;
		memcpy(ctx->last_block + ctx->nlast_block, data, nleft);
		dlen -= nleft;
		ctx->nlast_block += nleft;
		/* If no more to process return */
		if (dlen == 0)
			return 1;
		data += nleft;
		/* Else not final block so encrypt it */
		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block, bl))
			return 0;
	}
	/* Encrypt all but one of the complete blocks left */
	while (dlen > bl) {
		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl))
			return 0;
		dlen -= bl;
		data += bl;
	}
	/* Copy any data left to last block buffer */
	memcpy(ctx->last_block, data, dlen);
	ctx->nlast_block = dlen;
	return 1;
}

int
CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen)
{
	int i, bl, lb;

	if (ctx->nlast_block == -1)
		return 0;
	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
	*poutlen = (size_t)bl;
	if (!out)
		return 1;
	lb = ctx->nlast_block;
	/* Is last block complete? */
	if (lb == bl) {
		for (i = 0; i < bl; i++)
			out[i] = ctx->last_block[i] ^ ctx->k1[i];
	} else {
		ctx->last_block[lb] = 0x80;
		if (bl - lb > 1)
			memset(ctx->last_block + lb + 1, 0, bl - lb - 1);
		for (i = 0; i < bl; i++)
			out[i] = ctx->last_block[i] ^ ctx->k2[i];
	}
	if (!EVP_Cipher(&ctx->cctx, out, out, bl)) {
		explicit_bzero(out, bl);
		return 0;
	}
	return 1;
}

int
CMAC_resume(CMAC_CTX *ctx)
{
	if (ctx->nlast_block == -1)
		return 0;
	/* The buffer "tbl" containes the last fully encrypted block
	 * which is the last IV (or all zeroes if no last encrypted block).
	 * The last block has not been modified since CMAC_final().
	 * So reinitialising using the last decrypted block will allow
	 * CMAC to continue after calling CMAC_Final().
	 */
	return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: cmac.c,v 1.10 2015/09/10 15:56:25 jsing Exp $ */
2			/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3			* project.
4			*/
5			/* ====================================================================
6			* Copyright (c) 2010 The OpenSSL Project. All rights reserved.
7			*
8			* Redistribution and use in source and binary forms, with or without
9			* modification, are permitted provided that the following conditions
10			* are met:
11			*
12			* 1. Redistributions of source code must retain the above copyright
13			* notice, this list of conditions and the following disclaimer.
14			*
15			* 2. Redistributions in binary form must reproduce the above copyright
16			* notice, this list of conditions and the following disclaimer in
17			* the documentation and/or other materials provided with the
18			* distribution.
19			*
20			* 3. All advertising materials mentioning features or use of this
21			* software must display the following acknowledgment:
22			* "This product includes software developed by the OpenSSL Project
23			* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24			*
25			* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26			* endorse or promote products derived from this software without
27			* prior written permission. For written permission, please contact
28			* licensing@OpenSSL.org.
29			*
30			* 5. Products derived from this software may not be called "OpenSSL"
31			* nor may "OpenSSL" appear in their names without prior written
32			* permission of the OpenSSL Project.
33			*
34			* 6. Redistributions of any form whatsoever must retain the following
35			* acknowledgment:
36			* "This product includes software developed by the OpenSSL Project
37			* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38			*
39			* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40			* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42			* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46			* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48			* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49			* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50			* OF THE POSSIBILITY OF SUCH DAMAGE.
51			* ====================================================================
52			*/
53
54			#include <stdio.h>
55			#include <stdlib.h>
56			#include <string.h>
57
58			#include <openssl/cmac.h>
59
60			struct CMAC_CTX_st {
61			/* Cipher context to use */
62			EVP_CIPHER_CTX cctx;
63			/* Keys k1 and k2 */
64			unsigned char k1[EVP_MAX_BLOCK_LENGTH];
65			unsigned char k2[EVP_MAX_BLOCK_LENGTH];
66			/* Temporary block */
67			unsigned char tbl[EVP_MAX_BLOCK_LENGTH];
68			/* Last (possibly partial) block */
69			unsigned char last_block[EVP_MAX_BLOCK_LENGTH];
70			/* Number of bytes in last block: -1 means context not initialised */
71			int nlast_block;
72			};
73
74
75			/* Make temporary keys K1 and K2 */
76
77			static void
78			make_kn(unsigned char k1, unsigned char l, int bl)
79			{
80			int i;
81
82			/* Shift block to left, including carry */
83	✓✓	1820	for (i = 0; i < bl; i++) {
84		832	k1[i] = l[i] << 1;
85	✓✓✓✓	1612	if (i < bl - 1 && l[i + 1] & 0x80)
86		338	k1[i] \|= 1;
87			}
88			/* If MSB set fixup with R */
89	✓✓	52	if (l[0] & 0x80)
90		26	k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b;
91		52	}
92
93			CMAC_CTX *
94			CMAC_CTX_new(void)
95			{
96			CMAC_CTX *ctx;
97
98		208	ctx = malloc(sizeof(CMAC_CTX));
99	✗✓	104	if (!ctx)
100			return NULL;
101		104	EVP_CIPHER_CTX_init(&ctx->cctx);
102		104	ctx->nlast_block = -1;
103		104	return ctx;
104		104	}
105
106			void
107			CMAC_CTX_cleanup(CMAC_CTX *ctx)
108			{
109		208	EVP_CIPHER_CTX_cleanup(&ctx->cctx);
110		104	explicit_bzero(ctx->tbl, EVP_MAX_BLOCK_LENGTH);
111		104	explicit_bzero(ctx->k1, EVP_MAX_BLOCK_LENGTH);
112		104	explicit_bzero(ctx->k2, EVP_MAX_BLOCK_LENGTH);
113		104	explicit_bzero(ctx->last_block, EVP_MAX_BLOCK_LENGTH);
114		104	ctx->nlast_block = -1;
115		104	}
116
117			EVP_CIPHER_CTX *
118			CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx)
119			{
120			return &ctx->cctx;
121			}
122
123			void
124			CMAC_CTX_free(CMAC_CTX *ctx)
125			{
126	✓✗	208	if (ctx == NULL)
127			return;
128
129		104	CMAC_CTX_cleanup(ctx);
130		104	free(ctx);
131		208	}
132
133			int
134			CMAC_CTX_copy(CMAC_CTX out, const CMAC_CTX in)
135			{
136			int bl;
137
138	✗✓	156	if (in->nlast_block == -1)
139			return 0;
140	✗✓	78	if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx))
141			return 0;
142		78	bl = EVP_CIPHER_CTX_block_size(&in->cctx);
143		78	memcpy(out->k1, in->k1, bl);
144		78	memcpy(out->k2, in->k2, bl);
145		78	memcpy(out->tbl, in->tbl, bl);
146		78	memcpy(out->last_block, in->last_block, bl);
147		78	out->nlast_block = in->nlast_block;
148		78	return 1;
149		78	}
150
151			int
152			CMAC_Init(CMAC_CTX ctx, const void key, size_t keylen,
153			const EVP_CIPHER cipher, ENGINE impl)
154			{
155			static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];
156
157			/* All zeros means restart */
158	✓✓	156	if (!key && !cipher && !impl && keylen == 0) {
159			/* Not initialised */
160	✗✓	26	if (ctx->nlast_block == -1)
161			return 0;
162	✗✓	26	if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
163			return 0;
164		26	memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx));
165		26	ctx->nlast_block = 0;
166		26	return 1;
167			}
168			/* Initialiase context */
169	✓✓✗✓	78	if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL))
170			return 0;
171			/* Non-NULL key means initialisation complete */
172	✓✓	52	if (key) {
173			int bl;
174
175	✗✓	26	if (!EVP_CIPHER_CTX_cipher(&ctx->cctx))
176			return 0;
177	✗✓	26	if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen))
178			return 0;
179	✗✓	26	if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv))
180			return 0;
181		26	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
182	✗✓	26	if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl))
183			return 0;
184		26	make_kn(ctx->k1, ctx->tbl, bl);
185		26	make_kn(ctx->k2, ctx->k1, bl);
186		26	explicit_bzero(ctx->tbl, bl);
187			/* Reset context again ready for first data block */
188	✗✓	26	if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
189			return 0;
190			/* Zero tbl so resume works */
191		26	memset(ctx->tbl, 0, bl);
192		26	ctx->nlast_block = 0;
193	✓✗	26	}
194		52	return 1;
195		78	}
196
197			int
198			CMAC_Update(CMAC_CTX ctx, const void in, size_t dlen)
199			{
200			const unsigned char *data = in;
201			size_t bl;
202
203	✗✓	52	if (ctx->nlast_block == -1)
204			return 0;
205	✗✓	26	if (dlen == 0)
206			return 1;
207		26	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
208			/* Copy into partial block if we need to */
209	✗✓	26	if (ctx->nlast_block > 0) {
210			size_t nleft;
211
212			nleft = bl - ctx->nlast_block;
213			if (dlen < nleft)
214			nleft = dlen;
215			memcpy(ctx->last_block + ctx->nlast_block, data, nleft);
216			dlen -= nleft;
217			ctx->nlast_block += nleft;
218			/* If no more to process return */
219			if (dlen == 0)
220			return 1;
221			data += nleft;
222			/* Else not final block so encrypt it */
223			if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block, bl))
224			return 0;
225			}
226			/* Encrypt all but one of the complete blocks left */
227	✓✓	130	while (dlen > bl) {
228	✗✓	52	if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl))
229			return 0;
230		52	dlen -= bl;
231		52	data += bl;
232			}
233			/* Copy any data left to last block buffer */
234		26	memcpy(ctx->last_block, data, dlen);
235		26	ctx->nlast_block = dlen;
236		26	return 1;
237		26	}
238
239			int
240			CMAC_Final(CMAC_CTX ctx, unsigned char out, size_t *poutlen)
241			{
242			int i, bl, lb;
243
244	✗✓	52	if (ctx->nlast_block == -1)
245			return 0;
246		26	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
247		26	*poutlen = (size_t)bl;
248	✗✓	26	if (!out)
249			return 1;
250		26	lb = ctx->nlast_block;
251			/* Is last block complete? */
252	✗✓	26	if (lb == bl) {
253			for (i = 0; i < bl; i++)
254			out[i] = ctx->last_block[i] ^ ctx->k1[i];
255			} else {
256		26	ctx->last_block[lb] = 0x80;
257	✓✗	26	if (bl - lb > 1)
258		26	memset(ctx->last_block + lb + 1, 0, bl - lb - 1);
259	✓✓	884	for (i = 0; i < bl; i++)
260		416	out[i] = ctx->last_block[i] ^ ctx->k2[i];
261			}
262	✗✓	26	if (!EVP_Cipher(&ctx->cctx, out, out, bl)) {
263			explicit_bzero(out, bl);
264			return 0;
265			}
266		26	return 1;
267		26	}
268
269			int
270			CMAC_resume(CMAC_CTX *ctx)
271			{
272			if (ctx->nlast_block == -1)
273			return 0;
274			/* The buffer "tbl" containes the last fully encrypted block
275			* which is the last IV (or all zeroes if no last encrypted block).
276			* The last block has not been modified since CMAC_final().
277			* So reinitialising using the last decrypted block will allow
278			* CMAC to continue after calling CMAC_Final().
279			*/
280			return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl);
281			}