/src/openssl/crypto/modes/cfb128.c

Source (jump to first uncovered line)
/* ====================================================================
 * Copyright (c) 2008 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
 *    openssl-core@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 <openssl/crypto.h>
#include "modes_lcl.h"
#include <string.h>

#ifndef MODES_DEBUG
# ifndef NDEBUG
#  define NDEBUG
# endif
#endif
#include <assert.h>

/*
 * The input and output encrypted as though 128bit cfb mode is being used.
 * The extra state information to record how much of the 128bit block we have
 * used is contained in *num;
 */
void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
                           size_t len, const void *key,
                           unsigned char ivec[16], int *num,
                           int enc, block128_f block)
{
    unsigned int n;
    size_t l = 0;

    assert(in && out && key && ivec && num);

    n = *num;

    if (enc) {
#if !defined(OPENSSL_SMALL_FOOTPRINT)
        if (16 % sizeof(size_t) == 0) { /* always true actually */
            do {
                while (n && len) {
                    *(out++) = ivec[n] ^= *(in++);
                    --len;
                    n = (n + 1) % 16;
                }
# if defined(STRICT_ALIGNMENT)
                if (((size_t)in | (size_t)out | (size_t)ivec) %
                    sizeof(size_t) != 0)
                    break;
# endif
                while (len >= 16) {
                    (*block) (ivec, ivec, key);
                    for (; n < 16; n += sizeof(size_t)) {
                        *(size_t *)(out + n) =
                            *(size_t *)(ivec + n) ^= *(size_t *)(in + n);
                    }
                    len -= 16;
                    out += 16;
                    in += 16;
                    n = 0;
                }
                if (len) {
                    (*block) (ivec, ivec, key);
                    while (len--) {
                        out[n] = ivec[n] ^= in[n];
                        ++n;
                    }
                }
                *num = n;
                return;
            } while (0);
        }
        /* the rest would be commonly eliminated by x86* compiler */
#endif
        while (l < len) {
            if (n == 0) {
                (*block) (ivec, ivec, key);
            }
            out[l] = ivec[n] ^= in[l];
            ++l;
            n = (n + 1) % 16;
        }
        *num = n;
    } else {
#if !defined(OPENSSL_SMALL_FOOTPRINT)
        if (16 % sizeof(size_t) == 0) { /* always true actually */
            do {
                while (n && len) {
                    unsigned char c;
                    *(out++) = ivec[n] ^ (c = *(in++));
                    ivec[n] = c;
                    --len;
                    n = (n + 1) % 16;
                }
# if defined(STRICT_ALIGNMENT)
                if (((size_t)in | (size_t)out | (size_t)ivec) %
                    sizeof(size_t) != 0)
                    break;
# endif
                while (len >= 16) {
                    (*block) (ivec, ivec, key);
                    for (; n < 16; n += sizeof(size_t)) {
                        size_t t = *(size_t *)(in + n);
                        *(size_t *)(out + n) = *(size_t *)(ivec + n) ^ t;
                        *(size_t *)(ivec + n) = t;
                    }
                    len -= 16;
                    out += 16;
                    in += 16;
                    n = 0;
                }
                if (len) {
                    (*block) (ivec, ivec, key);
                    while (len--) {
                        unsigned char c;
                        out[n] = ivec[n] ^ (c = in[n]);
                        ivec[n] = c;
                        ++n;
                    }
                }
                *num = n;
                return;
            } while (0);
        }
        /* the rest would be commonly eliminated by x86* compiler */
#endif
        while (l < len) {
            unsigned char c;
            if (n == 0) {
                (*block) (ivec, ivec, key);
            }
            out[l] = ivec[n] ^ (c = in[l]);
            ivec[n] = c;
            ++l;
            n = (n + 1) % 16;
        }
        *num = n;
    }
}

/*
 * This expects a single block of size nbits for both in and out. Note that
 * it corrupts any extra bits in the last byte of out
 */
static void cfbr_encrypt_block(const unsigned char *in, unsigned char *out,
                               int nbits, const void *key,
                               unsigned char ivec[16], int enc,
                               block128_f block)
{
    int n, rem, num;
    unsigned char ovec[16 * 2 + 1]; /* +1 because we dererefence (but don't
                                     * use) one byte off the end */

    if (nbits <= 0 || nbits > 128)
        return;

    /* fill in the first half of the new IV with the current IV */
    memcpy(ovec, ivec, 16);
    /* construct the new IV */
    (*block) (ivec, ivec, key);
    num = (nbits + 7) / 8;
    if (enc)                    /* encrypt the input */
        for (n = 0; n < num; ++n)
            out[n] = (ovec[16 + n] = in[n] ^ ivec[n]);
    else                        /* decrypt the input */
        for (n = 0; n < num; ++n)
            out[n] = (ovec[16 + n] = in[n]) ^ ivec[n];
    /* shift ovec left... */
    rem = nbits % 8;
    num = nbits / 8;
    if (rem == 0)
        memcpy(ivec, ovec + num, 16);
    else
        for (n = 0; n < 16; ++n)
            ivec[n] = ovec[n + num] << rem | ovec[n + num + 1] >> (8 - rem);

    /* it is not necessary to cleanse ovec, since the IV is not secret */
}

/* N.B. This expects the input to be packed, MS bit first */
void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out,
                             size_t bits, const void *key,
                             unsigned char ivec[16], int *num,
                             int enc, block128_f block)
{
    size_t n;
    unsigned char c[1], d[1];

    assert(in && out && key && ivec && num);
    assert(*num == 0);

    for (n = 0; n < bits; ++n) {
        c[0] = (in[n / 8] & (1 << (7 - n % 8))) ? 0x80 : 0;
        cfbr_encrypt_block(c, d, 1, key, ivec, enc, block);
        out[n / 8] = (out[n / 8] & ~(1 << (unsigned int)(7 - n % 8))) |
            ((d[0] & 0x80) >> (unsigned int)(n % 8));
    }
}

void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
                             size_t length, const void *key,
                             unsigned char ivec[16], int *num,
                             int enc, block128_f block)
{
    size_t n;

    assert(in && out && key && ivec && num);
    assert(*num == 0);

    for (n = 0; n < length; ++n)
        cfbr_encrypt_block(&in[n], &out[n], 8, key, ivec, enc, block);
}

Coverage Report

Created: 2022-11-30 06:20

Line	Count	Source (jump to first uncovered line)
1		/* ====================================================================
2		* Copyright (c) 2008 The OpenSSL Project. All rights reserved.
3		*
4		* Redistribution and use in source and binary forms, with or without
5		* modification, are permitted provided that the following conditions
6		* are met:
7		*
8		* 1. Redistributions of source code must retain the above copyright
9		* notice, this list of conditions and the following disclaimer.
10		*
11		* 2. Redistributions in binary form must reproduce the above copyright
12		* notice, this list of conditions and the following disclaimer in
13		* the documentation and/or other materials provided with the
14		* distribution.
15		*
16		* 3. All advertising materials mentioning features or use of this
17		* software must display the following acknowledgment:
18		* "This product includes software developed by the OpenSSL Project
19		* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
20		*
21		* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22		* endorse or promote products derived from this software without
23		* prior written permission. For written permission, please contact
24		* openssl-core@openssl.org.
25		*
26		* 5. Products derived from this software may not be called "OpenSSL"
27		* nor may "OpenSSL" appear in their names without prior written
28		* permission of the OpenSSL Project.
29		*
30		* 6. Redistributions of any form whatsoever must retain the following
31		* acknowledgment:
32		* "This product includes software developed by the OpenSSL Project
33		* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34		*
35		* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36		* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37		* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38		* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
39		* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40		* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41		* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42		* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43		* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44		* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45		* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46		* OF THE POSSIBILITY OF SUCH DAMAGE.
47		* ====================================================================
48		*
49		*/
50
51		#include <openssl/crypto.h>
52		#include "modes_lcl.h"
53		#include <string.h>
54
55		#ifndef MODES_DEBUG
56		# ifndef NDEBUG
57		# define NDEBUG
58		# endif
59		#endif
60		#include <assert.h>
61
62		/*
63		* The input and output encrypted as though 128bit cfb mode is being used.
64		* The extra state information to record how much of the 128bit block we have
65		* used is contained in *num;
66		*/
67		void CRYPTO_cfb128_encrypt(const unsigned char in, unsigned char out,
68		size_t len, const void *key,
69		unsigned char ivec[16], int *num,
70		int enc, block128_f block)
71	0	{
72	0	unsigned int n;
73	0	size_t l = 0;
74
75	0	assert(in && out && key && ivec && num);
76
77	0	n = *num;
78
79	0	if (enc) {
80	0	#if !defined(OPENSSL_SMALL_FOOTPRINT)
81	0	if (16 % sizeof(size_t) == 0) { /* always true actually */
82	0	do {
83	0	while (n && len) {
84	0	(out++) = ivec[n] ^= (in++);
85	0	--len;
86	0	n = (n + 1) % 16;
87	0	}
88	0	# if defined(STRICT_ALIGNMENT)
89	0	if (((size_t)in \| (size_t)out \| (size_t)ivec) %
90	0	sizeof(size_t) != 0)
91	0	break;
92	0	# endif
93	0	while (len >= 16) {
94	0	(*block) (ivec, ivec, key);
95	0	for (; n < 16; n += sizeof(size_t)) {
96	0	(size_t )(out + n) =
97	0	(size_t )(ivec + n) ^= (size_t )(in + n);
98	0	}
99	0	len -= 16;
100	0	out += 16;
101	0	in += 16;
102	0	n = 0;
103	0	}
104	0	if (len) {
105	0	(*block) (ivec, ivec, key);
106	0	while (len--) {
107	0	out[n] = ivec[n] ^= in[n];
108	0	++n;
109	0	}
110	0	}
111	0	*num = n;
112	0	return;
113	0	} while (0);
114	0	}
115		/* the rest would be commonly eliminated by x86* compiler */
116	0	#endif
117	0	while (l < len) {
118	0	if (n == 0) {
119	0	(*block) (ivec, ivec, key);
120	0	}
121	0	out[l] = ivec[n] ^= in[l];
122	0	++l;
123	0	n = (n + 1) % 16;
124	0	}
125	0	*num = n;
126	0	} else {
127	0	#if !defined(OPENSSL_SMALL_FOOTPRINT)
128	0	if (16 % sizeof(size_t) == 0) { /* always true actually */
129	0	do {
130	0	while (n && len) {
131	0	unsigned char c;
132	0	(out++) = ivec[n] ^ (c = (in++));
133	0	ivec[n] = c;
134	0	--len;
135	0	n = (n + 1) % 16;
136	0	}
137	0	# if defined(STRICT_ALIGNMENT)
138	0	if (((size_t)in \| (size_t)out \| (size_t)ivec) %
139	0	sizeof(size_t) != 0)
140	0	break;
141	0	# endif
142	0	while (len >= 16) {
143	0	(*block) (ivec, ivec, key);
144	0	for (; n < 16; n += sizeof(size_t)) {
145	0	size_t t = (size_t )(in + n);
146	0	(size_t )(out + n) = (size_t )(ivec + n) ^ t;
147	0	(size_t )(ivec + n) = t;
148	0	}
149	0	len -= 16;
150	0	out += 16;
151	0	in += 16;
152	0	n = 0;
153	0	}
154	0	if (len) {
155	0	(*block) (ivec, ivec, key);
156	0	while (len--) {
157	0	unsigned char c;
158	0	out[n] = ivec[n] ^ (c = in[n]);
159	0	ivec[n] = c;
160	0	++n;
161	0	}
162	0	}
163	0	*num = n;
164	0	return;
165	0	} while (0);
166	0	}
167		/* the rest would be commonly eliminated by x86* compiler */
168	0	#endif
169	0	while (l < len) {
170	0	unsigned char c;
171	0	if (n == 0) {
172	0	(*block) (ivec, ivec, key);
173	0	}
174	0	out[l] = ivec[n] ^ (c = in[l]);
175	0	ivec[n] = c;
176	0	++l;
177	0	n = (n + 1) % 16;
178	0	}
179	0	*num = n;
180	0	}
181	0	}
182
183		/*
184		* This expects a single block of size nbits for both in and out. Note that
185		* it corrupts any extra bits in the last byte of out
186		*/
187		static void cfbr_encrypt_block(const unsigned char in, unsigned char out,
188		int nbits, const void *key,
189		unsigned char ivec[16], int enc,
190		block128_f block)
191	0	{
192	0	int n, rem, num;
193	0	unsigned char ovec[16 * 2 + 1]; /* +1 because we dererefence (but don't
194		* use) one byte off the end */
195
196	0	if (nbits <= 0 \|\| nbits > 128)
197	0	return;
198
199		/* fill in the first half of the new IV with the current IV */
200	0	memcpy(ovec, ivec, 16);
201		/* construct the new IV */
202	0	(*block) (ivec, ivec, key);
203	0	num = (nbits + 7) / 8;
204	0	if (enc) /* encrypt the input */
205	0	for (n = 0; n < num; ++n)
206	0	out[n] = (ovec[16 + n] = in[n] ^ ivec[n]);
207	0	else /* decrypt the input */
208	0	for (n = 0; n < num; ++n)
209	0	out[n] = (ovec[16 + n] = in[n]) ^ ivec[n];
210		/* shift ovec left... */
211	0	rem = nbits % 8;
212	0	num = nbits / 8;
213	0	if (rem == 0)
214	0	memcpy(ivec, ovec + num, 16);
215	0	else
216	0	for (n = 0; n < 16; ++n)
217	0	ivec[n] = ovec[n + num] << rem \| ovec[n + num + 1] >> (8 - rem);
218
219		/* it is not necessary to cleanse ovec, since the IV is not secret */
220	0	}
221
222		/* N.B. This expects the input to be packed, MS bit first */
223		void CRYPTO_cfb128_1_encrypt(const unsigned char in, unsigned char out,
224		size_t bits, const void *key,
225		unsigned char ivec[16], int *num,
226		int enc, block128_f block)
227	0	{
228	0	size_t n;
229	0	unsigned char c[1], d[1];
230
231	0	assert(in && out && key && ivec && num);
232	0	assert(*num == 0);
233
234	0	for (n = 0; n < bits; ++n) {
235	0	c[0] = (in[n / 8] & (1 << (7 - n % 8))) ? 0x80 : 0;
236	0	cfbr_encrypt_block(c, d, 1, key, ivec, enc, block);
237	0	out[n / 8] = (out[n / 8] & ~(1 << (unsigned int)(7 - n % 8))) \|
238	0	((d[0] & 0x80) >> (unsigned int)(n % 8));
239	0	}
240	0	}
241
242		void CRYPTO_cfb128_8_encrypt(const unsigned char in, unsigned char out,
243		size_t length, const void *key,
244		unsigned char ivec[16], int *num,
245		int enc, block128_f block)
246	0	{
247	0	size_t n;
248
249	0	assert(in && out && key && ivec && num);
250	0	assert(*num == 0);
251
252	0	for (n = 0; n < length; ++n)
253	0	cfbr_encrypt_block(&in[n], &out[n], 8, key, ivec, enc, block);
254	0	}