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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libcrypto/modes/ctr128.c	Lines:	26	66	39.4 %
Date:	2017-11-13	Branches:	10	32	31.3 %


/* $OpenBSD: ctr128.c,v 1.7 2017/08/13 17:46:24 bcook Exp $ */
/* ====================================================================
 * 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>

/* NOTE: the IV/counter CTR mode is big-endian.  The code itself
 * is endian-neutral. */

/* increment counter (128-bit int) by 1 */
static void ctr128_inc(unsigned char *counter) {
	u32 n=16;
	u8  c;

	do {
		--n;
		c = counter[n];
		++c;
		counter[n] = c;
		if (c) return;
	} while (n);
}

#if !defined(OPENSSL_SMALL_FOOTPRINT)
static void
ctr128_inc_aligned(unsigned char *counter)
{
#if BYTE_ORDER == LITTLE_ENDIAN
	ctr128_inc(counter);
#else
	size_t *data, c, n;
	data = (size_t *)counter;
	n = 16 / sizeof(size_t);
	do {
		--n;
		c = data[n];
		++c;
		data[n] = c;
		if (c)
			return;
	} while (n);
#endif
}
#endif

/* The input encrypted as though 128bit counter mode is being
 * used.  The extra state information to record how much of the
 * 128bit block we have used is contained in *num, and the
 * encrypted counter is kept in ecount_buf.  Both *num and
 * ecount_buf must be initialised with zeros before the first
 * call to CRYPTO_ctr128_encrypt().
 *
 * This algorithm assumes that the counter is in the x lower bits
 * of the IV (ivec), and that the application has full control over
 * overflow and the rest of the IV.  This implementation takes NO
 * responsability for checking that the counter doesn't overflow
 * into the rest of the IV when incremented.
 */
void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out,
			size_t len, const void *key,
			unsigned char ivec[16], unsigned char ecount_buf[16],
			unsigned int *num, block128_f block)
{
	unsigned int n;
	size_t l=0;

	assert(*num < 16);

	n = *num;

#if !defined(OPENSSL_SMALL_FOOTPRINT)
	if (16%sizeof(size_t) == 0) do { /* always true actually */
		while (n && len) {
			*(out++) = *(in++) ^ ecount_buf[n];
			--len;
			n = (n+1) % 16;
		}

#ifdef __STRICT_ALIGNMENT
		if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
			break;
#endif
		while (len>=16) {
			(*block)(ivec, ecount_buf, key);
			ctr128_inc_aligned(ivec);
			for (; n<16; n+=sizeof(size_t))
				*(size_t *)(out+n) =
				*(size_t *)(in+n) ^ *(size_t *)(ecount_buf+n);
			len -= 16;
			out += 16;
			in  += 16;
			n = 0;
		}
		if (len) {
			(*block)(ivec, ecount_buf, key);
 			ctr128_inc_aligned(ivec);
			while (len--) {
				out[n] = in[n] ^ ecount_buf[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, ecount_buf, key);
 			ctr128_inc(ivec);
		}
		out[l] = in[l] ^ ecount_buf[n];
		++l;
		n = (n+1) % 16;
	}

	*num=n;
}

/* increment upper 96 bits of 128-bit counter by 1 */
static void ctr96_inc(unsigned char *counter) {
	u32 n=12;
	u8  c;

	do {
		--n;
		c = counter[n];
		++c;
		counter[n] = c;
		if (c) return;
	} while (n);
}

void CRYPTO_ctr128_encrypt_ctr32(const unsigned char *in, unsigned char *out,
			size_t len, const void *key,
			unsigned char ivec[16], unsigned char ecount_buf[16],
			unsigned int *num, ctr128_f func)
{
	unsigned int n,ctr32;

	assert(*num < 16);

	n = *num;

	while (n && len) {
		*(out++) = *(in++) ^ ecount_buf[n];
		--len;
		n = (n+1) % 16;
	}

	ctr32 = GETU32(ivec+12);
	while (len>=16) {
		size_t blocks = len/16;
		/*
		 * 1<<28 is just a not-so-small yet not-so-large number...
		 * Below condition is practically never met, but it has to
		 * be checked for code correctness.
		 */
		if (sizeof(size_t)>sizeof(unsigned int) && blocks>(1U<<28))
			blocks = (1U<<28);
		/*
		 * As (*func) operates on 32-bit counter, caller
		 * has to handle overflow. 'if' below detects the
		 * overflow, which is then handled by limiting the
		 * amount of blocks to the exact overflow point...
		 */
		ctr32 += (u32)blocks;
		if (ctr32 < blocks) {
			blocks -= ctr32;
			ctr32   = 0;
		}
		(*func)(in,out,blocks,key,ivec);
		/* (*ctr) does not update ivec, caller does: */
		PUTU32(ivec+12,ctr32);
		/* ... overflow was detected, propogate carry. */
		if (ctr32 == 0)	ctr96_inc(ivec);
		blocks *= 16;
		len -= blocks;
		out += blocks;
		in  += blocks;
	}
	if (len) {
		memset(ecount_buf,0,16);
		(*func)(ecount_buf,ecount_buf,1,key,ivec);
		++ctr32;
		PUTU32(ivec+12,ctr32);
		if (ctr32 == 0)	ctr96_inc(ivec);
		while (len--) {
			out[n] = in[n] ^ ecount_buf[n];
			++n;
		}
	}

	*num=n;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: ctr128.c,v 1.7 2017/08/13 17:46:24 bcook Exp $ */
2			/* ====================================================================
3			* Copyright (c) 2008 The OpenSSL Project. All rights reserved.
4			*
5			* Redistribution and use in source and binary forms, with or without
6			* modification, are permitted provided that the following conditions
7			* are met:
8			*
9			* 1. Redistributions of source code must retain the above copyright
10			* notice, this list of conditions and the following disclaimer.
11			*
12			* 2. Redistributions in binary form must reproduce the above copyright
13			* notice, this list of conditions and the following disclaimer in
14			* the documentation and/or other materials provided with the
15			* distribution.
16			*
17			* 3. All advertising materials mentioning features or use of this
18			* software must display the following acknowledgment:
19			* "This product includes software developed by the OpenSSL Project
20			* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21			*
22			* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23			* endorse or promote products derived from this software without
24			* prior written permission. For written permission, please contact
25			* openssl-core@openssl.org.
26			*
27			* 5. Products derived from this software may not be called "OpenSSL"
28			* nor may "OpenSSL" appear in their names without prior written
29			* permission of the OpenSSL Project.
30			*
31			* 6. Redistributions of any form whatsoever must retain the following
32			* acknowledgment:
33			* "This product includes software developed by the OpenSSL Project
34			* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35			*
36			* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37			* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39			* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43			* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45			* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46			* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47			* OF THE POSSIBILITY OF SUCH DAMAGE.
48			* ====================================================================
49			*
50			*/
51
52			#include <openssl/crypto.h>
53			#include "modes_lcl.h"
54			#include <string.h>
55
56			#ifndef MODES_DEBUG
57			# ifndef NDEBUG
58			# define NDEBUG
59			# endif
60			#endif
61			#include <assert.h>
62
63			/* NOTE: the IV/counter CTR mode is big-endian. The code itself
64			* is endian-neutral. */
65
66			/* increment counter (128-bit int) by 1 */
67			static void ctr128_inc(unsigned char *counter) {
68			u32 n=16;
69			u8 c;
70
71			do {
72			--n;
73			c = counter[n];
74			++c;
75			counter[n] = c;
76			if (c) return;
77			} while (n);
78			}
79
80			#if !defined(OPENSSL_SMALL_FOOTPRINT)
81			static void
82			ctr128_inc_aligned(unsigned char *counter)
83			{
84			#if BYTE_ORDER == LITTLE_ENDIAN
85			ctr128_inc(counter);
86			#else
87			size_t *data, c, n;
88			data = (size_t *)counter;
89			n = 16 / sizeof(size_t);
90			do {
91			--n;
92			c = data[n];
93			++c;
94			data[n] = c;
95			if (c)
96			return;
97			} while (n);
98			#endif
99			}
100			#endif
101
102			/* The input encrypted as though 128bit counter mode is being
103			* used. The extra state information to record how much of the
104			* 128bit block we have used is contained in *num, and the
105			* encrypted counter is kept in ecount_buf. Both *num and
106			* ecount_buf must be initialised with zeros before the first
107			* call to CRYPTO_ctr128_encrypt().
108			*
109			* This algorithm assumes that the counter is in the x lower bits
110			* of the IV (ivec), and that the application has full control over
111			* overflow and the rest of the IV. This implementation takes NO
112			* responsability for checking that the counter doesn't overflow
113			* into the rest of the IV when incremented.
114			*/
115			void CRYPTO_ctr128_encrypt(const unsigned char in, unsigned char out,
116			size_t len, const void *key,
117			unsigned char ivec[16], unsigned char ecount_buf[16],
118			unsigned int *num, block128_f block)
119			{
120			unsigned int n;
121			size_t l=0;
122
123			assert(*num < 16);
124
125			n = *num;
126
127			#if !defined(OPENSSL_SMALL_FOOTPRINT)
128			if (16%sizeof(size_t) == 0) do { /* always true actually */
129			while (n && len) {
130			(out++) = (in++) ^ ecount_buf[n];
131			--len;
132			n = (n+1) % 16;
133			}
134
135			#ifdef __STRICT_ALIGNMENT
136			if (((size_t)in\|(size_t)out\|(size_t)ivec)%sizeof(size_t) != 0)
137			break;
138			#endif
139			while (len>=16) {
140			(*block)(ivec, ecount_buf, key);
141			ctr128_inc_aligned(ivec);
142			for (; n<16; n+=sizeof(size_t))
143			(size_t )(out+n) =
144			(size_t )(in+n) ^ (size_t )(ecount_buf+n);
145			len -= 16;
146			out += 16;
147			in += 16;
148			n = 0;
149			}
150			if (len) {
151			(*block)(ivec, ecount_buf, key);
152			ctr128_inc_aligned(ivec);
153			while (len--) {
154			out[n] = in[n] ^ ecount_buf[n];
155			++n;
156			}
157			}
158			*num = n;
159			return;
160			} while(0);
161			/* the rest would be commonly eliminated by x86* compiler */
162			#endif
163			while (l<len) {
164			if (n==0) {
165			(*block)(ivec, ecount_buf, key);
166			ctr128_inc(ivec);
167			}
168			out[l] = in[l] ^ ecount_buf[n];
169			++l;
170			n = (n+1) % 16;
171			}
172
173			*num=n;
174			}
175
176			/* increment upper 96 bits of 128-bit counter by 1 */
177			static void ctr96_inc(unsigned char *counter) {
178			u32 n=12;
179			u8 c;
180
181			do {
182			--n;
183			c = counter[n];
184			++c;
185			counter[n] = c;
186			if (c) return;
187			} while (n);
188			}
189
190			void CRYPTO_ctr128_encrypt_ctr32(const unsigned char in, unsigned char out,
191			size_t len, const void *key,
192			unsigned char ivec[16], unsigned char ecount_buf[16],
193			unsigned int *num, ctr128_f func)
194			{
195			unsigned int n,ctr32;
196
197			assert(*num < 16);
198
199		54	n = *num;
200
201	✗✓	54	while (n && len) {
202			(out++) = (in++) ^ ecount_buf[n];
203			--len;
204			n = (n+1) % 16;
205			}
206
207		27	ctr32 = GETU32(ivec+12);
208	✓✓	108	while (len>=16) {
209		27	size_t blocks = len/16;
210			/*
211			* 1<<28 is just a not-so-small yet not-so-large number...
212			* Below condition is practically never met, but it has to
213			* be checked for code correctness.
214			*/
215		27	if (sizeof(size_t)>sizeof(unsigned int) && blocks>(1U<<28))
216			blocks = (1U<<28);
217			/*
218			* As (*func) operates on 32-bit counter, caller
219			* has to handle overflow. 'if' below detects the
220			* overflow, which is then handled by limiting the
221			* amount of blocks to the exact overflow point...
222			*/
223		27	ctr32 += (u32)blocks;
224	✗✓	27	if (ctr32 < blocks) {
225			blocks -= ctr32;
226			ctr32 = 0;
227			}
228		27	(*func)(in,out,blocks,key,ivec);
229			/* (ctr) does not update ivec, caller does: /
230		27	PUTU32(ivec+12,ctr32);
231			/* ... overflow was detected, propogate carry. */
232	✗✓	27	if (ctr32 == 0) ctr96_inc(ivec);
233		27	blocks *= 16;
234		27	len -= blocks;
235		27	out += blocks;
236		27	in += blocks;
237			}
238	✓✓	27	if (len) {
239		9	memset(ecount_buf,0,16);
240		9	(*func)(ecount_buf,ecount_buf,1,key,ivec);
241		9	++ctr32;
242		9	PUTU32(ivec+12,ctr32);
243	✗✓	9	if (ctr32 == 0) ctr96_inc(ivec);
244	✓✓	90	while (len--) {
245		36	out[n] = in[n] ^ ecount_buf[n];
246		36	++n;
247			}
248			}
249
250		27	*num=n;
251		27	}