GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libcrypto/modes/cfb128.c Lines: 69 69 100.0 %
Date: 2017-11-07 Branches: 37 38 97.4 %

Line Branch Exec Source
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/* $OpenBSD: cfb128.c,v 1.4 2015/02/10 09:46:30 miod Exp $ */
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/* ====================================================================
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 * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 *
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in
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 *    the documentation and/or other materials provided with the
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 *    distribution.
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 *
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 * 3. All advertising materials mentioning features or use of this
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 *    software must display the following acknowledgment:
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 *    "This product includes software developed by the OpenSSL Project
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 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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 *
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 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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 *    endorse or promote products derived from this software without
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 *    prior written permission. For written permission, please contact
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 *    openssl-core@openssl.org.
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 *
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 * 5. Products derived from this software may not be called "OpenSSL"
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 *    nor may "OpenSSL" appear in their names without prior written
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 *    permission of the OpenSSL Project.
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 *
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 * 6. Redistributions of any form whatsoever must retain the following
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 *    acknowledgment:
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 *    "This product includes software developed by the OpenSSL Project
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 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 * OF THE POSSIBILITY OF SUCH DAMAGE.
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 * ====================================================================
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 *
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 */
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#include <openssl/crypto.h>
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#include "modes_lcl.h"
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#include <string.h>
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#ifndef MODES_DEBUG
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# ifndef NDEBUG
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#  define NDEBUG
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# endif
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#endif
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/* The input and output encrypted as though 128bit cfb mode is being
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 * used.  The extra state information to record how much of the
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 * 128bit block we have used is contained in *num;
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 */
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void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
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			size_t len, const void *key,
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			unsigned char ivec[16], int *num,
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			int enc, block128_f block)
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{
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    unsigned int n;
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    size_t l = 0;
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920
    n = *num;
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460
    if (enc) {
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#if !defined(OPENSSL_SMALL_FOOTPRINT)
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	if (16%sizeof(size_t) == 0) do {	/* always true actually */
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2258
		while (n && len) {
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1008
			*(out++) = ivec[n] ^= *(in++);
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1008
			--len;
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1008
			n = (n+1) % 16;
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		}
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#ifdef __STRICT_ALIGNMENT
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		if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
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			break;
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#endif
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1646
		while (len>=16) {
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702
			(*block)(ivec, ivec, key);
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4212
			for (; n<16; n+=sizeof(size_t)) {
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1404
				*(size_t*)(out+n) =
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1404
				*(size_t*)(ivec+n) ^= *(size_t*)(in+n);
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			}
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702
			len -= 16;
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			out += 16;
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702
			in  += 16;
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			n = 0;
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		}
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		if (len) {
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			(*block)(ivec, ivec, key);
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1040
			while (len--) {
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422
				out[n] = ivec[n] ^= in[n];
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				++n;
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			}
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		}
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		*num = n;
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		return;
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	} while (0);
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	/* the rest would be commonly eliminated by x86* compiler */
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#endif
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	while (l<len) {
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		if (n == 0) {
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			(*block)(ivec, ivec, key);
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		}
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		out[l] = ivec[n] ^= in[l];
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		++l;
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		n = (n+1) % 16;
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	}
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	*num = n;
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    } else {
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#if !defined(OPENSSL_SMALL_FOOTPRINT)
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	if (16%sizeof(size_t) == 0) do {	/* always true actually */
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		while (n && len) {
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			unsigned char c;
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			*(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
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			--len;
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			n = (n+1) % 16;
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 		}
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#ifdef __STRICT_ALIGNMENT
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		if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
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			break;
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#endif
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		while (len>=16) {
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			(*block)(ivec, ivec, key);
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			for (; n<16; n+=sizeof(size_t)) {
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				size_t t = *(size_t*)(in+n);
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				*(size_t*)(out+n) = *(size_t*)(ivec+n) ^ t;
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				*(size_t*)(ivec+n) = t;
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			}
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			len -= 16;
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			out += 16;
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			in  += 16;
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			n = 0;
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		}
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		if (len) {
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			(*block)(ivec, ivec, key);
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			while (len--) {
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				unsigned char c;
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				out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c;
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				++n;
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			}
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 		}
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		*num = n;
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		return;
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	} while (0);
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	/* the rest would be commonly eliminated by x86* compiler */
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#endif
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	while (l<len) {
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		unsigned char c;
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		if (n == 0) {
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			(*block)(ivec, ivec, key);
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		}
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		out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
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		++l;
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		n = (n+1) % 16;
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	}
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	*num=n;
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    }
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}
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/* This expects a single block of size nbits for both in and out. Note that
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   it corrupts any extra bits in the last byte of out */
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static void cfbr_encrypt_block(const unsigned char *in,unsigned char *out,
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			    int nbits,const void *key,
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			    unsigned char ivec[16],int enc,
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			    block128_f block)
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{
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    int n,rem,num;
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369360
    unsigned char ovec[16*2 + 1];  /* +1 because we dererefence (but don't use) one byte off the end */
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184680
    if (nbits<=0 || nbits>128) return;
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	/* fill in the first half of the new IV with the current IV */
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184680
	memcpy(ovec,ivec,16);
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	/* construct the new IV */
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184680
	(*block)(ivec,ivec,key);
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184680
	num = (nbits+7)/8;
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184680
	if (enc)	/* encrypt the input */
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277020
	    for(n=0 ; n < num ; ++n)
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92340
		out[n] = (ovec[16+n] = in[n] ^ ivec[n]);
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	else		/* decrypt the input */
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277020
	    for(n=0 ; n < num ; ++n)
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		out[n] = (ovec[16+n] = in[n]) ^ ivec[n];
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	/* shift ovec left... */
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184680
	rem = nbits%8;
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184680
	num = nbits/8;
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184680
	if(rem==0)
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20520
	    memcpy(ivec,ovec+num,16);
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	else
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	    for(n=0 ; n < 16 ; ++n)
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		ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem);
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    /* it is not necessary to cleanse ovec, since the IV is not secret */
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369360
}
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/* N.B. This expects the input to be packed, MS bit first */
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void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out,
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		 	size_t bits, const void *key,
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			unsigned char ivec[16], int *num,
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			int enc, block128_f block)
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{
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    size_t n;
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    unsigned char c[1],d[1];
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328656
    for(n=0 ; n<bits ; ++n)
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	{
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164160
	c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0;
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164160
	cfbr_encrypt_block(c,d,1,key,ivec,enc,block);
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328320
	out[n/8]=(out[n/8]&~(1 << (unsigned int)(7-n%8))) |
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		 ((d[0]&0x80) >> (unsigned int)(n%8));
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	}
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}
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void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
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			size_t length, const void *key,
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			unsigned char ivec[16], int *num,
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			int enc, block128_f block)
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{
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    size_t n;
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41544
    for(n=0 ; n<length ; ++n)
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20520
	cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc,block);
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}
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