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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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     *  | 
    
    
    12  | 
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     * 2. Redistributions in binary form must reproduce the above copyright  | 
    
    
    13  | 
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     *    notice, this list of conditions and the following disclaimer in  | 
    
    
    14  | 
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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  | 
    
    
    18  | 
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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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     *  | 
    
    
    36  | 
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     * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY  | 
    
    
    37  | 
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     * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE  | 
    
    
    38  | 
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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,  | 
    
    
    41  | 
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     * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT  | 
    
    
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     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;  | 
    
    
    43  | 
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     * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)  | 
    
    
    44  | 
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     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,  | 
    
    
    45  | 
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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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    56  | 
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    #ifndef MODES_DEBUG  | 
    
    
    57  | 
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    # ifndef NDEBUG  | 
    
    
    58  | 
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    #  define NDEBUG  | 
    
    
    59  | 
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    # endif  | 
    
    
    60  | 
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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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     */  | 
    
    
    66  | 
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    void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,  | 
    
    
    67  | 
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    			size_t len, const void *key,  | 
    
    
    68  | 
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    			unsigned char ivec[16], int *num,  | 
    
    
    69  | 
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    			int enc, block128_f block)  | 
    
    
    70  | 
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    { | 
    
    
    71  | 
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        unsigned int n;  | 
    
    
    72  | 
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        size_t l = 0;  | 
    
    
    73  | 
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    920  | 
        n = *num;  | 
    
    
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    76  | 
    ✓✓ | 
    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++);  | 
    
    
    81  | 
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    1008  | 
    			--len;  | 
    
    
    82  | 
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    1008  | 
    			n = (n+1) % 16;  | 
    
    
    83  | 
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    		}  | 
    
    
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    #ifdef __STRICT_ALIGNMENT  | 
    
    
    85  | 
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    		if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)  | 
    
    
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    			break;  | 
    
    
    87  | 
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    #endif  | 
    
    
    88  | 
    ✓✓ | 
    1646  | 
    		while (len>=16) { | 
    
    
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    702  | 
    			(*block)(ivec, ivec, key);  | 
    
    
    90  | 
    ✓✓ | 
    4212  | 
    			for (; n<16; n+=sizeof(size_t)) { | 
    
    
    91  | 
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    				*(size_t*)(out+n) =  | 
    
    
    92  | 
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    				*(size_t*)(ivec+n) ^= *(size_t*)(in+n);  | 
    
    
    93  | 
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    			}  | 
    
    
    94  | 
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    702  | 
    			len -= 16;  | 
    
    
    95  | 
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    			out += 16;  | 
    
    
    96  | 
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    			in  += 16;  | 
    
    
    97  | 
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    			n = 0;  | 
    
    
    98  | 
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    		}  | 
    
    
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    ✓✓ | 
    242  | 
    		if (len) { | 
    
    
    100  | 
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    			(*block)(ivec, ivec, key);  | 
    
    
    101  | 
    ✓✓ | 
    1040  | 
    			while (len--) { | 
    
    
    102  | 
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    422  | 
    				out[n] = ivec[n] ^= in[n];  | 
    
    
    103  | 
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    				++n;  | 
    
    
    104  | 
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    			}  | 
    
    
    105  | 
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    		}  | 
    
    
    106  | 
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    		*num = n;  | 
    
    
    107  | 
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    242  | 
    		return;  | 
    
    
    108  | 
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    	} while (0);  | 
    
    
    109  | 
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    	/* the rest would be commonly eliminated by x86* compiler */  | 
    
    
    110  | 
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    #endif  | 
    
    
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    	while (l<len) { | 
    
    
    112  | 
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    		if (n == 0) { | 
    
    
    113  | 
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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;  | 
    
    
    117  | 
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    		n = (n+1) % 16;  | 
    
    
    118  | 
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    	}  | 
    
    
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    	*num = n;  | 
    
    
    120  | 
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        } else { | 
    
    
    121  | 
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    #if !defined(OPENSSL_SMALL_FOOTPRINT)  | 
    
    
    122  | 
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    	if (16%sizeof(size_t) == 0) do {	/* always true actually */ | 
    
    
    123  | 
    ✓✓ | 
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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;  | 
    
    
    127  | 
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    			n = (n+1) % 16;  | 
    
    
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     		}  | 
    
    
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    #ifdef __STRICT_ALIGNMENT  | 
    
    
    130  | 
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    		if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)  | 
    
    
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    			break;  | 
    
    
    132  | 
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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)) { | 
    
    
    136  | 
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    				size_t t = *(size_t*)(in+n);  | 
    
    
    137  | 
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    				*(size_t*)(out+n) = *(size_t*)(ivec+n) ^ t;  | 
    
    
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    				*(size_t*)(ivec+n) = t;  | 
    
    
    139  | 
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    			}  | 
    
    
    140  | 
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    			len -= 16;  | 
    
    
    141  | 
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    			out += 16;  | 
    
    
    142  | 
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    			in  += 16;  | 
    
    
    143  | 
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    			n = 0;  | 
    
    
    144  | 
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    		}  | 
    
    
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    		if (len) { | 
    
    
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    			(*block)(ivec, ivec, key);  | 
    
    
    147  | 
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    			while (len--) { | 
    
    
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    				unsigned char c;  | 
    
    
    149  | 
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    				out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c;  | 
    
    
    150  | 
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    				++n;  | 
    
    
    151  | 
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    			}  | 
    
    
    152  | 
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     		}  | 
    
    
    153  | 
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    218  | 
    		*num = n;  | 
    
    
    154  | 
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    218  | 
    		return;  | 
    
    
    155  | 
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    	} while (0);  | 
    
    
    156  | 
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    	/* the rest would be commonly eliminated by x86* compiler */  | 
    
    
    157  | 
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    #endif  | 
    
    
    158  | 
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    	while (l<len) { | 
    
    
    159  | 
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    		unsigned char c;  | 
    
    
    160  | 
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    		if (n == 0) { | 
    
    
    161  | 
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    			(*block)(ivec, ivec, key);  | 
    
    
    162  | 
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    		}  | 
    
    
    163  | 
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    		out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;  | 
    
    
    164  | 
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    		++l;  | 
    
    
    165  | 
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    		n = (n+1) % 16;  | 
    
    
    166  | 
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    	}  | 
    
    
    167  | 
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    	*num=n;  | 
    
    
    168  | 
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        }  | 
    
    
    169  | 
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    460  | 
    }  | 
    
    
    170  | 
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    171  | 
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    /* This expects a single block of size nbits for both in and out. Note that  | 
    
    
    172  | 
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       it corrupts any extra bits in the last byte of out */  | 
    
    
    173  | 
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    static void cfbr_encrypt_block(const unsigned char *in,unsigned char *out,  | 
    
    
    174  | 
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    			    int nbits,const void *key,  | 
    
    
    175  | 
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    			    unsigned char ivec[16],int enc,  | 
    
    
    176  | 
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    			    block128_f block)  | 
    
    
    177  | 
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    { | 
    
    
    178  | 
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        int n,rem,num;  | 
    
    
    179  | 
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    369360  | 
        unsigned char ovec[16*2 + 1];  /* +1 because we dererefence (but don't use) one byte off the end */  | 
    
    
    180  | 
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    181  | 
    ✗✓ | 
    184680  | 
        if (nbits<=0 || nbits>128) return;  | 
    
    
    182  | 
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    183  | 
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    	/* fill in the first half of the new IV with the current IV */  | 
    
    
    184  | 
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    184680  | 
    	memcpy(ovec,ivec,16);  | 
    
    
    185  | 
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    	/* construct the new IV */  | 
    
    
    186  | 
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    184680  | 
    	(*block)(ivec,ivec,key);  | 
    
    
    187  | 
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    184680  | 
    	num = (nbits+7)/8;  | 
    
    
    188  | 
    ✓✓ | 
    184680  | 
    	if (enc)	/* encrypt the input */  | 
    
    
    189  | 
    ✓✓ | 
    277020  | 
    	    for(n=0 ; n < num ; ++n)  | 
    
    
    190  | 
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    92340  | 
    		out[n] = (ovec[16+n] = in[n] ^ ivec[n]);  | 
    
    
    191  | 
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    	else		/* decrypt the input */  | 
    
    
    192  | 
    ✓✓ | 
    277020  | 
    	    for(n=0 ; n < num ; ++n)  | 
    
    
    193  | 
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    92340  | 
    		out[n] = (ovec[16+n] = in[n]) ^ ivec[n];  | 
    
    
    194  | 
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    	/* shift ovec left... */  | 
    
    
    195  | 
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    184680  | 
    	rem = nbits%8;  | 
    
    
    196  | 
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    184680  | 
    	num = nbits/8;  | 
    
    
    197  | 
    ✓✓ | 
    184680  | 
    	if(rem==0)  | 
    
    
    198  | 
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    20520  | 
    	    memcpy(ivec,ovec+num,16);  | 
    
    
    199  | 
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    	else  | 
    
    
    200  | 
    ✓✓ | 
    5581440  | 
    	    for(n=0 ; n < 16 ; ++n)  | 
    
    
    201  | 
     | 
    2626560  | 
    		ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem);  | 
    
    
    202  | 
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    203  | 
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        /* it is not necessary to cleanse ovec, since the IV is not secret */  | 
    
    
    204  | 
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    369360  | 
    }  | 
    
    
    205  | 
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    206  | 
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    /* N.B. This expects the input to be packed, MS bit first */  | 
    
    
    207  | 
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    void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out,  | 
    
    
    208  | 
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    		 	size_t bits, const void *key,  | 
    
    
    209  | 
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    			unsigned char ivec[16], int *num,  | 
    
    
    210  | 
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    			int enc, block128_f block)  | 
    
    
    211  | 
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    { | 
    
    
    212  | 
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        size_t n;  | 
    
    
    213  | 
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    336  | 
        unsigned char c[1],d[1];  | 
    
    
    214  | 
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    215  | 
    ✓✓ | 
    328656  | 
        for(n=0 ; n<bits ; ++n)  | 
    
    
    216  | 
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    	{ | 
    
    
    217  | 
     | 
    164160  | 
    	c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0;  | 
    
    
    218  | 
     | 
    164160  | 
    	cfbr_encrypt_block(c,d,1,key,ivec,enc,block);  | 
    
    
    219  | 
     | 
    328320  | 
    	out[n/8]=(out[n/8]&~(1 << (unsigned int)(7-n%8))) |  | 
    
    
    220  | 
     | 
    164160  | 
    		 ((d[0]&0x80) >> (unsigned int)(n%8));  | 
    
    
    221  | 
     | 
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    	}  | 
    
    
    222  | 
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    168  | 
    }  | 
    
    
    223  | 
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    224  | 
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    void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,  | 
    
    
    225  | 
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    			size_t length, const void *key,  | 
    
    
    226  | 
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    			unsigned char ivec[16], int *num,  | 
    
    
    227  | 
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    			int enc, block128_f block)  | 
    
    
    228  | 
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    { | 
    
    
    229  | 
     | 
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        size_t n;  | 
    
    
    230  | 
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     | 
    
    
    231  | 
    ✓✓ | 
    41544  | 
        for(n=0 ; n<length ; ++n)  | 
    
    
    232  | 
     | 
    20520  | 
    	cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc,block);  | 
    
    
    233  | 
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    168  | 
    }  | 
    
    
    234  | 
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