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| 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 "modes.h" |
| 52 #include <string.h> |
| 53 |
| 54 #ifndef MODES_DEBUG |
| 55 # ifndef NDEBUG |
| 56 # define NDEBUG |
| 57 # endif |
| 58 #endif |
| 59 #include <assert.h> |
| 60 |
| 61 #define STRICT_ALIGNMENT |
| 62 #if defined(__i386) || defined(__i386__) || \ |
| 63 defined(__x86_64) || defined(__x86_64__) || \ |
| 64 defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \ |
| 65 defined(__s390__) || defined(__s390x__) |
| 66 # undef STRICT_ALIGNMENT |
| 67 #endif |
| 68 |
| 69 /* The input and output encrypted as though 128bit cfb mode is being |
| 70 * used. The extra state information to record how much of the |
| 71 * 128bit block we have used is contained in *num; |
| 72 */ |
| 73 void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out, |
| 74 size_t len, const void *key, |
| 75 unsigned char ivec[16], int *num, |
| 76 int enc, block128_f block) |
| 77 { |
| 78 unsigned int n; |
| 79 size_t l = 0; |
| 80 |
| 81 assert(in && out && key && ivec && num); |
| 82 |
| 83 n = *num; |
| 84 |
| 85 if (enc) { |
| 86 #if !defined(OPENSSL_SMALL_FOOTPRINT) |
| 87 if (16%sizeof(size_t) == 0) do { /* always true actually */ |
| 88 while (n && len) { |
| 89 *(out++) = ivec[n] ^= *(in++); |
| 90 --len; |
| 91 n = (n+1) % 16; |
| 92 } |
| 93 #if defined(STRICT_ALIGNMENT) |
| 94 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) |
| 95 break; |
| 96 #endif |
| 97 while (len>=16) { |
| 98 (*block)(ivec, ivec, key); |
| 99 for (; n<16; n+=sizeof(size_t)) { |
| 100 *(size_t*)(out+n) = |
| 101 *(size_t*)(ivec+n) ^= *(size_t*)(in+n); |
| 102 } |
| 103 len -= 16; |
| 104 out += 16; |
| 105 in += 16; |
| 106 n = 0; |
| 107 } |
| 108 if (len) { |
| 109 (*block)(ivec, ivec, key); |
| 110 while (len--) { |
| 111 out[n] = ivec[n] ^= in[n]; |
| 112 ++n; |
| 113 } |
| 114 } |
| 115 *num = n; |
| 116 return; |
| 117 } while (0); |
| 118 /* the rest would be commonly eliminated by x86* compiler */ |
| 119 #endif |
| 120 while (l<len) { |
| 121 if (n == 0) { |
| 122 (*block)(ivec, ivec, key); |
| 123 } |
| 124 out[l] = ivec[n] ^= in[l]; |
| 125 ++l; |
| 126 n = (n+1) % 16; |
| 127 } |
| 128 *num = n; |
| 129 } else { |
| 130 #if !defined(OPENSSL_SMALL_FOOTPRINT) |
| 131 if (16%sizeof(size_t) == 0) do { /* always true actually */ |
| 132 while (n && len) { |
| 133 unsigned char c; |
| 134 *(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c; |
| 135 --len; |
| 136 n = (n+1) % 16; |
| 137 } |
| 138 #if defined(STRICT_ALIGNMENT) |
| 139 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) |
| 140 break; |
| 141 #endif |
| 142 while (len>=16) { |
| 143 (*block)(ivec, ivec, key); |
| 144 for (; n<16; n+=sizeof(size_t)) { |
| 145 size_t t = *(size_t*)(in+n); |
| 146 *(size_t*)(out+n) = *(size_t*)(ivec+n) ^ t; |
| 147 *(size_t*)(ivec+n) = t; |
| 148 } |
| 149 len -= 16; |
| 150 out += 16; |
| 151 in += 16; |
| 152 n = 0; |
| 153 } |
| 154 if (len) { |
| 155 (*block)(ivec, ivec, key); |
| 156 while (len--) { |
| 157 unsigned char c; |
| 158 out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c; |
| 159 ++n; |
| 160 } |
| 161 } |
| 162 *num = n; |
| 163 return; |
| 164 } while (0); |
| 165 /* the rest would be commonly eliminated by x86* compiler */ |
| 166 #endif |
| 167 while (l<len) { |
| 168 unsigned char c; |
| 169 if (n == 0) { |
| 170 (*block)(ivec, ivec, key); |
| 171 } |
| 172 out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c; |
| 173 ++l; |
| 174 n = (n+1) % 16; |
| 175 } |
| 176 *num=n; |
| 177 } |
| 178 } |
| 179 |
| 180 /* This expects a single block of size nbits for both in and out. Note that |
| 181 it corrupts any extra bits in the last byte of out */ |
| 182 static void cfbr_encrypt_block(const unsigned char *in,unsigned char *out, |
| 183 int nbits,const void *key, |
| 184 unsigned char ivec[16],int enc, |
| 185 block128_f block) |
| 186 { |
| 187 int n,rem,num; |
| 188 unsigned char ovec[16*2 + 1]; /* +1 because we dererefence (but don't use)
one byte off the end */ |
| 189 |
| 190 if (nbits<=0 || nbits>128) return; |
| 191 |
| 192 /* fill in the first half of the new IV with the current IV */ |
| 193 memcpy(ovec,ivec,16); |
| 194 /* construct the new IV */ |
| 195 (*block)(ivec,ivec,key); |
| 196 num = (nbits+7)/8; |
| 197 if (enc) /* encrypt the input */ |
| 198 for(n=0 ; n < num ; ++n) |
| 199 out[n] = (ovec[16+n] = in[n] ^ ivec[n]); |
| 200 else /* decrypt the input */ |
| 201 for(n=0 ; n < num ; ++n) |
| 202 out[n] = (ovec[16+n] = in[n]) ^ ivec[n]; |
| 203 /* shift ovec left... */ |
| 204 rem = nbits%8; |
| 205 num = nbits/8; |
| 206 if(rem==0) |
| 207 memcpy(ivec,ovec+num,16); |
| 208 else |
| 209 for(n=0 ; n < 16 ; ++n) |
| 210 ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem); |
| 211 |
| 212 /* it is not necessary to cleanse ovec, since the IV is not secret */ |
| 213 } |
| 214 |
| 215 /* N.B. This expects the input to be packed, MS bit first */ |
| 216 void CRYPTO_cfb128_1_encrypt(const unsigned char *in, unsigned char *out, |
| 217 size_t bits, const void *key, |
| 218 unsigned char ivec[16], int *num, |
| 219 int enc, block128_f block) |
| 220 { |
| 221 size_t n; |
| 222 unsigned char c[1],d[1]; |
| 223 |
| 224 assert(in && out && key && ivec && num); |
| 225 assert(*num == 0); |
| 226 |
| 227 for(n=0 ; n<bits ; ++n) |
| 228 { |
| 229 c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0; |
| 230 cfbr_encrypt_block(c,d,1,key,ivec,enc,block); |
| 231 out[n/8]=(out[n/8]&~(1 << (unsigned int)(7-n%8))) | |
| 232 ((d[0]&0x80) >> (unsigned int)(n%8)); |
| 233 } |
| 234 } |
| 235 |
| 236 void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out, |
| 237 size_t length, const void *key, |
| 238 unsigned char ivec[16], int *num, |
| 239 int enc, block128_f block) |
| 240 { |
| 241 size_t n; |
| 242 |
| 243 assert(in && out && key && ivec && num); |
| 244 assert(*num == 0); |
| 245 |
| 246 for(n=0 ; n<length ; ++n) |
| 247 cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc,block); |
| 248 } |
| 249 |
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