1 /* $OpenBSD: xts128.c,v 1.5 2014/07/09 16:06:13 miod Exp $ */ 2 /* ==================================================================== 3 * Copyright (c) 2011 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 #include <machine/endian.h> 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 62 int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char iv[16], 63 const unsigned char *inp, unsigned char *out, 64 size_t len, int enc) 65 { 66 union { u64 u[2]; u32 d[4]; u8 c[16]; } tweak, scratch; 67 unsigned int i; 68 69 if (len<16) return -1; 70 71 memcpy(tweak.c, iv, 16); 72 73 (*ctx->block2)(tweak.c,tweak.c,ctx->key2); 74 75 if (!enc && (len%16)) len-=16; 76 77 while (len>=16) { 78 #ifdef __STRICT_ALIGNMENT 79 memcpy(scratch.c,inp,16); 80 scratch.u[0] ^= tweak.u[0]; 81 scratch.u[1] ^= tweak.u[1]; 82 #else 83 scratch.u[0] = ((u64*)inp)[0]^tweak.u[0]; 84 scratch.u[1] = ((u64*)inp)[1]^tweak.u[1]; 85 #endif 86 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 87 #ifdef __STRICT_ALIGNMENT 88 scratch.u[0] ^= tweak.u[0]; 89 scratch.u[1] ^= tweak.u[1]; 90 memcpy(out,scratch.c,16); 91 #else 92 ((u64*)out)[0] = scratch.u[0]^=tweak.u[0]; 93 ((u64*)out)[1] = scratch.u[1]^=tweak.u[1]; 94 #endif 95 inp += 16; 96 out += 16; 97 len -= 16; 98 99 if (len==0) return 0; 100 101 if (BYTE_ORDER == LITTLE_ENDIAN) { 102 unsigned int carry,res; 103 104 res = 0x87&(((int)tweak.d[3])>>31); 105 carry = (unsigned int)(tweak.u[0]>>63); 106 tweak.u[0] = (tweak.u[0]<<1)^res; 107 tweak.u[1] = (tweak.u[1]<<1)|carry; 108 } 109 else { 110 size_t c; 111 112 for (c=0,i=0;i<16;++i) { 113 /*+ substitutes for |, because c is 1 bit */ 114 c += ((size_t)tweak.c[i])<<1; 115 tweak.c[i] = (u8)c; 116 c = c>>8; 117 } 118 tweak.c[0] ^= (u8)(0x87&(0-c)); 119 } 120 } 121 if (enc) { 122 for (i=0;i<len;++i) { 123 u8 c = inp[i]; 124 out[i] = scratch.c[i]; 125 scratch.c[i] = c; 126 } 127 scratch.u[0] ^= tweak.u[0]; 128 scratch.u[1] ^= tweak.u[1]; 129 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 130 scratch.u[0] ^= tweak.u[0]; 131 scratch.u[1] ^= tweak.u[1]; 132 memcpy(out-16,scratch.c,16); 133 } 134 else { 135 union { u64 u[2]; u8 c[16]; } tweak1; 136 137 if (BYTE_ORDER == LITTLE_ENDIAN) { 138 unsigned int carry,res; 139 140 res = 0x87&(((int)tweak.d[3])>>31); 141 carry = (unsigned int)(tweak.u[0]>>63); 142 tweak1.u[0] = (tweak.u[0]<<1)^res; 143 tweak1.u[1] = (tweak.u[1]<<1)|carry; 144 } 145 else { 146 size_t c; 147 148 for (c=0,i=0;i<16;++i) { 149 /*+ substitutes for |, because c is 1 bit */ 150 c += ((size_t)tweak.c[i])<<1; 151 tweak1.c[i] = (u8)c; 152 c = c>>8; 153 } 154 tweak1.c[0] ^= (u8)(0x87&(0-c)); 155 } 156 #ifdef __STRICT_ALIGNMENT 157 memcpy(scratch.c,inp,16); 158 scratch.u[0] ^= tweak1.u[0]; 159 scratch.u[1] ^= tweak1.u[1]; 160 #else 161 scratch.u[0] = ((u64*)inp)[0]^tweak1.u[0]; 162 scratch.u[1] = ((u64*)inp)[1]^tweak1.u[1]; 163 #endif 164 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 165 scratch.u[0] ^= tweak1.u[0]; 166 scratch.u[1] ^= tweak1.u[1]; 167 168 for (i=0;i<len;++i) { 169 u8 c = inp[16+i]; 170 out[16+i] = scratch.c[i]; 171 scratch.c[i] = c; 172 } 173 scratch.u[0] ^= tweak.u[0]; 174 scratch.u[1] ^= tweak.u[1]; 175 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 176 #ifdef __STRICT_ALIGNMENT 177 scratch.u[0] ^= tweak.u[0]; 178 scratch.u[1] ^= tweak.u[1]; 179 memcpy (out,scratch.c,16); 180 #else 181 ((u64*)out)[0] = scratch.u[0]^tweak.u[0]; 182 ((u64*)out)[1] = scratch.u[1]^tweak.u[1]; 183 #endif 184 } 185 186 return 0; 187 } 188