1 /* $OpenBSD: xts128.c,v 1.7 2017/08/13 17:46:24 bcook 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 #else /* BIG_ENDIAN */ 109 size_t c; 110 111 for (c=0,i=0;i<16;++i) { 112 /*+ substitutes for |, because c is 1 bit */ 113 c += ((size_t)tweak.c[i])<<1; 114 tweak.c[i] = (u8)c; 115 c = c>>8; 116 } 117 tweak.c[0] ^= (u8)(0x87&(0-c)); 118 #endif 119 } 120 if (enc) { 121 for (i=0;i<len;++i) { 122 u8 c = inp[i]; 123 out[i] = scratch.c[i]; 124 scratch.c[i] = c; 125 } 126 scratch.u[0] ^= tweak.u[0]; 127 scratch.u[1] ^= tweak.u[1]; 128 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 129 scratch.u[0] ^= tweak.u[0]; 130 scratch.u[1] ^= tweak.u[1]; 131 memcpy(out-16,scratch.c,16); 132 } 133 else { 134 union { u64 u[2]; u8 c[16]; } tweak1; 135 136 #if BYTE_ORDER == LITTLE_ENDIAN 137 unsigned int carry,res; 138 139 res = 0x87&(((int)tweak.d[3])>>31); 140 carry = (unsigned int)(tweak.u[0]>>63); 141 tweak1.u[0] = (tweak.u[0]<<1)^res; 142 tweak1.u[1] = (tweak.u[1]<<1)|carry; 143 #else 144 size_t c; 145 146 for (c=0,i=0;i<16;++i) { 147 /*+ substitutes for |, because c is 1 bit */ 148 c += ((size_t)tweak.c[i])<<1; 149 tweak1.c[i] = (u8)c; 150 c = c>>8; 151 } 152 tweak1.c[0] ^= (u8)(0x87&(0-c)); 153 #endif 154 #ifdef __STRICT_ALIGNMENT 155 memcpy(scratch.c,inp,16); 156 scratch.u[0] ^= tweak1.u[0]; 157 scratch.u[1] ^= tweak1.u[1]; 158 #else 159 scratch.u[0] = ((u64*)inp)[0]^tweak1.u[0]; 160 scratch.u[1] = ((u64*)inp)[1]^tweak1.u[1]; 161 #endif 162 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 163 scratch.u[0] ^= tweak1.u[0]; 164 scratch.u[1] ^= tweak1.u[1]; 165 166 for (i=0;i<len;++i) { 167 u8 c = inp[16+i]; 168 out[16+i] = scratch.c[i]; 169 scratch.c[i] = c; 170 } 171 scratch.u[0] ^= tweak.u[0]; 172 scratch.u[1] ^= tweak.u[1]; 173 (*ctx->block1)(scratch.c,scratch.c,ctx->key1); 174 #ifdef __STRICT_ALIGNMENT 175 scratch.u[0] ^= tweak.u[0]; 176 scratch.u[1] ^= tweak.u[1]; 177 memcpy (out,scratch.c,16); 178 #else 179 ((u64*)out)[0] = scratch.u[0]^tweak.u[0]; 180 ((u64*)out)[1] = scratch.u[1]^tweak.u[1]; 181 #endif 182 } 183 184 return 0; 185 } 186