1 /* 2 * An 32-bit implementation of the XTEA algorithm 3 * 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 6 * 7 * This file is provided under the Apache License 2.0, or the 8 * GNU General Public License v2.0 or later. 9 * 10 * ********** 11 * Apache License 2.0: 12 * 13 * Licensed under the Apache License, Version 2.0 (the "License"); you may 14 * not use this file except in compliance with the License. 15 * You may obtain a copy of the License at 16 * 17 * http://www.apache.org/licenses/LICENSE-2.0 18 * 19 * Unless required by applicable law or agreed to in writing, software 20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 22 * See the License for the specific language governing permissions and 23 * limitations under the License. 24 * 25 * ********** 26 * 27 * ********** 28 * GNU General Public License v2.0 or later: 29 * 30 * This program is free software; you can redistribute it and/or modify 31 * it under the terms of the GNU General Public License as published by 32 * the Free Software Foundation; either version 2 of the License, or 33 * (at your option) any later version. 34 * 35 * This program is distributed in the hope that it will be useful, 36 * but WITHOUT ANY WARRANTY; without even the implied warranty of 37 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 38 * GNU General Public License for more details. 39 * 40 * You should have received a copy of the GNU General Public License along 41 * with this program; if not, write to the Free Software Foundation, Inc., 42 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 43 * 44 * ********** 45 * 46 * This file is part of mbed TLS (https://tls.mbed.org) 47 */ 48 49 #if !defined(MBEDTLS_CONFIG_FILE) 50 #include "mbedtls/config.h" 51 #else 52 #include MBEDTLS_CONFIG_FILE 53 #endif 54 55 #if defined(MBEDTLS_XTEA_C) 56 57 #include "mbedtls/xtea.h" 58 59 #include <string.h> 60 61 #if defined(MBEDTLS_SELF_TEST) 62 #if defined(MBEDTLS_PLATFORM_C) 63 #include "mbedtls/platform.h" 64 #else 65 #include <stdio.h> 66 #define mbedtls_printf printf 67 #endif /* MBEDTLS_PLATFORM_C */ 68 #endif /* MBEDTLS_SELF_TEST */ 69 70 #if !defined(MBEDTLS_XTEA_ALT) 71 72 /* Implementation that should never be optimized out by the compiler */ 73 static void mbedtls_zeroize( void *v, size_t n ) { 74 volatile unsigned char *p = v; while( n-- ) *p++ = 0; 75 } 76 77 /* 78 * 32-bit integer manipulation macros (big endian) 79 */ 80 #ifndef GET_UINT32_BE 81 #define GET_UINT32_BE(n,b,i) \ 82 { \ 83 (n) = ( (uint32_t) (b)[(i) ] << 24 ) \ 84 | ( (uint32_t) (b)[(i) + 1] << 16 ) \ 85 | ( (uint32_t) (b)[(i) + 2] << 8 ) \ 86 | ( (uint32_t) (b)[(i) + 3] ); \ 87 } 88 #endif 89 90 #ifndef PUT_UINT32_BE 91 #define PUT_UINT32_BE(n,b,i) \ 92 { \ 93 (b)[(i) ] = (unsigned char) ( (n) >> 24 ); \ 94 (b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \ 95 (b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \ 96 (b)[(i) + 3] = (unsigned char) ( (n) ); \ 97 } 98 #endif 99 100 void mbedtls_xtea_init( mbedtls_xtea_context *ctx ) 101 { 102 memset( ctx, 0, sizeof( mbedtls_xtea_context ) ); 103 } 104 105 void mbedtls_xtea_free( mbedtls_xtea_context *ctx ) 106 { 107 if( ctx == NULL ) 108 return; 109 110 mbedtls_zeroize( ctx, sizeof( mbedtls_xtea_context ) ); 111 } 112 113 /* 114 * XTEA key schedule 115 */ 116 void mbedtls_xtea_setup( mbedtls_xtea_context *ctx, const unsigned char key[16] ) 117 { 118 int i; 119 120 memset( ctx, 0, sizeof(mbedtls_xtea_context) ); 121 122 for( i = 0; i < 4; i++ ) 123 { 124 GET_UINT32_BE( ctx->k[i], key, i << 2 ); 125 } 126 } 127 128 /* 129 * XTEA encrypt function 130 */ 131 int mbedtls_xtea_crypt_ecb( mbedtls_xtea_context *ctx, int mode, 132 const unsigned char input[8], unsigned char output[8]) 133 { 134 uint32_t *k, v0, v1, i; 135 136 k = ctx->k; 137 138 GET_UINT32_BE( v0, input, 0 ); 139 GET_UINT32_BE( v1, input, 4 ); 140 141 if( mode == MBEDTLS_XTEA_ENCRYPT ) 142 { 143 uint32_t sum = 0, delta = 0x9E3779B9; 144 145 for( i = 0; i < 32; i++ ) 146 { 147 v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]); 148 sum += delta; 149 v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]); 150 } 151 } 152 else /* MBEDTLS_XTEA_DECRYPT */ 153 { 154 uint32_t delta = 0x9E3779B9, sum = delta * 32; 155 156 for( i = 0; i < 32; i++ ) 157 { 158 v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]); 159 sum -= delta; 160 v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]); 161 } 162 } 163 164 PUT_UINT32_BE( v0, output, 0 ); 165 PUT_UINT32_BE( v1, output, 4 ); 166 167 return( 0 ); 168 } 169 170 #if defined(MBEDTLS_CIPHER_MODE_CBC) 171 /* 172 * XTEA-CBC buffer encryption/decryption 173 */ 174 int mbedtls_xtea_crypt_cbc( mbedtls_xtea_context *ctx, int mode, size_t length, 175 unsigned char iv[8], const unsigned char *input, 176 unsigned char *output) 177 { 178 int i; 179 unsigned char temp[8]; 180 181 if( length % 8 ) 182 return( MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH ); 183 184 if( mode == MBEDTLS_XTEA_DECRYPT ) 185 { 186 while( length > 0 ) 187 { 188 memcpy( temp, input, 8 ); 189 mbedtls_xtea_crypt_ecb( ctx, mode, input, output ); 190 191 for( i = 0; i < 8; i++ ) 192 output[i] = (unsigned char)( output[i] ^ iv[i] ); 193 194 memcpy( iv, temp, 8 ); 195 196 input += 8; 197 output += 8; 198 length -= 8; 199 } 200 } 201 else 202 { 203 while( length > 0 ) 204 { 205 for( i = 0; i < 8; i++ ) 206 output[i] = (unsigned char)( input[i] ^ iv[i] ); 207 208 mbedtls_xtea_crypt_ecb( ctx, mode, output, output ); 209 memcpy( iv, output, 8 ); 210 211 input += 8; 212 output += 8; 213 length -= 8; 214 } 215 } 216 217 return( 0 ); 218 } 219 #endif /* MBEDTLS_CIPHER_MODE_CBC */ 220 #endif /* !MBEDTLS_XTEA_ALT */ 221 222 #if defined(MBEDTLS_SELF_TEST) 223 224 /* 225 * XTEA tests vectors (non-official) 226 */ 227 228 static const unsigned char xtea_test_key[6][16] = 229 { 230 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 231 0x0c, 0x0d, 0x0e, 0x0f }, 232 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 233 0x0c, 0x0d, 0x0e, 0x0f }, 234 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 235 0x0c, 0x0d, 0x0e, 0x0f }, 236 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 237 0x00, 0x00, 0x00, 0x00 }, 238 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 239 0x00, 0x00, 0x00, 0x00 }, 240 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 241 0x00, 0x00, 0x00, 0x00 } 242 }; 243 244 static const unsigned char xtea_test_pt[6][8] = 245 { 246 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 }, 247 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }, 248 { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f }, 249 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 }, 250 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }, 251 { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 } 252 }; 253 254 static const unsigned char xtea_test_ct[6][8] = 255 { 256 { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 }, 257 { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 }, 258 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }, 259 { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 }, 260 { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d }, 261 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 } 262 }; 263 264 /* 265 * Checkup routine 266 */ 267 int mbedtls_xtea_self_test( int verbose ) 268 { 269 int i, ret = 0; 270 unsigned char buf[8]; 271 mbedtls_xtea_context ctx; 272 273 mbedtls_xtea_init( &ctx ); 274 for( i = 0; i < 6; i++ ) 275 { 276 if( verbose != 0 ) 277 mbedtls_printf( " XTEA test #%d: ", i + 1 ); 278 279 memcpy( buf, xtea_test_pt[i], 8 ); 280 281 mbedtls_xtea_setup( &ctx, xtea_test_key[i] ); 282 mbedtls_xtea_crypt_ecb( &ctx, MBEDTLS_XTEA_ENCRYPT, buf, buf ); 283 284 if( memcmp( buf, xtea_test_ct[i], 8 ) != 0 ) 285 { 286 if( verbose != 0 ) 287 mbedtls_printf( "failed\n" ); 288 289 ret = 1; 290 goto exit; 291 } 292 293 if( verbose != 0 ) 294 mbedtls_printf( "passed\n" ); 295 } 296 297 if( verbose != 0 ) 298 mbedtls_printf( "\n" ); 299 300 exit: 301 mbedtls_xtea_free( &ctx ); 302 303 return( ret ); 304 } 305 306 #endif /* MBEDTLS_SELF_TEST */ 307 308 #endif /* MBEDTLS_XTEA_C */ 309