1 /*
2 * An 32-bit implementation of the XTEA algorithm
3 *
4 * Copyright The Mbed TLS Contributors
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
47 #if !defined(MBEDTLS_CONFIG_FILE)
48 #include "mbedtls/config.h"
49 #else
50 #include MBEDTLS_CONFIG_FILE
51 #endif
52
53 #if defined(MBEDTLS_XTEA_C)
54
55 #include "mbedtls/xtea.h"
56 #include "mbedtls/platform_util.h"
57
58 #include <string.h>
59
60 #if defined(MBEDTLS_SELF_TEST)
61 #if defined(MBEDTLS_PLATFORM_C)
62 #include "mbedtls/platform.h"
63 #else
64 #include <stdio.h>
65 #define mbedtls_printf printf
66 #endif /* MBEDTLS_PLATFORM_C */
67 #endif /* MBEDTLS_SELF_TEST */
68
69 #if !defined(MBEDTLS_XTEA_ALT)
70
71 /*
72 * 32-bit integer manipulation macros (big endian)
73 */
74 #ifndef GET_UINT32_BE
75 #define GET_UINT32_BE(n,b,i) \
76 { \
77 (n) = ( (uint32_t) (b)[(i) ] << 24 ) \
78 | ( (uint32_t) (b)[(i) + 1] << 16 ) \
79 | ( (uint32_t) (b)[(i) + 2] << 8 ) \
80 | ( (uint32_t) (b)[(i) + 3] ); \
81 }
82 #endif
83
84 #ifndef PUT_UINT32_BE
85 #define PUT_UINT32_BE(n,b,i) \
86 { \
87 (b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
88 (b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
89 (b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
90 (b)[(i) + 3] = (unsigned char) ( (n) ); \
91 }
92 #endif
93
mbedtls_xtea_init(mbedtls_xtea_context * ctx)94 void mbedtls_xtea_init( mbedtls_xtea_context *ctx )
95 {
96 memset( ctx, 0, sizeof( mbedtls_xtea_context ) );
97 }
98
mbedtls_xtea_free(mbedtls_xtea_context * ctx)99 void mbedtls_xtea_free( mbedtls_xtea_context *ctx )
100 {
101 if( ctx == NULL )
102 return;
103
104 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_xtea_context ) );
105 }
106
107 /*
108 * XTEA key schedule
109 */
mbedtls_xtea_setup(mbedtls_xtea_context * ctx,const unsigned char key[16])110 void mbedtls_xtea_setup( mbedtls_xtea_context *ctx, const unsigned char key[16] )
111 {
112 int i;
113
114 memset( ctx, 0, sizeof(mbedtls_xtea_context) );
115
116 for( i = 0; i < 4; i++ )
117 {
118 GET_UINT32_BE( ctx->k[i], key, i << 2 );
119 }
120 }
121
122 /*
123 * XTEA encrypt function
124 */
mbedtls_xtea_crypt_ecb(mbedtls_xtea_context * ctx,int mode,const unsigned char input[8],unsigned char output[8])125 int mbedtls_xtea_crypt_ecb( mbedtls_xtea_context *ctx, int mode,
126 const unsigned char input[8], unsigned char output[8])
127 {
128 uint32_t *k, v0, v1, i;
129
130 k = ctx->k;
131
132 GET_UINT32_BE( v0, input, 0 );
133 GET_UINT32_BE( v1, input, 4 );
134
135 if( mode == MBEDTLS_XTEA_ENCRYPT )
136 {
137 uint32_t sum = 0, delta = 0x9E3779B9;
138
139 for( i = 0; i < 32; i++ )
140 {
141 v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
142 sum += delta;
143 v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
144 }
145 }
146 else /* MBEDTLS_XTEA_DECRYPT */
147 {
148 uint32_t delta = 0x9E3779B9, sum = delta * 32;
149
150 for( i = 0; i < 32; i++ )
151 {
152 v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
153 sum -= delta;
154 v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
155 }
156 }
157
158 PUT_UINT32_BE( v0, output, 0 );
159 PUT_UINT32_BE( v1, output, 4 );
160
161 return( 0 );
162 }
163
164 #if defined(MBEDTLS_CIPHER_MODE_CBC)
165 /*
166 * XTEA-CBC buffer encryption/decryption
167 */
mbedtls_xtea_crypt_cbc(mbedtls_xtea_context * ctx,int mode,size_t length,unsigned char iv[8],const unsigned char * input,unsigned char * output)168 int mbedtls_xtea_crypt_cbc( mbedtls_xtea_context *ctx, int mode, size_t length,
169 unsigned char iv[8], const unsigned char *input,
170 unsigned char *output)
171 {
172 int i;
173 unsigned char temp[8];
174
175 if( length % 8 )
176 return( MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH );
177
178 if( mode == MBEDTLS_XTEA_DECRYPT )
179 {
180 while( length > 0 )
181 {
182 memcpy( temp, input, 8 );
183 mbedtls_xtea_crypt_ecb( ctx, mode, input, output );
184
185 for( i = 0; i < 8; i++ )
186 output[i] = (unsigned char)( output[i] ^ iv[i] );
187
188 memcpy( iv, temp, 8 );
189
190 input += 8;
191 output += 8;
192 length -= 8;
193 }
194 }
195 else
196 {
197 while( length > 0 )
198 {
199 for( i = 0; i < 8; i++ )
200 output[i] = (unsigned char)( input[i] ^ iv[i] );
201
202 mbedtls_xtea_crypt_ecb( ctx, mode, output, output );
203 memcpy( iv, output, 8 );
204
205 input += 8;
206 output += 8;
207 length -= 8;
208 }
209 }
210
211 return( 0 );
212 }
213 #endif /* MBEDTLS_CIPHER_MODE_CBC */
214 #endif /* !MBEDTLS_XTEA_ALT */
215
216 #if defined(MBEDTLS_SELF_TEST)
217
218 /*
219 * XTEA tests vectors (non-official)
220 */
221
222 static const unsigned char xtea_test_key[6][16] =
223 {
224 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
225 0x0c, 0x0d, 0x0e, 0x0f },
226 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
227 0x0c, 0x0d, 0x0e, 0x0f },
228 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
229 0x0c, 0x0d, 0x0e, 0x0f },
230 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
231 0x00, 0x00, 0x00, 0x00 },
232 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
233 0x00, 0x00, 0x00, 0x00 },
234 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
235 0x00, 0x00, 0x00, 0x00 }
236 };
237
238 static const unsigned char xtea_test_pt[6][8] =
239 {
240 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
241 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
242 { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
243 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
244 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
245 { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }
246 };
247
248 static const unsigned char xtea_test_ct[6][8] =
249 {
250 { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 },
251 { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 },
252 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
253 { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 },
254 { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d },
255 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
256 };
257
258 /*
259 * Checkup routine
260 */
mbedtls_xtea_self_test(int verbose)261 int mbedtls_xtea_self_test( int verbose )
262 {
263 int i, ret = 0;
264 unsigned char buf[8];
265 mbedtls_xtea_context ctx;
266
267 mbedtls_xtea_init( &ctx );
268 for( i = 0; i < 6; i++ )
269 {
270 if( verbose != 0 )
271 mbedtls_printf( " XTEA test #%d: ", i + 1 );
272
273 memcpy( buf, xtea_test_pt[i], 8 );
274
275 mbedtls_xtea_setup( &ctx, xtea_test_key[i] );
276 mbedtls_xtea_crypt_ecb( &ctx, MBEDTLS_XTEA_ENCRYPT, buf, buf );
277
278 if( memcmp( buf, xtea_test_ct[i], 8 ) != 0 )
279 {
280 if( verbose != 0 )
281 mbedtls_printf( "failed\n" );
282
283 ret = 1;
284 goto exit;
285 }
286
287 if( verbose != 0 )
288 mbedtls_printf( "passed\n" );
289 }
290
291 if( verbose != 0 )
292 mbedtls_printf( "\n" );
293
294 exit:
295 mbedtls_xtea_free( &ctx );
296
297 return( ret );
298 }
299
300 #endif /* MBEDTLS_SELF_TEST */
301
302 #endif /* MBEDTLS_XTEA_C */
303