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[proxmark3-svn] / common / mbedtls / pem.c
1 /*
2 * Privacy Enhanced Mail (PEM) decoding
3 *
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: GPL-2.0
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * This file is part of mbed TLS (https://tls.mbed.org)
22 */
23
24 #if !defined(MBEDTLS_CONFIG_FILE)
25 #include "mbedtls/config.h"
26 #else
27 #include MBEDTLS_CONFIG_FILE
28 #endif
29
30 #if defined(MBEDTLS_PEM_PARSE_C) || defined(MBEDTLS_PEM_WRITE_C)
31
32 #include "mbedtls/pem.h"
33 #include "mbedtls/base64.h"
34 #include "mbedtls/des.h"
35 #include "mbedtls/aes.h"
36 #include "mbedtls/md5.h"
37 #include "mbedtls/cipher.h"
38 #include "mbedtls/platform_util.h"
39
40 #include <string.h>
41
42 #if defined(MBEDTLS_PLATFORM_C)
43 #include "mbedtls/platform.h"
44 #else
45 #include <stdlib.h>
46 #define mbedtls_calloc calloc
47 #define mbedtls_free free
48 #endif
49
50 #if defined(MBEDTLS_PEM_PARSE_C)
51 void mbedtls_pem_init( mbedtls_pem_context *ctx )
52 {
53 memset( ctx, 0, sizeof( mbedtls_pem_context ) );
54 }
55
56 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
57 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
58 /*
59 * Read a 16-byte hex string and convert it to binary
60 */
61 static int pem_get_iv( const unsigned char *s, unsigned char *iv,
62 size_t iv_len )
63 {
64 size_t i, j, k;
65
66 memset( iv, 0, iv_len );
67
68 for( i = 0; i < iv_len * 2; i++, s++ )
69 {
70 if( *s >= '0' && *s <= '9' ) j = *s - '0'; else
71 if( *s >= 'A' && *s <= 'F' ) j = *s - '7'; else
72 if( *s >= 'a' && *s <= 'f' ) j = *s - 'W'; else
73 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
74
75 k = ( ( i & 1 ) != 0 ) ? j : j << 4;
76
77 iv[i >> 1] = (unsigned char)( iv[i >> 1] | k );
78 }
79
80 return( 0 );
81 }
82
83 static int pem_pbkdf1( unsigned char *key, size_t keylen,
84 unsigned char *iv,
85 const unsigned char *pwd, size_t pwdlen )
86 {
87 mbedtls_md5_context md5_ctx;
88 unsigned char md5sum[16];
89 size_t use_len;
90 int ret;
91
92 mbedtls_md5_init( &md5_ctx );
93
94 /*
95 * key[ 0..15] = MD5(pwd || IV)
96 */
97 if( ( ret = mbedtls_md5_starts_ret( &md5_ctx ) ) != 0 )
98 goto exit;
99 if( ( ret = mbedtls_md5_update_ret( &md5_ctx, pwd, pwdlen ) ) != 0 )
100 goto exit;
101 if( ( ret = mbedtls_md5_update_ret( &md5_ctx, iv, 8 ) ) != 0 )
102 goto exit;
103 if( ( ret = mbedtls_md5_finish_ret( &md5_ctx, md5sum ) ) != 0 )
104 goto exit;
105
106 if( keylen <= 16 )
107 {
108 memcpy( key, md5sum, keylen );
109 goto exit;
110 }
111
112 memcpy( key, md5sum, 16 );
113
114 /*
115 * key[16..23] = MD5(key[ 0..15] || pwd || IV])
116 */
117 if( ( ret = mbedtls_md5_starts_ret( &md5_ctx ) ) != 0 )
118 goto exit;
119 if( ( ret = mbedtls_md5_update_ret( &md5_ctx, md5sum, 16 ) ) != 0 )
120 goto exit;
121 if( ( ret = mbedtls_md5_update_ret( &md5_ctx, pwd, pwdlen ) ) != 0 )
122 goto exit;
123 if( ( ret = mbedtls_md5_update_ret( &md5_ctx, iv, 8 ) ) != 0 )
124 goto exit;
125 if( ( ret = mbedtls_md5_finish_ret( &md5_ctx, md5sum ) ) != 0 )
126 goto exit;
127
128 use_len = 16;
129 if( keylen < 32 )
130 use_len = keylen - 16;
131
132 memcpy( key + 16, md5sum, use_len );
133
134 exit:
135 mbedtls_md5_free( &md5_ctx );
136 mbedtls_platform_zeroize( md5sum, 16 );
137
138 return( ret );
139 }
140
141 #if defined(MBEDTLS_DES_C)
142 /*
143 * Decrypt with DES-CBC, using PBKDF1 for key derivation
144 */
145 static int pem_des_decrypt( unsigned char des_iv[8],
146 unsigned char *buf, size_t buflen,
147 const unsigned char *pwd, size_t pwdlen )
148 {
149 mbedtls_des_context des_ctx;
150 unsigned char des_key[8];
151 int ret;
152
153 mbedtls_des_init( &des_ctx );
154
155 if( ( ret = pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen ) ) != 0 )
156 goto exit;
157
158 if( ( ret = mbedtls_des_setkey_dec( &des_ctx, des_key ) ) != 0 )
159 goto exit;
160 ret = mbedtls_des_crypt_cbc( &des_ctx, MBEDTLS_DES_DECRYPT, buflen,
161 des_iv, buf, buf );
162
163 exit:
164 mbedtls_des_free( &des_ctx );
165 mbedtls_platform_zeroize( des_key, 8 );
166
167 return( ret );
168 }
169
170 /*
171 * Decrypt with 3DES-CBC, using PBKDF1 for key derivation
172 */
173 static int pem_des3_decrypt( unsigned char des3_iv[8],
174 unsigned char *buf, size_t buflen,
175 const unsigned char *pwd, size_t pwdlen )
176 {
177 mbedtls_des3_context des3_ctx;
178 unsigned char des3_key[24];
179 int ret;
180
181 mbedtls_des3_init( &des3_ctx );
182
183 if( ( ret = pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen ) ) != 0 )
184 goto exit;
185
186 if( ( ret = mbedtls_des3_set3key_dec( &des3_ctx, des3_key ) ) != 0 )
187 goto exit;
188 ret = mbedtls_des3_crypt_cbc( &des3_ctx, MBEDTLS_DES_DECRYPT, buflen,
189 des3_iv, buf, buf );
190
191 exit:
192 mbedtls_des3_free( &des3_ctx );
193 mbedtls_platform_zeroize( des3_key, 24 );
194
195 return( ret );
196 }
197 #endif /* MBEDTLS_DES_C */
198
199 #if defined(MBEDTLS_AES_C)
200 /*
201 * Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation
202 */
203 static int pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen,
204 unsigned char *buf, size_t buflen,
205 const unsigned char *pwd, size_t pwdlen )
206 {
207 mbedtls_aes_context aes_ctx;
208 unsigned char aes_key[32];
209 int ret;
210
211 mbedtls_aes_init( &aes_ctx );
212
213 if( ( ret = pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen ) ) != 0 )
214 goto exit;
215
216 if( ( ret = mbedtls_aes_setkey_dec( &aes_ctx, aes_key, keylen * 8 ) ) != 0 )
217 goto exit;
218 ret = mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_DECRYPT, buflen,
219 aes_iv, buf, buf );
220
221 exit:
222 mbedtls_aes_free( &aes_ctx );
223 mbedtls_platform_zeroize( aes_key, keylen );
224
225 return( ret );
226 }
227 #endif /* MBEDTLS_AES_C */
228
229 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
230 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
231
232 int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const char *footer,
233 const unsigned char *data, const unsigned char *pwd,
234 size_t pwdlen, size_t *use_len )
235 {
236 int ret, enc;
237 size_t len;
238 unsigned char *buf;
239 const unsigned char *s1, *s2, *end;
240 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
241 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
242 unsigned char pem_iv[16];
243 mbedtls_cipher_type_t enc_alg = MBEDTLS_CIPHER_NONE;
244 #else
245 ((void) pwd);
246 ((void) pwdlen);
247 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
248 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
249
250 if( ctx == NULL )
251 return( MBEDTLS_ERR_PEM_BAD_INPUT_DATA );
252
253 s1 = (unsigned char *) strstr( (const char *) data, header );
254
255 if( s1 == NULL )
256 return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
257
258 s2 = (unsigned char *) strstr( (const char *) data, footer );
259
260 if( s2 == NULL || s2 <= s1 )
261 return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
262
263 s1 += strlen( header );
264 if( *s1 == ' ' ) s1++;
265 if( *s1 == '\r' ) s1++;
266 if( *s1 == '\n' ) s1++;
267 else return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
268
269 end = s2;
270 end += strlen( footer );
271 if( *end == ' ' ) end++;
272 if( *end == '\r' ) end++;
273 if( *end == '\n' ) end++;
274 *use_len = end - data;
275
276 enc = 0;
277
278 if( s2 - s1 >= 22 && memcmp( s1, "Proc-Type: 4,ENCRYPTED", 22 ) == 0 )
279 {
280 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
281 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
282 enc++;
283
284 s1 += 22;
285 if( *s1 == '\r' ) s1++;
286 if( *s1 == '\n' ) s1++;
287 else return( MBEDTLS_ERR_PEM_INVALID_DATA );
288
289
290 #if defined(MBEDTLS_DES_C)
291 if( s2 - s1 >= 23 && memcmp( s1, "DEK-Info: DES-EDE3-CBC,", 23 ) == 0 )
292 {
293 enc_alg = MBEDTLS_CIPHER_DES_EDE3_CBC;
294
295 s1 += 23;
296 if( s2 - s1 < 16 || pem_get_iv( s1, pem_iv, 8 ) != 0 )
297 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
298
299 s1 += 16;
300 }
301 else if( s2 - s1 >= 18 && memcmp( s1, "DEK-Info: DES-CBC,", 18 ) == 0 )
302 {
303 enc_alg = MBEDTLS_CIPHER_DES_CBC;
304
305 s1 += 18;
306 if( s2 - s1 < 16 || pem_get_iv( s1, pem_iv, 8) != 0 )
307 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
308
309 s1 += 16;
310 }
311 #endif /* MBEDTLS_DES_C */
312
313 #if defined(MBEDTLS_AES_C)
314 if( s2 - s1 >= 14 && memcmp( s1, "DEK-Info: AES-", 14 ) == 0 )
315 {
316 if( s2 - s1 < 22 )
317 return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
318 else if( memcmp( s1, "DEK-Info: AES-128-CBC,", 22 ) == 0 )
319 enc_alg = MBEDTLS_CIPHER_AES_128_CBC;
320 else if( memcmp( s1, "DEK-Info: AES-192-CBC,", 22 ) == 0 )
321 enc_alg = MBEDTLS_CIPHER_AES_192_CBC;
322 else if( memcmp( s1, "DEK-Info: AES-256-CBC,", 22 ) == 0 )
323 enc_alg = MBEDTLS_CIPHER_AES_256_CBC;
324 else
325 return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
326
327 s1 += 22;
328 if( s2 - s1 < 32 || pem_get_iv( s1, pem_iv, 16 ) != 0 )
329 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
330
331 s1 += 32;
332 }
333 #endif /* MBEDTLS_AES_C */
334
335 if( enc_alg == MBEDTLS_CIPHER_NONE )
336 return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
337
338 if( *s1 == '\r' ) s1++;
339 if( *s1 == '\n' ) s1++;
340 else return( MBEDTLS_ERR_PEM_INVALID_DATA );
341 #else
342 return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
343 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
344 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
345 }
346
347 if( s1 >= s2 )
348 return( MBEDTLS_ERR_PEM_INVALID_DATA );
349
350 ret = mbedtls_base64_decode( NULL, 0, &len, s1, s2 - s1 );
351
352 if( ret == MBEDTLS_ERR_BASE64_INVALID_CHARACTER )
353 return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
354
355 if( ( buf = mbedtls_calloc( 1, len ) ) == NULL )
356 return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
357
358 if( ( ret = mbedtls_base64_decode( buf, len, &len, s1, s2 - s1 ) ) != 0 )
359 {
360 mbedtls_platform_zeroize( buf, len );
361 mbedtls_free( buf );
362 return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
363 }
364
365 if( enc != 0 )
366 {
367 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
368 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
369 if( pwd == NULL )
370 {
371 mbedtls_platform_zeroize( buf, len );
372 mbedtls_free( buf );
373 return( MBEDTLS_ERR_PEM_PASSWORD_REQUIRED );
374 }
375
376 ret = 0;
377
378 #if defined(MBEDTLS_DES_C)
379 if( enc_alg == MBEDTLS_CIPHER_DES_EDE3_CBC )
380 ret = pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen );
381 else if( enc_alg == MBEDTLS_CIPHER_DES_CBC )
382 ret = pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen );
383 #endif /* MBEDTLS_DES_C */
384
385 #if defined(MBEDTLS_AES_C)
386 if( enc_alg == MBEDTLS_CIPHER_AES_128_CBC )
387 ret = pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen );
388 else if( enc_alg == MBEDTLS_CIPHER_AES_192_CBC )
389 ret = pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen );
390 else if( enc_alg == MBEDTLS_CIPHER_AES_256_CBC )
391 ret = pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen );
392 #endif /* MBEDTLS_AES_C */
393
394 if( ret != 0 )
395 {
396 mbedtls_free( buf );
397 return( ret );
398 }
399
400 /*
401 * The result will be ASN.1 starting with a SEQUENCE tag, with 1 to 3
402 * length bytes (allow 4 to be sure) in all known use cases.
403 *
404 * Use that as a heuristic to try to detect password mismatches.
405 */
406 if( len <= 2 || buf[0] != 0x30 || buf[1] > 0x83 )
407 {
408 mbedtls_platform_zeroize( buf, len );
409 mbedtls_free( buf );
410 return( MBEDTLS_ERR_PEM_PASSWORD_MISMATCH );
411 }
412 #else
413 mbedtls_platform_zeroize( buf, len );
414 mbedtls_free( buf );
415 return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
416 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
417 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
418 }
419
420 ctx->buf = buf;
421 ctx->buflen = len;
422
423 return( 0 );
424 }
425
426 void mbedtls_pem_free( mbedtls_pem_context *ctx )
427 {
428 if( ctx->buf != NULL )
429 mbedtls_platform_zeroize( ctx->buf, ctx->buflen );
430 mbedtls_free( ctx->buf );
431 mbedtls_free( ctx->info );
432
433 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pem_context ) );
434 }
435 #endif /* MBEDTLS_PEM_PARSE_C */
436
437 #if defined(MBEDTLS_PEM_WRITE_C)
438 int mbedtls_pem_write_buffer( const char *header, const char *footer,
439 const unsigned char *der_data, size_t der_len,
440 unsigned char *buf, size_t buf_len, size_t *olen )
441 {
442 int ret;
443 unsigned char *encode_buf = NULL, *c, *p = buf;
444 size_t len = 0, use_len, add_len = 0;
445
446 mbedtls_base64_encode( NULL, 0, &use_len, der_data, der_len );
447 add_len = strlen( header ) + strlen( footer ) + ( use_len / 64 ) + 1;
448
449 if( use_len + add_len > buf_len )
450 {
451 *olen = use_len + add_len;
452 return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
453 }
454
455 if( use_len != 0 &&
456 ( ( encode_buf = mbedtls_calloc( 1, use_len ) ) == NULL ) )
457 return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
458
459 if( ( ret = mbedtls_base64_encode( encode_buf, use_len, &use_len, der_data,
460 der_len ) ) != 0 )
461 {
462 mbedtls_free( encode_buf );
463 return( ret );
464 }
465
466 memcpy( p, header, strlen( header ) );
467 p += strlen( header );
468 c = encode_buf;
469
470 while( use_len )
471 {
472 len = ( use_len > 64 ) ? 64 : use_len;
473 memcpy( p, c, len );
474 use_len -= len;
475 p += len;
476 c += len;
477 *p++ = '\n';
478 }
479
480 memcpy( p, footer, strlen( footer ) );
481 p += strlen( footer );
482
483 *p++ = '\0';
484 *olen = p - buf;
485
486 mbedtls_free( encode_buf );
487 return( 0 );
488 }
489 #endif /* MBEDTLS_PEM_WRITE_C */
490 #endif /* MBEDTLS_PEM_PARSE_C || MBEDTLS_PEM_WRITE_C */
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