1 /*
2  *  PKCS#12 Personal Information Exchange Syntax
3  *
4  *  Copyright The Mbed TLS Contributors
5  *  SPDX-License-Identifier: Apache-2.0
6  *
7  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
8  *  not use this file except in compliance with the License.
9  *  You may obtain a copy of the License at
10  *
11  *  http://www.apache.org/licenses/LICENSE-2.0
12  *
13  *  Unless required by applicable law or agreed to in writing, software
14  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  *  See the License for the specific language governing permissions and
17  *  limitations under the License.
18  */
19 /*
20  *  The PKCS #12 Personal Information Exchange Syntax Standard v1.1
21  *
22  *  http://www.rsa.com/rsalabs/pkcs/files/h11301-wp-pkcs-12v1-1-personal-information-exchange-syntax.pdf
23  *  ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1-1.asn
24  */
25 
26 #include "common.h"
27 
28 #if defined(MBEDTLS_PKCS12_C)
29 
30 #include "mbedtls/pkcs12.h"
31 #include "mbedtls/asn1.h"
32 #include "mbedtls/cipher.h"
33 #include "mbedtls/platform_util.h"
34 #include "mbedtls/error.h"
35 
36 #include <string.h>
37 
38 #if defined(MBEDTLS_ARC4_C)
39 #include "mbedtls/arc4.h"
40 #endif
41 
42 #if defined(MBEDTLS_DES_C)
43 #include "mbedtls/des.h"
44 #endif
45 
46 #if defined(MBEDTLS_ASN1_PARSE_C)
47 
pkcs12_parse_pbe_params(mbedtls_asn1_buf * params,mbedtls_asn1_buf * salt,int * iterations)48 static int pkcs12_parse_pbe_params( mbedtls_asn1_buf *params,
49                                     mbedtls_asn1_buf *salt, int *iterations )
50 {
51     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
52     unsigned char **p = &params->p;
53     const unsigned char *end = params->p + params->len;
54 
55     /*
56      *  pkcs-12PbeParams ::= SEQUENCE {
57      *    salt          OCTET STRING,
58      *    iterations    INTEGER
59      *  }
60      *
61      */
62     if( params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
63         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT,
64                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
65 
66     if( ( ret = mbedtls_asn1_get_tag( p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
67         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT, ret ) );
68 
69     salt->p = *p;
70     *p += salt->len;
71 
72     if( ( ret = mbedtls_asn1_get_int( p, end, iterations ) ) != 0 )
73         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT, ret ) );
74 
75     if( *p != end )
76         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT,
77                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
78 
79     return( 0 );
80 }
81 
82 #define PKCS12_MAX_PWDLEN 128
83 
pkcs12_pbe_derive_key_iv(mbedtls_asn1_buf * pbe_params,mbedtls_md_type_t md_type,const unsigned char * pwd,size_t pwdlen,unsigned char * key,size_t keylen,unsigned char * iv,size_t ivlen)84 static int pkcs12_pbe_derive_key_iv( mbedtls_asn1_buf *pbe_params, mbedtls_md_type_t md_type,
85                                      const unsigned char *pwd,  size_t pwdlen,
86                                      unsigned char *key, size_t keylen,
87                                      unsigned char *iv,  size_t ivlen )
88 {
89     int ret, iterations = 0;
90     mbedtls_asn1_buf salt;
91     size_t i;
92     unsigned char unipwd[PKCS12_MAX_PWDLEN * 2 + 2];
93 
94     if( pwdlen > PKCS12_MAX_PWDLEN )
95         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
96 
97     memset( &salt, 0, sizeof(mbedtls_asn1_buf) );
98     memset( &unipwd, 0, sizeof(unipwd) );
99 
100     if( ( ret = pkcs12_parse_pbe_params( pbe_params, &salt,
101                                          &iterations ) ) != 0 )
102         return( ret );
103 
104     for( i = 0; i < pwdlen; i++ )
105         unipwd[i * 2 + 1] = pwd[i];
106 
107     if( ( ret = mbedtls_pkcs12_derivation( key, keylen, unipwd, pwdlen * 2 + 2,
108                                    salt.p, salt.len, md_type,
109                                    MBEDTLS_PKCS12_DERIVE_KEY, iterations ) ) != 0 )
110     {
111         return( ret );
112     }
113 
114     if( iv == NULL || ivlen == 0 )
115         return( 0 );
116 
117     if( ( ret = mbedtls_pkcs12_derivation( iv, ivlen, unipwd, pwdlen * 2 + 2,
118                                    salt.p, salt.len, md_type,
119                                    MBEDTLS_PKCS12_DERIVE_IV, iterations ) ) != 0 )
120     {
121         return( ret );
122     }
123     return( 0 );
124 }
125 
126 #undef PKCS12_MAX_PWDLEN
127 
mbedtls_pkcs12_pbe_sha1_rc4_128(mbedtls_asn1_buf * pbe_params,int mode,const unsigned char * pwd,size_t pwdlen,const unsigned char * data,size_t len,unsigned char * output)128 int mbedtls_pkcs12_pbe_sha1_rc4_128( mbedtls_asn1_buf *pbe_params, int mode,
129                              const unsigned char *pwd,  size_t pwdlen,
130                              const unsigned char *data, size_t len,
131                              unsigned char *output )
132 {
133 #if !defined(MBEDTLS_ARC4_C)
134     ((void) pbe_params);
135     ((void) mode);
136     ((void) pwd);
137     ((void) pwdlen);
138     ((void) data);
139     ((void) len);
140     ((void) output);
141     return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
142 #else
143     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
144     unsigned char key[16];
145     mbedtls_arc4_context ctx;
146     ((void) mode);
147 
148     mbedtls_arc4_init( &ctx );
149 
150     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, MBEDTLS_MD_SHA1,
151                                           pwd, pwdlen,
152                                           key, 16, NULL, 0 ) ) != 0 )
153     {
154         return( ret );
155     }
156 
157     mbedtls_arc4_setup( &ctx, key, 16 );
158     if( ( ret = mbedtls_arc4_crypt( &ctx, len, data, output ) ) != 0 )
159         goto exit;
160 
161 exit:
162     mbedtls_platform_zeroize( key, sizeof( key ) );
163     mbedtls_arc4_free( &ctx );
164 
165     return( ret );
166 #endif /* MBEDTLS_ARC4_C */
167 }
168 
mbedtls_pkcs12_pbe(mbedtls_asn1_buf * pbe_params,int mode,mbedtls_cipher_type_t cipher_type,mbedtls_md_type_t md_type,const unsigned char * pwd,size_t pwdlen,const unsigned char * data,size_t len,unsigned char * output)169 int mbedtls_pkcs12_pbe( mbedtls_asn1_buf *pbe_params, int mode,
170                 mbedtls_cipher_type_t cipher_type, mbedtls_md_type_t md_type,
171                 const unsigned char *pwd,  size_t pwdlen,
172                 const unsigned char *data, size_t len,
173                 unsigned char *output )
174 {
175     int ret, keylen = 0;
176     unsigned char key[32];
177     unsigned char iv[16];
178     const mbedtls_cipher_info_t *cipher_info;
179     mbedtls_cipher_context_t cipher_ctx;
180     size_t olen = 0;
181 
182     if( pwd == NULL && pwdlen != 0 )
183         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
184 
185     cipher_info = mbedtls_cipher_info_from_type( cipher_type );
186     if( cipher_info == NULL )
187         return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
188 
189     keylen = cipher_info->key_bitlen / 8;
190 
191     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, md_type, pwd, pwdlen,
192                                           key, keylen,
193                                           iv, cipher_info->iv_size ) ) != 0 )
194     {
195         return( ret );
196     }
197 
198     mbedtls_cipher_init( &cipher_ctx );
199 
200     if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info ) ) != 0 )
201         goto exit;
202 
203     if( ( ret = mbedtls_cipher_setkey( &cipher_ctx, key, 8 * keylen, (mbedtls_operation_t) mode ) ) != 0 )
204         goto exit;
205 
206     if( ( ret = mbedtls_cipher_set_iv( &cipher_ctx, iv, cipher_info->iv_size ) ) != 0 )
207         goto exit;
208 
209     if( ( ret = mbedtls_cipher_reset( &cipher_ctx ) ) != 0 )
210         goto exit;
211 
212     if( ( ret = mbedtls_cipher_update( &cipher_ctx, data, len,
213                                 output, &olen ) ) != 0 )
214     {
215         goto exit;
216     }
217 
218     if( ( ret = mbedtls_cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
219         ret = MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH;
220 
221 exit:
222     mbedtls_platform_zeroize( key, sizeof( key ) );
223     mbedtls_platform_zeroize( iv,  sizeof( iv  ) );
224     mbedtls_cipher_free( &cipher_ctx );
225 
226     return( ret );
227 }
228 
229 #endif /* MBEDTLS_ASN1_PARSE_C */
230 
pkcs12_fill_buffer(unsigned char * data,size_t data_len,const unsigned char * filler,size_t fill_len)231 static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
232                                 const unsigned char *filler, size_t fill_len )
233 {
234     unsigned char *p = data;
235     size_t use_len;
236 
237     if( filler != NULL && fill_len != 0 )
238     {
239         while( data_len > 0 )
240         {
241             use_len = ( data_len > fill_len ) ? fill_len : data_len;
242             memcpy( p, filler, use_len );
243             p += use_len;
244             data_len -= use_len;
245         }
246     }
247     else
248     {
249         /* If either of the above are not true then clearly there is nothing
250          * that this function can do. The function should *not* be called
251          * under either of those circumstances, as you could end up with an
252          * incorrect output but for safety's sake, leaving the check in as
253          * otherwise we could end up with memory corruption.*/
254     }
255 }
256 
mbedtls_pkcs12_derivation(unsigned char * data,size_t datalen,const unsigned char * pwd,size_t pwdlen,const unsigned char * salt,size_t saltlen,mbedtls_md_type_t md_type,int id,int iterations)257 int mbedtls_pkcs12_derivation( unsigned char *data, size_t datalen,
258                        const unsigned char *pwd, size_t pwdlen,
259                        const unsigned char *salt, size_t saltlen,
260                        mbedtls_md_type_t md_type, int id, int iterations )
261 {
262     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
263     unsigned int j;
264 
265     unsigned char diversifier[128];
266     unsigned char salt_block[128], pwd_block[128], hash_block[128];
267     unsigned char hash_output[MBEDTLS_MD_MAX_SIZE];
268     unsigned char *p;
269     unsigned char c;
270     int           use_password = 0;
271     int           use_salt = 0;
272 
273     size_t hlen, use_len, v, i;
274 
275     const mbedtls_md_info_t *md_info;
276     mbedtls_md_context_t md_ctx;
277 
278     // This version only allows max of 64 bytes of password or salt
279     if( datalen > 128 || pwdlen > 64 || saltlen > 64 )
280         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
281 
282     if( pwd == NULL && pwdlen != 0 )
283         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
284 
285     if( salt == NULL && saltlen != 0 )
286         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
287 
288     use_password = ( pwd && pwdlen != 0 );
289     use_salt = ( salt && saltlen != 0 );
290 
291     md_info = mbedtls_md_info_from_type( md_type );
292     if( md_info == NULL )
293         return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
294 
295     mbedtls_md_init( &md_ctx );
296 
297     if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
298         return( ret );
299     hlen = mbedtls_md_get_size( md_info );
300 
301     if( hlen <= 32 )
302         v = 64;
303     else
304         v = 128;
305 
306     memset( diversifier, (unsigned char) id, v );
307 
308     if( use_salt != 0 )
309     {
310         pkcs12_fill_buffer( salt_block, v, salt, saltlen );
311     }
312 
313     if( use_password != 0 )
314     {
315         pkcs12_fill_buffer( pwd_block,  v, pwd,  pwdlen  );
316     }
317 
318     p = data;
319     while( datalen > 0 )
320     {
321         // Calculate hash( diversifier || salt_block || pwd_block )
322         if( ( ret = mbedtls_md_starts( &md_ctx ) ) != 0 )
323             goto exit;
324 
325         if( ( ret = mbedtls_md_update( &md_ctx, diversifier, v ) ) != 0 )
326             goto exit;
327 
328         if( use_salt != 0 )
329         {
330             if( ( ret = mbedtls_md_update( &md_ctx, salt_block, v )) != 0 )
331                 goto exit;
332         }
333 
334         if( use_password != 0)
335         {
336             if( ( ret = mbedtls_md_update( &md_ctx, pwd_block, v )) != 0 )
337                 goto exit;
338         }
339 
340         if( ( ret = mbedtls_md_finish( &md_ctx, hash_output ) ) != 0 )
341             goto exit;
342 
343         // Perform remaining ( iterations - 1 ) recursive hash calculations
344         for( i = 1; i < (size_t) iterations; i++ )
345         {
346             if( ( ret = mbedtls_md( md_info, hash_output, hlen, hash_output ) ) != 0 )
347                 goto exit;
348         }
349 
350         use_len = ( datalen > hlen ) ? hlen : datalen;
351         memcpy( p, hash_output, use_len );
352         datalen -= use_len;
353         p += use_len;
354 
355         if( datalen == 0 )
356             break;
357 
358         // Concatenating copies of hash_output into hash_block (B)
359         pkcs12_fill_buffer( hash_block, v, hash_output, hlen );
360 
361         // B += 1
362         for( i = v; i > 0; i-- )
363             if( ++hash_block[i - 1] != 0 )
364                 break;
365 
366         if( use_salt != 0 )
367         {
368             // salt_block += B
369             c = 0;
370             for( i = v; i > 0; i-- )
371             {
372                 j = salt_block[i - 1] + hash_block[i - 1] + c;
373                 c = MBEDTLS_BYTE_1( j );
374                 salt_block[i - 1] = MBEDTLS_BYTE_0( j );
375             }
376         }
377 
378         if( use_password != 0 )
379         {
380             // pwd_block  += B
381             c = 0;
382             for( i = v; i > 0; i-- )
383             {
384                 j = pwd_block[i - 1] + hash_block[i - 1] + c;
385                 c = MBEDTLS_BYTE_1( j );
386                 pwd_block[i - 1] = MBEDTLS_BYTE_0( j );
387             }
388         }
389     }
390 
391     ret = 0;
392 
393 exit:
394     mbedtls_platform_zeroize( salt_block, sizeof( salt_block ) );
395     mbedtls_platform_zeroize( pwd_block, sizeof( pwd_block ) );
396     mbedtls_platform_zeroize( hash_block, sizeof( hash_block ) );
397     mbedtls_platform_zeroize( hash_output, sizeof( hash_output ) );
398 
399     mbedtls_md_free( &md_ctx );
400 
401     return( ret );
402 }
403 
404 #endif /* MBEDTLS_PKCS12_C */
405