• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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_DES_C)
39 #include "mbedtls/des.h"
40 #endif
41 
42 #if defined(MBEDTLS_ASN1_PARSE_C)
43 
pkcs12_parse_pbe_params(mbedtls_asn1_buf * params,mbedtls_asn1_buf * salt,int * iterations)44 static int pkcs12_parse_pbe_params( mbedtls_asn1_buf *params,
45                                     mbedtls_asn1_buf *salt, int *iterations )
46 {
47     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
48     unsigned char **p = &params->p;
49     const unsigned char *end = params->p + params->len;
50 
51     /*
52      *  pkcs-12PbeParams ::= SEQUENCE {
53      *    salt          OCTET STRING,
54      *    iterations    INTEGER
55      *  }
56      *
57      */
58     if( params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
59         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT,
60                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
61 
62     if( ( ret = mbedtls_asn1_get_tag( p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
63         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT, ret ) );
64 
65     salt->p = *p;
66     *p += salt->len;
67 
68     if( ( ret = mbedtls_asn1_get_int( p, end, iterations ) ) != 0 )
69         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT, ret ) );
70 
71     if( *p != end )
72         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT,
73                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
74 
75     return( 0 );
76 }
77 
78 #define PKCS12_MAX_PWDLEN 128
79 
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)80 static int pkcs12_pbe_derive_key_iv( mbedtls_asn1_buf *pbe_params, mbedtls_md_type_t md_type,
81                                      const unsigned char *pwd,  size_t pwdlen,
82                                      unsigned char *key, size_t keylen,
83                                      unsigned char *iv,  size_t ivlen )
84 {
85     int ret, iterations = 0;
86     mbedtls_asn1_buf salt;
87     size_t i;
88     unsigned char unipwd[PKCS12_MAX_PWDLEN * 2 + 2];
89 
90     if( pwdlen > PKCS12_MAX_PWDLEN )
91         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
92 
93     memset( &salt, 0, sizeof(mbedtls_asn1_buf) );
94     memset( &unipwd, 0, sizeof(unipwd) );
95 
96     if( ( ret = pkcs12_parse_pbe_params( pbe_params, &salt,
97                                          &iterations ) ) != 0 )
98         return( ret );
99 
100     for( i = 0; i < pwdlen; i++ )
101         unipwd[i * 2 + 1] = pwd[i];
102 
103     if( ( ret = mbedtls_pkcs12_derivation( key, keylen, unipwd, pwdlen * 2 + 2,
104                                    salt.p, salt.len, md_type,
105                                    MBEDTLS_PKCS12_DERIVE_KEY, iterations ) ) != 0 )
106     {
107         return( ret );
108     }
109 
110     if( iv == NULL || ivlen == 0 )
111         return( 0 );
112 
113     if( ( ret = mbedtls_pkcs12_derivation( iv, ivlen, unipwd, pwdlen * 2 + 2,
114                                    salt.p, salt.len, md_type,
115                                    MBEDTLS_PKCS12_DERIVE_IV, iterations ) ) != 0 )
116     {
117         return( ret );
118     }
119     return( 0 );
120 }
121 
122 #undef PKCS12_MAX_PWDLEN
123 
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)124 int mbedtls_pkcs12_pbe( mbedtls_asn1_buf *pbe_params, int mode,
125                 mbedtls_cipher_type_t cipher_type, mbedtls_md_type_t md_type,
126                 const unsigned char *pwd,  size_t pwdlen,
127                 const unsigned char *data, size_t len,
128                 unsigned char *output )
129 {
130     int ret, keylen = 0;
131     unsigned char key[32];
132     unsigned char iv[16];
133     const mbedtls_cipher_info_t *cipher_info;
134     mbedtls_cipher_context_t cipher_ctx;
135     size_t olen = 0;
136 
137     if( pwd == NULL && pwdlen != 0 )
138         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
139 
140     cipher_info = mbedtls_cipher_info_from_type( cipher_type );
141     if( cipher_info == NULL )
142         return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
143 
144     keylen = cipher_info->key_bitlen / 8;
145 
146     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, md_type, pwd, pwdlen,
147                                           key, keylen,
148                                           iv, cipher_info->iv_size ) ) != 0 )
149     {
150         return( ret );
151     }
152 
153     mbedtls_cipher_init( &cipher_ctx );
154 
155     if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info ) ) != 0 )
156         goto exit;
157 
158     if( ( ret = mbedtls_cipher_setkey( &cipher_ctx, key, 8 * keylen, (mbedtls_operation_t) mode ) ) != 0 )
159         goto exit;
160 
161     if( ( ret = mbedtls_cipher_set_iv( &cipher_ctx, iv, cipher_info->iv_size ) ) != 0 )
162         goto exit;
163 
164     if( ( ret = mbedtls_cipher_reset( &cipher_ctx ) ) != 0 )
165         goto exit;
166 
167     if( ( ret = mbedtls_cipher_update( &cipher_ctx, data, len,
168                                 output, &olen ) ) != 0 )
169     {
170         goto exit;
171     }
172 
173     if( ( ret = mbedtls_cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
174         ret = MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH;
175 
176 exit:
177     mbedtls_platform_zeroize( key, sizeof( key ) );
178     mbedtls_platform_zeroize( iv,  sizeof( iv  ) );
179     mbedtls_cipher_free( &cipher_ctx );
180 
181     return( ret );
182 }
183 
184 #endif /* MBEDTLS_ASN1_PARSE_C */
185 
pkcs12_fill_buffer(unsigned char * data,size_t data_len,const unsigned char * filler,size_t fill_len)186 static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
187                                 const unsigned char *filler, size_t fill_len )
188 {
189     unsigned char *p = data;
190     size_t use_len;
191 
192     if( filler != NULL && fill_len != 0 )
193     {
194         while( data_len > 0 )
195         {
196             use_len = ( data_len > fill_len ) ? fill_len : data_len;
197             memcpy( p, filler, use_len );
198             p += use_len;
199             data_len -= use_len;
200         }
201     }
202     else
203     {
204         /* If either of the above are not true then clearly there is nothing
205          * that this function can do. The function should *not* be called
206          * under either of those circumstances, as you could end up with an
207          * incorrect output but for safety's sake, leaving the check in as
208          * otherwise we could end up with memory corruption.*/
209     }
210 }
211 
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)212 int mbedtls_pkcs12_derivation( unsigned char *data, size_t datalen,
213                        const unsigned char *pwd, size_t pwdlen,
214                        const unsigned char *salt, size_t saltlen,
215                        mbedtls_md_type_t md_type, int id, int iterations )
216 {
217     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
218     unsigned int j;
219 
220     unsigned char diversifier[128];
221     unsigned char salt_block[128], pwd_block[128], hash_block[128];
222     unsigned char hash_output[MBEDTLS_MD_MAX_SIZE];
223     unsigned char *p;
224     unsigned char c;
225     int           use_password = 0;
226     int           use_salt = 0;
227 
228     size_t hlen, use_len, v, i;
229 
230     const mbedtls_md_info_t *md_info;
231     mbedtls_md_context_t md_ctx;
232 
233     // This version only allows max of 64 bytes of password or salt
234     if( datalen > 128 || pwdlen > 64 || saltlen > 64 )
235         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
236 
237     if( pwd == NULL && pwdlen != 0 )
238         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
239 
240     if( salt == NULL && saltlen != 0 )
241         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
242 
243     use_password = ( pwd && pwdlen != 0 );
244     use_salt = ( salt && saltlen != 0 );
245 
246     md_info = mbedtls_md_info_from_type( md_type );
247     if( md_info == NULL )
248         return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
249 
250     mbedtls_md_init( &md_ctx );
251 
252     if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
253         return( ret );
254     hlen = mbedtls_md_get_size( md_info );
255 
256     if( hlen <= 32 )
257         v = 64;
258     else
259         v = 128;
260 
261     memset( diversifier, (unsigned char) id, v );
262 
263     if( use_salt != 0 )
264     {
265         pkcs12_fill_buffer( salt_block, v, salt, saltlen );
266     }
267 
268     if( use_password != 0 )
269     {
270         pkcs12_fill_buffer( pwd_block,  v, pwd,  pwdlen  );
271     }
272 
273     p = data;
274     while( datalen > 0 )
275     {
276         // Calculate hash( diversifier || salt_block || pwd_block )
277         if( ( ret = mbedtls_md_starts( &md_ctx ) ) != 0 )
278             goto exit;
279 
280         if( ( ret = mbedtls_md_update( &md_ctx, diversifier, v ) ) != 0 )
281             goto exit;
282 
283         if( use_salt != 0 )
284         {
285             if( ( ret = mbedtls_md_update( &md_ctx, salt_block, v )) != 0 )
286                 goto exit;
287         }
288 
289         if( use_password != 0)
290         {
291             if( ( ret = mbedtls_md_update( &md_ctx, pwd_block, v )) != 0 )
292                 goto exit;
293         }
294 
295         if( ( ret = mbedtls_md_finish( &md_ctx, hash_output ) ) != 0 )
296             goto exit;
297 
298         // Perform remaining ( iterations - 1 ) recursive hash calculations
299         for( i = 1; i < (size_t) iterations; i++ )
300         {
301             if( ( ret = mbedtls_md( md_info, hash_output, hlen, hash_output ) ) != 0 )
302                 goto exit;
303         }
304 
305         use_len = ( datalen > hlen ) ? hlen : datalen;
306         memcpy( p, hash_output, use_len );
307         datalen -= use_len;
308         p += use_len;
309 
310         if( datalen == 0 )
311             break;
312 
313         // Concatenating copies of hash_output into hash_block (B)
314         pkcs12_fill_buffer( hash_block, v, hash_output, hlen );
315 
316         // B += 1
317         for( i = v; i > 0; i-- )
318             if( ++hash_block[i - 1] != 0 )
319                 break;
320 
321         if( use_salt != 0 )
322         {
323             // salt_block += B
324             c = 0;
325             for( i = v; i > 0; i-- )
326             {
327                 j = salt_block[i - 1] + hash_block[i - 1] + c;
328                 c = MBEDTLS_BYTE_1( j );
329                 salt_block[i - 1] = MBEDTLS_BYTE_0( j );
330             }
331         }
332 
333         if( use_password != 0 )
334         {
335             // pwd_block  += B
336             c = 0;
337             for( i = v; i > 0; i-- )
338             {
339                 j = pwd_block[i - 1] + hash_block[i - 1] + c;
340                 c = MBEDTLS_BYTE_1( j );
341                 pwd_block[i - 1] = MBEDTLS_BYTE_0( j );
342             }
343         }
344     }
345 
346     ret = 0;
347 
348 exit:
349     mbedtls_platform_zeroize( salt_block, sizeof( salt_block ) );
350     mbedtls_platform_zeroize( pwd_block, sizeof( pwd_block ) );
351     mbedtls_platform_zeroize( hash_block, sizeof( hash_block ) );
352     mbedtls_platform_zeroize( hash_output, sizeof( hash_output ) );
353 
354     mbedtls_md_free( &md_ctx );
355 
356     return( ret );
357 }
358 
359 #endif /* MBEDTLS_PKCS12_C */
360