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     cipher_info = mbedtls_cipher_info_from_type( cipher_type );
138     if( cipher_info == NULL )
139         return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
140 
141     keylen = cipher_info->key_bitlen / 8;
142 
143     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, md_type, pwd, pwdlen,
144                                           key, keylen,
145                                           iv, cipher_info->iv_size ) ) != 0 )
146     {
147         return( ret );
148     }
149 
150     mbedtls_cipher_init( &cipher_ctx );
151 
152     if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info ) ) != 0 )
153         goto exit;
154 
155     if( ( ret = mbedtls_cipher_setkey( &cipher_ctx, key, 8 * keylen, (mbedtls_operation_t) mode ) ) != 0 )
156         goto exit;
157 
158     if( ( ret = mbedtls_cipher_set_iv( &cipher_ctx, iv, cipher_info->iv_size ) ) != 0 )
159         goto exit;
160 
161     if( ( ret = mbedtls_cipher_reset( &cipher_ctx ) ) != 0 )
162         goto exit;
163 
164     if( ( ret = mbedtls_cipher_update( &cipher_ctx, data, len,
165                                 output, &olen ) ) != 0 )
166     {
167         goto exit;
168     }
169 
170     if( ( ret = mbedtls_cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
171         ret = MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH;
172 
173 exit:
174     mbedtls_platform_zeroize( key, sizeof( key ) );
175     mbedtls_platform_zeroize( iv,  sizeof( iv  ) );
176     mbedtls_cipher_free( &cipher_ctx );
177 
178     return( ret );
179 }
180 
181 #endif /* MBEDTLS_ASN1_PARSE_C */
182 
pkcs12_fill_buffer(unsigned char * data,size_t data_len,const unsigned char * filler,size_t fill_len)183 static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
184                                 const unsigned char *filler, size_t fill_len )
185 {
186     unsigned char *p = data;
187     size_t use_len;
188 
189     while( data_len > 0 )
190     {
191         use_len = ( data_len > fill_len ) ? fill_len : data_len;
192         memcpy( p, filler, use_len );
193         p += use_len;
194         data_len -= use_len;
195     }
196 }
197 
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)198 int mbedtls_pkcs12_derivation( unsigned char *data, size_t datalen,
199                        const unsigned char *pwd, size_t pwdlen,
200                        const unsigned char *salt, size_t saltlen,
201                        mbedtls_md_type_t md_type, int id, int iterations )
202 {
203     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
204     unsigned int j;
205 
206     unsigned char diversifier[128];
207     unsigned char salt_block[128], pwd_block[128], hash_block[128];
208     unsigned char hash_output[MBEDTLS_MD_MAX_SIZE];
209     unsigned char *p;
210     unsigned char c;
211 
212     size_t hlen, use_len, v, i;
213 
214     const mbedtls_md_info_t *md_info;
215     mbedtls_md_context_t md_ctx;
216 
217     // This version only allows max of 64 bytes of password or salt
218     if( datalen > 128 || pwdlen > 64 || saltlen > 64 )
219         return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
220 
221     md_info = mbedtls_md_info_from_type( md_type );
222     if( md_info == NULL )
223         return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
224 
225     mbedtls_md_init( &md_ctx );
226 
227     if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
228         return( ret );
229     hlen = mbedtls_md_get_size( md_info );
230 
231     if( hlen <= 32 )
232         v = 64;
233     else
234         v = 128;
235 
236     memset( diversifier, (unsigned char) id, v );
237 
238     pkcs12_fill_buffer( salt_block, v, salt, saltlen );
239     pkcs12_fill_buffer( pwd_block,  v, pwd,  pwdlen  );
240 
241     p = data;
242     while( datalen > 0 )
243     {
244         // Calculate hash( diversifier || salt_block || pwd_block )
245         if( ( ret = mbedtls_md_starts( &md_ctx ) ) != 0 )
246             goto exit;
247 
248         if( ( ret = mbedtls_md_update( &md_ctx, diversifier, v ) ) != 0 )
249             goto exit;
250 
251         if( ( ret = mbedtls_md_update( &md_ctx, salt_block, v ) ) != 0 )
252             goto exit;
253 
254         if( ( ret = mbedtls_md_update( &md_ctx, pwd_block, v ) ) != 0 )
255             goto exit;
256 
257         if( ( ret = mbedtls_md_finish( &md_ctx, hash_output ) ) != 0 )
258             goto exit;
259 
260         // Perform remaining ( iterations - 1 ) recursive hash calculations
261         for( i = 1; i < (size_t) iterations; i++ )
262         {
263             if( ( ret = mbedtls_md( md_info, hash_output, hlen, hash_output ) ) != 0 )
264                 goto exit;
265         }
266 
267         use_len = ( datalen > hlen ) ? hlen : datalen;
268         memcpy( p, hash_output, use_len );
269         datalen -= use_len;
270         p += use_len;
271 
272         if( datalen == 0 )
273             break;
274 
275         // Concatenating copies of hash_output into hash_block (B)
276         pkcs12_fill_buffer( hash_block, v, hash_output, hlen );
277 
278         // B += 1
279         for( i = v; i > 0; i-- )
280             if( ++hash_block[i - 1] != 0 )
281                 break;
282 
283         // salt_block += B
284         c = 0;
285         for( i = v; i > 0; i-- )
286         {
287             j = salt_block[i - 1] + hash_block[i - 1] + c;
288             c = MBEDTLS_BYTE_1( j );
289             salt_block[i - 1] = MBEDTLS_BYTE_0( j );
290         }
291 
292         // pwd_block  += B
293         c = 0;
294         for( i = v; i > 0; i-- )
295         {
296             j = pwd_block[i - 1] + hash_block[i - 1] + c;
297             c = MBEDTLS_BYTE_1( j );
298             pwd_block[i - 1] = MBEDTLS_BYTE_0( j );
299         }
300     }
301 
302     ret = 0;
303 
304 exit:
305     mbedtls_platform_zeroize( salt_block, sizeof( salt_block ) );
306     mbedtls_platform_zeroize( pwd_block, sizeof( pwd_block ) );
307     mbedtls_platform_zeroize( hash_block, sizeof( hash_block ) );
308     mbedtls_platform_zeroize( hash_output, sizeof( hash_output ) );
309 
310     mbedtls_md_free( &md_ctx );
311 
312     return( ret );
313 }
314 
315 #endif /* MBEDTLS_PKCS12_C */
316