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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2  *
3  * LibTomCrypt is a library that provides various cryptographic
4  * algorithms in a highly modular and flexible manner.
5  *
6  * The library is free for all purposes without any express
7  * guarantee it works.
8  *
9  * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
10  */
11 #include "tomcrypt.h"
12 #include <stdarg.h>
13 
14 
15 /**
16   @file der_decode_sequence_ex.c
17   ASN.1 DER, decode a SEQUENCE, Tom St Denis
18 */
19 
20 #ifdef LTC_DER
21 
22 /**
23    Decode a SEQUENCE
24    @param in       The DER encoded input
25    @param inlen    The size of the input
26    @param list     The list of items to decode
27    @param outlen   The number of items in the list
28    @param ordered  Search an unordeded or ordered list
29    @return CRYPT_OK on success
30 */
der_decode_sequence_ex(const unsigned char * in,unsigned long inlen,ltc_asn1_list * list,unsigned long outlen,int ordered)31 int der_decode_sequence_ex(const unsigned char *in, unsigned long  inlen,
32                            ltc_asn1_list *list,     unsigned long  outlen, int ordered)
33 {
34    int           err, type;
35    unsigned long size, x, y, z, i, blksize;
36    void          *data;
37 
38    LTC_ARGCHK(in   != NULL);
39    LTC_ARGCHK(list != NULL);
40 
41    /* get blk size */
42    if (inlen < 2) {
43       return CRYPT_INVALID_PACKET;
44    }
45 
46    /* sequence type? We allow 0x30 SEQUENCE and 0x31 SET since fundamentally they're the same structure */
47    x = 0;
48    if (in[x] != 0x30 && in[x] != 0x31) {
49       return CRYPT_INVALID_PACKET;
50    }
51    ++x;
52 
53    if (in[x] < 128) {
54       blksize = in[x++];
55    } else if (in[x] & 0x80) {
56       if (in[x] < 0x81 || in[x] > 0x83) {
57          return CRYPT_INVALID_PACKET;
58       }
59       y = in[x++] & 0x7F;
60 
61       /* would reading the len bytes overrun? */
62       if (x + y > inlen) {
63          return CRYPT_INVALID_PACKET;
64       }
65 
66       /* read len */
67       blksize = 0;
68       while (y--) {
69           blksize = (blksize << 8) | (unsigned long)in[x++];
70       }
71   }
72 
73   /* would this blksize overflow? */
74   if (x + blksize > inlen) {
75      return CRYPT_INVALID_PACKET;
76   }
77 
78    /* mark all as unused */
79    for (i = 0; i < outlen; i++) {
80        list[i].used = 0;
81    }
82 
83   /* ok read data */
84    inlen = blksize;
85    for (i = 0; i < outlen; i++) {
86        z    = 0;
87        type = list[i].type;
88        size = list[i].size;
89        data = list[i].data;
90        if (!ordered && list[i].used == 1) { continue; }
91 
92        if (type == LTC_ASN1_EOL) {
93           break;
94        }
95 
96        switch (type) {
97            case LTC_ASN1_BOOLEAN:
98                z = inlen;
99                if ((err = der_decode_boolean(in + x, z, ((int *)data))) != CRYPT_OK) {
100                    goto LBL_ERR;
101                }
102                if ((err = der_length_boolean(&z)) != CRYPT_OK) {
103                    goto LBL_ERR;
104                 }
105                 break;
106 
107            case LTC_ASN1_INTEGER:
108                z = inlen;
109                if ((err = der_decode_integer(in + x, z, data)) != CRYPT_OK) {
110                   if (!ordered) {  continue; }
111                   goto LBL_ERR;
112                }
113                if ((err = der_length_integer(data, &z)) != CRYPT_OK) {
114                   goto LBL_ERR;
115                }
116                break;
117 
118            case LTC_ASN1_SHORT_INTEGER:
119                z = inlen;
120                if ((err = der_decode_short_integer(in + x, z, data)) != CRYPT_OK) {
121                   if (!ordered) { continue; }
122                   goto LBL_ERR;
123                }
124                if ((err = der_length_short_integer(((unsigned long*)data)[0], &z)) != CRYPT_OK) {
125                   goto LBL_ERR;
126                }
127 
128                break;
129 
130            case LTC_ASN1_BIT_STRING:
131                z = inlen;
132                if ((err = der_decode_bit_string(in + x, z, data, &size)) != CRYPT_OK) {
133                   if (!ordered) { continue; }
134                   goto LBL_ERR;
135                }
136                list[i].size = size;
137                if ((err = der_length_bit_string(size, &z)) != CRYPT_OK) {
138                   goto LBL_ERR;
139                }
140                break;
141 
142            case LTC_ASN1_OCTET_STRING:
143                z = inlen;
144                if ((err = der_decode_octet_string(in + x, z, data, &size)) != CRYPT_OK) {
145                   if (!ordered) { continue; }
146                   goto LBL_ERR;
147                }
148                list[i].size = size;
149                if ((err = der_length_octet_string(size, &z)) != CRYPT_OK) {
150                   goto LBL_ERR;
151                }
152                break;
153 
154            case LTC_ASN1_NULL:
155                if (inlen < 2 || in[x] != 0x05 || in[x+1] != 0x00) {
156                   if (!ordered) { continue; }
157                   err = CRYPT_INVALID_PACKET;
158                   goto LBL_ERR;
159                }
160                z = 2;
161                break;
162 
163            case LTC_ASN1_OBJECT_IDENTIFIER:
164                z = inlen;
165                if ((err = der_decode_object_identifier(in + x, z, data, &size)) != CRYPT_OK) {
166                   if (!ordered) { continue; }
167                   goto LBL_ERR;
168                }
169                list[i].size = size;
170                if ((err = der_length_object_identifier(data, size, &z)) != CRYPT_OK) {
171                   goto LBL_ERR;
172                }
173                break;
174 
175            case LTC_ASN1_IA5_STRING:
176                z = inlen;
177                if ((err = der_decode_ia5_string(in + x, z, data, &size)) != CRYPT_OK) {
178                   if (!ordered) { continue; }
179                   goto LBL_ERR;
180                }
181                list[i].size = size;
182                if ((err = der_length_ia5_string(data, size, &z)) != CRYPT_OK) {
183                   goto LBL_ERR;
184                }
185                break;
186 
187 
188            case LTC_ASN1_PRINTABLE_STRING:
189                z = inlen;
190                if ((err = der_decode_printable_string(in + x, z, data, &size)) != CRYPT_OK) {
191                   if (!ordered) { continue; }
192                   goto LBL_ERR;
193                }
194                list[i].size = size;
195                if ((err = der_length_printable_string(data, size, &z)) != CRYPT_OK) {
196                   goto LBL_ERR;
197                }
198                break;
199 
200            case LTC_ASN1_UTF8_STRING:
201                z = inlen;
202                if ((err = der_decode_utf8_string(in + x, z, data, &size)) != CRYPT_OK) {
203                   if (!ordered) { continue; }
204                   goto LBL_ERR;
205                }
206                list[i].size = size;
207                if ((err = der_length_utf8_string(data, size, &z)) != CRYPT_OK) {
208                   goto LBL_ERR;
209                }
210                break;
211 
212            case LTC_ASN1_UTCTIME:
213                z = inlen;
214                if ((err = der_decode_utctime(in + x, &z, data)) != CRYPT_OK) {
215                   if (!ordered) { continue; }
216                   goto LBL_ERR;
217                }
218                break;
219 
220            case LTC_ASN1_SET:
221                z = inlen;
222                if ((err = der_decode_set(in + x, z, data, size)) != CRYPT_OK) {
223                   if (!ordered) { continue; }
224                   goto LBL_ERR;
225                }
226                if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
227                   goto LBL_ERR;
228                }
229                break;
230 
231            case LTC_ASN1_SETOF:
232            case LTC_ASN1_SEQUENCE:
233                /* detect if we have the right type */
234                if ((type == LTC_ASN1_SETOF && (in[x] & 0x3F) != 0x31) || (type == LTC_ASN1_SEQUENCE && (in[x] & 0x3F) != 0x30)) {
235                   err = CRYPT_INVALID_PACKET;
236                   goto LBL_ERR;
237                }
238 
239                z = inlen;
240                if ((err = der_decode_sequence(in + x, z, data, size)) != CRYPT_OK) {
241                   if (!ordered) { continue; }
242                   goto LBL_ERR;
243                }
244                if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
245                   goto LBL_ERR;
246                }
247                break;
248 
249 
250            case LTC_ASN1_CHOICE:
251                z = inlen;
252                if ((err = der_decode_choice(in + x, &z, data, size)) != CRYPT_OK) {
253                   if (!ordered) { continue; }
254                   goto LBL_ERR;
255                }
256                break;
257 
258            default:
259                err = CRYPT_INVALID_ARG;
260                goto LBL_ERR;
261        }
262        x           += z;
263        inlen       -= z;
264        list[i].used = 1;
265        if (!ordered) {
266           /* restart the decoder */
267           i = -1;
268        }
269    }
270 
271    for (i = 0; i < outlen; i++) {
272       if (list[i].used == 0) {
273           err = CRYPT_INVALID_PACKET;
274           goto LBL_ERR;
275       }
276    }
277    err = CRYPT_OK;
278 
279 LBL_ERR:
280    return err;
281 }
282 
283 #endif
284 
285 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_ex.c,v $ */
286 /* $Revision: 1.15 $ */
287 /* $Date: 2006/11/26 02:25:18 $ */
288