Fix potential access of null pointer (pp)
[openssl.git] / crypto / x509 / x_crl.c
1 /*
2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9
10 #include <stdio.h>
11 #include "internal/cryptlib.h"
12 #include <openssl/asn1t.h>
13 #include <openssl/x509.h>
14 #include "internal/x509_int.h"
15 #include <openssl/x509v3.h>
16 #include "x509_lcl.h"
17
18 static int X509_REVOKED_cmp(const X509_REVOKED *const *a,
19                             const X509_REVOKED *const *b);
20 static void setup_idp(X509_CRL *crl, ISSUING_DIST_POINT *idp);
21
22 ASN1_SEQUENCE(X509_REVOKED) = {
23         ASN1_EMBED(X509_REVOKED,serialNumber, ASN1_INTEGER),
24         ASN1_SIMPLE(X509_REVOKED,revocationDate, ASN1_TIME),
25         ASN1_SEQUENCE_OF_OPT(X509_REVOKED,extensions, X509_EXTENSION)
26 } ASN1_SEQUENCE_END(X509_REVOKED)
27
28 static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r);
29 static int def_crl_lookup(X509_CRL *crl,
30                           X509_REVOKED **ret, ASN1_INTEGER *serial,
31                           X509_NAME *issuer);
32
33 static X509_CRL_METHOD int_crl_meth = {
34     0,
35     0, 0,
36     def_crl_lookup,
37     def_crl_verify
38 };
39
40 static const X509_CRL_METHOD *default_crl_method = &int_crl_meth;
41
42 /*
43  * The X509_CRL_INFO structure needs a bit of customisation. Since we cache
44  * the original encoding the signature wont be affected by reordering of the
45  * revoked field.
46  */
47 static int crl_inf_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
48                       void *exarg)
49 {
50     X509_CRL_INFO *a = (X509_CRL_INFO *)*pval;
51
52     if (!a || !a->revoked)
53         return 1;
54     switch (operation) {
55         /*
56          * Just set cmp function here. We don't sort because that would
57          * affect the output of X509_CRL_print().
58          */
59     case ASN1_OP_D2I_POST:
60         (void)sk_X509_REVOKED_set_cmp_func(a->revoked, X509_REVOKED_cmp);
61         break;
62     }
63     return 1;
64 }
65
66
67 ASN1_SEQUENCE_enc(X509_CRL_INFO, enc, crl_inf_cb) = {
68         ASN1_OPT(X509_CRL_INFO, version, ASN1_INTEGER),
69         ASN1_EMBED(X509_CRL_INFO, sig_alg, X509_ALGOR),
70         ASN1_SIMPLE(X509_CRL_INFO, issuer, X509_NAME),
71         ASN1_SIMPLE(X509_CRL_INFO, lastUpdate, ASN1_TIME),
72         ASN1_OPT(X509_CRL_INFO, nextUpdate, ASN1_TIME),
73         ASN1_SEQUENCE_OF_OPT(X509_CRL_INFO, revoked, X509_REVOKED),
74         ASN1_EXP_SEQUENCE_OF_OPT(X509_CRL_INFO, extensions, X509_EXTENSION, 0)
75 } ASN1_SEQUENCE_END_enc(X509_CRL_INFO, X509_CRL_INFO)
76
77 /*
78  * Set CRL entry issuer according to CRL certificate issuer extension. Check
79  * for unhandled critical CRL entry extensions.
80  */
81
82 static int crl_set_issuers(X509_CRL *crl)
83 {
84
85     int i, j;
86     GENERAL_NAMES *gens, *gtmp;
87     STACK_OF(X509_REVOKED) *revoked;
88
89     revoked = X509_CRL_get_REVOKED(crl);
90
91     gens = NULL;
92     for (i = 0; i < sk_X509_REVOKED_num(revoked); i++) {
93         X509_REVOKED *rev = sk_X509_REVOKED_value(revoked, i);
94         STACK_OF(X509_EXTENSION) *exts;
95         ASN1_ENUMERATED *reason;
96         X509_EXTENSION *ext;
97         gtmp = X509_REVOKED_get_ext_d2i(rev,
98                                         NID_certificate_issuer, &j, NULL);
99         if (!gtmp && (j != -1)) {
100             crl->flags |= EXFLAG_INVALID;
101             return 1;
102         }
103
104         if (gtmp) {
105             gens = gtmp;
106             if (!crl->issuers) {
107                 crl->issuers = sk_GENERAL_NAMES_new_null();
108                 if (!crl->issuers)
109                     return 0;
110             }
111             if (!sk_GENERAL_NAMES_push(crl->issuers, gtmp))
112                 return 0;
113         }
114         rev->issuer = gens;
115
116         reason = X509_REVOKED_get_ext_d2i(rev, NID_crl_reason, &j, NULL);
117         if (!reason && (j != -1)) {
118             crl->flags |= EXFLAG_INVALID;
119             return 1;
120         }
121
122         if (reason) {
123             rev->reason = ASN1_ENUMERATED_get(reason);
124             ASN1_ENUMERATED_free(reason);
125         } else
126             rev->reason = CRL_REASON_NONE;
127
128         /* Check for critical CRL entry extensions */
129
130         exts = rev->extensions;
131
132         for (j = 0; j < sk_X509_EXTENSION_num(exts); j++) {
133             ext = sk_X509_EXTENSION_value(exts, j);
134             if (X509_EXTENSION_get_critical(ext)) {
135                 if (OBJ_obj2nid(X509_EXTENSION_get_object(ext)) == NID_certificate_issuer)
136                     continue;
137                 crl->flags |= EXFLAG_CRITICAL;
138                 break;
139             }
140         }
141
142     }
143
144     return 1;
145
146 }
147
148 /*
149  * The X509_CRL structure needs a bit of customisation. Cache some extensions
150  * and hash of the whole CRL.
151  */
152 static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
153                   void *exarg)
154 {
155     X509_CRL *crl = (X509_CRL *)*pval;
156     STACK_OF(X509_EXTENSION) *exts;
157     X509_EXTENSION *ext;
158     int idx;
159
160     switch (operation) {
161     case ASN1_OP_NEW_POST:
162         crl->idp = NULL;
163         crl->akid = NULL;
164         crl->flags = 0;
165         crl->idp_flags = 0;
166         crl->idp_reasons = CRLDP_ALL_REASONS;
167         crl->meth = default_crl_method;
168         crl->meth_data = NULL;
169         crl->issuers = NULL;
170         crl->crl_number = NULL;
171         crl->base_crl_number = NULL;
172         break;
173
174     case ASN1_OP_D2I_POST:
175         X509_CRL_digest(crl, EVP_sha1(), crl->sha1_hash, NULL);
176         crl->idp = X509_CRL_get_ext_d2i(crl,
177                                         NID_issuing_distribution_point, NULL,
178                                         NULL);
179         if (crl->idp)
180             setup_idp(crl, crl->idp);
181
182         crl->akid = X509_CRL_get_ext_d2i(crl,
183                                          NID_authority_key_identifier, NULL,
184                                          NULL);
185
186         crl->crl_number = X509_CRL_get_ext_d2i(crl,
187                                                NID_crl_number, NULL, NULL);
188
189         crl->base_crl_number = X509_CRL_get_ext_d2i(crl,
190                                                     NID_delta_crl, NULL,
191                                                     NULL);
192         /* Delta CRLs must have CRL number */
193         if (crl->base_crl_number && !crl->crl_number)
194             crl->flags |= EXFLAG_INVALID;
195
196         /*
197          * See if we have any unhandled critical CRL extensions and indicate
198          * this in a flag. We only currently handle IDP so anything else
199          * critical sets the flag. This code accesses the X509_CRL structure
200          * directly: applications shouldn't do this.
201          */
202
203         exts = crl->crl.extensions;
204
205         for (idx = 0; idx < sk_X509_EXTENSION_num(exts); idx++) {
206             int nid;
207             ext = sk_X509_EXTENSION_value(exts, idx);
208             nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext));
209             if (nid == NID_freshest_crl)
210                 crl->flags |= EXFLAG_FRESHEST;
211             if (X509_EXTENSION_get_critical(ext)) {
212                 /* We handle IDP and deltas */
213                 if ((nid == NID_issuing_distribution_point)
214                     || (nid == NID_authority_key_identifier)
215                     || (nid == NID_delta_crl))
216                     break;;
217                 crl->flags |= EXFLAG_CRITICAL;
218                 break;
219             }
220         }
221
222         if (!crl_set_issuers(crl))
223             return 0;
224
225         if (crl->meth->crl_init) {
226             if (crl->meth->crl_init(crl) == 0)
227                 return 0;
228         }
229         break;
230
231     case ASN1_OP_FREE_POST:
232         if (crl->meth->crl_free) {
233             if (!crl->meth->crl_free(crl))
234                 return 0;
235         }
236         AUTHORITY_KEYID_free(crl->akid);
237         ISSUING_DIST_POINT_free(crl->idp);
238         ASN1_INTEGER_free(crl->crl_number);
239         ASN1_INTEGER_free(crl->base_crl_number);
240         sk_GENERAL_NAMES_pop_free(crl->issuers, GENERAL_NAMES_free);
241         break;
242     }
243     return 1;
244 }
245
246 /* Convert IDP into a more convenient form */
247
248 static void setup_idp(X509_CRL *crl, ISSUING_DIST_POINT *idp)
249 {
250     int idp_only = 0;
251     /* Set various flags according to IDP */
252     crl->idp_flags |= IDP_PRESENT;
253     if (idp->onlyuser > 0) {
254         idp_only++;
255         crl->idp_flags |= IDP_ONLYUSER;
256     }
257     if (idp->onlyCA > 0) {
258         idp_only++;
259         crl->idp_flags |= IDP_ONLYCA;
260     }
261     if (idp->onlyattr > 0) {
262         idp_only++;
263         crl->idp_flags |= IDP_ONLYATTR;
264     }
265
266     if (idp_only > 1)
267         crl->idp_flags |= IDP_INVALID;
268
269     if (idp->indirectCRL > 0)
270         crl->idp_flags |= IDP_INDIRECT;
271
272     if (idp->onlysomereasons) {
273         crl->idp_flags |= IDP_REASONS;
274         if (idp->onlysomereasons->length > 0)
275             crl->idp_reasons = idp->onlysomereasons->data[0];
276         if (idp->onlysomereasons->length > 1)
277             crl->idp_reasons |= (idp->onlysomereasons->data[1] << 8);
278         crl->idp_reasons &= CRLDP_ALL_REASONS;
279     }
280
281     DIST_POINT_set_dpname(idp->distpoint, X509_CRL_get_issuer(crl));
282 }
283
284 ASN1_SEQUENCE_ref(X509_CRL, crl_cb) = {
285         ASN1_EMBED(X509_CRL, crl, X509_CRL_INFO),
286         ASN1_EMBED(X509_CRL, sig_alg, X509_ALGOR),
287         ASN1_EMBED(X509_CRL, signature, ASN1_BIT_STRING)
288 } ASN1_SEQUENCE_END_ref(X509_CRL, X509_CRL)
289
290 IMPLEMENT_ASN1_FUNCTIONS(X509_REVOKED)
291
292 IMPLEMENT_ASN1_DUP_FUNCTION(X509_REVOKED)
293
294 IMPLEMENT_ASN1_FUNCTIONS(X509_CRL_INFO)
295
296 IMPLEMENT_ASN1_FUNCTIONS(X509_CRL)
297
298 IMPLEMENT_ASN1_DUP_FUNCTION(X509_CRL)
299
300 static int X509_REVOKED_cmp(const X509_REVOKED *const *a,
301                             const X509_REVOKED *const *b)
302 {
303     return (ASN1_STRING_cmp((ASN1_STRING *)&(*a)->serialNumber,
304                             (ASN1_STRING *)&(*b)->serialNumber));
305 }
306
307 int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev)
308 {
309     X509_CRL_INFO *inf;
310     inf = &crl->crl;
311     if (inf->revoked == NULL)
312         inf->revoked = sk_X509_REVOKED_new(X509_REVOKED_cmp);
313     if (inf->revoked == NULL || !sk_X509_REVOKED_push(inf->revoked, rev)) {
314         ASN1err(ASN1_F_X509_CRL_ADD0_REVOKED, ERR_R_MALLOC_FAILURE);
315         return 0;
316     }
317     inf->enc.modified = 1;
318     return 1;
319 }
320
321 int X509_CRL_verify(X509_CRL *crl, EVP_PKEY *r)
322 {
323     if (crl->meth->crl_verify)
324         return crl->meth->crl_verify(crl, r);
325     return 0;
326 }
327
328 int X509_CRL_get0_by_serial(X509_CRL *crl,
329                             X509_REVOKED **ret, ASN1_INTEGER *serial)
330 {
331     if (crl->meth->crl_lookup)
332         return crl->meth->crl_lookup(crl, ret, serial, NULL);
333     return 0;
334 }
335
336 int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **ret, X509 *x)
337 {
338     if (crl->meth->crl_lookup)
339         return crl->meth->crl_lookup(crl, ret,
340                                      X509_get_serialNumber(x),
341                                      X509_get_issuer_name(x));
342     return 0;
343 }
344
345 static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r)
346 {
347     return (ASN1_item_verify(ASN1_ITEM_rptr(X509_CRL_INFO),
348                              &crl->sig_alg, &crl->signature, &crl->crl, r));
349 }
350
351 static int crl_revoked_issuer_match(X509_CRL *crl, X509_NAME *nm,
352                                     X509_REVOKED *rev)
353 {
354     int i;
355
356     if (!rev->issuer) {
357         if (!nm)
358             return 1;
359         if (!X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
360             return 1;
361         return 0;
362     }
363
364     if (!nm)
365         nm = X509_CRL_get_issuer(crl);
366
367     for (i = 0; i < sk_GENERAL_NAME_num(rev->issuer); i++) {
368         GENERAL_NAME *gen = sk_GENERAL_NAME_value(rev->issuer, i);
369         if (gen->type != GEN_DIRNAME)
370             continue;
371         if (!X509_NAME_cmp(nm, gen->d.directoryName))
372             return 1;
373     }
374     return 0;
375
376 }
377
378 static int def_crl_lookup(X509_CRL *crl,
379                           X509_REVOKED **ret, ASN1_INTEGER *serial,
380                           X509_NAME *issuer)
381 {
382     X509_REVOKED rtmp, *rev;
383     int idx;
384     rtmp.serialNumber = *serial;
385     /*
386      * Sort revoked into serial number order if not already sorted. Do this
387      * under a lock to avoid race condition.
388      */
389     if (!sk_X509_REVOKED_is_sorted(crl->crl.revoked)) {
390         CRYPTO_THREAD_write_lock(crl->lock);
391         sk_X509_REVOKED_sort(crl->crl.revoked);
392         CRYPTO_THREAD_unlock(crl->lock);
393     }
394     idx = sk_X509_REVOKED_find(crl->crl.revoked, &rtmp);
395     if (idx < 0)
396         return 0;
397     /* Need to look for matching name */
398     for (; idx < sk_X509_REVOKED_num(crl->crl.revoked); idx++) {
399         rev = sk_X509_REVOKED_value(crl->crl.revoked, idx);
400         if (ASN1_INTEGER_cmp(&rev->serialNumber, serial))
401             return 0;
402         if (crl_revoked_issuer_match(crl, issuer, rev)) {
403             if (ret)
404                 *ret = rev;
405             if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
406                 return 2;
407             return 1;
408         }
409     }
410     return 0;
411 }
412
413 void X509_CRL_set_default_method(const X509_CRL_METHOD *meth)
414 {
415     if (meth == NULL)
416         default_crl_method = &int_crl_meth;
417     else
418         default_crl_method = meth;
419 }
420
421 X509_CRL_METHOD *X509_CRL_METHOD_new(int (*crl_init) (X509_CRL *crl),
422                                      int (*crl_free) (X509_CRL *crl),
423                                      int (*crl_lookup) (X509_CRL *crl,
424                                                         X509_REVOKED **ret,
425                                                         ASN1_INTEGER *ser,
426                                                         X509_NAME *issuer),
427                                      int (*crl_verify) (X509_CRL *crl,
428                                                         EVP_PKEY *pk))
429 {
430     X509_CRL_METHOD *m;
431     m = OPENSSL_malloc(sizeof(*m));
432     if (m == NULL)
433         return NULL;
434     m->crl_init = crl_init;
435     m->crl_free = crl_free;
436     m->crl_lookup = crl_lookup;
437     m->crl_verify = crl_verify;
438     m->flags = X509_CRL_METHOD_DYNAMIC;
439     return m;
440 }
441
442 void X509_CRL_METHOD_free(X509_CRL_METHOD *m)
443 {
444     if (!(m->flags & X509_CRL_METHOD_DYNAMIC))
445         return;
446     OPENSSL_free(m);
447 }
448
449 void X509_CRL_set_meth_data(X509_CRL *crl, void *dat)
450 {
451     crl->meth_data = dat;
452 }
453
454 void *X509_CRL_get_meth_data(X509_CRL *crl)
455 {
456     return crl->meth_data;
457 }