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1 /*
2  * Copyright 2006-2018 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 /*
11  * Implementation of RFC 3779 section 3.2.
12  */
13 
14 #include <assert.h>
15 #include <stdio.h>
16 #include <string.h>
17 #include "internal/cryptlib.h"
18 #include <openssl/conf.h>
19 #include <openssl/asn1.h>
20 #include <openssl/asn1t.h>
21 #include <openssl/x509v3.h>
22 #include <openssl/x509.h>
23 #include "crypto/x509.h"
24 #include <openssl/bn.h>
25 #include "ext_dat.h"
26 
27 #ifndef OPENSSL_NO_RFC3779
28 
29 /*
30  * OpenSSL ASN.1 template translation of RFC 3779 3.2.3.
31  */
32 
33 ASN1_SEQUENCE(ASRange) = {
34   ASN1_SIMPLE(ASRange, min, ASN1_INTEGER),
35   ASN1_SIMPLE(ASRange, max, ASN1_INTEGER)
36 } ASN1_SEQUENCE_END(ASRange)
37 
38 ASN1_CHOICE(ASIdOrRange) = {
39   ASN1_SIMPLE(ASIdOrRange, u.id,    ASN1_INTEGER),
40   ASN1_SIMPLE(ASIdOrRange, u.range, ASRange)
41 } ASN1_CHOICE_END(ASIdOrRange)
42 
43 ASN1_CHOICE(ASIdentifierChoice) = {
44   ASN1_SIMPLE(ASIdentifierChoice,      u.inherit,       ASN1_NULL),
45   ASN1_SEQUENCE_OF(ASIdentifierChoice, u.asIdsOrRanges, ASIdOrRange)
46 } ASN1_CHOICE_END(ASIdentifierChoice)
47 
48 ASN1_SEQUENCE(ASIdentifiers) = {
49   ASN1_EXP_OPT(ASIdentifiers, asnum, ASIdentifierChoice, 0),
50   ASN1_EXP_OPT(ASIdentifiers, rdi,   ASIdentifierChoice, 1)
51 } ASN1_SEQUENCE_END(ASIdentifiers)
52 
53 IMPLEMENT_ASN1_FUNCTIONS(ASRange)
54 IMPLEMENT_ASN1_FUNCTIONS(ASIdOrRange)
55 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifierChoice)
56 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifiers)
57 
58 /*
59  * i2r method for an ASIdentifierChoice.
60  */
61 static int i2r_ASIdentifierChoice(BIO *out,
62                                   ASIdentifierChoice *choice,
63                                   int indent, const char *msg)
64 {
65     int i;
66     char *s;
67     if (choice == NULL)
68         return 1;
69     BIO_printf(out, "%*s%s:\n", indent, "", msg);
70     switch (choice->type) {
71     case ASIdentifierChoice_inherit:
72         BIO_printf(out, "%*sinherit\n", indent + 2, "");
73         break;
74     case ASIdentifierChoice_asIdsOrRanges:
75         for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges); i++) {
76             ASIdOrRange *aor =
77                 sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
78             switch (aor->type) {
79             case ASIdOrRange_id:
80                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.id)) == NULL)
81                     return 0;
82                 BIO_printf(out, "%*s%s\n", indent + 2, "", s);
83                 OPENSSL_free(s);
84                 break;
85             case ASIdOrRange_range:
86                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->min)) == NULL)
87                     return 0;
88                 BIO_printf(out, "%*s%s-", indent + 2, "", s);
89                 OPENSSL_free(s);
90                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->max)) == NULL)
91                     return 0;
92                 BIO_printf(out, "%s\n", s);
93                 OPENSSL_free(s);
94                 break;
95             default:
96                 return 0;
97             }
98         }
99         break;
100     default:
101         return 0;
102     }
103     return 1;
104 }
105 
106 /*
107  * i2r method for an ASIdentifier extension.
108  */
i2r_ASIdentifiers(const X509V3_EXT_METHOD * method,void * ext,BIO * out,int indent)109 static int i2r_ASIdentifiers(const X509V3_EXT_METHOD *method,
110                              void *ext, BIO *out, int indent)
111 {
112     ASIdentifiers *asid = ext;
113     return (i2r_ASIdentifierChoice(out, asid->asnum, indent,
114                                    "Autonomous System Numbers") &&
115             i2r_ASIdentifierChoice(out, asid->rdi, indent,
116                                    "Routing Domain Identifiers"));
117 }
118 
119 /*
120  * Sort comparison function for a sequence of ASIdOrRange elements.
121  */
ASIdOrRange_cmp(const ASIdOrRange * const * a_,const ASIdOrRange * const * b_)122 static int ASIdOrRange_cmp(const ASIdOrRange *const *a_,
123                            const ASIdOrRange *const *b_)
124 {
125     const ASIdOrRange *a = *a_, *b = *b_;
126 
127     assert((a->type == ASIdOrRange_id && a->u.id != NULL) ||
128            (a->type == ASIdOrRange_range && a->u.range != NULL &&
129             a->u.range->min != NULL && a->u.range->max != NULL));
130 
131     assert((b->type == ASIdOrRange_id && b->u.id != NULL) ||
132            (b->type == ASIdOrRange_range && b->u.range != NULL &&
133             b->u.range->min != NULL && b->u.range->max != NULL));
134 
135     if (a->type == ASIdOrRange_id && b->type == ASIdOrRange_id)
136         return ASN1_INTEGER_cmp(a->u.id, b->u.id);
137 
138     if (a->type == ASIdOrRange_range && b->type == ASIdOrRange_range) {
139         int r = ASN1_INTEGER_cmp(a->u.range->min, b->u.range->min);
140         return r != 0 ? r : ASN1_INTEGER_cmp(a->u.range->max,
141                                              b->u.range->max);
142     }
143 
144     if (a->type == ASIdOrRange_id)
145         return ASN1_INTEGER_cmp(a->u.id, b->u.range->min);
146     else
147         return ASN1_INTEGER_cmp(a->u.range->min, b->u.id);
148 }
149 
150 /*
151  * Add an inherit element.
152  */
X509v3_asid_add_inherit(ASIdentifiers * asid,int which)153 int X509v3_asid_add_inherit(ASIdentifiers *asid, int which)
154 {
155     ASIdentifierChoice **choice;
156     if (asid == NULL)
157         return 0;
158     switch (which) {
159     case V3_ASID_ASNUM:
160         choice = &asid->asnum;
161         break;
162     case V3_ASID_RDI:
163         choice = &asid->rdi;
164         break;
165     default:
166         return 0;
167     }
168     if (*choice == NULL) {
169         if ((*choice = ASIdentifierChoice_new()) == NULL)
170             return 0;
171         if (((*choice)->u.inherit = ASN1_NULL_new()) == NULL)
172             return 0;
173         (*choice)->type = ASIdentifierChoice_inherit;
174     }
175     return (*choice)->type == ASIdentifierChoice_inherit;
176 }
177 
178 /*
179  * Add an ID or range to an ASIdentifierChoice.
180  */
X509v3_asid_add_id_or_range(ASIdentifiers * asid,int which,ASN1_INTEGER * min,ASN1_INTEGER * max)181 int X509v3_asid_add_id_or_range(ASIdentifiers *asid,
182                                 int which, ASN1_INTEGER *min, ASN1_INTEGER *max)
183 {
184     ASIdentifierChoice **choice;
185     ASIdOrRange *aor;
186     if (asid == NULL)
187         return 0;
188     switch (which) {
189     case V3_ASID_ASNUM:
190         choice = &asid->asnum;
191         break;
192     case V3_ASID_RDI:
193         choice = &asid->rdi;
194         break;
195     default:
196         return 0;
197     }
198     if (*choice != NULL && (*choice)->type == ASIdentifierChoice_inherit)
199         return 0;
200     if (*choice == NULL) {
201         if ((*choice = ASIdentifierChoice_new()) == NULL)
202             return 0;
203         (*choice)->u.asIdsOrRanges = sk_ASIdOrRange_new(ASIdOrRange_cmp);
204         if ((*choice)->u.asIdsOrRanges == NULL)
205             return 0;
206         (*choice)->type = ASIdentifierChoice_asIdsOrRanges;
207     }
208     if ((aor = ASIdOrRange_new()) == NULL)
209         return 0;
210     if (max == NULL) {
211         aor->type = ASIdOrRange_id;
212         aor->u.id = min;
213     } else {
214         aor->type = ASIdOrRange_range;
215         if ((aor->u.range = ASRange_new()) == NULL)
216             goto err;
217         ASN1_INTEGER_free(aor->u.range->min);
218         aor->u.range->min = min;
219         ASN1_INTEGER_free(aor->u.range->max);
220         aor->u.range->max = max;
221     }
222     if (!(sk_ASIdOrRange_push((*choice)->u.asIdsOrRanges, aor)))
223         goto err;
224     return 1;
225 
226  err:
227     ASIdOrRange_free(aor);
228     return 0;
229 }
230 
231 /*
232  * Extract min and max values from an ASIdOrRange.
233  */
extract_min_max(ASIdOrRange * aor,ASN1_INTEGER ** min,ASN1_INTEGER ** max)234 static int extract_min_max(ASIdOrRange *aor,
235                            ASN1_INTEGER **min, ASN1_INTEGER **max)
236 {
237     if (!ossl_assert(aor != NULL))
238         return 0;
239     switch (aor->type) {
240     case ASIdOrRange_id:
241         *min = aor->u.id;
242         *max = aor->u.id;
243         return 1;
244     case ASIdOrRange_range:
245         *min = aor->u.range->min;
246         *max = aor->u.range->max;
247         return 1;
248     }
249 
250     return 0;
251 }
252 
253 /*
254  * Check whether an ASIdentifierChoice is in canonical form.
255  */
ASIdentifierChoice_is_canonical(ASIdentifierChoice * choice)256 static int ASIdentifierChoice_is_canonical(ASIdentifierChoice *choice)
257 {
258     ASN1_INTEGER *a_max_plus_one = NULL;
259     ASN1_INTEGER *orig;
260     BIGNUM *bn = NULL;
261     int i, ret = 0;
262 
263     /*
264      * Empty element or inheritance is canonical.
265      */
266     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
267         return 1;
268 
269     /*
270      * If not a list, or if empty list, it's broken.
271      */
272     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
273         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0)
274         return 0;
275 
276     /*
277      * It's a list, check it.
278      */
279     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
280         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
281         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
282         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
283             NULL;
284 
285         if (!extract_min_max(a, &a_min, &a_max)
286                 || !extract_min_max(b, &b_min, &b_max))
287             goto done;
288 
289         /*
290          * Punt misordered list, overlapping start, or inverted range.
291          */
292         if (ASN1_INTEGER_cmp(a_min, b_min) >= 0 ||
293             ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
294             ASN1_INTEGER_cmp(b_min, b_max) > 0)
295             goto done;
296 
297         /*
298          * Calculate a_max + 1 to check for adjacency.
299          */
300         if ((bn == NULL && (bn = BN_new()) == NULL) ||
301             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
302             !BN_add_word(bn, 1)) {
303             X509V3err(X509V3_F_ASIDENTIFIERCHOICE_IS_CANONICAL,
304                       ERR_R_MALLOC_FAILURE);
305             goto done;
306         }
307 
308         if ((a_max_plus_one =
309                 BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
310             a_max_plus_one = orig;
311             X509V3err(X509V3_F_ASIDENTIFIERCHOICE_IS_CANONICAL,
312                       ERR_R_MALLOC_FAILURE);
313             goto done;
314         }
315 
316         /*
317          * Punt if adjacent or overlapping.
318          */
319         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) >= 0)
320             goto done;
321     }
322 
323     /*
324      * Check for inverted range.
325      */
326     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
327     {
328         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
329         ASN1_INTEGER *a_min, *a_max;
330         if (a != NULL && a->type == ASIdOrRange_range) {
331             if (!extract_min_max(a, &a_min, &a_max)
332                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
333                 goto done;
334         }
335     }
336 
337     ret = 1;
338 
339  done:
340     ASN1_INTEGER_free(a_max_plus_one);
341     BN_free(bn);
342     return ret;
343 }
344 
345 /*
346  * Check whether an ASIdentifier extension is in canonical form.
347  */
X509v3_asid_is_canonical(ASIdentifiers * asid)348 int X509v3_asid_is_canonical(ASIdentifiers *asid)
349 {
350     return (asid == NULL ||
351             (ASIdentifierChoice_is_canonical(asid->asnum) &&
352              ASIdentifierChoice_is_canonical(asid->rdi)));
353 }
354 
355 /*
356  * Whack an ASIdentifierChoice into canonical form.
357  */
ASIdentifierChoice_canonize(ASIdentifierChoice * choice)358 static int ASIdentifierChoice_canonize(ASIdentifierChoice *choice)
359 {
360     ASN1_INTEGER *a_max_plus_one = NULL;
361     ASN1_INTEGER *orig;
362     BIGNUM *bn = NULL;
363     int i, ret = 0;
364 
365     /*
366      * Nothing to do for empty element or inheritance.
367      */
368     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
369         return 1;
370 
371     /*
372      * If not a list, or if empty list, it's broken.
373      */
374     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
375         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0) {
376         X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,
377                   X509V3_R_EXTENSION_VALUE_ERROR);
378         return 0;
379     }
380 
381     /*
382      * We have a non-empty list.  Sort it.
383      */
384     sk_ASIdOrRange_sort(choice->u.asIdsOrRanges);
385 
386     /*
387      * Now check for errors and suboptimal encoding, rejecting the
388      * former and fixing the latter.
389      */
390     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
391         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
392         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
393         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
394             NULL;
395 
396         if (!extract_min_max(a, &a_min, &a_max)
397                 || !extract_min_max(b, &b_min, &b_max))
398             goto done;
399 
400         /*
401          * Make sure we're properly sorted (paranoia).
402          */
403         if (!ossl_assert(ASN1_INTEGER_cmp(a_min, b_min) <= 0))
404             goto done;
405 
406         /*
407          * Punt inverted ranges.
408          */
409         if (ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
410             ASN1_INTEGER_cmp(b_min, b_max) > 0)
411             goto done;
412 
413         /*
414          * Check for overlaps.
415          */
416         if (ASN1_INTEGER_cmp(a_max, b_min) >= 0) {
417             X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,
418                       X509V3_R_EXTENSION_VALUE_ERROR);
419             goto done;
420         }
421 
422         /*
423          * Calculate a_max + 1 to check for adjacency.
424          */
425         if ((bn == NULL && (bn = BN_new()) == NULL) ||
426             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
427             !BN_add_word(bn, 1)) {
428             X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,
429                       ERR_R_MALLOC_FAILURE);
430             goto done;
431         }
432 
433         if ((a_max_plus_one =
434                  BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
435             a_max_plus_one = orig;
436             X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,
437                       ERR_R_MALLOC_FAILURE);
438             goto done;
439         }
440 
441         /*
442          * If a and b are adjacent, merge them.
443          */
444         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) == 0) {
445             ASRange *r;
446             switch (a->type) {
447             case ASIdOrRange_id:
448                 if ((r = OPENSSL_malloc(sizeof(*r))) == NULL) {
449                     X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,
450                               ERR_R_MALLOC_FAILURE);
451                     goto done;
452                 }
453                 r->min = a_min;
454                 r->max = b_max;
455                 a->type = ASIdOrRange_range;
456                 a->u.range = r;
457                 break;
458             case ASIdOrRange_range:
459                 ASN1_INTEGER_free(a->u.range->max);
460                 a->u.range->max = b_max;
461                 break;
462             }
463             switch (b->type) {
464             case ASIdOrRange_id:
465                 b->u.id = NULL;
466                 break;
467             case ASIdOrRange_range:
468                 b->u.range->max = NULL;
469                 break;
470             }
471             ASIdOrRange_free(b);
472             (void)sk_ASIdOrRange_delete(choice->u.asIdsOrRanges, i + 1);
473             i--;
474             continue;
475         }
476     }
477 
478     /*
479      * Check for final inverted range.
480      */
481     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
482     {
483         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
484         ASN1_INTEGER *a_min, *a_max;
485         if (a != NULL && a->type == ASIdOrRange_range) {
486             if (!extract_min_max(a, &a_min, &a_max)
487                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
488                 goto done;
489         }
490     }
491 
492     /* Paranoia */
493     if (!ossl_assert(ASIdentifierChoice_is_canonical(choice)))
494         goto done;
495 
496     ret = 1;
497 
498  done:
499     ASN1_INTEGER_free(a_max_plus_one);
500     BN_free(bn);
501     return ret;
502 }
503 
504 /*
505  * Whack an ASIdentifier extension into canonical form.
506  */
X509v3_asid_canonize(ASIdentifiers * asid)507 int X509v3_asid_canonize(ASIdentifiers *asid)
508 {
509     return (asid == NULL ||
510             (ASIdentifierChoice_canonize(asid->asnum) &&
511              ASIdentifierChoice_canonize(asid->rdi)));
512 }
513 
514 /*
515  * v2i method for an ASIdentifier extension.
516  */
v2i_ASIdentifiers(const struct v3_ext_method * method,struct v3_ext_ctx * ctx,STACK_OF (CONF_VALUE)* values)517 static void *v2i_ASIdentifiers(const struct v3_ext_method *method,
518                                struct v3_ext_ctx *ctx,
519                                STACK_OF(CONF_VALUE) *values)
520 {
521     ASN1_INTEGER *min = NULL, *max = NULL;
522     ASIdentifiers *asid = NULL;
523     int i;
524 
525     if ((asid = ASIdentifiers_new()) == NULL) {
526         X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);
527         return NULL;
528     }
529 
530     for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
531         CONF_VALUE *val = sk_CONF_VALUE_value(values, i);
532         int i1 = 0, i2 = 0, i3 = 0, is_range = 0, which = 0;
533 
534         /*
535          * Figure out whether this is an AS or an RDI.
536          */
537         if (!name_cmp(val->name, "AS")) {
538             which = V3_ASID_ASNUM;
539         } else if (!name_cmp(val->name, "RDI")) {
540             which = V3_ASID_RDI;
541         } else {
542             X509V3err(X509V3_F_V2I_ASIDENTIFIERS,
543                       X509V3_R_EXTENSION_NAME_ERROR);
544             X509V3_conf_err(val);
545             goto err;
546         }
547 
548         /*
549          * Handle inheritance.
550          */
551         if (strcmp(val->value, "inherit") == 0) {
552             if (X509v3_asid_add_inherit(asid, which))
553                 continue;
554             X509V3err(X509V3_F_V2I_ASIDENTIFIERS,
555                       X509V3_R_INVALID_INHERITANCE);
556             X509V3_conf_err(val);
557             goto err;
558         }
559 
560         /*
561          * Number, range, or mistake, pick it apart and figure out which.
562          */
563         i1 = strspn(val->value, "0123456789");
564         if (val->value[i1] == '\0') {
565             is_range = 0;
566         } else {
567             is_range = 1;
568             i2 = i1 + strspn(val->value + i1, " \t");
569             if (val->value[i2] != '-') {
570                 X509V3err(X509V3_F_V2I_ASIDENTIFIERS,
571                           X509V3_R_INVALID_ASNUMBER);
572                 X509V3_conf_err(val);
573                 goto err;
574             }
575             i2++;
576             i2 = i2 + strspn(val->value + i2, " \t");
577             i3 = i2 + strspn(val->value + i2, "0123456789");
578             if (val->value[i3] != '\0') {
579                 X509V3err(X509V3_F_V2I_ASIDENTIFIERS,
580                           X509V3_R_INVALID_ASRANGE);
581                 X509V3_conf_err(val);
582                 goto err;
583             }
584         }
585 
586         /*
587          * Syntax is ok, read and add it.
588          */
589         if (!is_range) {
590             if (!X509V3_get_value_int(val, &min)) {
591                 X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);
592                 goto err;
593             }
594         } else {
595             char *s = OPENSSL_strdup(val->value);
596             if (s == NULL) {
597                 X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);
598                 goto err;
599             }
600             s[i1] = '\0';
601             min = s2i_ASN1_INTEGER(NULL, s);
602             max = s2i_ASN1_INTEGER(NULL, s + i2);
603             OPENSSL_free(s);
604             if (min == NULL || max == NULL) {
605                 X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);
606                 goto err;
607             }
608             if (ASN1_INTEGER_cmp(min, max) > 0) {
609                 X509V3err(X509V3_F_V2I_ASIDENTIFIERS,
610                           X509V3_R_EXTENSION_VALUE_ERROR);
611                 goto err;
612             }
613         }
614         if (!X509v3_asid_add_id_or_range(asid, which, min, max)) {
615             X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);
616             goto err;
617         }
618         min = max = NULL;
619     }
620 
621     /*
622      * Canonize the result, then we're done.
623      */
624     if (!X509v3_asid_canonize(asid))
625         goto err;
626     return asid;
627 
628  err:
629     ASIdentifiers_free(asid);
630     ASN1_INTEGER_free(min);
631     ASN1_INTEGER_free(max);
632     return NULL;
633 }
634 
635 /*
636  * OpenSSL dispatch.
637  */
638 const X509V3_EXT_METHOD v3_asid = {
639     NID_sbgp_autonomousSysNum,  /* nid */
640     0,                          /* flags */
641     ASN1_ITEM_ref(ASIdentifiers), /* template */
642     0, 0, 0, 0,                 /* old functions, ignored */
643     0,                          /* i2s */
644     0,                          /* s2i */
645     0,                          /* i2v */
646     v2i_ASIdentifiers,          /* v2i */
647     i2r_ASIdentifiers,          /* i2r */
648     0,                          /* r2i */
649     NULL                        /* extension-specific data */
650 };
651 
652 /*
653  * Figure out whether extension uses inheritance.
654  */
X509v3_asid_inherits(ASIdentifiers * asid)655 int X509v3_asid_inherits(ASIdentifiers *asid)
656 {
657     return (asid != NULL &&
658             ((asid->asnum != NULL &&
659               asid->asnum->type == ASIdentifierChoice_inherit) ||
660              (asid->rdi != NULL &&
661               asid->rdi->type == ASIdentifierChoice_inherit)));
662 }
663 
664 /*
665  * Figure out whether parent contains child.
666  */
asid_contains(ASIdOrRanges * parent,ASIdOrRanges * child)667 static int asid_contains(ASIdOrRanges *parent, ASIdOrRanges *child)
668 {
669     ASN1_INTEGER *p_min = NULL, *p_max = NULL, *c_min = NULL, *c_max = NULL;
670     int p, c;
671 
672     if (child == NULL || parent == child)
673         return 1;
674     if (parent == NULL)
675         return 0;
676 
677     p = 0;
678     for (c = 0; c < sk_ASIdOrRange_num(child); c++) {
679         if (!extract_min_max(sk_ASIdOrRange_value(child, c), &c_min, &c_max))
680             return 0;
681         for (;; p++) {
682             if (p >= sk_ASIdOrRange_num(parent))
683                 return 0;
684             if (!extract_min_max(sk_ASIdOrRange_value(parent, p), &p_min,
685                                  &p_max))
686                 return 0;
687             if (ASN1_INTEGER_cmp(p_max, c_max) < 0)
688                 continue;
689             if (ASN1_INTEGER_cmp(p_min, c_min) > 0)
690                 return 0;
691             break;
692         }
693     }
694 
695     return 1;
696 }
697 
698 /*
699  * Test whether a is a subset of b.
700  */
X509v3_asid_subset(ASIdentifiers * a,ASIdentifiers * b)701 int X509v3_asid_subset(ASIdentifiers *a, ASIdentifiers *b)
702 {
703     return (a == NULL ||
704             a == b ||
705             (b != NULL &&
706              !X509v3_asid_inherits(a) &&
707              !X509v3_asid_inherits(b) &&
708              asid_contains(b->asnum->u.asIdsOrRanges,
709                            a->asnum->u.asIdsOrRanges) &&
710              asid_contains(b->rdi->u.asIdsOrRanges,
711                            a->rdi->u.asIdsOrRanges)));
712 }
713 
714 /*
715  * Validation error handling via callback.
716  */
717 #define validation_err(_err_)           \
718   do {                                  \
719     if (ctx != NULL) {                  \
720       ctx->error = _err_;               \
721       ctx->error_depth = i;             \
722       ctx->current_cert = x;            \
723       ret = ctx->verify_cb(0, ctx);     \
724     } else {                            \
725       ret = 0;                          \
726     }                                   \
727     if (!ret)                           \
728       goto done;                        \
729   } while (0)
730 
731 /*
732  * Core code for RFC 3779 3.3 path validation.
733  */
asid_validate_path_internal(X509_STORE_CTX * ctx,STACK_OF (X509)* chain,ASIdentifiers * ext)734 static int asid_validate_path_internal(X509_STORE_CTX *ctx,
735                                        STACK_OF(X509) *chain,
736                                        ASIdentifiers *ext)
737 {
738     ASIdOrRanges *child_as = NULL, *child_rdi = NULL;
739     int i, ret = 1, inherit_as = 0, inherit_rdi = 0;
740     X509 *x;
741 
742     if (!ossl_assert(chain != NULL && sk_X509_num(chain) > 0)
743             || !ossl_assert(ctx != NULL || ext != NULL)
744             || !ossl_assert(ctx == NULL || ctx->verify_cb != NULL)) {
745         if (ctx != NULL)
746             ctx->error = X509_V_ERR_UNSPECIFIED;
747         return 0;
748     }
749 
750 
751     /*
752      * Figure out where to start.  If we don't have an extension to
753      * check, we're done.  Otherwise, check canonical form and
754      * set up for walking up the chain.
755      */
756     if (ext != NULL) {
757         i = -1;
758         x = NULL;
759     } else {
760         i = 0;
761         x = sk_X509_value(chain, i);
762         if ((ext = x->rfc3779_asid) == NULL)
763             goto done;
764     }
765     if (!X509v3_asid_is_canonical(ext))
766         validation_err(X509_V_ERR_INVALID_EXTENSION);
767     if (ext->asnum != NULL) {
768         switch (ext->asnum->type) {
769         case ASIdentifierChoice_inherit:
770             inherit_as = 1;
771             break;
772         case ASIdentifierChoice_asIdsOrRanges:
773             child_as = ext->asnum->u.asIdsOrRanges;
774             break;
775         }
776     }
777     if (ext->rdi != NULL) {
778         switch (ext->rdi->type) {
779         case ASIdentifierChoice_inherit:
780             inherit_rdi = 1;
781             break;
782         case ASIdentifierChoice_asIdsOrRanges:
783             child_rdi = ext->rdi->u.asIdsOrRanges;
784             break;
785         }
786     }
787 
788     /*
789      * Now walk up the chain.  Extensions must be in canonical form, no
790      * cert may list resources that its parent doesn't list.
791      */
792     for (i++; i < sk_X509_num(chain); i++) {
793         x = sk_X509_value(chain, i);
794         if (!ossl_assert(x != NULL)) {
795             if (ctx != NULL)
796                 ctx->error = X509_V_ERR_UNSPECIFIED;
797             return 0;
798         }
799         if (x->rfc3779_asid == NULL) {
800             if (child_as != NULL || child_rdi != NULL)
801                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
802             continue;
803         }
804         if (!X509v3_asid_is_canonical(x->rfc3779_asid))
805             validation_err(X509_V_ERR_INVALID_EXTENSION);
806         if (x->rfc3779_asid->asnum == NULL && child_as != NULL) {
807             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
808             child_as = NULL;
809             inherit_as = 0;
810         }
811         if (x->rfc3779_asid->asnum != NULL &&
812             x->rfc3779_asid->asnum->type ==
813             ASIdentifierChoice_asIdsOrRanges) {
814             if (inherit_as
815                 || asid_contains(x->rfc3779_asid->asnum->u.asIdsOrRanges,
816                                  child_as)) {
817                 child_as = x->rfc3779_asid->asnum->u.asIdsOrRanges;
818                 inherit_as = 0;
819             } else {
820                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
821             }
822         }
823         if (x->rfc3779_asid->rdi == NULL && child_rdi != NULL) {
824             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
825             child_rdi = NULL;
826             inherit_rdi = 0;
827         }
828         if (x->rfc3779_asid->rdi != NULL &&
829             x->rfc3779_asid->rdi->type == ASIdentifierChoice_asIdsOrRanges) {
830             if (inherit_rdi ||
831                 asid_contains(x->rfc3779_asid->rdi->u.asIdsOrRanges,
832                               child_rdi)) {
833                 child_rdi = x->rfc3779_asid->rdi->u.asIdsOrRanges;
834                 inherit_rdi = 0;
835             } else {
836                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
837             }
838         }
839     }
840 
841     /*
842      * Trust anchor can't inherit.
843      */
844     if (!ossl_assert(x != NULL)) {
845         if (ctx != NULL)
846             ctx->error = X509_V_ERR_UNSPECIFIED;
847         return 0;
848     }
849     if (x->rfc3779_asid != NULL) {
850         if (x->rfc3779_asid->asnum != NULL &&
851             x->rfc3779_asid->asnum->type == ASIdentifierChoice_inherit)
852             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
853         if (x->rfc3779_asid->rdi != NULL &&
854             x->rfc3779_asid->rdi->type == ASIdentifierChoice_inherit)
855             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
856     }
857 
858  done:
859     return ret;
860 }
861 
862 #undef validation_err
863 
864 /*
865  * RFC 3779 3.3 path validation -- called from X509_verify_cert().
866  */
X509v3_asid_validate_path(X509_STORE_CTX * ctx)867 int X509v3_asid_validate_path(X509_STORE_CTX *ctx)
868 {
869     if (ctx->chain == NULL
870             || sk_X509_num(ctx->chain) == 0
871             || ctx->verify_cb == NULL) {
872         ctx->error = X509_V_ERR_UNSPECIFIED;
873         return 0;
874     }
875     return asid_validate_path_internal(ctx, ctx->chain, NULL);
876 }
877 
878 /*
879  * RFC 3779 3.3 path validation of an extension.
880  * Test whether chain covers extension.
881  */
X509v3_asid_validate_resource_set(STACK_OF (X509)* chain,ASIdentifiers * ext,int allow_inheritance)882 int X509v3_asid_validate_resource_set(STACK_OF(X509) *chain,
883                                       ASIdentifiers *ext, int allow_inheritance)
884 {
885     if (ext == NULL)
886         return 1;
887     if (chain == NULL || sk_X509_num(chain) == 0)
888         return 0;
889     if (!allow_inheritance && X509v3_asid_inherits(ext))
890         return 0;
891     return asid_validate_path_internal(NULL, chain, ext);
892 }
893 
894 #endif                          /* OPENSSL_NO_RFC3779 */
895