xref: /freebsd/crypto/openssl/crypto/x509/v3_asid.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*
2  * Copyright 2006-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (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 #include "x509_local.h"
27 
28 #ifndef OPENSSL_NO_RFC3779
29 
30 /*
31  * OpenSSL ASN.1 template translation of RFC 3779 3.2.3.
32  */
33 
34 ASN1_SEQUENCE(ASRange) = {
35   ASN1_SIMPLE(ASRange, min, ASN1_INTEGER),
36   ASN1_SIMPLE(ASRange, max, ASN1_INTEGER)
37 } ASN1_SEQUENCE_END(ASRange)
38 
39 ASN1_CHOICE(ASIdOrRange) = {
40   ASN1_SIMPLE(ASIdOrRange, u.id,    ASN1_INTEGER),
41   ASN1_SIMPLE(ASIdOrRange, u.range, ASRange)
42 } ASN1_CHOICE_END(ASIdOrRange)
43 
44 ASN1_CHOICE(ASIdentifierChoice) = {
45   ASN1_SIMPLE(ASIdentifierChoice,      u.inherit,       ASN1_NULL),
46   ASN1_SEQUENCE_OF(ASIdentifierChoice, u.asIdsOrRanges, ASIdOrRange)
47 } ASN1_CHOICE_END(ASIdentifierChoice)
48 
49 ASN1_SEQUENCE(ASIdentifiers) = {
50   ASN1_EXP_OPT(ASIdentifiers, asnum, ASIdentifierChoice, 0),
51   ASN1_EXP_OPT(ASIdentifiers, rdi,   ASIdentifierChoice, 1)
52 } ASN1_SEQUENCE_END(ASIdentifiers)
53 
54 IMPLEMENT_ASN1_FUNCTIONS(ASRange)
55 IMPLEMENT_ASN1_FUNCTIONS(ASIdOrRange)
56 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifierChoice)
57 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifiers)
58 
59 /*
60  * i2r method for an ASIdentifierChoice.
61  */
62 static int i2r_ASIdentifierChoice(BIO *out,
63                                   ASIdentifierChoice *choice,
64                                   int indent, const char *msg)
65 {
66     int i;
67     char *s;
68     if (choice == NULL)
69         return 1;
70     BIO_printf(out, "%*s%s:\n", indent, "", msg);
71     switch (choice->type) {
72     case ASIdentifierChoice_inherit:
73         BIO_printf(out, "%*sinherit\n", indent + 2, "");
74         break;
75     case ASIdentifierChoice_asIdsOrRanges:
76         for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges); i++) {
77             ASIdOrRange *aor =
78                 sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
79             switch (aor->type) {
80             case ASIdOrRange_id:
81                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.id)) == NULL)
82                     return 0;
83                 BIO_printf(out, "%*s%s\n", indent + 2, "", s);
84                 OPENSSL_free(s);
85                 break;
86             case ASIdOrRange_range:
87                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->min)) == NULL)
88                     return 0;
89                 BIO_printf(out, "%*s%s-", indent + 2, "", s);
90                 OPENSSL_free(s);
91                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->max)) == NULL)
92                     return 0;
93                 BIO_printf(out, "%s\n", s);
94                 OPENSSL_free(s);
95                 break;
96             default:
97                 return 0;
98             }
99         }
100         break;
101     default:
102         return 0;
103     }
104     return 1;
105 }
106 
107 /*
108  * i2r method for an ASIdentifier extension.
109  */
i2r_ASIdentifiers(const X509V3_EXT_METHOD * method,void * ext,BIO * out,int indent)110 static int i2r_ASIdentifiers(const X509V3_EXT_METHOD *method,
111                              void *ext, BIO *out, int indent)
112 {
113     ASIdentifiers *asid = ext;
114     return (i2r_ASIdentifierChoice(out, asid->asnum, indent,
115                                    "Autonomous System Numbers") &&
116             i2r_ASIdentifierChoice(out, asid->rdi, indent,
117                                    "Routing Domain Identifiers"));
118 }
119 
120 /*
121  * Sort comparison function for a sequence of ASIdOrRange elements.
122  */
ASIdOrRange_cmp(const ASIdOrRange * const * a_,const ASIdOrRange * const * b_)123 static int ASIdOrRange_cmp(const ASIdOrRange *const *a_,
124                            const ASIdOrRange *const *b_)
125 {
126     const ASIdOrRange *a = *a_, *b = *b_;
127 
128     assert((a->type == ASIdOrRange_id && a->u.id != NULL) ||
129            (a->type == ASIdOrRange_range && a->u.range != NULL &&
130             a->u.range->min != NULL && a->u.range->max != NULL));
131 
132     assert((b->type == ASIdOrRange_id && b->u.id != NULL) ||
133            (b->type == ASIdOrRange_range && b->u.range != NULL &&
134             b->u.range->min != NULL && b->u.range->max != NULL));
135 
136     if (a->type == ASIdOrRange_id && b->type == ASIdOrRange_id)
137         return ASN1_INTEGER_cmp(a->u.id, b->u.id);
138 
139     if (a->type == ASIdOrRange_range && b->type == ASIdOrRange_range) {
140         int r = ASN1_INTEGER_cmp(a->u.range->min, b->u.range->min);
141         return r != 0 ? r : ASN1_INTEGER_cmp(a->u.range->max,
142                                              b->u.range->max);
143     }
144 
145     if (a->type == ASIdOrRange_id)
146         return ASN1_INTEGER_cmp(a->u.id, b->u.range->min);
147     else
148         return ASN1_INTEGER_cmp(a->u.range->min, b->u.id);
149 }
150 
151 /*
152  * Add an inherit element.
153  */
X509v3_asid_add_inherit(ASIdentifiers * asid,int which)154 int X509v3_asid_add_inherit(ASIdentifiers *asid, int which)
155 {
156     ASIdentifierChoice **choice;
157     if (asid == NULL)
158         return 0;
159     switch (which) {
160     case V3_ASID_ASNUM:
161         choice = &asid->asnum;
162         break;
163     case V3_ASID_RDI:
164         choice = &asid->rdi;
165         break;
166     default:
167         return 0;
168     }
169     if (*choice == NULL) {
170         if ((*choice = ASIdentifierChoice_new()) == NULL)
171             return 0;
172         if (((*choice)->u.inherit = ASN1_NULL_new()) == NULL) {
173             ASIdentifierChoice_free(*choice);
174             *choice = NULL;
175             return 0;
176         }
177         (*choice)->type = ASIdentifierChoice_inherit;
178     }
179     return (*choice)->type == ASIdentifierChoice_inherit;
180 }
181 
182 /*
183  * Add an ID or range to an ASIdentifierChoice.
184  */
X509v3_asid_add_id_or_range(ASIdentifiers * asid,int which,ASN1_INTEGER * min,ASN1_INTEGER * max)185 int X509v3_asid_add_id_or_range(ASIdentifiers *asid,
186                                 int which, ASN1_INTEGER *min, ASN1_INTEGER *max)
187 {
188     ASIdentifierChoice **choice;
189     ASIdOrRange *aor;
190     if (asid == NULL)
191         return 0;
192     switch (which) {
193     case V3_ASID_ASNUM:
194         choice = &asid->asnum;
195         break;
196     case V3_ASID_RDI:
197         choice = &asid->rdi;
198         break;
199     default:
200         return 0;
201     }
202     if (*choice != NULL && (*choice)->type != ASIdentifierChoice_asIdsOrRanges)
203         return 0;
204     if (*choice == NULL) {
205         if ((*choice = ASIdentifierChoice_new()) == NULL)
206             return 0;
207         (*choice)->u.asIdsOrRanges = sk_ASIdOrRange_new(ASIdOrRange_cmp);
208         if ((*choice)->u.asIdsOrRanges == NULL) {
209             ASIdentifierChoice_free(*choice);
210             *choice = NULL;
211             return 0;
212         }
213         (*choice)->type = ASIdentifierChoice_asIdsOrRanges;
214     }
215     if ((aor = ASIdOrRange_new()) == NULL)
216         return 0;
217     if (!sk_ASIdOrRange_reserve((*choice)->u.asIdsOrRanges, 1))
218         goto err;
219     if (max == NULL) {
220         aor->type = ASIdOrRange_id;
221         aor->u.id = min;
222     } else {
223         aor->type = ASIdOrRange_range;
224         if ((aor->u.range = ASRange_new()) == NULL)
225             goto err;
226         ASN1_INTEGER_free(aor->u.range->min);
227         aor->u.range->min = min;
228         ASN1_INTEGER_free(aor->u.range->max);
229         aor->u.range->max = max;
230     }
231     /* Cannot fail due to the reservation above */
232     if (!ossl_assert(sk_ASIdOrRange_push((*choice)->u.asIdsOrRanges, aor)))
233         goto err;
234     return 1;
235 
236  err:
237     ASIdOrRange_free(aor);
238     return 0;
239 }
240 
241 /*
242  * Extract min and max values from an ASIdOrRange.
243  */
extract_min_max(ASIdOrRange * aor,ASN1_INTEGER ** min,ASN1_INTEGER ** max)244 static int extract_min_max(ASIdOrRange *aor,
245                            ASN1_INTEGER **min, ASN1_INTEGER **max)
246 {
247     if (!ossl_assert(aor != NULL))
248         return 0;
249     switch (aor->type) {
250     case ASIdOrRange_id:
251         *min = aor->u.id;
252         *max = aor->u.id;
253         return 1;
254     case ASIdOrRange_range:
255         *min = aor->u.range->min;
256         *max = aor->u.range->max;
257         return 1;
258     }
259 
260     return 0;
261 }
262 
263 /*
264  * Check whether an ASIdentifierChoice is in canonical form.
265  */
ASIdentifierChoice_is_canonical(ASIdentifierChoice * choice)266 static int ASIdentifierChoice_is_canonical(ASIdentifierChoice *choice)
267 {
268     ASN1_INTEGER *a_max_plus_one = NULL;
269     ASN1_INTEGER *orig;
270     BIGNUM *bn = NULL;
271     int i, ret = 0;
272 
273     /*
274      * Empty element or inheritance is canonical.
275      */
276     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
277         return 1;
278 
279     /*
280      * If not a list, or if empty list, it's broken.
281      */
282     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
283         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0)
284         return 0;
285 
286     /*
287      * It's a list, check it.
288      */
289     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
290         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
291         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
292         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
293             NULL;
294 
295         if (!extract_min_max(a, &a_min, &a_max)
296                 || !extract_min_max(b, &b_min, &b_max))
297             goto done;
298 
299         /*
300          * Punt misordered list, overlapping start, or inverted range.
301          */
302         if (ASN1_INTEGER_cmp(a_min, b_min) >= 0 ||
303             ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
304             ASN1_INTEGER_cmp(b_min, b_max) > 0)
305             goto done;
306 
307         /*
308          * Calculate a_max + 1 to check for adjacency.
309          */
310         if ((bn == NULL && (bn = BN_new()) == NULL) ||
311             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
312             !BN_add_word(bn, 1)) {
313             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
314             goto done;
315         }
316 
317         if ((a_max_plus_one =
318                 BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
319             a_max_plus_one = orig;
320             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
321             goto done;
322         }
323 
324         /*
325          * Punt if adjacent or overlapping.
326          */
327         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) >= 0)
328             goto done;
329     }
330 
331     /*
332      * Check for inverted range.
333      */
334     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
335     {
336         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
337         ASN1_INTEGER *a_min, *a_max;
338         if (a != NULL && a->type == ASIdOrRange_range) {
339             if (!extract_min_max(a, &a_min, &a_max)
340                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
341                 goto done;
342         }
343     }
344 
345     ret = 1;
346 
347  done:
348     ASN1_INTEGER_free(a_max_plus_one);
349     BN_free(bn);
350     return ret;
351 }
352 
353 /*
354  * Check whether an ASIdentifier extension is in canonical form.
355  */
X509v3_asid_is_canonical(ASIdentifiers * asid)356 int X509v3_asid_is_canonical(ASIdentifiers *asid)
357 {
358     return (asid == NULL ||
359             (ASIdentifierChoice_is_canonical(asid->asnum) &&
360              ASIdentifierChoice_is_canonical(asid->rdi)));
361 }
362 
363 /*
364  * Whack an ASIdentifierChoice into canonical form.
365  */
ASIdentifierChoice_canonize(ASIdentifierChoice * choice)366 static int ASIdentifierChoice_canonize(ASIdentifierChoice *choice)
367 {
368     ASN1_INTEGER *a_max_plus_one = NULL;
369     ASN1_INTEGER *orig;
370     BIGNUM *bn = NULL;
371     int i, ret = 0;
372 
373     /*
374      * Nothing to do for empty element or inheritance.
375      */
376     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
377         return 1;
378 
379     /*
380      * If not a list, or if empty list, it's broken.
381      */
382     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
383         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0) {
384         ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
385         return 0;
386     }
387 
388     /*
389      * We have a non-empty list.  Sort it.
390      */
391     sk_ASIdOrRange_sort(choice->u.asIdsOrRanges);
392 
393     /*
394      * Now check for errors and suboptimal encoding, rejecting the
395      * former and fixing the latter.
396      */
397     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
398         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
399         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
400         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
401             NULL;
402 
403         if (!extract_min_max(a, &a_min, &a_max)
404                 || !extract_min_max(b, &b_min, &b_max))
405             goto done;
406 
407         /*
408          * Make sure we're properly sorted (paranoia).
409          */
410         if (!ossl_assert(ASN1_INTEGER_cmp(a_min, b_min) <= 0))
411             goto done;
412 
413         /*
414          * Punt inverted ranges.
415          */
416         if (ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
417             ASN1_INTEGER_cmp(b_min, b_max) > 0)
418             goto done;
419 
420         /*
421          * Check for overlaps.
422          */
423         if (ASN1_INTEGER_cmp(a_max, b_min) >= 0) {
424             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
425             goto done;
426         }
427 
428         /*
429          * Calculate a_max + 1 to check for adjacency.
430          */
431         if ((bn == NULL && (bn = BN_new()) == NULL) ||
432             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
433             !BN_add_word(bn, 1)) {
434             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
435             goto done;
436         }
437 
438         if ((a_max_plus_one =
439                  BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
440             a_max_plus_one = orig;
441             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
442             goto done;
443         }
444 
445         /*
446          * If a and b are adjacent, merge them.
447          */
448         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) == 0) {
449             ASRange *r;
450             switch (a->type) {
451             case ASIdOrRange_id:
452                 if ((r = OPENSSL_malloc(sizeof(*r))) == NULL) {
453                     ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
454                     goto done;
455                 }
456                 r->min = a_min;
457                 r->max = b_max;
458                 a->type = ASIdOrRange_range;
459                 a->u.range = r;
460                 break;
461             case ASIdOrRange_range:
462                 ASN1_INTEGER_free(a->u.range->max);
463                 a->u.range->max = b_max;
464                 break;
465             }
466             switch (b->type) {
467             case ASIdOrRange_id:
468                 b->u.id = NULL;
469                 break;
470             case ASIdOrRange_range:
471                 b->u.range->max = NULL;
472                 break;
473             }
474             ASIdOrRange_free(b);
475             (void)sk_ASIdOrRange_delete(choice->u.asIdsOrRanges, i + 1);
476             i--;
477             continue;
478         }
479     }
480 
481     /*
482      * Check for final inverted range.
483      */
484     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
485     {
486         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
487         ASN1_INTEGER *a_min, *a_max;
488         if (a != NULL && a->type == ASIdOrRange_range) {
489             if (!extract_min_max(a, &a_min, &a_max)
490                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
491                 goto done;
492         }
493     }
494 
495     /* Paranoia */
496     if (!ossl_assert(ASIdentifierChoice_is_canonical(choice)))
497         goto done;
498 
499     ret = 1;
500 
501  done:
502     ASN1_INTEGER_free(a_max_plus_one);
503     BN_free(bn);
504     return ret;
505 }
506 
507 /*
508  * Whack an ASIdentifier extension into canonical form.
509  */
X509v3_asid_canonize(ASIdentifiers * asid)510 int X509v3_asid_canonize(ASIdentifiers *asid)
511 {
512     return (asid == NULL ||
513             (ASIdentifierChoice_canonize(asid->asnum) &&
514              ASIdentifierChoice_canonize(asid->rdi)));
515 }
516 
517 /*
518  * v2i method for an ASIdentifier extension.
519  */
v2i_ASIdentifiers(const struct v3_ext_method * method,struct v3_ext_ctx * ctx,STACK_OF (CONF_VALUE)* values)520 static void *v2i_ASIdentifiers(const struct v3_ext_method *method,
521                                struct v3_ext_ctx *ctx,
522                                STACK_OF(CONF_VALUE) *values)
523 {
524     ASN1_INTEGER *min = NULL, *max = NULL;
525     ASIdentifiers *asid = NULL;
526     int i;
527 
528     if ((asid = ASIdentifiers_new()) == NULL) {
529         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
530         return NULL;
531     }
532 
533     for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
534         CONF_VALUE *val = sk_CONF_VALUE_value(values, i);
535         int i1 = 0, i2 = 0, i3 = 0, is_range = 0, which = 0;
536 
537         /*
538          * Figure out whether this is an AS or an RDI.
539          */
540         if (!ossl_v3_name_cmp(val->name, "AS")) {
541             which = V3_ASID_ASNUM;
542         } else if (!ossl_v3_name_cmp(val->name, "RDI")) {
543             which = V3_ASID_RDI;
544         } else {
545             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_NAME_ERROR);
546             X509V3_conf_add_error_name_value(val);
547             goto err;
548         }
549 
550         if (val->value == NULL) {
551             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
552             goto err;
553         }
554 
555         /*
556          * Handle inheritance.
557          */
558         if (strcmp(val->value, "inherit") == 0) {
559             if (X509v3_asid_add_inherit(asid, which))
560                 continue;
561             ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_INHERITANCE);
562             X509V3_conf_add_error_name_value(val);
563             goto err;
564         }
565 
566         /*
567          * Number, range, or mistake, pick it apart and figure out which.
568          */
569         i1 = strspn(val->value, "0123456789");
570         if (val->value[i1] == '\0') {
571             is_range = 0;
572         } else {
573             is_range = 1;
574             i2 = i1 + strspn(val->value + i1, " \t");
575             if (val->value[i2] != '-') {
576                 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASNUMBER);
577                 X509V3_conf_add_error_name_value(val);
578                 goto err;
579             }
580             i2++;
581             i2 = i2 + strspn(val->value + i2, " \t");
582             i3 = i2 + strspn(val->value + i2, "0123456789");
583             if (val->value[i3] != '\0') {
584                 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASRANGE);
585                 X509V3_conf_add_error_name_value(val);
586                 goto err;
587             }
588         }
589 
590         /*
591          * Syntax is ok, read and add it.
592          */
593         if (!is_range) {
594             if (!X509V3_get_value_int(val, &min)) {
595                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
596                 goto err;
597             }
598         } else {
599             char *s = OPENSSL_strdup(val->value);
600             if (s == NULL) {
601                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
602                 goto err;
603             }
604             s[i1] = '\0';
605             min = s2i_ASN1_INTEGER(NULL, s);
606             max = s2i_ASN1_INTEGER(NULL, s + i2);
607             OPENSSL_free(s);
608             if (min == NULL || max == NULL) {
609                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
610                 goto err;
611             }
612             if (ASN1_INTEGER_cmp(min, max) > 0) {
613                 ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
614                 goto err;
615             }
616         }
617         if (!X509v3_asid_add_id_or_range(asid, which, min, max)) {
618             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
619             goto err;
620         }
621         min = max = NULL;
622     }
623 
624     /*
625      * Canonize the result, then we're done.
626      */
627     if (!X509v3_asid_canonize(asid))
628         goto err;
629     return asid;
630 
631  err:
632     ASIdentifiers_free(asid);
633     ASN1_INTEGER_free(min);
634     ASN1_INTEGER_free(max);
635     return NULL;
636 }
637 
638 /*
639  * OpenSSL dispatch.
640  */
641 const X509V3_EXT_METHOD ossl_v3_asid = {
642     NID_sbgp_autonomousSysNum,  /* nid */
643     0,                          /* flags */
644     ASN1_ITEM_ref(ASIdentifiers), /* template */
645     0, 0, 0, 0,                 /* old functions, ignored */
646     0,                          /* i2s */
647     0,                          /* s2i */
648     0,                          /* i2v */
649     v2i_ASIdentifiers,          /* v2i */
650     i2r_ASIdentifiers,          /* i2r */
651     0,                          /* r2i */
652     NULL                        /* extension-specific data */
653 };
654 
655 /*
656  * Figure out whether extension uses inheritance.
657  */
X509v3_asid_inherits(ASIdentifiers * asid)658 int X509v3_asid_inherits(ASIdentifiers *asid)
659 {
660     return (asid != NULL &&
661             ((asid->asnum != NULL &&
662               asid->asnum->type == ASIdentifierChoice_inherit) ||
663              (asid->rdi != NULL &&
664               asid->rdi->type == ASIdentifierChoice_inherit)));
665 }
666 
667 /*
668  * Figure out whether parent contains child.
669  */
asid_contains(ASIdOrRanges * parent,ASIdOrRanges * child)670 static int asid_contains(ASIdOrRanges *parent, ASIdOrRanges *child)
671 {
672     ASN1_INTEGER *p_min = NULL, *p_max = NULL, *c_min = NULL, *c_max = NULL;
673     int p, c;
674 
675     if (child == NULL || parent == child)
676         return 1;
677     if (parent == NULL)
678         return 0;
679 
680     p = 0;
681     for (c = 0; c < sk_ASIdOrRange_num(child); c++) {
682         if (!extract_min_max(sk_ASIdOrRange_value(child, c), &c_min, &c_max))
683             return 0;
684         for (;; p++) {
685             if (p >= sk_ASIdOrRange_num(parent))
686                 return 0;
687             if (!extract_min_max(sk_ASIdOrRange_value(parent, p), &p_min,
688                                  &p_max))
689                 return 0;
690             if (ASN1_INTEGER_cmp(p_max, c_max) < 0)
691                 continue;
692             if (ASN1_INTEGER_cmp(p_min, c_min) > 0)
693                 return 0;
694             break;
695         }
696     }
697 
698     return 1;
699 }
700 
701 /*
702  * Test whether a is a subset of b.
703  */
X509v3_asid_subset(ASIdentifiers * a,ASIdentifiers * b)704 int X509v3_asid_subset(ASIdentifiers *a, ASIdentifiers *b)
705 {
706     int subset;
707 
708     if (a == NULL || a == b)
709         return 1;
710 
711     if (b == NULL)
712         return 0;
713 
714     if (X509v3_asid_inherits(a) || X509v3_asid_inherits(b))
715         return 0;
716 
717     subset = a->asnum == NULL
718              || (b->asnum != NULL
719                  && asid_contains(b->asnum->u.asIdsOrRanges,
720                                   a->asnum->u.asIdsOrRanges));
721     if (!subset)
722         return 0;
723 
724     return a->rdi == NULL
725            || (b->rdi != NULL
726                && asid_contains(b->rdi->u.asIdsOrRanges,
727                                 a->rdi->u.asIdsOrRanges));
728 }
729 
730 /*
731  * Validation error handling via callback.
732  */
733 #define validation_err(_err_)           \
734   do {                                  \
735     if (ctx != NULL) {                  \
736       ctx->error = _err_;               \
737       ctx->error_depth = i;             \
738       ctx->current_cert = x;            \
739       ret = ctx->verify_cb(0, ctx);     \
740     } else {                            \
741       ret = 0;                          \
742     }                                   \
743     if (!ret)                           \
744       goto done;                        \
745   } while (0)
746 
747 /*
748  * Core code for RFC 3779 3.3 path validation.
749  */
asid_validate_path_internal(X509_STORE_CTX * ctx,STACK_OF (X509)* chain,ASIdentifiers * ext)750 static int asid_validate_path_internal(X509_STORE_CTX *ctx,
751                                        STACK_OF(X509) *chain,
752                                        ASIdentifiers *ext)
753 {
754     ASIdOrRanges *child_as = NULL, *child_rdi = NULL;
755     int i, ret = 1, inherit_as = 0, inherit_rdi = 0;
756     X509 *x;
757 
758     if (!ossl_assert(chain != NULL && sk_X509_num(chain) > 0)
759             || !ossl_assert(ctx != NULL || ext != NULL)
760             || !ossl_assert(ctx == NULL || ctx->verify_cb != NULL)) {
761         if (ctx != NULL)
762             ctx->error = X509_V_ERR_UNSPECIFIED;
763         return 0;
764     }
765 
766 
767     /*
768      * Figure out where to start.  If we don't have an extension to
769      * check, we're done.  Otherwise, check canonical form and
770      * set up for walking up the chain.
771      */
772     if (ext != NULL) {
773         i = -1;
774         x = NULL;
775     } else {
776         i = 0;
777         x = sk_X509_value(chain, i);
778         if ((ext = x->rfc3779_asid) == NULL)
779             goto done;
780     }
781     if (!X509v3_asid_is_canonical(ext))
782         validation_err(X509_V_ERR_INVALID_EXTENSION);
783     if (ext->asnum != NULL) {
784         switch (ext->asnum->type) {
785         case ASIdentifierChoice_inherit:
786             inherit_as = 1;
787             break;
788         case ASIdentifierChoice_asIdsOrRanges:
789             child_as = ext->asnum->u.asIdsOrRanges;
790             break;
791         }
792     }
793     if (ext->rdi != NULL) {
794         switch (ext->rdi->type) {
795         case ASIdentifierChoice_inherit:
796             inherit_rdi = 1;
797             break;
798         case ASIdentifierChoice_asIdsOrRanges:
799             child_rdi = ext->rdi->u.asIdsOrRanges;
800             break;
801         }
802     }
803 
804     /*
805      * Now walk up the chain.  Extensions must be in canonical form, no
806      * cert may list resources that its parent doesn't list.
807      */
808     for (i++; i < sk_X509_num(chain); i++) {
809         x = sk_X509_value(chain, i);
810         if (!ossl_assert(x != NULL)) {
811             if (ctx != NULL)
812                 ctx->error = X509_V_ERR_UNSPECIFIED;
813             return 0;
814         }
815         if (x->rfc3779_asid == NULL) {
816             if (child_as != NULL || child_rdi != NULL)
817                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
818             continue;
819         }
820         if (!X509v3_asid_is_canonical(x->rfc3779_asid))
821             validation_err(X509_V_ERR_INVALID_EXTENSION);
822         if (x->rfc3779_asid->asnum == NULL && child_as != NULL) {
823             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
824             child_as = NULL;
825             inherit_as = 0;
826         }
827         if (x->rfc3779_asid->asnum != NULL &&
828             x->rfc3779_asid->asnum->type ==
829             ASIdentifierChoice_asIdsOrRanges) {
830             if (inherit_as
831                 || asid_contains(x->rfc3779_asid->asnum->u.asIdsOrRanges,
832                                  child_as)) {
833                 child_as = x->rfc3779_asid->asnum->u.asIdsOrRanges;
834                 inherit_as = 0;
835             } else {
836                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
837             }
838         }
839         if (x->rfc3779_asid->rdi == NULL && child_rdi != NULL) {
840             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
841             child_rdi = NULL;
842             inherit_rdi = 0;
843         }
844         if (x->rfc3779_asid->rdi != NULL &&
845             x->rfc3779_asid->rdi->type == ASIdentifierChoice_asIdsOrRanges) {
846             if (inherit_rdi ||
847                 asid_contains(x->rfc3779_asid->rdi->u.asIdsOrRanges,
848                               child_rdi)) {
849                 child_rdi = x->rfc3779_asid->rdi->u.asIdsOrRanges;
850                 inherit_rdi = 0;
851             } else {
852                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
853             }
854         }
855     }
856 
857     /*
858      * Trust anchor can't inherit.
859      */
860     if (!ossl_assert(x != NULL)) {
861         if (ctx != NULL)
862             ctx->error = X509_V_ERR_UNSPECIFIED;
863         return 0;
864     }
865     if (x->rfc3779_asid != NULL) {
866         if (x->rfc3779_asid->asnum != NULL &&
867             x->rfc3779_asid->asnum->type == ASIdentifierChoice_inherit)
868             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
869         if (x->rfc3779_asid->rdi != NULL &&
870             x->rfc3779_asid->rdi->type == ASIdentifierChoice_inherit)
871             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
872     }
873 
874  done:
875     return ret;
876 }
877 
878 #undef validation_err
879 
880 /*
881  * RFC 3779 3.3 path validation -- called from X509_verify_cert().
882  */
X509v3_asid_validate_path(X509_STORE_CTX * ctx)883 int X509v3_asid_validate_path(X509_STORE_CTX *ctx)
884 {
885     if (ctx->chain == NULL
886             || sk_X509_num(ctx->chain) == 0
887             || ctx->verify_cb == NULL) {
888         ctx->error = X509_V_ERR_UNSPECIFIED;
889         return 0;
890     }
891     return asid_validate_path_internal(ctx, ctx->chain, NULL);
892 }
893 
894 /*
895  * RFC 3779 3.3 path validation of an extension.
896  * Test whether chain covers extension.
897  */
X509v3_asid_validate_resource_set(STACK_OF (X509)* chain,ASIdentifiers * ext,int allow_inheritance)898 int X509v3_asid_validate_resource_set(STACK_OF(X509) *chain,
899                                       ASIdentifiers *ext, int allow_inheritance)
900 {
901     if (ext == NULL)
902         return 1;
903     if (chain == NULL || sk_X509_num(chain) == 0)
904         return 0;
905     if (!allow_inheritance && X509v3_asid_inherits(ext))
906         return 0;
907     return asid_validate_path_internal(NULL, chain, ext);
908 }
909 
910 #endif                          /* OPENSSL_NO_RFC3779 */
911