1 /* $OpenBSD: as.c,v 1.16 2023/12/27 07:15:55 tb Exp $ */
2 /*
3 * Copyright (c) 2019 Kristaps Dzonsons <kristaps@bsd.lv>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <err.h>
19 #include <stdint.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include "extern.h"
25
26 /* Parse a uint32_t AS identifier from an ASN1_INTEGER. */
27 int
as_id_parse(const ASN1_INTEGER * v,uint32_t * out)28 as_id_parse(const ASN1_INTEGER *v, uint32_t *out)
29 {
30 uint64_t res = 0;
31
32 if (!ASN1_INTEGER_get_uint64(&res, v))
33 return 0;
34 if (res > UINT32_MAX)
35 return 0;
36 *out = res;
37 return 1;
38 }
39
40 /*
41 * Given a newly-parsed AS number or range "a", make sure that "a" does
42 * not overlap with any other numbers or ranges in the "as" array.
43 * This is defined by RFC 3779 section 3.2.3.4.
44 * Returns zero on failure, non-zero on success.
45 */
46 int
as_check_overlap(const struct cert_as * a,const char * fn,const struct cert_as * as,size_t asz,int quiet)47 as_check_overlap(const struct cert_as *a, const char *fn,
48 const struct cert_as *as, size_t asz, int quiet)
49 {
50 size_t i;
51
52 /* We can have only one inheritance statement. */
53
54 if (asz &&
55 (a->type == CERT_AS_INHERIT || as[0].type == CERT_AS_INHERIT)) {
56 if (!quiet) {
57 warnx("%s: RFC 3779 section 3.2.3.3: "
58 "cannot have inheritance and multiple ASnum or "
59 "multiple inheritance", fn);
60 }
61 return 0;
62 }
63
64 /* Now check for overlaps between singletons/ranges. */
65
66 for (i = 0; i < asz; i++) {
67 switch (as[i].type) {
68 case CERT_AS_ID:
69 switch (a->type) {
70 case CERT_AS_ID:
71 if (a->id != as[i].id)
72 continue;
73 break;
74 case CERT_AS_RANGE:
75 if (as->range.min > as[i].id ||
76 as->range.max < as[i].id)
77 continue;
78 break;
79 default:
80 abort();
81 }
82 break;
83 case CERT_AS_RANGE:
84 switch (a->type) {
85 case CERT_AS_ID:
86 if (as[i].range.min > a->id ||
87 as[i].range.max < a->id)
88 continue;
89 break;
90 case CERT_AS_RANGE:
91 if (a->range.max < as[i].range.min ||
92 a->range.min > as[i].range.max)
93 continue;
94 break;
95 default:
96 abort();
97 }
98 break;
99 default:
100 abort();
101 }
102 if (!quiet) {
103 warnx("%s: RFC 3779 section 3.2.3.4: "
104 "cannot have overlapping ASnum", fn);
105 }
106 return 0;
107 }
108
109 return 1;
110 }
111
112 /*
113 * See if a given AS range (which may be the same number, in the case of
114 * singleton AS identifiers) is covered by the AS numbers or ranges
115 * specified in the "as" array.
116 * Return <0 if there is no cover, 0 if we're inheriting, >0 if there is.
117 */
118 int
as_check_covered(uint32_t min,uint32_t max,const struct cert_as * as,size_t asz)119 as_check_covered(uint32_t min, uint32_t max,
120 const struct cert_as *as, size_t asz)
121 {
122 size_t i;
123 uint32_t amin, amax;
124
125 for (i = 0; i < asz; i++) {
126 if (as[i].type == CERT_AS_INHERIT)
127 return 0;
128 amin = as[i].type == CERT_AS_RANGE ?
129 as[i].range.min : as[i].id;
130 amax = as[i].type == CERT_AS_RANGE ?
131 as[i].range.max : as[i].id;
132 if (min >= amin && max <= amax)
133 return 1;
134 }
135
136 return -1;
137 }
138
139 void
as_warn(const char * fn,const char * msg,const struct cert_as * as)140 as_warn(const char *fn, const char *msg, const struct cert_as *as)
141 {
142 switch (as->type) {
143 case CERT_AS_ID:
144 warnx("%s: %s: AS %u", fn, msg, as->id);
145 break;
146 case CERT_AS_RANGE:
147 warnx("%s: %s: AS range %u--%u", fn, msg, as->range.min,
148 as->range.max);
149 break;
150 case CERT_AS_INHERIT:
151 warnx("%s: %s: AS (inherit)", fn, msg);
152 break;
153 default:
154 warnx("%s: corrupt cert", fn);
155 break;
156 }
157 }
158