xref: /netbsd-src/external/mpl/bind/dist/bin/named/tsigconf.c (revision bcda20f65a8566e103791ec395f7f499ef322704)
1 /*	$NetBSD: tsigconf.c,v 1.9 2025/01/26 16:24:33 christos Exp $	*/
2 
3 /*
4  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5  *
6  * SPDX-License-Identifier: MPL-2.0
7  *
8  * This Source Code Form is subject to the terms of the Mozilla Public
9  * License, v. 2.0. If a copy of the MPL was not distributed with this
10  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11  *
12  * See the COPYRIGHT file distributed with this work for additional
13  * information regarding copyright ownership.
14  */
15 
16 /*! \file */
17 
18 #include <inttypes.h>
19 
20 #include <isc/base64.h>
21 #include <isc/buffer.h>
22 #include <isc/mem.h>
23 #include <isc/result.h>
24 #include <isc/string.h>
25 #include <isc/util.h>
26 
27 #include <dns/tsig.h>
28 
29 #include <isccfg/cfg.h>
30 
31 #include <named/config.h>
32 #include <named/log.h>
33 #include <named/tsigconf.h>
34 
35 static isc_result_t
36 add_initial_keys(const cfg_obj_t *list, dns_tsigkeyring_t *ring,
37 		 isc_mem_t *mctx) {
38 	dns_tsigkey_t *tsigkey = NULL;
39 	const cfg_listelt_t *element;
40 	const cfg_obj_t *key = NULL;
41 	const char *keyid = NULL;
42 	unsigned char *secret = NULL;
43 	int secretalloc = 0;
44 	isc_result_t ret;
45 
46 	for (element = cfg_list_first(list); element != NULL;
47 	     element = cfg_list_next(element))
48 	{
49 		const cfg_obj_t *algobj = NULL;
50 		const cfg_obj_t *secretobj = NULL;
51 		dns_name_t keyname;
52 		dst_algorithm_t alg = DST_ALG_UNKNOWN;
53 		const char *algstr = NULL;
54 		char keynamedata[1024];
55 		isc_buffer_t keynamesrc, keynamebuf;
56 		const char *secretstr = NULL;
57 		isc_buffer_t secretbuf;
58 		int secretlen = 0;
59 		uint16_t bits;
60 
61 		key = cfg_listelt_value(element);
62 		keyid = cfg_obj_asstring(cfg_map_getname(key));
63 
64 		algobj = NULL;
65 		secretobj = NULL;
66 		(void)cfg_map_get(key, "algorithm", &algobj);
67 		(void)cfg_map_get(key, "secret", &secretobj);
68 		INSIST(algobj != NULL && secretobj != NULL);
69 
70 		/*
71 		 * Create the key name.
72 		 */
73 		dns_name_init(&keyname, NULL);
74 		isc_buffer_constinit(&keynamesrc, keyid, strlen(keyid));
75 		isc_buffer_add(&keynamesrc, strlen(keyid));
76 		isc_buffer_init(&keynamebuf, keynamedata, sizeof(keynamedata));
77 		ret = dns_name_fromtext(&keyname, &keynamesrc, dns_rootname,
78 					DNS_NAME_DOWNCASE, &keynamebuf);
79 		if (ret != ISC_R_SUCCESS) {
80 			goto failure;
81 		}
82 
83 		/*
84 		 * Create the algorithm.
85 		 */
86 		algstr = cfg_obj_asstring(algobj);
87 		if (named_config_getkeyalgorithm(algstr, &alg, &bits) !=
88 		    ISC_R_SUCCESS)
89 		{
90 			cfg_obj_log(algobj, named_g_lctx, ISC_LOG_ERROR,
91 				    "key '%s': has a "
92 				    "unsupported algorithm '%s'",
93 				    keyid, algstr);
94 			ret = DNS_R_BADALG;
95 			goto failure;
96 		}
97 
98 		secretstr = cfg_obj_asstring(secretobj);
99 		secretalloc = secretlen = strlen(secretstr) * 3 / 4;
100 		secret = isc_mem_get(mctx, secretlen);
101 		isc_buffer_init(&secretbuf, secret, secretlen);
102 		ret = isc_base64_decodestring(secretstr, &secretbuf);
103 		if (ret != ISC_R_SUCCESS) {
104 			goto failure;
105 		}
106 		secretlen = isc_buffer_usedlength(&secretbuf);
107 
108 		ret = dns_tsigkey_create(&keyname, alg, secret, secretlen, mctx,
109 					 &tsigkey);
110 		isc_mem_put(mctx, secret, secretalloc);
111 		secret = NULL;
112 		if (ret == ISC_R_SUCCESS) {
113 			ret = dns_tsigkeyring_add(ring, tsigkey);
114 		}
115 		if (ret != ISC_R_SUCCESS) {
116 			if (tsigkey != NULL) {
117 				dns_tsigkey_detach(&tsigkey);
118 			}
119 			goto failure;
120 		}
121 		/*
122 		 * Set digest bits.
123 		 */
124 		dst_key_setbits(tsigkey->key, bits);
125 		dns_tsigkey_detach(&tsigkey);
126 	}
127 
128 	return ISC_R_SUCCESS;
129 
130 failure:
131 	if (secret != NULL) {
132 		isc_mem_put(mctx, secret, secretalloc);
133 	}
134 	cfg_obj_log(key, named_g_lctx, ISC_LOG_ERROR,
135 		    "configuring key '%s': %s", keyid, isc_result_totext(ret));
136 	return ret;
137 }
138 
139 isc_result_t
140 named_tsigkeyring_fromconfig(const cfg_obj_t *config, const cfg_obj_t *vconfig,
141 			     isc_mem_t *mctx, dns_tsigkeyring_t **ringp) {
142 	const cfg_obj_t *maps[3];
143 	const cfg_obj_t *keylist;
144 	dns_tsigkeyring_t *ring = NULL;
145 	isc_result_t result;
146 	int i;
147 
148 	REQUIRE(ringp != NULL && *ringp == NULL);
149 
150 	i = 0;
151 	if (config != NULL) {
152 		maps[i++] = config;
153 	}
154 	if (vconfig != NULL) {
155 		maps[i++] = cfg_tuple_get(vconfig, "options");
156 	}
157 	maps[i] = NULL;
158 
159 	dns_tsigkeyring_create(mctx, &ring);
160 
161 	for (i = 0;; i++) {
162 		if (maps[i] == NULL) {
163 			break;
164 		}
165 		keylist = NULL;
166 		result = cfg_map_get(maps[i], "key", &keylist);
167 		if (result != ISC_R_SUCCESS) {
168 			continue;
169 		}
170 		result = add_initial_keys(keylist, ring, mctx);
171 		if (result != ISC_R_SUCCESS) {
172 			goto failure;
173 		}
174 	}
175 
176 	*ringp = ring;
177 	return ISC_R_SUCCESS;
178 
179 failure:
180 	dns_tsigkeyring_detach(&ring);
181 	return result;
182 }
183