xref: /netbsd-src/external/mpl/dhcp/bind/dist/lib/dns/ds.c (revision 4afad4b7fa6d4a0d3dedf41d1587a7250710ae54)
1 /*	$NetBSD: ds.c,v 1.1 2024/02/18 20:57:31 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 <string.h>
19 
20 #include <isc/buffer.h>
21 #include <isc/md.h>
22 #include <isc/region.h>
23 #include <isc/util.h>
24 
25 #include <dns/ds.h>
26 #include <dns/fixedname.h>
27 #include <dns/name.h>
28 #include <dns/rdata.h>
29 #include <dns/rdatastruct.h>
30 #include <dns/result.h>
31 
32 #include <dst/dst.h>
33 
34 isc_result_t
dns_ds_fromkeyrdata(const dns_name_t * owner,dns_rdata_t * key,dns_dsdigest_t digest_type,unsigned char * digest,dns_rdata_ds_t * dsrdata)35 dns_ds_fromkeyrdata(const dns_name_t *owner, dns_rdata_t *key,
36 		    dns_dsdigest_t digest_type, unsigned char *digest,
37 		    dns_rdata_ds_t *dsrdata) {
38 	isc_result_t result;
39 	dns_fixedname_t fname;
40 	dns_name_t *name;
41 	unsigned int digestlen;
42 	isc_region_t r;
43 	isc_md_t *md;
44 	const isc_md_type_t *md_type = NULL;
45 
46 	REQUIRE(key != NULL);
47 	REQUIRE(key->type == dns_rdatatype_dnskey ||
48 		key->type == dns_rdatatype_cdnskey);
49 
50 	if (!dst_ds_digest_supported(digest_type)) {
51 		return (ISC_R_NOTIMPLEMENTED);
52 	}
53 
54 	switch (digest_type) {
55 	case DNS_DSDIGEST_SHA1:
56 		md_type = ISC_MD_SHA1;
57 		break;
58 
59 	case DNS_DSDIGEST_SHA384:
60 		md_type = ISC_MD_SHA384;
61 		break;
62 
63 	case DNS_DSDIGEST_SHA256:
64 		md_type = ISC_MD_SHA256;
65 		break;
66 
67 	default:
68 		UNREACHABLE();
69 	}
70 
71 	name = dns_fixedname_initname(&fname);
72 	(void)dns_name_downcase(owner, name, NULL);
73 
74 	md = isc_md_new();
75 	if (md == NULL) {
76 		return (ISC_R_NOMEMORY);
77 	}
78 
79 	result = isc_md_init(md, md_type);
80 	if (result != ISC_R_SUCCESS) {
81 		goto end;
82 	}
83 
84 	dns_name_toregion(name, &r);
85 
86 	result = isc_md_update(md, r.base, r.length);
87 	if (result != ISC_R_SUCCESS) {
88 		goto end;
89 	}
90 
91 	dns_rdata_toregion(key, &r);
92 	INSIST(r.length >= 4);
93 
94 	result = isc_md_update(md, r.base, r.length);
95 	if (result != ISC_R_SUCCESS) {
96 		goto end;
97 	}
98 
99 	result = isc_md_final(md, digest, &digestlen);
100 	if (result != ISC_R_SUCCESS) {
101 		goto end;
102 	}
103 
104 	dsrdata->mctx = NULL;
105 	dsrdata->common.rdclass = key->rdclass;
106 	dsrdata->common.rdtype = dns_rdatatype_ds;
107 	dsrdata->algorithm = r.base[3];
108 	dsrdata->key_tag = dst_region_computeid(&r);
109 	dsrdata->digest_type = digest_type;
110 	dsrdata->digest = digest;
111 	dsrdata->length = digestlen;
112 
113 end:
114 	isc_md_free(md);
115 	return (result);
116 }
117 
118 isc_result_t
dns_ds_buildrdata(dns_name_t * owner,dns_rdata_t * key,dns_dsdigest_t digest_type,unsigned char * buffer,dns_rdata_t * rdata)119 dns_ds_buildrdata(dns_name_t *owner, dns_rdata_t *key,
120 		  dns_dsdigest_t digest_type, unsigned char *buffer,
121 		  dns_rdata_t *rdata) {
122 	isc_result_t result;
123 	unsigned char digest[ISC_MAX_MD_SIZE];
124 	dns_rdata_ds_t ds;
125 	isc_buffer_t b;
126 
127 	result = dns_ds_fromkeyrdata(owner, key, digest_type, digest, &ds);
128 	if (result != ISC_R_SUCCESS) {
129 		return (result);
130 	}
131 
132 	memset(buffer, 0, DNS_DS_BUFFERSIZE);
133 	isc_buffer_init(&b, buffer, DNS_DS_BUFFERSIZE);
134 	result = dns_rdata_fromstruct(rdata, key->rdclass, dns_rdatatype_ds,
135 				      &ds, &b);
136 	return (result);
137 }
138