ds.c revision 193149 
1/*
2 * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2002, 2003  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: ds.c,v 1.11 2007/06/19 23:47:16 tbox Exp $ */
19
20/*! \file */
21
22#include <config.h>
23
24#include <string.h>
25
26#include <isc/buffer.h>
27#include <isc/region.h>
28#include <isc/sha1.h>
29#include <isc/sha2.h>
30#include <isc/util.h>
31
32#include <dns/ds.h>
33#include <dns/fixedname.h>
34#include <dns/name.h>
35#include <dns/rdata.h>
36#include <dns/rdatastruct.h>
37#include <dns/result.h>
38
39#include <dst/dst.h>
40
41isc_result_t
42dns_ds_buildrdata(dns_name_t *owner, dns_rdata_t *key,
43		  unsigned int digest_type, unsigned char *buffer,
44		  dns_rdata_t *rdata)
45{
46	dns_fixedname_t fname;
47	dns_name_t *name;
48	unsigned char digest[ISC_SHA256_DIGESTLENGTH];
49	isc_region_t r;
50	isc_buffer_t b;
51	dns_rdata_ds_t ds;
52
53	REQUIRE(key != NULL);
54	REQUIRE(key->type == dns_rdatatype_dnskey);
55
56	if (!dns_ds_digest_supported(digest_type))
57		return (ISC_R_NOTIMPLEMENTED);
58
59	dns_fixedname_init(&fname);
60	name = dns_fixedname_name(&fname);
61	(void)dns_name_downcase(owner, name, NULL);
62
63	memset(buffer, 0, DNS_DS_BUFFERSIZE);
64	isc_buffer_init(&b, buffer, DNS_DS_BUFFERSIZE);
65
66	if (digest_type == DNS_DSDIGEST_SHA1) {
67		isc_sha1_t sha1;
68		isc_sha1_init(&sha1);
69		dns_name_toregion(name, &r);
70		isc_sha1_update(&sha1, r.base, r.length);
71		dns_rdata_toregion(key, &r);
72		INSIST(r.length >= 4);
73		isc_sha1_update(&sha1, r.base, r.length);
74		isc_sha1_final(&sha1, digest);
75	} else {
76		isc_sha256_t sha256;
77		isc_sha256_init(&sha256);
78		dns_name_toregion(name, &r);
79		isc_sha256_update(&sha256, r.base, r.length);
80		dns_rdata_toregion(key, &r);
81		INSIST(r.length >= 4);
82		isc_sha256_update(&sha256, r.base, r.length);
83		isc_sha256_final(digest, &sha256);
84	}
85
86	ds.mctx = NULL;
87	ds.common.rdclass = key->rdclass;
88	ds.common.rdtype = dns_rdatatype_ds;
89	ds.algorithm = r.base[3];
90	ds.key_tag = dst_region_computeid(&r, ds.algorithm);
91	ds.digest_type = digest_type;
92	ds.length = (digest_type == DNS_DSDIGEST_SHA1) ?
93		    ISC_SHA1_DIGESTLENGTH : ISC_SHA256_DIGESTLENGTH;
94	ds.digest = digest;
95
96	return (dns_rdata_fromstruct(rdata, key->rdclass, dns_rdatatype_ds,
97				     &ds, &b));
98}
99
100isc_boolean_t
101dns_ds_digest_supported(unsigned int digest_type) {
102	return  (ISC_TF(digest_type == DNS_DSDIGEST_SHA1 ||
103			digest_type == DNS_DSDIGEST_SHA256));
104}
105