contrib/bind-9.5.2/lib/dns/ds.c

   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
  41 isc_result_t
  42 dns_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
 100 isc_boolean_t
 101 dns_ds_digest_supported(unsigned int digest_type) {
 102         return  (ISC_TF(digest_type == DNS_DSDIGEST_SHA1 ||
 103                         digest_type == DNS_DSDIGEST_SHA256));
 104 }