1 files changed, 135 insertions, 0 deletions
diff --git a/lib/dns/ds.c b/lib/dns/ds.c
new file mode 100644
index 0000000..22f158b
--- /dev/null
+++ b/lib/dns/ds.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <string.h>
+
+#include <isc/buffer.h>
+#include <isc/md.h>
+#include <isc/region.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/ds.h>
+#include <dns/fixedname.h>
+#include <dns/name.h>
+#include <dns/rdata.h>
+#include <dns/rdatastruct.h>
+
+#include <dst/dst.h>
+
+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) {
+	isc_result_t result;
+	dns_fixedname_t fname;
+	dns_name_t *name;
+	unsigned int digestlen;
+	isc_region_t r;
+	isc_md_t *md;
+	const isc_md_type_t *md_type = NULL;
+
+	REQUIRE(key != NULL);
+	REQUIRE(key->type == dns_rdatatype_dnskey ||
+		key->type == dns_rdatatype_cdnskey);
+
+	if (!dst_ds_digest_supported(digest_type)) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	switch (digest_type) {
+	case DNS_DSDIGEST_SHA1:
+		md_type = ISC_MD_SHA1;
+		break;
+
+	case DNS_DSDIGEST_SHA384:
+		md_type = ISC_MD_SHA384;
+		break;
+
+	case DNS_DSDIGEST_SHA256:
+		md_type = ISC_MD_SHA256;
+		break;
+
+	default:
+		UNREACHABLE();
+	}
+
+	name = dns_fixedname_initname(&fname);
+	(void)dns_name_downcase(owner, name, NULL);
+
+	md = isc_md_new();
+	if (md == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	result = isc_md_init(md, md_type);
+	if (result != ISC_R_SUCCESS) {
+		goto end;
+	}
+
+	dns_name_toregion(name, &r);
+
+	result = isc_md_update(md, r.base, r.length);
+	if (result != ISC_R_SUCCESS) {
+		goto end;
+	}
+
+	dns_rdata_toregion(key, &r);
+	INSIST(r.length >= 4);
+
+	result = isc_md_update(md, r.base, r.length);
+	if (result != ISC_R_SUCCESS) {
+		goto end;
+	}
+
+	result = isc_md_final(md, digest, &digestlen);
+	if (result != ISC_R_SUCCESS) {
+		goto end;
+	}
+
+	dsrdata->mctx = NULL;
+	dsrdata->common.rdclass = key->rdclass;
+	dsrdata->common.rdtype = dns_rdatatype_ds;
+	dsrdata->algorithm = r.base[3];
+	dsrdata->key_tag = dst_region_computeid(&r);
+	dsrdata->digest_type = digest_type;
+	dsrdata->digest = digest;
+	dsrdata->length = digestlen;
+
+end:
+	isc_md_free(md);
+	return (result);
+}
+
+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) {
+	isc_result_t result;
+	unsigned char digest[ISC_MAX_MD_SIZE];
+	dns_rdata_ds_t ds;
+	isc_buffer_t b;
+
+	result = dns_ds_fromkeyrdata(owner, key, digest_type, digest, &ds);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	memset(buffer, 0, DNS_DS_BUFFERSIZE);
+	isc_buffer_init(&b, buffer, DNS_DS_BUFFERSIZE);
+	result = dns_rdata_fromstruct(rdata, key->rdclass, dns_rdatatype_ds,
+				      &ds, &b);
+	return (result);
+}