1 files changed, 439 insertions, 0 deletions
diff --git a/src/libdnssec/key/key.c b/src/libdnssec/key/key.c
new file mode 100644
index 0000000..f363167
--- /dev/null
+++ b/src/libdnssec/key/key.c
@@ -0,0 +1,439 @@
+/*  Copyright (C) 2019 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <gnutls/abstract.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libdnssec/binary.h"
+#include "libdnssec/error.h"
+#include "libdnssec/key.h"
+#include "libdnssec/key/algorithm.h"
+#include "libdnssec/key/convert.h"
+#include "libdnssec/key/dnskey.h"
+#include "libdnssec/key/internal.h"
+#include "libdnssec/shared/keyid_gnutls.h"
+#include "libdnssec/keystore.h"
+#include "libdnssec/keytag.h"
+#include "libdnssec/shared/shared.h"
+#include "libdnssec/shared/binary_wire.h"
+#include "contrib/wire_ctx.h"
+
+/*!
+ * Minimal size of DNSKEY RDATA.
+ */
+#define DNSKEY_RDATA_MIN_SIZE DNSKEY_RDATA_OFFSET_PUBKEY
+
+/*!
+ * RDATA template for newly allocated keys.
+ */
+static const dnssec_binary_t DNSKEY_RDATA_TEMPLATE = {
+	.size = 4,
+	.data = (uint8_t []) { 0x01, 0x00, 0x03, 0x00 }
+};
+
+/* -- key allocation ------------------------------------------------------- */
+
+_public_
+int dnssec_key_new(dnssec_key_t **key_ptr)
+{
+	if (!key_ptr) {
+		return DNSSEC_EINVAL;
+	}
+
+	dnssec_key_t *key = calloc(1, sizeof(*key));
+	if (!key) {
+		return DNSSEC_ENOMEM;
+	}
+
+	int r = dnssec_binary_dup(&DNSKEY_RDATA_TEMPLATE, &key->rdata);
+	if (r != DNSSEC_EOK) {
+		free(key);
+		return DNSSEC_ENOMEM;
+	}
+
+	*key_ptr = key;
+
+	return DNSSEC_EOK;
+}
+
+/*!
+ * Clear allocated fields inside the key structure, except RDATA.
+ */
+static void key_free_internals(dnssec_key_t *key)
+{
+	assert(key);
+
+	free(key->dname);
+	key->dname = NULL;
+
+	gnutls_privkey_deinit(key->private_key);
+	key->private_key = NULL;
+
+	gnutls_pubkey_deinit(key->public_key);
+	key->public_key = NULL;
+}
+
+_public_
+void dnssec_key_clear(dnssec_key_t *key)
+{
+	if (!key) {
+		return;
+	}
+
+	// reuse RDATA
+	dnssec_binary_t rdata = key->rdata;
+
+	// clear the structure
+	key_free_internals(key);
+	clear_struct(key);
+
+	// restore template RDATA (downsize, no need to realloc)
+	assert(rdata.size >= DNSKEY_RDATA_MIN_SIZE);
+	rdata.size = DNSKEY_RDATA_MIN_SIZE;
+	memmove(rdata.data, DNSKEY_RDATA_TEMPLATE.data, rdata.size);
+
+	key->rdata = rdata;
+}
+
+_public_
+void dnssec_key_free(dnssec_key_t *key)
+{
+	if (!key) {
+		return;
+	}
+
+	key_free_internals(key);
+	dnssec_binary_free(&key->rdata);
+
+	free(key);
+}
+
+_public_
+dnssec_key_t *dnssec_key_dup(const dnssec_key_t *key)
+{
+	if (!key) {
+		return NULL;
+	}
+
+	dnssec_key_t *dup = NULL;
+
+	if (dnssec_key_new(&dup) != DNSSEC_EOK ||
+	    dnssec_key_set_dname(dup, key->dname) != DNSSEC_EOK ||
+	    dnssec_key_set_rdata(dup, &key->rdata) != DNSSEC_EOK
+	) {
+		dnssec_key_free(dup);
+		return NULL;
+	}
+
+	return dup;
+}
+
+/* -- freely modifiable attributes ----------------------------------------- */
+
+_public_
+const uint8_t *dnssec_key_get_dname(const dnssec_key_t *key)
+{
+	if (!key) {
+		return NULL;
+	}
+
+	return key->dname;
+}
+
+_public_
+int dnssec_key_set_dname(dnssec_key_t *key, const uint8_t *dname)
+{
+	if (!key) {
+		return DNSSEC_EINVAL;
+	}
+
+	uint8_t *copy = NULL;
+	if (dname) {
+		copy = dname_copy(dname);
+		if (!copy) {
+			return DNSSEC_ENOMEM;
+		}
+
+		dname_normalize(copy);
+	}
+
+	free(key->dname);
+	key->dname = copy;
+
+	return DNSSEC_EOK;
+}
+
+_public_
+uint16_t dnssec_key_get_flags(const dnssec_key_t *key)
+{
+	if (!key) {
+		return 0;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_FLAGS);
+	return wire_ctx_read_u16(&wire);
+}
+
+_public_
+int dnssec_key_set_flags(dnssec_key_t *key, uint16_t flags)
+{
+	if (!key) {
+		return DNSSEC_EINVAL;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_FLAGS);
+	wire_ctx_write_u16(&wire, flags);
+
+	return DNSSEC_EOK;
+}
+
+_public_
+uint8_t dnssec_key_get_protocol(const dnssec_key_t *key)
+{
+	if (!key) {
+		return 0;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_PROTOCOL);
+	return wire_ctx_read_u8(&wire);
+}
+
+_public_
+int dnssec_key_set_protocol(dnssec_key_t *key, uint8_t protocol)
+{
+	if (!key) {
+		return DNSSEC_EINVAL;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_PROTOCOL);
+	wire_ctx_write_u8(&wire, protocol);
+
+	return DNSSEC_EOK;
+}
+
+/* -- restricted attributes ------------------------------------------------ */
+
+_public_
+uint16_t dnssec_key_get_keytag(const dnssec_key_t *key)
+{
+	uint16_t keytag = 0;
+	if (dnssec_key_can_verify(key)) {
+		dnssec_keytag(&key->rdata, &keytag);
+	}
+
+	return keytag;
+}
+
+/*!
+ * Check if current public key algorithm matches with the new algorithm.
+ */
+static bool can_change_algorithm(dnssec_key_t *key, uint8_t algorithm)
+{
+	assert(key);
+
+	if (!key->public_key) {
+		return true;
+	}
+
+	gnutls_pk_algorithm_t update = algorithm_to_gnutls(algorithm);
+	if (update == GNUTLS_PK_UNKNOWN) {
+		return false;
+	}
+
+	int current = gnutls_pubkey_get_pk_algorithm(key->public_key, NULL);
+	assert(current >= 0);
+
+	return current == update;
+}
+
+_public_
+uint8_t dnssec_key_get_algorithm(const dnssec_key_t *key)
+{
+	if (!key) {
+		return 0;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_ALGORITHM);
+	return wire_ctx_read_u8(&wire);
+}
+
+_public_
+int dnssec_key_set_algorithm(dnssec_key_t *key, uint8_t algorithm)
+{
+	if (!key) {
+		return DNSSEC_EINVAL;
+	}
+
+	if (!can_change_algorithm(key, algorithm)) {
+		return DNSSEC_INVALID_KEY_ALGORITHM;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_ALGORITHM);
+	wire_ctx_write_u8(&wire, algorithm);
+
+	return DNSSEC_EOK;
+}
+
+_public_
+int dnssec_key_get_pubkey(const dnssec_key_t *key, dnssec_binary_t *pubkey)
+{
+	if (!key || !pubkey) {
+		return DNSSEC_EINVAL;
+	}
+
+	wire_ctx_t wire = binary_init(&key->rdata);
+	wire_ctx_set_offset(&wire, DNSKEY_RDATA_OFFSET_PUBKEY);
+	binary_available(&wire, pubkey);
+
+	return DNSSEC_EOK;
+}
+
+_public_
+int dnssec_key_set_pubkey(dnssec_key_t *key, const dnssec_binary_t *pubkey)
+{
+	if (!key || !pubkey || !pubkey->data) {
+		return DNSSEC_EINVAL;
+	}
+
+	if (key->public_key) {
+		return DNSSEC_KEY_ALREADY_PRESENT;
+	}
+
+	if (dnssec_key_get_algorithm(key) == 0) {
+		return DNSSEC_INVALID_KEY_ALGORITHM;
+	}
+
+	int result = dnskey_rdata_set_pubkey(&key->rdata, pubkey);
+	if (result != DNSSEC_EOK) {
+		return result;
+	}
+
+	result = dnskey_rdata_to_crypto_key(&key->rdata, &key->public_key);
+	if (result != DNSSEC_EOK) {
+		key->rdata.size = DNSKEY_RDATA_OFFSET_PUBKEY; // downsize
+		return result;
+	}
+
+	return DNSSEC_EOK;
+}
+
+_public_
+unsigned dnssec_key_get_size(const dnssec_key_t *key)
+{
+	if (!key || !key->public_key) {
+		return 0;
+	}
+
+	unsigned bits = 0;
+	uint8_t algorithm = dnssec_key_get_algorithm(key);
+	switch (algorithm) {
+	case 13:
+		bits = 256;
+		break;
+	case 14:
+		bits = 384;
+		break;
+	case 15:
+		bits = 256;
+		break;
+	case 16:
+		bits = 456;
+		break;
+	default:
+		gnutls_pubkey_get_pk_algorithm(key->public_key, &bits);
+	}
+
+	return bits;
+}
+
+_public_
+int dnssec_key_get_keyid(const dnssec_key_t *key, char **id)
+{
+	if (!key || !id) {
+		return DNSSEC_EINVAL;
+	}
+
+	return keyid_pubkey_hex(key->public_key, id);
+}
+
+_public_
+int dnssec_key_get_rdata(const dnssec_key_t *key, dnssec_binary_t *rdata)
+{
+	if (!key || !rdata) {
+		return DNSSEC_EINVAL;
+	}
+
+	*rdata = key->rdata;
+
+	return DNSSEC_EOK;
+}
+
+_public_
+int dnssec_key_set_rdata(dnssec_key_t *key, const dnssec_binary_t *rdata)
+{
+	if (!key || !rdata || !rdata->data) {
+		return DNSSEC_EINVAL;
+	}
+
+	if (rdata->size < DNSKEY_RDATA_MIN_SIZE) {
+		return DNSSEC_MALFORMED_DATA;
+	}
+
+	if (key->public_key) {
+		return DNSSEC_KEY_ALREADY_PRESENT;
+	}
+
+	gnutls_pubkey_t new_pubkey = NULL;
+	int result = dnskey_rdata_to_crypto_key(rdata, &new_pubkey);
+	if (result != DNSSEC_EOK) {
+		return result;
+	}
+
+	result = dnssec_binary_resize(&key->rdata, rdata->size);
+	if (result != DNSSEC_EOK) {
+		gnutls_pubkey_deinit(new_pubkey);
+		return result;
+	}
+
+	// commit result
+	memmove(key->rdata.data, rdata->data, rdata->size);
+	key->public_key = new_pubkey;
+
+	return DNSSEC_EOK;
+}
+
+/* -- key presence checking ------------------------------------------------ */
+
+_public_
+bool dnssec_key_can_sign(const dnssec_key_t *key)
+{
+	return key && key->private_key;
+}
+
+_public_
+bool dnssec_key_can_verify(const dnssec_key_t *key)
+{
+	return key && key->public_key;
+}