1 files changed, 99 insertions, 0 deletions
diff --git a/src/libdnssec/shared/keyid_gnutls.c b/src/libdnssec/shared/keyid_gnutls.c
new file mode 100644
index 0000000..eee27d3
--- /dev/null
+++ b/src/libdnssec/shared/keyid_gnutls.c
@@ -0,0 +1,99 @@
+/*  Copyright (C) 2022 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 <gnutls/gnutls.h>
+#include <gnutls/x509.h>
+#include <string.h>
+
+#include "contrib/string.h"
+#include "libdnssec/binary.h"
+#include "libdnssec/error.h"
+#include "libdnssec/keyid.h"
+#include "libdnssec/shared/keyid_gnutls.h"
+#include "libdnssec/shared/shared.h"
+
+/*!
+ * Get binary key ID from a key (public or private).
+ */
+static int keyid_bin(gnutls_x509_privkey_t key, gnutls_pubkey_t pubkey, dnssec_binary_t *id)
+{
+	assert(key || pubkey);
+	assert(id);
+
+	// Flags can be used to enable SHA-2 since GnuTLS 3.4.7.
+
+	int flags = 0;
+	uint8_t buffer[DNSSEC_KEYID_BINARY_SIZE];
+	size_t size = DNSSEC_KEYID_SIZE;
+
+	int r = key ? gnutls_x509_privkey_get_key_id(key, flags, buffer, &size)
+	            : gnutls_pubkey_get_key_id(pubkey, flags, buffer, &size);
+
+	if (r != GNUTLS_E_SUCCESS || size != DNSSEC_KEYID_BINARY_SIZE) {
+		return DNSSEC_INVALID_KEY_ID;
+	}
+
+	assert(size == DNSSEC_KEYID_BINARY_SIZE);
+	r = dnssec_binary_resize(id, size);
+	if (r != DNSSEC_EOK) {
+		return r;
+	}
+
+	memcpy(id->data, buffer, size);
+
+	return DNSSEC_EOK;
+}
+
+/*!
+ * Get hexadecimal key ID from a key (public or private).
+ */
+static int keyid_hex(gnutls_x509_privkey_t key, gnutls_pubkey_t pubkey, char **id)
+{
+	_cleanup_binary_ dnssec_binary_t bin = { 0 };
+	int r = keyid_bin(key, pubkey, &bin);
+	if (r != DNSSEC_EOK) {
+		return r;
+	}
+
+	*id = bin_to_hex(bin.data, bin.size, false);
+	if (*id == NULL) {
+		return DNSSEC_ENOMEM;
+	}
+
+	return DNSSEC_EOK;
+}
+
+int keyid_x509(gnutls_x509_privkey_t key, dnssec_binary_t *id)
+{
+	return keyid_bin(key, NULL, id);
+}
+
+int keyid_x509_hex(gnutls_x509_privkey_t key, char **id)
+{
+	return keyid_hex(key, NULL, id);
+}
+
+int keyid_pubkey(gnutls_pubkey_t pubkey, dnssec_binary_t *id)
+{
+	return keyid_bin(NULL, pubkey, id);
+}
+
+int keyid_pubkey_hex(gnutls_pubkey_t pubkey, char **id)
+{
+	return keyid_hex(NULL, pubkey, id);
+}