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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:24:08 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:24:08 +0000
commitf449f278dd3c70e479a035f50a9bb817a9b433ba (patch)
tree8ca2bfb785dda9bb4d573acdf9b42aea9cd51383 /src/libdnssec/shared/dname.c
parentInitial commit. (diff)
downloadknot-upstream.tar.xz
knot-upstream.zip
Adding upstream version 3.2.6.upstream/3.2.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libdnssec/shared/dname.c')
-rw-r--r--src/libdnssec/shared/dname.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/src/libdnssec/shared/dname.c b/src/libdnssec/shared/dname.c
new file mode 100644
index 0000000..61a5034
--- /dev/null
+++ b/src/libdnssec/shared/dname.c
@@ -0,0 +1,165 @@
+/* Copyright (C) 2018 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 <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "libdnssec/shared/dname.h"
+#include "libdnssec/shared/shared.h"
+#include "contrib/tolower.h"
+
+/*!
+ * Get length of a domain name in wire format.
+ */
+size_t dname_length(const uint8_t *dname)
+{
+ if (!dname) {
+ return 0;
+ }
+
+ const uint8_t *scan = dname;
+ uint8_t label_len;
+ do {
+ label_len = *scan;
+ scan += 1 + label_len;
+ } while (label_len > 0);
+ assert(scan > dname);
+
+ size_t length = scan - dname;
+ if (length > DNAME_MAX_LENGTH) {
+ return 0;
+ }
+
+ return length;
+}
+
+/*!
+ * Copy domain name in wire format.
+ */
+uint8_t *dname_copy(const uint8_t *dname)
+{
+ if (!dname) {
+ return NULL;
+ }
+
+ size_t length = dname_length(dname);
+ if (length == 0) {
+ return NULL;
+ }
+
+ uint8_t *copy = malloc(length);
+ if (!copy) {
+ return NULL;
+ }
+
+ memmove(copy, dname, length);
+ return copy;
+}
+
+/*!
+ * Normalize dname label in-place.
+ *
+ * \return Number of processed bytes, 0 if we encounter the last label.
+ */
+static uint8_t normalize_label(uint8_t *label)
+{
+ assert(label);
+
+ uint8_t len = *label;
+ if (len == 0 || len > DNAME_MAX_LABEL_LENGTH) {
+ return 0;
+ }
+
+ for (uint8_t *scan = label + 1, *end = scan + len; scan < end; scan++) {
+ *scan = knot_tolower(*scan);
+ }
+
+ return len + 1;
+}
+
+/*!
+ * Normalize domain name in wire format.
+ */
+void dname_normalize(uint8_t *dname)
+{
+ if (!dname) {
+ return;
+ }
+
+ uint8_t read, *scan = dname;
+ do {
+ read = normalize_label(scan);
+ scan += read;
+ } while (read > 0);
+}
+
+/*!
+ * Compare dname labels case insensitively.
+ */
+static int label_casecmp(const uint8_t *a, const uint8_t *b, uint8_t len)
+{
+ assert(a);
+ assert(b);
+
+ for (const uint8_t *a_end = a + len; a < a_end; a++, b++) {
+ if (knot_tolower(*a) != knot_tolower(*b)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/*!
+ * Check if two dnames are equal.
+ */
+bool dname_equal(const uint8_t *one, const uint8_t *two)
+{
+ if (!one || !two) {
+ return false;
+ }
+
+ const uint8_t *scan_one = one;
+ const uint8_t *scan_two = two;
+
+ for (;;) {
+ if (*scan_one != *scan_two) {
+ return false;
+ }
+
+ uint8_t len = *scan_one;
+ if (len == 0) {
+ return true;
+ } else if (len > DNAME_MAX_LABEL_LENGTH) {
+ return false;
+ }
+
+ scan_one += 1;
+ scan_two += 1;
+
+ if (!label_casecmp(scan_one, scan_two, len)) {
+ return false;
+ }
+
+ scan_one += len;
+ scan_two += len;
+ }
+
+ return true;
+}