lib: Add CRC-8 and CRC-16 checksums

These checksum will be handy for header checksums.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

1 files changed, 67 insertions, 0 deletions

diff --git a/src/lib/tests/crc16_test.c b/src/lib/tests/crc16_test.c
new file mode 100644
index 00000000..03a5b504
--- /dev/null
+++ b/src/lib/tests/crc16_test.c
@@ -0,0 +1,67 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2026
+ *
+ * Test of the CRC-16/CCITT-FALSE function
+ *
+ *    Dimitri Staessens <dimitri@ouroboros.rocks>
+ *    Sander Vrijders   <sander@ouroboros.rocks>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#include "config.h"
+
+#include <ouroboros/crc16.h>
+
+#include <test/test.h>
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+/* reveng-catalog smoke vectors. */
+static int test_crc16_ccitt_false_basic(void)
+{
+        uint16_t crc;
+
+        TEST_START();
+
+        crc = 0;
+        crc16_ccitt_false(&crc, "", 0);
+        if (crc != 0xffff)
+                goto fail;
+
+        crc = 0;
+        crc16_ccitt_false(&crc, "123456789", 9);
+        if (crc != 0x29b1)
+                goto fail;
+
+        TEST_SUCCESS();
+        return TEST_RC_SUCCESS;
+ fail:
+        TEST_FAIL();
+        return TEST_RC_FAIL;
+}
+
+int crc16_test(int     argc,
+               char ** argv)
+{
+        int ret = 0;
+
+        (void) argc;
+        (void) argv;
+
+        ret |= test_crc16_ccitt_false_basic();
+        return ret;
+}