c: cover binding ownership and invalid crypto input

tests/test_c.c

@@ -0,0 +1,39 @@
+#ifdef NDEBUG
+#undef NDEBUG
+#endif
+
+#include "opendht_c.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+int main(void)
+{
+    const uint8_t invalid[] = {1, 2, 3};
+    assert(dht_publickey_import(invalid, sizeof(invalid)) == NULL);
+    assert(dht_privatekey_import(invalid, sizeof(invalid), "") == NULL);
+    assert(dht_certificate_import(invalid, sizeof(invalid)) == NULL);
+    assert(dht_privatekey_generate(1) == NULL);
+
+    dht_infohash hash;
+    dht_infohash_get_from_string(&hash, "binding regression");
+    assert(!dht_infohash_is_zero(&hash));
+    dht_infohash restored;
+    dht_infohash_from_hex_null(&restored, dht_infohash_print(&hash));
+    assert(memcmp(&hash, &restored, sizeof(hash)) == 0);
+
+    dht_value* value = dht_value_with_id_new(invalid, sizeof(invalid), 42);
+    assert(value != NULL);
+    assert(dht_value_get_id(value) == 42);
+    dht_value_set_user_type(value, "application/octet-stream");
+    assert(strcmp(dht_value_get_user_type(value), "application/octet-stream") == 0);
+    dht_value* copy = dht_value_ref(value);
+    dht_value_unref(value);
+    dht_data_view data = dht_value_get_data(copy);
+    assert(data.size == sizeof(invalid));
+    assert(memcmp(data.data, invalid, data.size) == 0);
+    dht_value_unref(copy);
+    puts("C binding regressions passed");
+    return 0;
+}