--- /dev/null
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * crypto/hkdf_sha256 - RFC5869 Hardened Key Derivation Functions using SHA256
+ *
+ * This code implements the hkdf described in RFC5869.
+ *
+ * License: BSD-MIT
+ * Maintainer: Rusty Russell <rusty@rustcorp.com.au>
+ */
+int main(int argc, char *argv[])
+{
+ /* Expect exactly one argument */
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ printf("ccan/crypto/hmac_sha256\n");
+ return 0;
+ }
+
+ if (strcmp(argv[1], "testdepends") == 0) {
+ printf("ccan/str/hex\n");
+ return 0;
+ }
+
+ return 1;
+}