1 files changed, 55 insertions, 0 deletions
diff --git a/extra/libkeccak_state_marshal.c b/extra/libkeccak_state_marshal.c
new file mode 100644
index 0000000..7541164
--- /dev/null
+++ b/extra/libkeccak_state_marshal.c
@@ -0,0 +1,55 @@
+/* See LICENSE file for copyright and license details. */
+#include "../common.h"
+
+
+#if defined(__clang__)
+# pragma clang diagnostic ignored "-Wcast-align"
+#endif
+
+
+/**
+ * Marshal a `struct libkeccak_state` into a buffer
+ * 
+ * @param   state  The state to marshal
+ * @param   data_  The output buffer, can be `NULL`
+ * @return         The number of bytes stored to `data`
+ */
+size_t
+libkeccak_state_marshal(const struct libkeccak_state *restrict state, void *restrict data_)
+{
+#define set(VAR)\
+	do {\
+		__builtin_memcpy(data, &state->VAR, sizeof(state->VAR));\
+		data += sizeof(state->VAR);\
+	} while (0)
+
+	unsigned char *restrict start = data_;
+	unsigned char *restrict data = start;
+
+	if (!data) {
+		return 7 * sizeof(long int) +
+		       1 * sizeof(int64_t) +
+		       sizeof(state->S) +
+		       2 * sizeof(size_t) +
+		       state->mptr;
+	}
+
+	set(r);
+	set(c);
+	set(n);
+	set(b);
+	set(w);
+	set(wmod);
+	set(l);
+	set(nr);
+	__builtin_memcpy(data, state->S, sizeof(state->S));
+	data += sizeof(state->S);
+	set(mptr);
+	set(mlen);
+	memcpy(data, state->M, state->mptr * sizeof(char));
+	data += state->mptr;
+
+	return (size_t)(data - start);
+
+#undef set
+}