Organise files

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 59 insertions, 0 deletions

diff --git a/hmac/libkeccak_hmac_unmarshal.c b/hmac/libkeccak_hmac_unmarshal.c
new file mode 100644
index 0000000..ddada17
--- /dev/null
+++ b/hmac/libkeccak_hmac_unmarshal.c
@@ -0,0 +1,59 @@
+/* See LICENSE file for copyright and license details. */
+#include "../common.h"
+
+#if defined(__clang__)
+# pragma clang diagnostic ignored "-Wcast-align"
+#endif
+
+
+/**
+ * Unmarshal a `struct libkeccak_hmac_state` from a buffer
+ * 
+ * @param   state  The slot for the unmarshalled state, must not be
+ *                 initialised (memory leak otherwise), can be `NULL`
+ * @param   data_  The input buffer
+ * @return         The number of bytes read from `data`, 0 on error
+ */
+size_t
+libkeccak_hmac_unmarshal(struct libkeccak_hmac_state *restrict state, const void *restrict data_)
+{
+	const unsigned char *restrict data = data_;
+	size_t parsed, size, i;
+
+	state->key_opad = NULL;
+	state->key_ipad = NULL;
+
+	parsed = libkeccak_state_unmarshal(state ? &state->sponge : NULL, data);
+	if (!parsed)
+		return 0;
+	data += parsed;
+
+	__builtin_memcpy(&size, data, sizeof(size));
+	data += sizeof(size_t);
+	if (state)
+		size = state->key_length;
+	size = (state->key_length + 7) >> 3;
+
+	if (state) {
+		state->key_opad = malloc(2 * size);
+		if (!state->key_opad) {
+			libkeccak_state_destroy(&state->sponge);
+			return 0;
+		}
+		memcpy(state->key_opad, data, size);
+		data += size;
+
+		if (data[0]) {
+			state->key_ipad = &state->key_opad[size];
+			memcpy(state->key_ipad, state->key_opad, size);
+			for (i = 0; i < size; i++)
+				state->key_ipad[i] ^= (char)(HMAC_OUTER_PAD ^ HMAC_INNER_PAD);
+		}
+
+		state->leftover = data[1];
+		state->buffer = NULL;
+		state->buffer_size = 0;
+	}
+
+	return parsed + sizeof(size_t) + size + 2 * sizeof(char);
+}