Add libsha2_hmac_[un]marshal

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

1 files changed, 41 insertions, 0 deletions

diff --git a/hmac_marshal.c b/hmac_marshal.c
new file mode 100644
index 0000000..2cb0816
--- /dev/null
+++ b/hmac_marshal.c
@@ -0,0 +1,41 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+/**
+ * Marshal an HMAC state into a buffer
+ * 
+ * @param   state  The state to marshal
+ * @param   buf    Output buffer, `NULL` to only return the required size
+ * @return         The number of bytes marshalled to `buf`
+ */
+size_t
+libsha2_hmac_marshal(const struct libsha2_hmac_state *restrict state, void *restrict buf_)
+{
+	char *restrict buf = buf_;
+	size_t off = 0;
+
+	if (buf)
+		*(int *)buf = 0; /* version */
+	off += sizeof(int);
+
+	off += libsha2_marshal(&state->sha2_state, buf ? &buf[off] : NULL);
+
+	if (buf)
+		*(size_t *)&buf[off] = state->outsize;
+	off += sizeof(size_t);
+
+	if (buf)
+		*(unsigned char *)&buf[off] = state->inited;
+	off += sizeof(unsigned char);
+
+	if (buf)
+		memcpy(&buf[off], state->ipad, state->sha2_state.chunk_size);
+	off += state->sha2_state.chunk_size;
+
+	if (buf)
+		memcpy(&buf[off], state->opad, state->sha2_state.chunk_size);
+	off += state->sha2_state.chunk_size;
+
+	return off;
+}