diff --git a/src/crypto/oaes_lib.h b/src/crypto/oaes_lib.h
index 9155bce0..16b914c7 100644
--- a/src/crypto/oaes_lib.h
+++ b/src/crypto/oaes_lib.h
@@ -101,6 +101,32 @@ typedef int ( * oaes_step_cb ) (
 
 typedef uint16_t OAES_OPTION;
 
+
+typedef struct _oaes_key
+{
+	size_t data_len;
+	uint8_t *data;
+	size_t exp_data_len;
+	uint8_t *exp_data;
+	size_t num_keys;
+	size_t key_base;
+} oaes_key;
+
+typedef struct _oaes_ctx
+{
+#ifdef OAES_HAVE_ISAAC
+  randctx * rctx;
+#endif // OAES_HAVE_ISAAC
+
+#ifdef OAES_DEBUG
+	oaes_step_cb step_cb;
+#endif // OAES_DEBUG
+
+	oaes_key * key;
+	OAES_OPTION options;
+	uint8_t iv[OAES_BLOCK_SIZE];
+} oaes_ctx;
+
 /*
  * // usage:
  *