diff --git a/rijndael.h b/rijndael.h
new file mode 100644
index 0000000..c13f18c
--- /dev/null
+++ b/rijndael.h
@@ -0,0 +1,31 @@
+#ifndef _RIJNDAEL_H_
+#define _RIJNDAEL_H_
+
+/* 1. Standard types for AES cryptography source code               */
+
+typedef u_int8_t   u1byte; /* an 8 bit unsigned character type */
+typedef u_int16_t  u2byte; /* a 16 bit unsigned integer type   */
+typedef u_int32_t  u4byte; /* a 32 bit unsigned integer type   */
+
+typedef int8_t     s1byte; /* an 8 bit signed character type   */
+typedef int16_t    s2byte; /* a 16 bit signed integer type     */
+typedef int32_t    s4byte; /* a 32 bit signed integer type     */
+
+typedef struct _rijndael_ctx {
+	u4byte  k_len;
+	int decrypt;
+	u4byte  e_key[64];
+	u4byte  d_key[64];
+} rijndael_ctx;
+
+
+/* 2. Standard interface for AES cryptographic routines             */
+
+/* These are all based on 32 bit unsigned values and will therefore */
+/* require endian conversions for big-endian architectures          */
+
+rijndael_ctx *rijndael_set_key  __P((rijndael_ctx *, const u4byte *, u4byte, int));
+void rijndael_encrypt __P((rijndael_ctx *, const u4byte *, u4byte *));
+void rijndael_decrypt __P((rijndael_ctx *, const u4byte *, u4byte *));
+
+#endif /* _RIJNDAEL_H_ */