diff --git a/include/crypto/md5.h b/include/crypto/md5.h
new file mode 100644
index 0000000..65f299b
--- /dev/null
+++ b/include/crypto/md5.h
@@ -0,0 +1,17 @@
+#ifndef _CRYPTO_MD5_H
+#define _CRYPTO_MD5_H
+
+#include <linux/types.h>
+
+#define MD5_DIGEST_SIZE		16
+#define MD5_HMAC_BLOCK_SIZE	64
+#define MD5_BLOCK_WORDS		16
+#define MD5_HASH_WORDS		4
+
+struct md5_state {
+	u32 hash[MD5_HASH_WORDS];
+	u32 block[MD5_BLOCK_WORDS];
+	u64 byte_count;
+};
+
+#endif