Minor updates to blowfish encryption.
diff --git a/src/proto/sha256.pro b/src/proto/sha256.pro
index 635721c..a6d6be7 100644
--- a/src/proto/sha256.pro
+++ b/src/proto/sha256.pro
@@ -1,5 +1,5 @@
 /* sha256.c */
-char *sha256_key __ARGS((char *buf));
+char_u *sha256_key __ARGS((char_u *buf));
 int sha256_self_test __ARGS((void));
 void sha2_seed __ARGS((char_u header[], int header_len));
 /* vim: set ft=c : */