keep const when casting

diff --git a/ykpbkdf2.c b/ykpbkdf2.c
index 535b4147b484b26851822196fadabe3f53264dc6..e64d582fd0c66acd6a3b0507bf3ee400c7dbbef4 100644 (file)
--- a/ykpbkdf2.c
+++ b/ykpbkdf2.c
@@ -41,8 +41,8 @@ int yk_hmac_sha1(const char *key, size_t key_len,
                return 0;
 
        if (hmac(SHA1,
-                (unsigned char *)text, (int)text_len,
-                (unsigned char *)key, (int)key_len,
+                (const unsigned char *)text, (int)text_len,
+                (const unsigned char *)key, (int)key_len,
                 output))
                return 0;
        return 1;