diff -r 3cfb4670d9e6 -r b85248a8aee2 libidav/resource.c
--- a/libidav/resource.c	Mon Oct 12 14:36:16 2015 +0200
+++ b/libidav/resource.c	Mon Oct 12 14:36:54 2015 +0200
@@ -678,7 +678,7 @@
         // get hash
         char sha[SHA256_DIGEST_LENGTH];
         dav_get_hash(&dec->sha256, sha);
-        hash = util_hexstr(sha, 32);
+        hash = util_hexstr((unsigned char*)sha, 32);
         
         aes_decrypter_close(dec);
     }
@@ -694,7 +694,7 @@
             if(res_hash) {
                 size_t len = 0;
                 char *dec_hash = aes_decrypt(res_hash, &len, key);
-                char *hex_hash = util_hexstr(dec_hash, 32);
+                char *hex_hash = util_hexstr((unsigned char*)dec_hash, 32);
                 if(strcmp(hash, hex_hash)) {
                     verify_failed = 1;
                 }