more error checking

diff --git a/lib/gnutls_ui.c b/lib/gnutls_ui.c
index 25ca7f2f8ebae2a783a8ed2074cebbd51eb3b15e..059e6088237ef2ab48e07808705f1041f86dbddd 100644 (file)
--- a/lib/gnutls_ui.c
+++ b/lib/gnutls_ui.c
@@ -190,7 +190,7 @@ int gnutls_fingerprint_calc(DigestAlgorithm algo, gnutls_datum data, char* resul
        GNUTLS_HASH_HANDLE td;
        int hash_len = gnutls_hash_get_algo_len(algo);
        
-       if (hash_len > *result_size) {
+       if (hash_len > *result_size || hash_len < 0) {
                *result_size = hash_len;
                return GNUTLS_E_INVALID_REQUEST;
        }