EAP-SIM server: Avoid void pointer arithmetic

This is a compiler specific extension and not compliant with the C
standard.

Fixes: 1c16b257a081 ("EAP-SIM: Add Session-Id derivation during fast-reauth")
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

diff --git a/src/eap_server/eap_server_sim.c b/src/eap_server/eap_server_sim.c
index 66a087212fe50846f1cd43835a1babe3864f8511..f8aa508ecd5fa073e351fe9e12c1c8c8df445bff 100644 (file)
--- a/src/eap_server/eap_server_sim.c
+++ b/src/eap_server/eap_server_sim.c
@@ -286,7 +286,7 @@ static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm,
         * Session-Id calculation after receiving response from the peer and
         * after all other checks pass. */
        os_memcpy(data->reauth_mac,
-                 wpabuf_head(buf) + wpabuf_len(buf) - EAP_SIM_MAC_LEN,
+                 wpabuf_head_u8(buf) + wpabuf_len(buf) - EAP_SIM_MAC_LEN,
                  EAP_SIM_MAC_LEN);
 
        return buf;