EAP-FAST: Make PAC file A_ID parser easier to analyze

Some static analyzers seem to have issues with "pos + len > end"
validation (CID 62875), so convert this to "len > end - pos" to make it
more obvious that len is validated against its bounds.

Signed-off-by: Jouni Malinen <j@w1.fi>

diff --git a/src/eap_peer/eap_fast_pac.c b/src/eap_peer/eap_fast_pac.c
index 377080f834971b7d2fb0b52e9eb3c49f948d13fe..32da82ce8871f5732664d1dc77f223b953354a38 100644 (file)
--- a/src/eap_peer/eap_fast_pac.c
+++ b/src/eap_peer/eap_fast_pac.c
@@ -714,7 +714,7 @@ static void eap_fast_pac_get_a_id(struct eap_fast_pac *pac)
                pos += 2;
                len = WPA_GET_BE16(pos);
                pos += 2;
-               if (pos + len > end)
+               if (len > (unsigned int) (end - pos))
                        break;
 
                if (type == PAC_TYPE_A_ID) {