ERP: Do not pass full EAP header to eap_peer_erp_reauth_start()

That function does not need the full EAP header -- it only needs to know
which EAP identifier to use in the message. Make this usable for cases
where the previous EAP message may not exist (FILS).

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/eap_peer/eap.c

@@ -571,8 +571,7 @@ fail:
 
 
 #ifdef CONFIG_ERP
-static int eap_peer_erp_reauth_start(struct eap_sm *sm,
-				     const struct eap_hdr *hdr, size_t len)
+static int eap_peer_erp_reauth_start(struct eap_sm *sm, u8 eap_id)
 {
 	char *realm;
 	struct eap_erp_key *erp;
@@ -599,7 +598,7 @@ static int eap_peer_erp_reauth_start(struct eap_sm *sm,
 
 	msg = eap_msg_alloc(EAP_VENDOR_IETF, (EapType) EAP_ERP_TYPE_REAUTH,
 			    1 + 2 + 2 + os_strlen(erp->keyname_nai) + 1 + 16,
-			    EAP_CODE_INITIATE, hdr->identifier);
+			    EAP_CODE_INITIATE, eap_id);
 	if (msg == NULL)
 		return -1;
 
@@ -1566,7 +1565,7 @@ static void eap_peer_initiate(struct eap_sm *sm, const struct eap_hdr *hdr,
 		/* TODO: Derivation of domain specific keys for local ER */
 	}
 
-	if (eap_peer_erp_reauth_start(sm, hdr, len) == 0)
+	if (eap_peer_erp_reauth_start(sm, hdr->identifier) == 0)
 		return;
 
 invalid: