tls13: srv: Always parse the pre-shared key extension
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 873f909..3b7fc83 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1744,10 +1744,11 @@
/* Update checksum with either
* - The entire content of the CH message, if no PSK extension is present
* - The content up to but excluding the PSK extension, if present.
+ * Always parse the pre-shared key extension when present in the
+ * ClientHello even if some pre-requisites for PSK key exchange modes are
+ * not met. That way we always validate the syntax of the extension.
*/
- /* If we've settled on a PSK-based exchange, parse PSK identity ext */
- if (ssl_tls13_key_exchange_is_psk_available(ssl) ||
- ssl_tls13_key_exchange_is_psk_ephemeral_available(ssl)) {
+ if (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY)) {
ret = handshake->update_checksum(ssl, buf,
pre_shared_key_ext - buf);
if (0 != ret) {