commit 263dbf71679c359be8549e111fcd0160a1ed1ed4
author Jerry Yu <jerry.h.yu@arm.com> Wed Oct 26 10:51:27 2022 +0800
committer Ronald Cron <ronald.cron@arm.com> Fri Feb 02 17:31:20 2024 +0100
tree d4d0e3516c525d8b52acb049b2690091c1b84491
parent 1483dc3bdedfc3279f84e4aa26427cf7e0c82851

tls13: srv: Do not allow early data indication in 2nd ClientHello

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
Signed-off-by: Ronald Cron <ronald.cron@arm.com>

library/ssl_tls13_server.c

diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 6e87d7b..93748a6 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1533,6 +1533,12 @@
         unsigned int extension_type;
         size_t extension_data_len;
         const unsigned char *extension_data_end;
+        uint32_t allowed_exts = MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CH;
+
+        if (ssl->handshake->hello_retry_request_count > 0) {
+            /* Do not accept early data extension in 2nd ClientHello */
+            allowed_exts &= ~MBEDTLS_SSL_EXT_MASK(EARLY_DATA);
+        }
 
         /* RFC 8446, section 4.2.11
          *
@@ -1560,7 +1566,7 @@
 
         ret = mbedtls_ssl_tls13_check_received_extension(
             ssl, MBEDTLS_SSL_HS_CLIENT_HELLO, extension_type,
-            MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CH);
+            allowed_exts);
         if (ret != 0) {
             return ret;
         }