commit 90e223364ca559042710316d4ba4e6eb86178284
author Ronald Cron <ronald.cron@arm.com> Mon Jan 22 15:24:21 2024 +0100
committer Ronald Cron <ronald.cron@arm.com> Tue Feb 06 16:43:33 2024 +0100
tree 9d6f526f758041b1add14b843b19516fe83e42cf
parent fe59ff794d2e198665ca9456c097eae0b30fab66

tls13: cli: Refine early data status

The main purpose of the change is to
know from the status, at any point in
the handshake, if early data can be
sent or not and why.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>

library/ssl_tls13_client.c

diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index e6680c7..5d7a495 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1180,26 +1180,21 @@
 #endif
 
 #if defined(MBEDTLS_SSL_EARLY_DATA)
-    if (mbedtls_ssl_conf_tls13_is_some_psk_enabled(ssl) &&
-        ssl_tls13_early_data_has_valid_ticket(ssl) &&
-        ssl->conf->early_data_enabled == MBEDTLS_SSL_EARLY_DATA_ENABLED &&
-        ssl->handshake->hello_retry_request_count == 0) {
+    if (ssl->handshake->hello_retry_request_count == 0) {
+        if (mbedtls_ssl_conf_tls13_is_some_psk_enabled(ssl) &&
+            ssl_tls13_early_data_has_valid_ticket(ssl) &&
+            ssl->conf->early_data_enabled == MBEDTLS_SSL_EARLY_DATA_ENABLED) {
+            ret = mbedtls_ssl_tls13_write_early_data_ext(
+                ssl, 0, p, end, &ext_len);
+            if (ret != 0) {
+                return ret;
+            }
+            p += ext_len;
 
-        ret = mbedtls_ssl_tls13_write_early_data_ext(
-            ssl, 0, p, end, &ext_len);
-        if (ret != 0) {
-            return ret;
+            ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_SENT;
+        } else {
+            ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_SENT;
         }
-        p += ext_len;
-
-        /* Initializes the status to `rejected`. It will be updated to
-         * `accepted` if the EncryptedExtension message contain an early data
-         * indication extension.
-         */
-        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED;
-    } else {
-        MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write early_data extension"));
-        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_SENT;
     }
 #endif /* MBEDTLS_SSL_EARLY_DATA */
 
@@ -1236,7 +1231,7 @@
     size_t psk_len;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
 
-    if (ssl->early_data_status == MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED) {
+    if (ssl->early_data_status == MBEDTLS_SSL_EARLY_DATA_STATUS_SENT) {
         MBEDTLS_SSL_DEBUG_MSG(
             1, ("Set hs psk for early data when writing the first psk"));
 
@@ -1299,6 +1294,7 @@
             1, ("Switch to early data keys for outbound traffic"));
         mbedtls_ssl_set_outbound_transform(
             ssl, ssl->handshake->transform_earlydata);
+        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_CAN_WRITE;
 #endif
     }
 #endif /* MBEDTLS_SSL_EARLY_DATA */
@@ -1971,6 +1967,13 @@
     }
 
     ssl->session_negotiate->ciphersuite = ssl->handshake->ciphersuite_info->id;
+
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    if (ssl->early_data_status != MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_SENT) {
+        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED;
+    }
+#endif
+
     return 0;
 }
 
@@ -2230,6 +2233,8 @@
         }
 
         ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED;
+    } else if (ssl->early_data_status != MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_SENT) {
+        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED;
     }
 #endif
 
@@ -2567,6 +2572,7 @@
 
 #if defined(MBEDTLS_SSL_EARLY_DATA)
     if (ssl->early_data_status == MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED) {
+        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_SERVER_FINISHED_RECEIVED;
         mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_END_OF_EARLY_DATA);
     } else
 #endif /* MBEDTLS_SSL_EARLY_DATA */
@@ -3088,6 +3094,7 @@
                     1, ("Switch to early data keys for outbound traffic"));
                 mbedtls_ssl_set_outbound_transform(
                     ssl, ssl->handshake->transform_earlydata);
+                ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_CAN_WRITE;
             }
             break;
 #endif /* MBEDTLS_SSL_EARLY_DATA */