tls13: server: Fix spurious HRR
If the server during a TLS 1.3 handshake selects
the PSK key exchange mode, it does not matter
if it did not find in the key share extension
a key share for a group it supports. Such a
key share is used and necessary only in the
case of the ephemeral or PSK ephemeral key
exchange mode. This is a possible scenario in
the case of a server that supports only the PSK
key exchange mode and a client that also
supports a key exchange mode with ephemeral keys.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 1374bca..4e468da 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -13362,6 +13362,19 @@
-c "Verifying peer X.509 certificate... ok" \
-C "received HelloRetryRequest message"
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
+requires_config_enabled MBEDTLS_SSL_SRV_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test "TLS 1.3: no HRR in case of PSK key exchange mode" \
+ "$P_SRV nbio=2 psk=010203 psk_identity=0a0b0c tls13_kex_modes=psk curves=none" \
+ "$P_CLI nbio=2 debug_level=3 psk=010203 psk_identity=0a0b0c tls13_kex_modes=all" \
+ 0 \
+ -C "received HelloRetryRequest message" \
+ -c "Selected key exchange mode: psk$" \
+ -c "HTTP/1.0 200 OK"
+
# Test heap memory usage after handshake
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
requires_config_enabled MBEDTLS_MEMORY_DEBUG