Skip PMS generation on client if opaque PSK is used
For opaque PSKs, the PSK-to-MS expansion is performed atomatically
on the PSA-side.
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 90cafeb..3f91d4f 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -3165,6 +3165,17 @@
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
+#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
+ defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK &&
+ ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 &&
+ ssl_conf_has_raw_psk( ssl->conf ) == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "skip PMS generation for opaque PSK" ) );
+ }
+ else
+#endif /* MBEDTLS_USE_PSA_CRYPTO &&
+ MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
ciphersuite_info->key_exchange ) ) != 0 )
{
