SSL asynchronous decryption (server side)
Support SSL asynchronous private operation for the case of a
decryption operation on a server.
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 0c7e15d..5c3aacf 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -3416,6 +3416,25 @@
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
+
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE_C)
+static int ssl_resume_decrypt_pms( mbedtls_ssl_context *ssl,
+ unsigned char *peer_pms,
+ size_t *peer_pmslen,
+ size_t peer_pmssize )
+{
+ int ret = ssl->conf->f_async_resume( ssl->conf->p_async_connection_ctx,
+ ssl->handshake->p_async_operation_ctx,
+ peer_pms, peer_pmslen, peer_pmssize );
+ if( ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
+ {
+ ssl->handshake->p_async_operation_ctx = NULL;
+ }
+ MBEDTLS_SSL_DEBUG_RET( 2, "ssl_decrypt_encrypted_pms", ret );
+ return( ret );
+}
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE_C */
+
static int ssl_decrypt_encrypted_pms( mbedtls_ssl_context *ssl,
const unsigned char *p,
const unsigned char *end,
@@ -3428,6 +3447,17 @@
mbedtls_pk_context *public_key = &mbedtls_ssl_own_cert( ssl )->pk;
size_t len = mbedtls_pk_get_len( public_key );
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE_C)
+ /* If we have already started decoding the message and there is an ongoing
+ decryption operation, resume signing. */
+ if( ssl->handshake->p_async_operation_ctx != NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "resuming decryption operation" ) );
+ return( ssl_resume_decrypt_pms( ssl,
+ peer_pms, peer_pmslen, peer_pmssize ) );
+ }
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE_C */
+
/*
* Prepare to decrypt the premaster using own private RSA key
*/
@@ -3453,6 +3483,33 @@
/*
* Decrypt the premaster secret
*/
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE_C)
+ if( ssl->conf->f_async_decrypt_start != NULL )
+ {
+ ret = ssl->conf->f_async_decrypt_start(
+ ssl->conf->p_async_connection_ctx,
+ &ssl->handshake->p_async_operation_ctx,
+ mbedtls_ssl_own_cert( ssl ),
+ p, len );
+ switch( ret )
+ {
+ case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH:
+ /* act as if f_async_decrypt_start was null */
+ break;
+ case 0:
+ return( ssl_resume_decrypt_pms( ssl,
+ peer_pms,
+ peer_pmslen,
+ peer_pmssize ) );
+ case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS:
+ return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
+ default:
+ MBEDTLS_SSL_DEBUG_RET( 1, "f_async_sign", ret );
+ return( ret );
+ }
+ }
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE_C */
+
if( ! mbedtls_pk_can_do( private_key, MBEDTLS_PK_RSA ) )
{
/* */
@@ -3484,6 +3541,11 @@
&peer_pmslen,
sizeof( peer_pms ) );
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE_C)
+ if ( ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
+ return( ret );
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE_C */
+
/*
* Protection against Bleichenbacher's attack: invalid PKCS#1 v1.5 padding
* must not cause the connection to end immediately; instead, send a
@@ -3620,6 +3682,20 @@
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) );
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE_C) && \
+ ( defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
+ defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) )
+ if( ( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
+ ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA ) &&
+ ( ssl->handshake->p_async_operation_ctx != NULL ) )
+ {
+ /* We've already read a record and there is an asynchronous
+ * operation in progress to decrypt it. So skip reading the
+ record. */
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "will resume decryption of previously-read record" ) );
+ }
+ else
+#endif
if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
@@ -3732,6 +3808,19 @@
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
+#if defined(MBEDTLS_SSL_ASYNC_PRIVATE_C)
+ if ( ssl->handshake->p_async_operation_ctx != NULL )
+ {
+ /* There is an asynchronous operation in progress to
+ * decrypt the encrypted premaster secret, so skip
+ * directly to resuming this operation. */
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "PSK identity already parsed" ) );
+ /* Update p to skip the PSK identity. ssl_parse_encrypted_pms
+ * won't actually use it, but maintain p anyway for robustness. */
+ p += ssl->conf->psk_identity_len + 2;
+ }
+ else
+#endif /* MBEDTLS_SSL_ASYNC_PRIVATE_C */
if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
