Implement (partial) renego delay on client

This commit is contained in:
Manuel Pégourié-Gonnard 2014-08-19 13:58:40 +02:00
parent f07f421759
commit 44ade654c5
2 changed files with 24 additions and 11 deletions

View file

@ -1493,23 +1493,26 @@ void ssl_legacy_renegotiation( ssl_context *ssl, int allow_legacy );
/**
* \brief Enforce server-requested renegotiation.
* (Default: enforced, max_records = 16)
* (No effect on client.)
*
* When a server requests a renegotiation, the client can
* comply or ignore the request. This function allows the
* server to decide if it should enforce its renegotiation
* requests by closing the connection if the client doesn't
* initiate a renegotiation.
* When we request a renegotiation, the peer can comply or
* ignore the request. This function allows us to decide
* whether to enforce our renegotiation requests by closing
* the connection if the peer doesn't comply.
*
* However, records could already be in transit from the
* client to the server when the request is emitted. In order
* to increase reliability, the server can accept a number of
* records containing application data before the ClientHello
* that was requested.
* However, records could already be in transit from the peer
* when the request is emitted. In order to increase
* reliability, we can accept a number of records before the
* expected handshake records.
*
* The optimal value is highly dependent on the specific usage
* scenario.
*
* \warning On client, the grace period can only happen during
* ssl_read(), as opposed to ssl_write() and ssl_renegotiate()
* which always behave as if max_record was 0. The reason is,
* if we receive application data from the server, we need a
* place to write it, which only happens during ssl_read().
*
* \param ssl SSL context
* \param max_records Use SSL_RENEGOTIATION_NOT_ENFORCED if you don't want to
* enforce renegotiation, or a non-negative value to enforce

View file

@ -904,6 +904,16 @@ static int ssl_parse_server_hello( ssl_context *ssl )
{
if( ssl->renegotiation == SSL_RENEGOTIATION )
{
ssl->renego_records_seen++;
if( ssl->renego_max_records >= 0 &&
ssl->renego_records_seen > ssl->renego_max_records )
{
SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
"but not honored by server" ) );
return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
}
SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
return( POLARSSL_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
}