From a1071a58a3606e755e1e9832300bd4a35493e42b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Mon, 20 Aug 2018 11:56:14 +0200 Subject: [PATCH] Compute record expansion at the right time Depends on the current transform, which might change when retransmitting a flight containing a Finished message, so compute it only after the transform is swapped. --- library/ssl_tls.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/library/ssl_tls.c b/library/ssl_tls.c index 5f3abe5978..da21db237e 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -2845,20 +2845,8 @@ int mbedtls_ssl_resend( mbedtls_ssl_context *ssl ) */ int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl ) { - const int ret_payload = mbedtls_ssl_get_max_out_record_payload( ssl ); - const size_t max_record_payload = (size_t) ret_payload; - /* DTLS handshake headers are 12 bytes */ - const size_t max_hs_fragment_len = max_record_payload - 12; - MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_flight_transmit" ) ); - if( ret_payload < 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_max_out_record_payload", - ret_payload ); - return( ret_payload ); - } - if( ssl->handshake->retransmit_state != MBEDTLS_SSL_RETRANS_SENDING ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialise flight transmission" ) ); @@ -2895,6 +2883,10 @@ int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl ) } else { + const int ret_payload = mbedtls_ssl_get_max_out_record_payload( ssl ); + const size_t max_record_payload = (size_t) ret_payload; + /* DTLS handshake headers are 12 bytes */ + const size_t max_hs_fragment_len = max_record_payload - 12; const unsigned char * const p = ssl->handshake->cur_msg_p; const size_t hs_len = cur->len - 12; const size_t frag_off = p - ( cur->p + 12 ); @@ -2902,6 +2894,13 @@ int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl ) const size_t frag_len = rem_len > max_hs_fragment_len ? max_hs_fragment_len : rem_len; + if( ret_payload < 0 ) + { + MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_max_out_record_payload", + ret_payload ); + return( ret_payload ); + } + if( frag_off == 0 && frag_len != hs_len ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "fragmenting handshake message (%u > %u)",