From f7dad3cfbe49696dc2cd20642b1a05e372f3f699 Mon Sep 17 00:00:00 2001 From: Jerry Yu Date: Wed, 14 Sep 2022 22:31:39 +0800 Subject: [PATCH] fix various issues - Naming - format - Reduce negative tolerance window Signed-off-by: Jerry Yu --- library/ssl_tls13_client.c | 10 +++------- library/ssl_tls13_server.c | 23 ++++++++++++++--------- 2 files changed, 17 insertions(+), 16 deletions(-) diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c index 2c7d94638..33e8cc6aa 100644 --- a/library/ssl_tls13_client.c +++ b/library/ssl_tls13_client.c @@ -665,9 +665,7 @@ static int ssl_tls13_write_psk_key_exchange_modes_ext( mbedtls_ssl_context *ssl, return ( 0 ); } -/* Check if we have any PSK to offer, returns 0 if PSK is available. - * Assign the psk and ticket if pointers are present. - */ +/* Check if we have any PSK to offer, returns 0 if a PSK is available. */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_tls13_get_psk_to_offer( const mbedtls_ssl_context *ssl, @@ -810,12 +808,10 @@ int mbedtls_ssl_tls13_write_identities_of_pre_shared_key_ext( { #if defined(MBEDTLS_HAVE_TIME) mbedtls_time_t now = mbedtls_time( NULL ); - uint64_t age_in_ms = - ( now - ssl->session_negotiate->ticket_received ) * 1000; obfuscated_ticket_age = - (uint32_t)( ( age_in_ms + ssl->session_negotiate->ticket_age_add ) - & ( ( 1LL << 32 ) - 1 ) ); + ( (uint32_t)( now - ssl->session_negotiate->ticket_received ) * 1000 ) + + ssl->session_negotiate->ticket_age_add; #endif } else diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c index 55cb67067..b73b39c2a 100644 --- a/library/ssl_tls13_server.c +++ b/library/ssl_tls13_server.c @@ -137,7 +137,7 @@ static int ssl_tls13_offered_psks_check_identity_match_ticket( #if defined(MBEDTLS_HAVE_TIME) mbedtls_time_t now; uint64_t age_in_s; - int64_t diff_in_ms; + int64_t age_diff_in_ms; #endif ((void) obfuscated_ticket_age); @@ -183,7 +183,6 @@ static int ssl_tls13_offered_psks_check_identity_match_ticket( #if defined(MBEDTLS_HAVE_TIME) now = mbedtls_time( NULL ); - ret = MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED; if( now < session->start ) { MBEDTLS_SSL_DEBUG_MSG( @@ -220,15 +219,20 @@ static int ssl_tls13_offered_psks_check_identity_match_ticket( * the ticket age for the selected PSK identity (computed by subtracting * ticket_age_add from PskIdentity.obfuscated_ticket_age modulo 2^32) is * within a small tolerance of the time since the ticket was issued. + * + * NOTE: When `now == session->start`, `age_diff_in_ms` will get a negative + * result. That's reasonable, the age units are different between + * server and client sides. Add a -1000 tolerance window to resolve + * that. */ - diff_in_ms = age_in_s * 1000; - diff_in_ms -= ( obfuscated_ticket_age - session->ticket_age_add ); - diff_in_ms += MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE / 2; - if( diff_in_ms < 0 || diff_in_ms > MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE ) + age_diff_in_ms = age_in_s * 1000; + age_diff_in_ms -= ( obfuscated_ticket_age - session->ticket_age_add ); + if( age_diff_in_ms <= -1000 || + age_diff_in_ms > MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE ) { MBEDTLS_SSL_DEBUG_MSG( 3, ( "Ticket expired: Ticket age outside tolerance window " - "( diff=%d )", (int)diff_in_ms ) ); + "( diff=%d )", (int)age_diff_in_ms ) ); goto exit; } @@ -264,7 +268,7 @@ static int ssl_tls13_offered_psks_check_identity_match( #if defined(MBEDTLS_SSL_SESSION_TICKETS) if( ssl_tls13_offered_psks_check_identity_match_ticket( ssl, identity, identity_len, obfuscated_ticket_age, - (mbedtls_ssl_session *)session ) == SSL_TLS1_3_OFFERED_PSK_MATCH ) + session ) == SSL_TLS1_3_OFFERED_PSK_MATCH ) { mbedtls_ssl_session *i_session=(mbedtls_ssl_session *)session; ssl->handshake->resume = 1; @@ -626,7 +630,8 @@ static int ssl_tls13_parse_pre_shared_key_ext( mbedtls_ssl_context *ssl, #if defined(MBEDTLS_SSL_SESSION_TICKETS) if( psk_type == MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION ) { - ret = ssl_tls13_session_copy_ticket(ssl->session_negotiate, &session ); + ret = ssl_tls13_session_copy_ticket( ssl->session_negotiate, + &session ); mbedtls_ssl_session_free( &session ); if( ret != 0 ) return( ret );