Fixes different off by ones
diff --git a/ChangeLog b/ChangeLog
index 8ebe9bb..723539c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -25,6 +25,9 @@
* Support TLS testing in out-of-source builds using cmake. Fixes #1193.
* Fix redundant declaration of mbedtls_ssl_list_ciphersuites. Raised by
TrinityTonic. #1359.
+ * Adds of lengths checks in different functions (not a security issue as
+ original buffer is overgrown) thanks to Philippe Antoine from Catena
+ cyber. #1663.
= mbed TLS 2.9.0 branch released 2018-04-30
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 7455e99..f89972a 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1247,14 +1247,14 @@
size_t list_size;
const unsigned char *p;
- list_size = buf[0];
- if( list_size + 1 != len )
+ if( len == 0 || (size_t)( buf[0] + 1 ) != len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
+ list_size = buf[0];
p = buf + 1;
while( list_size > 0 )
@@ -2711,7 +2711,7 @@
* therefore the buffer length at this point must be greater than that
* regardless of the actual code path.
*/
- if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
+ if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 09b7a3f..457f9bb 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -91,6 +91,13 @@
MBEDTLS_SSL_DEBUG_MSG( 3, ( "parse ServerName extension" ) );
+ if( len < 2 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
if( servername_list_size + 2 != len )
{
@@ -101,7 +108,7 @@
}
p = buf + 2;
- while( servername_list_size > 0 )
+ while( servername_list_size > 2 )
{
hostname_len = ( ( p[1] << 8 ) | p[2] );
if( hostname_len + 3 > servername_list_size )
@@ -205,6 +212,12 @@
mbedtls_md_type_t md_cur;
mbedtls_pk_type_t sig_cur;
+ if ( len < 2 ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
if( sig_alg_list_size + 2 != len ||
sig_alg_list_size % 2 != 0 )
@@ -273,6 +286,12 @@
const unsigned char *p;
const mbedtls_ecp_curve_info *curve_info, **curves;
+ if ( len < 2 ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
if( list_size + 2 != len ||
list_size % 2 != 0 )
@@ -332,14 +351,14 @@
size_t list_size;
const unsigned char *p;
- list_size = buf[0];
- if( list_size + 1 != len )
+ if( len == 0 || (size_t)( buf[0] + 1 ) != len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
+ list_size = buf[0];
p = buf + 1;
while( list_size > 0 )
@@ -1656,10 +1675,16 @@
while( ext_len != 0 )
{
- unsigned int ext_id = ( ( ext[0] << 8 )
- | ( ext[1] ) );
- unsigned int ext_size = ( ( ext[2] << 8 )
- | ( ext[3] ) );
+ unsigned int ext_id;
+ unsigned int ext_size;
+ if ( ext_len < 4 ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ ext_id = ( ( ext[0] << 8 ) | ( ext[1] ) );
+ ext_size = ( ( ext[2] << 8 ) | ( ext[3] ) );
if( ext_size + 4 > ext_len )
{
@@ -3299,6 +3324,10 @@
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 )
{
+ if ( p + 2 > end ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
if( *p++ != ( ( len >> 8 ) & 0xFF ) ||
*p++ != ( ( len ) & 0xFF ) )
{
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index e8e0cd8..b8b8df2 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1151,6 +1151,9 @@
* other_secret already set by the ClientKeyExchange message,
* and is 48 bytes long
*/
+ if( end - p < 2 )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
*p++ = 0;
*p++ = 48;
p += 48;
@@ -4528,6 +4531,12 @@
while( i < ssl->in_hslen )
{
+ if ( i + 3 > ssl->in_hslen ) {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+ MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
+ }
if( ssl->in_msg[i] != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
