diff --git a/ChangeLog b/ChangeLog index 2bc462fb0..b7428b152 100644 --- a/ChangeLog +++ b/ChangeLog @@ -21,6 +21,10 @@ Bugfix overflow. #1179 * Fix memory allocation corner cases in memory_buffer_alloc.c module. Found by Guido Vranken. #639 + * Fix a possible arithmetic overflow in ssl_parse_server_key_exchange() + that could cause a key exchange to fail on valid data. + * Fix a possible arithmetic overflow in ssl_parse_server_psk_hint() that + could cause a key exchange to fail on valid data. Changes * Clarify the documentation of mbedtls_ssl_setup. @@ -108,6 +112,8 @@ Security manner. * Fix a buffer overread in ssl_parse_server_key_exchange() that could cause a crash on invalid input. + * Fix a buffer overread in ssl_parse_server_psk_hint() that could cause a + crash on invalid input. Features * Allow comments in test data files. @@ -242,8 +248,6 @@ Bugfix * In mbedtls_entropy_free(), properly free the message digest context. * Fix status handshake status message in programs/ssl/dtls_client.c. Found and fixed by muddog. - * Fix a possible arithmetic overflow in ssl_parse_server_key_exchange() - that could cause a key exchange to fail on valid data. Changes * Extend cert_write example program by options to set the certificate version diff --git a/library/ssl_cli.c b/library/ssl_cli.c index 2eec7665b..eeb2fe2e9 100644 --- a/library/ssl_cli.c +++ b/library/ssl_cli.c @@ -2057,10 +2057,16 @@ static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl, * * opaque psk_identity_hint<0..2^16-1>; */ + if( (*p) > end - 2 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message " + "(psk_identity_hint length)" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } len = (*p)[0] << 8 | (*p)[1]; *p += 2; - if( (*p) + len > end ) + if( (*p) > end - len ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message " "(psk_identity_hint length)" ) );