From de9e36e6b3729d79e38b77aafd78bfcfafee4f76 Mon Sep 17 00:00:00 2001 From: Hanno Becker Date: Wed, 3 Jul 2019 17:14:41 +0100 Subject: [PATCH] Pass dgrams to mbedtls_ssl_check_record in ssl_client2/server2 --- programs/ssl/ssl_client2.c | 72 +++++++++++++++++++++++++++++++++++-- programs/ssl/ssl_server2.c | 74 ++++++++++++++++++++++++++++++++++++-- 2 files changed, 142 insertions(+), 4 deletions(-) diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c index ad1936f43..cc1816cef 100644 --- a/programs/ssl/ssl_client2.c +++ b/programs/ssl/ssl_client2.c @@ -534,6 +534,68 @@ typedef struct mbedtls_net_context *net; } io_ctx_t; +#if defined(MBEDTLS_SSL_RECORD_CHECKING) +static int ssl_check_record( mbedtls_ssl_context const *ssl, + unsigned char const *buf, size_t len ) +{ + int ret; + unsigned char *tmp_buf; + + tmp_buf = mbedtls_calloc( 1, len ); + if( tmp_buf == NULL ) + return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); + memcpy( tmp_buf, buf, len ); + + ret = mbedtls_ssl_check_record( ssl, tmp_buf, len ); + if( ret != MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ) + { + int ret_repeated; + + /* Test-only: Make sure that mbedtls_ssl_check_record() + * doesn't alter state. */ + memcpy( tmp_buf, buf, len ); /* Restore buffer */ + ret_repeated = mbedtls_ssl_check_record( ssl, tmp_buf, len ); + if( ret != ret_repeated ) + { + ret = -1; + goto exit; + } + + switch( ret ) + { + case 0: + break; + + case MBEDTLS_ERR_SSL_INVALID_RECORD: + if( opt.debug_level > 1 ) + mbedtls_printf( "mbedtls_ssl_check_record() detected invalid record.\n" ); + break; + + case MBEDTLS_ERR_SSL_INVALID_MAC: + if( opt.debug_level > 1 ) + mbedtls_printf( "mbedtls_ssl_check_record() detected unauthentic record.\n" ); + break; + + case MBEDTLS_ERR_SSL_UNEXPECTED_RECORD: + if( opt.debug_level > 1 ) + mbedtls_printf( "mbedtls_ssl_check_record() detected unexpected record.\n" ); + break; + + default: + mbedtls_printf( "mbedtls_ssl_check_record() failed fatally with -%#04x.\n", -ret ); + return( -1 ); + } + + /* Regardless of the outcome, forward the record to the stack. */ + } + +exit: + mbedtls_free( tmp_buf ); + + return( 0 ); +} +#endif /* MBEDTLS_SSL_RECORD_CHECKING */ + static int recv_cb( void *ctx, unsigned char *buf, size_t len ) { io_ctx_t *io_ctx = (io_ctx_t*) ctx; @@ -553,7 +615,10 @@ static int recv_cb( void *ctx, unsigned char *buf, size_t len ) /* Here's the place to do any datagram/record checking * in between receiving the packet from the underlying * transport and passing it on to the TLS stack. */ - mbedtls_printf( "[RECV] Datagram of size %u\n", (unsigned) recv_len ); +#if defined(MBEDTLS_SSL_RECORD_CHECKING) + if( ssl_check_record( io_ctx->ssl, buf, recv_len ) != 0 ) + return( -1 ); +#endif /* MBEDTLS_SSL_RECORD_CHECKING */ } return( (int) recv_len ); @@ -576,7 +641,10 @@ static int recv_timeout_cb( void *ctx, unsigned char *buf, size_t len, /* Here's the place to do any datagram/record checking * in between receiving the packet from the underlying * transport and passing it on to the TLS stack. */ - mbedtls_printf( "[RECV] Datagram of size %u\n", (unsigned) recv_len ); +#if defined(MBEDTLS_SSL_RECORD_CHECKING) + if( ssl_check_record( io_ctx->ssl, buf, recv_len ) != 0 ) + return( -1 ); +#endif /* MBEDTLS_SSL_RECORD_CHECKING */ } return( (int) recv_len ); diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c index fe9ed6b2e..ddad7102a 100644 --- a/programs/ssl/ssl_server2.c +++ b/programs/ssl/ssl_server2.c @@ -664,6 +664,70 @@ typedef struct mbedtls_net_context *net; } io_ctx_t; +#if defined(MBEDTLS_SSL_RECORD_CHECKING) +static int ssl_check_record( mbedtls_ssl_context const *ssl, + unsigned char const *buf, size_t len ) +{ + int ret; + unsigned char *tmp_buf; + + /* Record checking may modify the input buffer, + * so make a copy. */ + tmp_buf = mbedtls_calloc( 1, len ); + if( tmp_buf == NULL ) + return( MBEDTLS_ERR_SSL_ALLOC_FAILED ); + memcpy( tmp_buf, buf, len ); + + ret = mbedtls_ssl_check_record( ssl, tmp_buf, len ); + if( ret != MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ) + { + int ret_repeated; + + /* Test-only: Make sure that mbedtls_ssl_check_record() + * doesn't alter state. */ + memcpy( tmp_buf, buf, len ); /* Restore buffer */ + ret_repeated = mbedtls_ssl_check_record( ssl, tmp_buf, len ); + if( ret != ret_repeated ) + { + ret = -1; + goto exit; + } + + switch( ret ) + { + case 0: + break; + + case MBEDTLS_ERR_SSL_INVALID_RECORD: + if( opt.debug_level > 1 ) + mbedtls_printf( "mbedtls_ssl_check_record() detected invalid record.\n" ); + break; + + case MBEDTLS_ERR_SSL_INVALID_MAC: + if( opt.debug_level > 1 ) + mbedtls_printf( "mbedtls_ssl_check_record() detected unauthentic record.\n" ); + break; + + case MBEDTLS_ERR_SSL_UNEXPECTED_RECORD: + if( opt.debug_level > 1 ) + mbedtls_printf( "mbedtls_ssl_check_record() detected unexpected record.\n" ); + break; + + default: + mbedtls_printf( "mbedtls_ssl_check_record() failed fatally with -%#04x.\n", -ret ); + return( -1 ); + } + + /* Regardless of the outcome, forward the record to the stack. */ + } + +exit: + mbedtls_free( tmp_buf ); + + return( 0 ); +} +#endif /* MBEDTLS_SSL_RECORD_CHECKING */ + static int recv_cb( void *ctx, unsigned char *buf, size_t len ) { io_ctx_t *io_ctx = (io_ctx_t*) ctx; @@ -683,7 +747,10 @@ static int recv_cb( void *ctx, unsigned char *buf, size_t len ) /* Here's the place to do any datagram/record checking * in between receiving the packet from the underlying * transport and passing it on to the TLS stack. */ - mbedtls_printf( "[RECV] Datagram of size %u\n", (unsigned) recv_len ); +#if defined(MBEDTLS_SSL_RECORD_CHECKING) + if( ssl_check_record( io_ctx->ssl, buf, recv_len ) != 0 ) + return( -1 ); +#endif /* MBEDTLS_SSL_RECORD_CHECKING */ } return( (int) recv_len ); @@ -706,7 +773,10 @@ static int recv_timeout_cb( void *ctx, unsigned char *buf, size_t len, /* Here's the place to do any datagram/record checking * in between receiving the packet from the underlying * transport and passing it on to the TLS stack. */ - mbedtls_printf( "[RECV] Datagram of size %u\n", (unsigned) recv_len ); +#if defined(MBEDTLS_SSL_RECORD_CHECKING) + if( ssl_check_record( io_ctx->ssl, buf, recv_len ) != 0 ) + return( -1 ); +#endif /* MBEDTLS_SSL_RECORD_CHECKING */ } return( (int) recv_len );