mbedtls/programs/test/zeroize.c
k-stachowiak 776521aee8 Return from the test and utility examples via exit()
All the core examples have been modified not to return from main
by the means of the return statement, but rather via exit() function,
which was done to make the examples more bare metal friendly.

This commit, for the sake of consistency, introduces the modifications
to the test and utility examples. These, while less likely to be used
in the low level environments, won't suffer from such a change.
2019-08-16 06:38:10 +02:00

103 lines
3 KiB
C

/*
* Zeroize application for debugger-driven testing
*
* This is a simple test application used for debugger-driven testing to check
* whether calls to mbedtls_platform_zeroize() are being eliminated by compiler
* optimizations. This application is used by the GDB script at
* tests/scripts/test_zeroize.gdb under the assumption that the code does not
* change often (as opposed to the library code) because the script sets a
* breakpoint at the last return statement in the main() function of this
* program. The debugger facilities are then used to manually inspect the
* memory and verify that the call to mbedtls_platform_zeroize() was not
* eliminated.
*
* Copyright (C) 2018, Arm Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include <stdio.h>
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_printf printf
#define mbedtls_exit exit
#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
#endif
#include "mbedtls/platform_util.h"
#define BUFFER_LEN 1024
void usage( void )
{
mbedtls_printf( "Zeroize is a simple program to assist with testing\n" );
mbedtls_printf( "the mbedtls_platform_zeroize() function by using the\n" );
mbedtls_printf( "debugger. This program takes a file as input and\n" );
mbedtls_printf( "prints the first %d characters. Usage:\n\n", BUFFER_LEN );
mbedtls_printf( " zeroize <FILE>\n" );
}
int main( int argc, char** argv )
{
int exit_code = MBEDTLS_EXIT_FAILURE;
FILE *fp;
char buf[BUFFER_LEN];
char *p = buf;
char *end = p + BUFFER_LEN;
int c;
if( argc != 2 )
{
mbedtls_printf( "This program takes exactly 1 agument\n" );
usage();
mbedtls_exit( exit_code );
}
fp = fopen( argv[1], "r" );
if( fp == NULL )
{
mbedtls_printf( "Could not open file '%s'\n", argv[1] );
mbedtls_exit( exit_code );
}
while( ( c = fgetc( fp ) ) != EOF && p < end - 1 )
*p++ = (char)c;
*p = '\0';
if( p - buf != 0 )
{
mbedtls_printf( "%s\n", buf );
exit_code = MBEDTLS_EXIT_SUCCESS;
}
else
mbedtls_printf( "The file is empty!\n" );
fclose( fp );
mbedtls_platform_zeroize( buf, sizeof( buf ) );
mbedtls_exit( exit_code );
}