1 /*
2 * Zeroize application for debugger-driven testing
3 *
4 * This is a simple test application used for debugger-driven testing to check
5 * whether calls to mbedtls_platform_zeroize() are being eliminated by compiler
6 * optimizations. This application is used by the GDB script at
7 * tests/scripts/test_zeroize.gdb under the assumption that the code does not
8 * change often (as opposed to the library code) because the script sets a
9 * breakpoint at the last return statement in the main() function of this
10 * program. The debugger facilities are then used to manually inspect the
11 * memory and verify that the call to mbedtls_platform_zeroize() was not
12 * eliminated.
13 *
14 * Copyright (C) 2018, Arm Limited, All Rights Reserved
15 * SPDX-License-Identifier: Apache-2.0
16 *
17 * Licensed under the Apache License, Version 2.0 (the "License"); you may
18 * not use this file except in compliance with the License.
19 * You may obtain a copy of the License at
20 *
21 * http://www.apache.org/licenses/LICENSE-2.0
22 *
23 * Unless required by applicable law or agreed to in writing, software
24 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
25 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
26 * See the License for the specific language governing permissions and
27 * limitations under the License.
28 *
29 * This file is part of mbed TLS (https://tls.mbed.org)
30 */
31
32 #if !defined(MBEDTLS_CONFIG_FILE)
33 #include "mbedtls/config.h"
34 #else
35 #include MBEDTLS_CONFIG_FILE
36 #endif
37
38 #include <stdio.h>
39
40 #if defined(MBEDTLS_PLATFORM_C)
41 #include "mbedtls/platform.h"
42 #else
43 #include <stdlib.h>
44 #define mbedtls_printf printf
45 #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
46 #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
47 #endif
48
49 #include "mbedtls/platform_util.h"
50
51 #define BUFFER_LEN 1024
52
usage(void)53 void usage( void )
54 {
55 mbedtls_printf( "Zeroize is a simple program to assist with testing\n" );
56 mbedtls_printf( "the mbedtls_platform_zeroize() function by using the\n" );
57 mbedtls_printf( "debugger. This program takes a file as input and\n" );
58 mbedtls_printf( "prints the first %d characters. Usage:\n\n", BUFFER_LEN );
59 mbedtls_printf( " zeroize <FILE>\n" );
60 }
61
main(int argc,char ** argv)62 int main( int argc, char** argv )
63 {
64 int exit_code = MBEDTLS_EXIT_FAILURE;
65 FILE *fp;
66 char buf[BUFFER_LEN];
67 char *p = buf;
68 char *end = p + BUFFER_LEN;
69 int c;
70
71 if( argc != 2 )
72 {
73 mbedtls_printf( "This program takes exactly 1 agument\n" );
74 usage();
75 return( exit_code );
76 }
77
78 fp = fopen( argv[1], "r" );
79 if( fp == NULL )
80 {
81 mbedtls_printf( "Could not open file '%s'\n", argv[1] );
82 return( exit_code );
83 }
84
85 while( ( c = fgetc( fp ) ) != EOF && p < end - 1 )
86 *p++ = (char)c;
87 *p = '\0';
88
89 if( p - buf != 0 )
90 {
91 mbedtls_printf( "%s\n", buf );
92 exit_code = MBEDTLS_EXIT_SUCCESS;
93 }
94 else
95 mbedtls_printf( "The file is empty!\n" );
96
97 fclose( fp );
98 mbedtls_platform_zeroize( buf, sizeof( buf ) );
99
100 return( exit_code );
101 }
102