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