zeroize.c (2097B)
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/programs/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 OR GPL-2.0-or-later 14 */ 15 16 #include "mbedtls/build_info.h" 17 18 #include <stdio.h> 19 20 #include "mbedtls/platform.h" 21 22 #include "mbedtls/platform_util.h" 23 24 #define BUFFER_LEN 1024 25 26 static void usage(void) 27 { 28 mbedtls_printf("Zeroize is a simple program to assist with testing\n"); 29 mbedtls_printf("the mbedtls_platform_zeroize() function by using the\n"); 30 mbedtls_printf("debugger. This program takes a file as input and\n"); 31 mbedtls_printf("prints the first %d characters. Usage:\n\n", BUFFER_LEN); 32 mbedtls_printf(" zeroize <FILE>\n"); 33 } 34 35 int main(int argc, char **argv) 36 { 37 int exit_code = MBEDTLS_EXIT_FAILURE; 38 FILE *fp; 39 char buf[BUFFER_LEN]; 40 char *p = buf; 41 char *end = p + BUFFER_LEN; 42 int c; 43 44 if (argc != 2) { 45 mbedtls_printf("This program takes exactly 1 argument\n"); 46 usage(); 47 mbedtls_exit(exit_code); 48 } 49 50 fp = fopen(argv[1], "r"); 51 if (fp == NULL) { 52 mbedtls_printf("Could not open file '%s'\n", argv[1]); 53 mbedtls_exit(exit_code); 54 } 55 56 while ((c = fgetc(fp)) != EOF && p < end - 1) { 57 *p++ = (char) c; 58 } 59 *p = '\0'; 60 61 if (p - buf != 0) { 62 mbedtls_printf("%s\n", buf); 63 exit_code = MBEDTLS_EXIT_SUCCESS; 64 } else { 65 mbedtls_printf("The file is empty!\n"); 66 } 67 68 fclose(fp); 69 mbedtls_platform_zeroize(buf, sizeof(buf)); 70 71 mbedtls_exit(exit_code); // GDB_BREAK_HERE -- don't remove this comment! 72 }