/* american fuzzy lop++ - sample argv fuzzing wrapper ------------------------------------------------ Originally written by Michal Zalewski Copyright 2015 Google Inc. All rights reserved. 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 This file shows a simple way to fuzz command-line parameters with stock afl-fuzz. To use, add: #include "/path/to/argv-fuzz-inl.h" ...to the file containing main(), ideally placing it after all the standard includes. Next, put AFL_INIT_ARGV(); near the very beginning of main(). This will cause the program to read NUL-delimited input from stdin and put it in argv[]. Two subsequent NULs terminate the array. Empty params are encoded as a lone 0x02. Lone 0x02 can't be generated, but that shouldn't matter in real life. If you would like to always preserve argv[0], use this instead: AFL_INIT_SET0("prog_name"); To enable persistent fuzzing, use the AFL_INIT_ARGV_PERSISTENT macro with buf as argument, or use AFL_INIT_SET0_PERSISTENT("prog_name", buf) to preserver argv[0]. buf is a pointer to a buffer containing the input data for the current test case being processed defined as: unsigned char *buf = __AFL_FUZZ_TESTCASE_BUF; */ #ifndef _HAVE_ARGV_FUZZ_INL #define _HAVE_ARGV_FUZZ_INL #include #include #define AFL_INIT_ARGV() \ do { \ \ argv = afl_init_argv(&argc); \ \ } while (0) #define AFL_INIT_SET0(_p) \ do { \ \ argv = afl_init_argv(&argc); \ argv[0] = (_p); \ if (!argc) argc = 1; \ \ } while (0) #define AFL_INIT_ARGV_PERSISTENT(persistent_buff) \ do { \ \ argv = afl_init_argv_persistent(&argc, persistent_buff); \ \ } while (0) #define AFL_INIT_SET0_PERSISTENT(_p, persistent_buff) \ do { \ \ argv = afl_init_argv_persistent(&argc, persistent_buff); \ argv[0] = (_p); \ if (!argc) argc = 1; \ \ } while (0) #define MAX_CMDLINE_LEN 100000 #define MAX_CMDLINE_PAR 50000 static char **afl_init_argv(int *argc) { static char in_buf[MAX_CMDLINE_LEN]; static char *ret[MAX_CMDLINE_PAR]; char *ptr = in_buf; int rc = 0; ssize_t num = read(0, in_buf, MAX_CMDLINE_LEN - 2); if (num < 1) { _exit(1); } in_buf[num] = '\0'; in_buf[num + 1] = '\0'; while (*ptr && rc < MAX_CMDLINE_PAR) { ret[rc] = ptr; if (ret[rc][0] == 0x02 && !ret[rc][1]) ret[rc]++; rc++; while (*ptr) ptr++; ptr++; } *argc = rc; return ret; } static char **afl_init_argv_persistent(int *argc, unsigned char *persistent_buff) { static char *ret[MAX_CMDLINE_PAR]; unsigned char *ptr = persistent_buff; int rc = 0; while (*ptr && rc < MAX_CMDLINE_PAR) { ret[rc] = (char *)ptr; if (ret[rc][0] == 0x02 && !ret[rc][1]) ret[rc]++; rc++; while (*ptr) ptr++; ptr++; } *argc = rc; return ret; } #undef MAX_CMDLINE_LEN #undef MAX_CMDLINE_PAR #endif /* !_HAVE_ARGV_FUZZ_INL */