/* american fuzzy lop++ - common routines -------------------------------------- Originally written by Michal Zalewski Now maintained by Marc Heuse , Heiko Eißfeldt and Andrea Fioraldi Copyright 2016, 2017 Google Inc. All rights reserved. Copyright 2019-2020 AFLplusplus Project. 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 Gather some functions common to multiple executables - detect_file_args */ #include #include #include #include "debug.h" #include "alloc-inl.h" #include "envs.h" /* Detect @@ in args. */ #ifndef __glibc__ #include #endif #include extern u8 be_quiet; char * afl_environment_variables[] = { "AFL_ALIGNED_ALLOC", "AFL_ALLOW_TMP", "AFL_ANALYZE_HEX", "AFL_AS", "AFL_AUTORESUME", "AFL_AS_FORCE_INSTRUMENT", "AFL_BENCH_JUST_ONE", "AFL_BENCH_UNTIL_CRASH", "AFL_CAL_FAST", "AFL_CC", "AFL_CMIN_ALLOW_ANY", "AFL_CMIN_CRASHES_ONLY", "AFL_CODE_END", "AFL_CODE_START", "AFL_COMPCOV_BINNAME", "AFL_COMPCOV_LEVEL", "AFL_CUSTOM_MUTATOR_LIBRARY", "AFL_CUSTOM_MUTATOR_ONLY", "AFL_CXX", "AFL_DEBUG", "AFL_DEBUG_CHILD_OUTPUT", //"AFL_DEFER_FORKSRV", // not implemented anymore, so warn additionally "AFL_DISABLE_TRIM", "AFL_DONT_OPTIMIZE", "AFL_DUMB_FORKSRV", "AFL_ENTRYPOINT", "AFL_EXIT_WHEN_DONE", "AFL_FAST_CAL", "AFL_FORCE_UI", "AFL_GCC_WHITELIST", "AFL_GCJ", "AFL_HANG_TMOUT", "AFL_HARDEN", "AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES", "AFL_IMPORT_FIRST", "AFL_INST_LIBS", "AFL_INST_RATIO", "AFL_KEEP_TRACES", "AFL_KEEP_ASSEMBLY", "AFL_LD_HARD_FAIL", "AFL_LD_LIMIT_MB", "AFL_LD_NO_CALLOC_OVER", "AFL_LD_PRELOAD", "AFL_LD_VERBOSE", "AFL_LLVM_CMPLOG", "AFL_LLVM_INSTRIM", "AFL_LLVM_INSTRIM_LOOPHEAD", "AFL_LLVM_INSTRIM_SKIPSINGLEBLOCK", "AFL_LLVM_LAF_SPLIT_COMPARES", "AFL_LLVM_LAF_SPLIT_COMPARES_BITW", "AFL_LLVM_LAF_SPLIT_FLOATS", "AFL_LLVM_LAF_SPLIT_SWITCHES", "AFL_LLVM_LAF_TRANSFORM_COMPARES", "AFL_LLVM_NGRAM_SIZE", "AFL_NGRAM_SIZE", "AFL_LLVM_NOT_ZERO", "AFL_LLVM_WHITELIST", "AFL_NO_AFFINITY", "AFL_LLVM_LTO_STARTID", "AFL_LLVM_LTO_DONTWRITEID", "AFL_NO_ARITH", "AFL_NO_BUILTIN", "AFL_NO_CPU_RED", "AFL_NO_FORKSRV", "AFL_NO_UI", "AFL_NO_X86", // not really an env but we dont want to warn on it "AFL_PATH", "AFL_PERFORMANCE_FILE", //"AFL_PERSISTENT", // not implemented anymore, so warn additionally "AFL_POST_LIBRARY", "AFL_PRELOAD", "AFL_PYTHON_MODULE", "AFL_QEMU_COMPCOV", "AFL_QEMU_COMPCOV_DEBUG", "AFL_QEMU_DEBUG_MAPS", "AFL_QEMU_DISABLE_CACHE", "AFL_QEMU_PERSISTENT_ADDR", "AFL_QEMU_PERSISTENT_CNT", "AFL_QEMU_PERSISTENT_GPR", "AFL_QEMU_PERSISTENT_HOOK", "AFL_QEMU_PERSISTENT_RET", "AFL_QEMU_PERSISTENT_RETADDR_OFFSET", "AFL_QUIET", "AFL_RANDOM_ALLOC_CANARY", "AFL_REAL_PATH", "AFL_SHUFFLE_QUEUE", "AFL_SKIP_BIN_CHECK", "AFL_SKIP_CPUFREQ", "AFL_SKIP_CRASHES", "AFL_TMIN_EXACT", "AFL_TMPDIR", "AFL_TOKEN_FILE", "AFL_TRACE_PC", "AFL_USE_ASAN", "AFL_USE_MSAN", "AFL_USE_TRACE_PC", "AFL_USE_UBSAN", "AFL_USE_CFISAN", "AFL_WINE_PATH", NULL}; void detect_file_args(char **argv, u8 *prog_in, u8 *use_stdin) { u32 i = 0; u8 cwd[PATH_MAX]; if (getcwd(cwd, (size_t)sizeof(cwd)) == NULL) { PFATAL("getcwd() failed"); } /* we are working with libc-heap-allocated argvs. So do not mix them with * other allocation APIs like ck_alloc. That would disturb the free() calls. */ while (argv[i]) { u8 *aa_loc = strstr(argv[i], "@@"); if (aa_loc) { if (!prog_in) FATAL("@@ syntax is not supported by this tool."); *use_stdin = 0; if (prog_in[0] != 0) { // not afl-showmap special case u8 *n_arg; /* Be sure that we're always using fully-qualified paths. */ *aa_loc = 0; /* Construct a replacement argv value. */ if (prog_in[0] == '/') { n_arg = alloc_printf("%s%s%s", argv[i], prog_in, aa_loc + 2); } else { n_arg = alloc_printf("%s%s/%s%s", argv[i], cwd, prog_in, aa_loc + 2); } ck_free(argv[i]); argv[i] = n_arg; } } i++; } /* argvs are automatically freed at exit. */ } /* duplicate the system argv so that we can edit (and free!) it later */ char **argv_cpy_dup(int argc, char **argv) { u32 i = 0; char **ret = ck_alloc((argc + 1) * sizeof(char *)); for (i = 0; i < argc; i++) { ret[i] = ck_strdup(argv[i]); } ret[i] = NULL; return ret; } /* frees all args in the given argv, previously created by argv_cpy_dup */ void argv_cpy_free(char **argv) { u32 i = 0; while (argv[i]) { ck_free(argv[i]); i++; } ck_free(argv); } /* Rewrite argv for QEMU. */ char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { char **new_argv = ck_alloc(sizeof(char *) * (argc + 4)); u8 * tmp, *cp = NULL, *rsl, *own_copy; memcpy(new_argv + 3, argv + 1, (int)(sizeof(char *)) * argc); new_argv[2] = *target_path_p; new_argv[1] = "--"; /* Now we need to actually find the QEMU binary to put in argv[0]. */ tmp = getenv("AFL_PATH"); if (tmp) { cp = alloc_printf("%s/afl-qemu-trace", tmp); if (access(cp, X_OK)) FATAL("Unable to find '%s'", tmp); *target_path_p = new_argv[0] = cp; return new_argv; } own_copy = ck_strdup(own_loc); rsl = strrchr(own_copy, '/'); if (rsl) { *rsl = 0; cp = alloc_printf("%s/afl-qemu-trace", own_copy); ck_free(own_copy); if (!access(cp, X_OK)) { *target_path_p = new_argv[0] = cp; return new_argv; } } else ck_free(own_copy); if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { if (cp) ck_free(cp); *target_path_p = new_argv[0] = ck_strdup(BIN_PATH "/afl-qemu-trace"); return new_argv; } SAYF("\n" cLRD "[-] " cRST "Oops, unable to find the 'afl-qemu-trace' binary. The binary must be " "built\n" " separately by following the instructions in " "afl->qemu_mode/README.md. " "If you\n" " already have the binary installed, you may need to specify " "AFL_PATH in the\n" " environment.\n\n" " Of course, even without QEMU, afl-fuzz can still work with " "binaries that are\n" " instrumented at compile time with afl-gcc. It is also possible to " "use it as a\n" " traditional \"dumb\" fuzzer by specifying '-n' in the command " "line.\n"); FATAL("Failed to locate 'afl-qemu-trace'."); } /* Rewrite argv for Wine+QEMU. */ char **get_wine_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) { char **new_argv = ck_alloc(sizeof(char *) * (argc + 3)); u8 * tmp, *cp = NULL, *rsl, *own_copy; memcpy(new_argv + 2, argv + 1, (int)(sizeof(char *)) * argc); new_argv[1] = *target_path_p; /* Now we need to actually find the QEMU binary to put in argv[0]. */ tmp = getenv("AFL_PATH"); if (tmp) { cp = alloc_printf("%s/afl-qemu-trace", tmp); if (access(cp, X_OK)) FATAL("Unable to find '%s'", tmp); ck_free(cp); cp = alloc_printf("%s/afl-wine-trace", tmp); if (access(cp, X_OK)) FATAL("Unable to find '%s'", tmp); *target_path_p = new_argv[0] = cp; return new_argv; } own_copy = ck_strdup(own_loc); rsl = strrchr(own_copy, '/'); if (rsl) { *rsl = 0; cp = alloc_printf("%s/afl-qemu-trace", own_copy); ck_free(own_copy); if (!access(cp, X_OK)) { if (cp != NULL) ck_free(cp); cp = alloc_printf("%s/afl-wine-trace", own_copy); if (!access(cp, X_OK)) { *target_path_p = new_argv[0] = cp; return new_argv; } } } else ck_free(own_copy); u8 *ncp = BIN_PATH "/afl-qemu-trace"; if (!access(ncp, X_OK)) { ncp = BIN_PATH "/afl-wine-trace"; if (!access(ncp, X_OK)) { *target_path_p = new_argv[0] = ck_strdup(ncp); return new_argv; } } SAYF("\n" cLRD "[-] " cRST "Oops, unable to find the '%s' binary. The binary must be " "built\n" " separately by following the instructions in " "afl->qemu_mode/README.md. " "If you\n" " already have the binary installed, you may need to specify " "AFL_PATH in the\n" " environment.\n\n" " Of course, even without QEMU, afl-fuzz can still work with " "binaries that are\n" " instrumented at compile time with afl-gcc. It is also possible to " "use it as a\n" " traditional \"dumb\" fuzzer by specifying '-n' in the command " "line.\n", ncp); FATAL("Failed to locate '%s'.", ncp); } void check_environment_vars(char **envp) { if (be_quiet) return; int index = 0, found = 0; char *env; while ((env = envp[index++]) != NULL) { if (strncmp(env, "ALF_", 4) == 0) { WARNF("Potentially mistyped AFL environment variable: %s", env); found++; } else if (strncmp(env, "AFL_", 4) == 0) { int i = 0, match = 0; while (match == 0 && afl_environment_variables[i] != NULL) if (strncmp(env, afl_environment_variables[i], strlen(afl_environment_variables[i])) == 0 && env[strlen(afl_environment_variables[i])] == '=') match = 1; else i++; if (match == 0) { WARNF("Mistyped AFL environment variable: %s", env); found++; } } } if (found) sleep(2); } char *get_afl_env(char *env) { char *val; if ((val = getenv(env)) != NULL) if (!be_quiet) OKF("Loaded environment variable %s with value %s", env, val); return val; }