diff options
Diffstat (limited to 'utils/afl_frida/afl-frida.c')
| -rw-r--r-- | utils/afl_frida/afl-frida.c | 173 |
1 files changed, 133 insertions, 40 deletions
diff --git a/utils/afl_frida/afl-frida.c b/utils/afl_frida/afl-frida.c index 087f18e8..711d8f33 100644 --- a/utils/afl_frida/afl-frida.c +++ b/utils/afl_frida/afl-frida.c @@ -78,11 +78,11 @@ extern unsigned int * __afl_fuzz_len; extern unsigned char *__afl_fuzz_ptr; // Notify AFL about persistent mode. -static volatile char AFL_PERSISTENT[] = "##SIG_AFL_PERSISTENT##"; +static volatile char AFL_PERSISTENT[] = "##SIG_AFL_PERSISTENT##\0"; int __afl_persistent_loop(unsigned int); // Notify AFL about deferred forkserver. -static volatile char AFL_DEFER_FORKSVR[] = "##SIG_AFL_DEFER_FORKSRV##"; +static volatile char AFL_DEFER_FORKSVR[] = "##SIG_AFL_DEFER_FORKSRV##\0"; void __afl_manual_init(); // Because we do our own logging. @@ -94,6 +94,8 @@ typedef struct { GumAddress base_address; guint64 code_start, code_end; + GumAddress current_log_impl; + uint64_t afl_prev_loc; } range_t; @@ -109,12 +111,58 @@ inline static void afl_maybe_log(guint64 current_pc) { } +#if GUM_NATIVE_CPU == GUM_CPU_AMD64 + +static const guint8 afl_maybe_log_code[] = { + + 0x9c, // pushfq + 0x50, // push rax + 0x51, // push rcx + 0x52, // push rdx + 0x56, // push rsi + + 0x89, 0xf8, // mov eax, edi + 0xc1, 0xe0, 0x08, // shl eax, 8 + 0xc1, 0xef, 0x04, // shr edi, 4 + 0x31, 0xc7, // xor edi, eax + 0x0f, 0xb7, 0xc7, // movzx eax, di + 0x48, 0x8d, 0x0d, 0x30, 0x00, 0x00, 0x00, // lea rcx, sym._afl_area_ptr_ptr + 0x48, 0x8b, 0x09, // mov rcx, qword [rcx] + 0x48, 0x8b, 0x09, // mov rcx, qword [rcx] + 0x48, 0x8d, 0x15, 0x1b, 0x00, 0x00, 0x00, // lea rdx, sym._afl_prev_loc_ptr + 0x48, 0x8b, 0x32, // mov rsi, qword [rdx] + 0x48, 0x8b, 0x36, // mov rsi, qword [rsi] + 0x48, 0x31, 0xc6, // xor rsi, rax + 0xfe, 0x04, 0x31, // inc byte [rcx + rsi] + + 0x48, 0xd1, 0xe8, // shr rax, 1 + 0x48, 0x8b, 0x0a, // mov rcx, qword [rdx] + 0x48, 0x89, 0x01, // mov qword [rcx], rax + + 0x5e, // pop rsi + 0x5a, // pop rdx + 0x59, // pop rcx + 0x58, // pop rax + 0x9d, // popfq + + 0xc3, // ret + // Read-only data goes here: + // uint64_t* afl_prev_loc_ptr + // uint8_t** afl_area_ptr_ptr + // unsigned int afl_instr_rms + +}; + +#else + static void on_basic_block(GumCpuContext *context, gpointer user_data) { afl_maybe_log((guint64)user_data); } +#endif + void instr_basic_block(GumStalkerIterator *iterator, GumStalkerOutput *output, gpointer user_data) { @@ -129,8 +177,45 @@ void instr_basic_block(GumStalkerIterator *iterator, GumStalkerOutput *output, if (instr->address >= range->code_start && instr->address <= range->code_end) { +#if GUM_NATIVE_CPU == GUM_CPU_AMD64 + GumX86Writer *cw = output->writer.x86; + if (range->current_log_impl == 0 || + !gum_x86_writer_can_branch_directly_between( + cw->pc, range->current_log_impl) || + !gum_x86_writer_can_branch_directly_between( + cw->pc + 128, range->current_log_impl)) { + + gconstpointer after_log_impl = cw->code + 1; + + gum_x86_writer_put_jmp_near_label(cw, after_log_impl); + + range->current_log_impl = cw->pc; + gum_x86_writer_put_bytes(cw, afl_maybe_log_code, + sizeof(afl_maybe_log_code)); + + uint64_t *afl_prev_loc_ptr = &range->afl_prev_loc; + uint8_t **afl_area_ptr_ptr = &__afl_area_ptr; + gum_x86_writer_put_bytes(cw, (const guint8 *)&afl_prev_loc_ptr, + sizeof(afl_prev_loc_ptr)); + gum_x86_writer_put_bytes(cw, (const guint8 *)&afl_area_ptr_ptr, + sizeof(afl_area_ptr_ptr)); + gum_x86_writer_put_label(cw, after_log_impl); + + } + + gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_RSP, GUM_REG_RSP, + -GUM_RED_ZONE_SIZE); + gum_x86_writer_put_push_reg(cw, GUM_REG_RDI); + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_RDI, + GUM_ADDRESS(instr->address)); + gum_x86_writer_put_call_address(cw, range->current_log_impl); + gum_x86_writer_put_pop_reg(cw, GUM_REG_RDI); + gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_RSP, GUM_REG_RSP, + GUM_RED_ZONE_SIZE); +#else gum_stalker_iterator_put_callout(iterator, on_basic_block, (gpointer)instr->address, NULL); +#endif begin = FALSE; } @@ -153,7 +238,7 @@ static int enumerate_ranges(const GumRangeDetails *details, } -int main(int argc, char** argv) { +int main(int argc, char **argv) { #ifndef __APPLE__ (void)personality(ADDR_NO_RANDOMIZE); // disable ASLR @@ -166,10 +251,15 @@ int main(int argc, char** argv) { void *dl = NULL; if (argc > 2) { + dl = dlopen(argv[1], RTLD_LAZY); + } else { + dl = dlopen(TARGET_LIBRARY, RTLD_LAZY); + } + if (!dl) { if (argc > 2) @@ -197,17 +287,18 @@ int main(int argc, char** argv) { // END STEP 2 if (!getenv("AFL_FRIDA_TEST_INPUT")) { + gum_init_embedded(); if (!gum_stalker_is_supported()) { - + gum_deinit_embedded(); return 1; - + } - + GumStalker *stalker = gum_stalker_new(); - - GumAddress base_address; + + GumAddress base_address; if (argc > 2) base_address = gum_module_find_base_address(argv[1]); else @@ -215,87 +306,89 @@ int main(int argc, char** argv) { GumMemoryRange code_range; if (argc > 2) gum_module_enumerate_ranges(argv[1], GUM_PAGE_RX, enumerate_ranges, - &code_range); + &code_range); else gum_module_enumerate_ranges(TARGET_LIBRARY, GUM_PAGE_RX, enumerate_ranges, - &code_range); - + &code_range); + guint64 code_start = code_range.base_address; guint64 code_end = code_range.base_address + code_range.size; - range_t instr_range = {0, code_start, code_end}; - + range_t instr_range = {0, code_start, code_end, 0, 0}; + printf("Frida instrumentation: base=0x%lx instrumenting=0x%lx-%lx\n", base_address, code_start, code_end); if (!code_start || !code_end) { - + if (argc > 2) fprintf(stderr, "Error: no valid memory address found for %s\n", - argv[1]); + argv[1]); else fprintf(stderr, "Error: no valid memory address found for %s\n", - TARGET_LIBRARY); + TARGET_LIBRARY); exit(-1); - + } - + GumStalkerTransformer *transformer = gum_stalker_transformer_make_from_callback(instr_basic_block, &instr_range, NULL); - + // to ensure that the signatures are not optimized out - memcpy(__afl_area_ptr, (void *)AFL_PERSISTENT, sizeof(AFL_PERSISTENT) + 1); + memcpy(__afl_area_ptr, (void *)AFL_PERSISTENT, sizeof(AFL_PERSISTENT)); memcpy(__afl_area_ptr + 32, (void *)AFL_DEFER_FORKSVR, - sizeof(AFL_DEFER_FORKSVR) + 1); + sizeof(AFL_DEFER_FORKSVR)); __afl_manual_init(); - + // // any expensive target library initialization that has to be done just once // - put that here // - + gum_stalker_follow_me(stalker, transformer, NULL); - + while (__afl_persistent_loop(UINT32_MAX) != 0) { - + previous_pc = 0; // Required! - - #ifdef _DEBUG + +#ifdef _DEBUG fprintf(stderr, "CLIENT crc: %016llx len: %u\n", hash64(__afl_fuzz_ptr, *__afl_fuzz_len), *__afl_fuzz_len); fprintf(stderr, "RECV:"); for (int i = 0; i < *__afl_fuzz_len; i++) fprintf(stderr, "%02x", __afl_fuzz_ptr[i]); fprintf(stderr, "\n"); - #endif - +#endif + // STEP 3: ensure the minimum length is present and setup the target // function to fuzz. - + if (*__afl_fuzz_len > 0) { - + __afl_fuzz_ptr[*__afl_fuzz_len] = 0; // if you need to null terminate (*o_function)(__afl_fuzz_ptr, *__afl_fuzz_len); - + } - + // END STEP 3 - + } - + gum_stalker_unfollow_me(stalker); - + while (gum_stalker_garbage_collect(stalker)) g_usleep(10000); - + g_object_unref(stalker); g_object_unref(transformer); gum_deinit_embedded(); } else { - char buf[8*1024] = {0}; - int count = read(0, buf, sizeof(buf)); - buf[8*1024-1] = '\0'; + + char buf[8 * 1024] = {0}; + int count = read(0, buf, sizeof(buf)); + buf[8 * 1024 - 1] = '\0'; (*o_function)(buf, count); + } return 0; |