diff options
Diffstat (limited to 'frida_mode/src/persistent/persistent_x86.c')
| -rw-r--r-- | frida_mode/src/persistent/persistent_x86.c | 233 |
1 files changed, 228 insertions, 5 deletions
diff --git a/frida_mode/src/persistent/persistent_x86.c b/frida_mode/src/persistent/persistent_x86.c index 9d39c4e9..bd7171b9 100644 --- a/frida_mode/src/persistent/persistent_x86.c +++ b/frida_mode/src/persistent/persistent_x86.c @@ -1,9 +1,9 @@ #include "frida-gum.h" -#include "debug.h" +#include "config.h" +#include "instrument.h" #include "persistent.h" -#include "util.h" #if defined(__i386__) @@ -38,16 +38,239 @@ struct x86_regs { typedef struct x86_regs arch_api_regs; +static arch_api_regs saved_regs = {0}; +static void * saved_return = NULL; + gboolean persistent_is_supported(void) { - return false; + return true; + +} + +static void instrument_persitent_save_regs(GumX86Writer * cw, + struct x86_regs *regs) { + + GumAddress regs_address = GUM_ADDRESS(regs); + + /* Should be pushing FPU here, but meh */ + gum_x86_writer_put_pushfx(cw); + gum_x86_writer_put_push_reg(cw, GUM_REG_EAX); + + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EAX, regs_address); + + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 1), + GUM_REG_EBX); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 2), + GUM_REG_ECX); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 3), + GUM_REG_EDX); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 4), + GUM_REG_EDI); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 5), + GUM_REG_ESI); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 6), + GUM_REG_EBP); + + /* Store RIP */ + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EBX, + GUM_ADDRESS(persistent_start)); + + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 7), + GUM_REG_EBX); + + /* Store adjusted RSP */ + gum_x86_writer_put_mov_reg_reg(cw, GUM_REG_EBX, GUM_REG_ESP); + + /* RED_ZONE + Saved flags, RAX */ + gum_x86_writer_put_add_reg_imm(cw, GUM_REG_EBX, (0x4 * 2)); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 8), + GUM_REG_EBX); + + /* Save the flags */ + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_ESP, 0x4); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 9), + GUM_REG_EBX); + + /* Save the RAX */ + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_ESP, 0x0); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, (0x4 * 0), + GUM_REG_EBX); + + /* Pop the saved values */ + gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_ESP, GUM_REG_ESP, 0x8); + +} + +static void instrument_persitent_restore_regs(GumX86Writer * cw, + struct x86_regs *regs) { + + GumAddress regs_address = GUM_ADDRESS(regs); + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EAX, regs_address); + + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_ECX, GUM_REG_EAX, + (0x4 * 2)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EDX, GUM_REG_EAX, + (0x4 * 3)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EDI, GUM_REG_EAX, + (0x4 * 4)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_ESI, GUM_REG_EAX, + (0x4 * 5)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBP, GUM_REG_EAX, + (0x4 * 6)); + + /* Don't restore RIP or RSP */ + + /* Restore RBX, RAX & Flags */ + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_EAX, + (0x4 * 1)); + gum_x86_writer_put_push_reg(cw, GUM_REG_EBX); + + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_EAX, + (0x4 * 0)); + gum_x86_writer_put_push_reg(cw, GUM_REG_EBX); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_EAX, + (0x4 * 9)); + gum_x86_writer_put_push_reg(cw, GUM_REG_EBX); + + gum_x86_writer_put_popfx(cw); + gum_x86_writer_put_pop_reg(cw, GUM_REG_EAX); + gum_x86_writer_put_pop_reg(cw, GUM_REG_EBX); + +} + +static void instrument_save_ret(GumX86Writer *cw, void **saved_return_ptr) { + + GumAddress saved_return_address = GUM_ADDRESS(saved_return_ptr); + + gum_x86_writer_put_push_reg(cw, GUM_REG_EAX); + gum_x86_writer_put_push_reg(cw, GUM_REG_EBX); + + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EAX, saved_return_address); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EBX, GUM_REG_ESP, 0x8); + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_EAX, 0, GUM_REG_EBX); + + gum_x86_writer_put_pop_reg(cw, GUM_REG_EBX); + gum_x86_writer_put_pop_reg(cw, GUM_REG_EAX); + +} + +static void instrument_jump_ret(GumX86Writer *cw, void **saved_return_ptr) { + + GumAddress saved_return_address = GUM_ADDRESS(saved_return_ptr); + + /* Place holder for ret */ + gum_x86_writer_put_push_reg(cw, GUM_REG_EAX); + gum_x86_writer_put_push_reg(cw, GUM_REG_EAX); + + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EAX, saved_return_address); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EAX, GUM_REG_EAX, 0); + + gum_x86_writer_put_mov_reg_offset_ptr_reg(cw, GUM_REG_ESP, 0x4, GUM_REG_EAX); + gum_x86_writer_put_pop_reg(cw, GUM_REG_EAX); + gum_x86_writer_put_ret(cw); + +} + +static int instrument_afl_persistent_loop_func(void) { + + int ret = __afl_persistent_loop(persistent_count); + previous_pc = 0; + return ret; + +} + +static void instrument_afl_persistent_loop(GumX86Writer *cw) { + + gum_x86_writer_put_call_address_with_arguments( + cw, GUM_CALL_CAPI, GUM_ADDRESS(instrument_afl_persistent_loop_func), 0); + gum_x86_writer_put_test_reg_reg(cw, GUM_REG_EAX, GUM_REG_EAX); + +} + +static void persistent_prologue_hook(GumX86Writer *cw, struct x86_regs *regs) { + + if (hook == NULL) return; + + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_ECX, + GUM_ADDRESS(&__afl_fuzz_len)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_ECX, GUM_REG_ECX, 0); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_ECX, GUM_REG_ECX, 0); + + gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EDX, + GUM_ADDRESS(&__afl_fuzz_ptr)); + gum_x86_writer_put_mov_reg_reg_offset_ptr(cw, GUM_REG_EDX, GUM_REG_EDX, 0); + + /* Base address is 64-bits (hence two zero arguments) */ + gum_x86_writer_put_call_address_with_arguments( + cw, GUM_CALL_CAPI, GUM_ADDRESS(hook), 5, GUM_ARG_ADDRESS, + GUM_ADDRESS(regs), GUM_ARG_ADDRESS, GUM_ADDRESS(0), GUM_ARG_ADDRESS, + GUM_ADDRESS(0), GUM_ARG_REGISTER, GUM_REG_EDX, GUM_ARG_REGISTER, + GUM_REG_ECX); } void persistent_prologue(GumStalkerOutput *output) { - UNUSED_PARAMETER(output); - FATAL("Persistent mode not supported on this architecture"); + /* + * SAVE REGS + * SAVE RET + * POP RET + * loop: + * CALL instrument_afl_persistent_loop + * TEST EAX, EAX + * JZ end: + * call hook (optionally) + * RESTORE REGS + * call original + * jmp loop: + * + * end: + * JMP SAVED RET + * + * original: + * INSTRUMENTED PERSISTENT FUNC + */ + + GumX86Writer *cw = output->writer.x86; + + gconstpointer loop = cw->code + 1; + + /* Stack must be 16-byte aligned per ABI */ + instrument_persitent_save_regs(cw, &saved_regs); + + /* Stash and pop the return value */ + instrument_save_ret(cw, &saved_return); + gum_x86_writer_put_lea_reg_reg_offset(cw, GUM_REG_ESP, GUM_REG_ESP, (4)); + + /* loop: */ + gum_x86_writer_put_label(cw, loop); + + /* call instrument_prologue_func */ + instrument_afl_persistent_loop(cw); + + /* jz done */ + gconstpointer done = cw->code + 1; + gum_x86_writer_put_jcc_near_label(cw, X86_INS_JE, done, GUM_UNLIKELY); + + /* Optionally call the persistent hook */ + persistent_prologue_hook(cw, &saved_regs); + + instrument_persitent_restore_regs(cw, &saved_regs); + gconstpointer original = cw->code + 1; + /* call original */ + gum_x86_writer_put_call_near_label(cw, original); + /* jmp loop */ + gum_x86_writer_put_jmp_near_label(cw, loop); + + /* done: */ + gum_x86_writer_put_label(cw, done); + + instrument_jump_ret(cw, &saved_return); + + /* original: */ + gum_x86_writer_put_label(cw, original); + + gum_x86_writer_flush(cw); } |