class Disassembler(): def __init__(self, filename, raw_type, raw_base, raw_big_endian, sym, rev_sym, jmptables, inline_comments, previous_comments, load_symbols=True): import capstone as CAPSTONE self.code = {} self.binary = Binary(filename, raw_type, raw_base, raw_big_endian) arch, mode = self.binary.get_arch() if arch is None or mode is None: raise ExcArch(self.binary.get_arch_string()) if load_symbols: self.binary.load_symbols() else: self.binary.symbols = sym self.binary.reverse_symbols = rev_sym self.binary.load_section_names() self.binary.load_data_sections() self.capstone = CAPSTONE self.md = CAPSTONE.Cs(arch, mode) self.md.detail = True self.arch = arch self.mode = mode self.jmptables = jmptables self.inline_comments = inline_comments self.previous_comments = previous_comments def get_unpack_str(self, size_word): if self.mode & self.capstone.CS_MODE_BIG_ENDIAN: endian = ">" else: endian = "<" if size_word == 1: unpack_str = endian + "B" elif size_word == 2: unpack_str = endian + "H" elif size_word == 4: unpack_str = endian + "L" elif size_word == 8: unpack_str = endian + "Q" return unpack_str def add_symbol(self, addr, name): if name in self.binary.symbols: last = self.binary.symbols[name] del self.binary.reverse_symbols[last] self.binary.symbols[name] = addr self.binary.reverse_symbols[addr] = name return name def read_array(self, ad, array_max_size, size_word): unpack_str = self.get_unpack_str(size_word) N = size_word * array_max_size s_name, s_start, s_end = self.binary.get_section_meta(ad) array = [] l = 0 while l < array_max_size: buf = self.binary.section_stream_read(ad, N) if not buf: break i = 0 while i < len(buf): b = buf[i:i + size_word] if ad > s_end or len(b) != size_word: return array w = struct.unpack(unpack_str, b)[0] array.append(w) ad += size_word i += size_word l += 1 if l >= array_max_size: return array return array def check_addr(self, ctx, addr): addr_exists, is_exec = self.binary.check_addr(addr) if not ctx.print_data and not is_exec: raise ExcNotExec(addr) if not addr_exists: raise ExcNotAddr(addr) def load_arch_module(self): if self.arch == self.capstone.CS_ARCH_X86: import lib.arch.x86 as ARCH elif self.arch == self.capstone.CS_ARCH_ARM: import lib.arch.arm as ARCH elif self.arch == self.capstone.CS_ARCH_MIPS: import lib.arch.mips as ARCH else: raise NotImplementedError return ARCH def get_addr_from_string(self, opt_addr, raw=False): if opt_addr is None: if raw: return 0 search = ["main", "_main"] else: search = [opt_addr] for s in search: if s.startswith("0x"): a = int(opt_addr, 16) else: a = self.binary.symbols.get(s, -1) if a == -1: a = self.binary.section_names.get(s, -1) if a != -1: return a raise ExcSymNotFound(search[0]) def print_section_meta(self, name, start, end): print_no_end(color_section(name.ljust(20))) print_no_end(" [ ") print_no_end(hex(start)) print_no_end(" - ") print_no_end(hex(end)) print_no_end(" - %d" % (end - start + 1)) print(" ]") def dump_asm(self, ctx, lines): from capstone import CS_OP_IMM ARCH = self.load_arch_module() ARCH_UTILS = ARCH.utils ARCH_OUTPUT = ARCH.output s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) # set jumps color ad = ctx.entry_addr l = 0 while l < lines and ad < s_end: i = self.lazy_disasm(ad, s_start) if i is None: ad += 1 else: if ARCH_UTILS.is_jump(i) and i.operands[-1].type == CS_OP_IMM: pick_color(i.operands[-1].value.imm) ad += i.size l += 1 # Here we have loaded all instructions we want to print if self.binary.type == T_BIN_PE: self.binary.pe_reverse_stripped_symbols(self) o = ARCH_OUTPUT.Output(ctx) # dump ad = ctx.entry_addr l = 0 while l < lines and ad < s_end: i = self.lazy_disasm(ad, s_start) if i is None: ad += 1 o.print_bad(ad) else: o.print_inst(i) ad += i.size l += 1 def dump_data_ascii(self, ctx, lines): N = 128 # read by block of 128 bytes addr = ctx.entry_addr s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) l = 0 ascii_str = [] addr_str = -1 while l < lines: buf = self.binary.section_stream_read(addr, N) if not buf: break i = 0 while i < len(buf): if addr > s_end: return j = i while j < len(buf): c = buf[j] if c not in BYTES_PRINTABLE_SET: break if addr_str == -1: addr_str = addr ascii_str.append(c) j += 1 if c != 0 and j == len(buf): addr += j - i break if c == 0 and len(ascii_str) >= 2: print_no_end(color_addr(addr_str)) print_no_end(color_string( "\"" + "".join(map(get_char, ascii_str)) + "\"")) print(", 0") addr += j - i i = j else: print_no_end(color_addr(addr)) print("0x%.2x " % buf[i]) addr += 1 i += 1 addr_str = -1 ascii_str = [] l += 1 if l >= lines: return def dump_data(self, ctx, lines, size_word): s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) ad = ctx.entry_addr for w in self.read_array(ctx.entry_addr, lines, size_word): if ad in self.binary.reverse_symbols: print(color_symbol(self.binary.reverse_symbols[ad])) print_no_end(color_addr(ad)) print_no_end("0x%.2x" % w) sec_name, is_data = self.binary.is_address(w) if sec_name is not None: print_no_end(" (") print_no_end(color_section(sec_name)) print_no_end(")") if size_word >= 4 and w in self.binary.reverse_symbols: print_no_end(" ") print_no_end(color_symbol(self.binary.reverse_symbols[w])) ad += size_word print() def print_calls(self, ctx): ARCH = self.load_arch_module() ARCH_UTILS = ARCH.utils ARCH_OUTPUT = ARCH.output s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) o = ARCH_OUTPUT.Output(ctx) ad = s_start while ad < s_end: i = self.lazy_disasm(ad, s_start) if i is None: ad += 1 else: ad += i.size if ARCH_UTILS.is_call(i): o.print_inst(i) def print_symbols(self, print_sections, sym_filter=None): if sym_filter is not None: sym_filter = sym_filter.lower() for sy in self.binary.symbols: addr = self.binary.symbols[sy] if sym_filter is None or sym_filter in sy.lower(): sec_name, _ = self.binary.is_address(addr) if sy: print_no_end(color_addr(addr) + " " + sy) if print_sections and sec_name is not None: print_no_end(" (" + color_section(sec_name) + ")") print() def lazy_disasm(self, addr, stay_in_section=-1): meta = self.binary.get_section_meta(addr) if meta is None: return None _, start, _ = meta if stay_in_section != -1 and start != stay_in_section: return None if addr in self.code: return self.code[addr] # Disassemble by block of N bytes N = 1024 d = self.binary.section_stream_read(addr, N) gen = self.md.disasm(d, addr) try: first = next(gen) except StopIteration: return None for i in gen: if i.address in self.code: break self.code[i.address] = i return first def __prefetch_inst(self, inst): return self.lazy_disasm(inst.address + inst.size) # Generate a flow graph of the given function (addr) def get_graph(self, entry_addr): from capstone import CS_OP_IMM, CS_ARCH_MIPS, CS_OP_REG ARCH_UTILS = self.load_arch_module().utils gph = Graph(self, entry_addr) stack = [entry_addr] start = time.clock() prefetch = None # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) while stack: ad = stack.pop() inst = self.lazy_disasm(ad) if inst is None: # Remove all previous instructions which have a link # to this instruction. if ad in gph.link_in: for i in gph.link_in[ad]: gph.link_out[i].remove(ad) for i in gph.link_in[ad]: if not gph.link_out[i]: del gph.link_out[i] del gph.link_in[ad] continue if gph.exists(inst): continue if ARCH_UTILS.is_ret(inst): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(inst) gph.add_node(inst, prefetch) elif ARCH_UTILS.is_uncond_jump(inst): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(inst) gph.uncond_jumps_set.add(ad) op = inst.operands[-1] if op.type == CS_OP_IMM: nxt = op.value.imm stack.append(nxt) gph.set_next(inst, nxt, prefetch) else: if inst.address in self.jmptables: table = self.jmptables[inst.address].table gph.set_jmptable_next(inst, table, prefetch) for ad in table: stack.append(ad) else: # Can't interpret jmp ADDR|reg gph.add_node(inst, prefetch) elif ARCH_UTILS.is_cond_jump(inst): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(inst) gph.cond_jumps_set.add(ad) op = inst.operands[-1] if op.type == CS_OP_IMM: if self.arch == CS_ARCH_MIPS: direct_nxt = prefetch.address + prefetch.size else: direct_nxt = inst.address + inst.size nxt_jmp = op.value.imm stack.append(direct_nxt) stack.append(nxt_jmp) gph.set_cond_next(inst, nxt_jmp, direct_nxt, prefetch) else: # Can't interpret jmp ADDR|reg gph.add_node(inst, prefetch) else: nxt = inst.address + inst.size stack.append(nxt) gph.set_next(inst, nxt) if len(gph.nodes) == 0: return None if self.binary.type == T_BIN_PE: self.binary.pe_reverse_stripped_symbols(self) elapsed = time.clock() elapsed = elapsed - start debug__("Graph built in %fs" % elapsed) return gph def add_jmptable(self, inst_addr, table_addr, entry_size, nb_entries): name = self.add_symbol(table_addr, "jmptable_0x%x" % table_addr) table = self.read_array(table_addr, nb_entries, entry_size) self.jmptables[inst_addr] = Jmptable(inst_addr, table_addr, table, name) self.inline_comments[inst_addr] = "switch statement %s" % name all_cases = {} for ad in table: all_cases[ad] = [] case = 0 for ad in table: all_cases[ad].append(case) case += 1 for ad in all_cases: self.previous_comments[ad] = \ ["case %s %s" % ( ", ".join(map(str, all_cases[ad])), name )]
class Disassembler(): def __init__(self, filename, raw_type, raw_base, raw_big_endian, load_symbols=True): import capstone as CAPSTONE self.code = {} self.binary = Binary(filename, raw_type, raw_base, raw_big_endian) arch, mode = self.binary.get_arch() if arch is None or mode is None: raise ExcArch(self.binary.get_arch_string()) if load_symbols: self.binary.load_symbols() self.binary.load_data_sections() self.capstone = CAPSTONE self.md = CAPSTONE.Cs(arch, mode) self.md.detail = True self.arch = arch self.mode = mode def check_addr(self, ctx, addr): addr_exists, is_exec = self.binary.check_addr(addr) if not ctx.print_data and not is_exec: raise ExcNotExec(addr) if not addr_exists: raise ExcNotAddr(addr) def load_arch_module(self): if self.arch == self.capstone.CS_ARCH_X86: import lib.arch.x86 as ARCH elif self.arch == self.capstone.CS_ARCH_ARM: import lib.arch.arm as ARCH elif self.arch == self.capstone.CS_ARCH_MIPS: import lib.arch.mips as ARCH else: raise NotImplementedError return ARCH def get_addr_from_string(self, opt_addr, raw=False): if opt_addr is None: if raw: return 0 search = ["main", "_main"] else: search = [opt_addr] for s in search: if s.startswith("0x"): a = int(opt_addr, 16) else: a = self.binary.symbols.get(s, -1) if a != -1: return a raise ExcSymNotFound(search[0]) def print_section_meta(self, name, start, end): print_no_end(color_section(name.ljust(20))) print_no_end(" [ ") print_no_end(hex(start)) print_no_end(" - ") print_no_end(hex(end)) print_no_end(" - %d" % (end - start + 1)) print(" ]") def dump_asm(self, ctx, lines): from capstone import CS_OP_IMM ARCH = self.load_arch_module() ARCH_UTILS = ARCH.utils ARCH_OUTPUT = ARCH.output s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) # set jumps color ad = ctx.entry_addr l = 0 while l < lines and ad < s_end: i = self.lazy_disasm(ad, s_start) if i is None: ad += 1 else: if ARCH_UTILS.is_jump(i) and i.operands[-1].type == CS_OP_IMM: pick_color(i.operands[-1].value.imm) ad += i.size l += 1 # Here we have loaded all instructions we want to print if self.binary.type == T_BIN_PE: self.binary.pe_reverse_stripped_symbols(self) o = ARCH_OUTPUT.Output(ctx) # dump ad = ctx.entry_addr l = 0 while l < lines and ad < s_end: i = self.lazy_disasm(ad, s_start) if i is None: ad += 1 o.print_bad(ad) else: o.print_inst(i) ad += i.size l += 1 def dump_data_ascii(self, ctx, lines): N = 128 # read by block of 128 bytes addr = ctx.entry_addr s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) l = 0 ascii_str = [] addr_str = -1 while l < lines: buf = self.binary.section_stream_read(addr, N) if not buf: break i = 0 while i < len(buf): if addr > s_end: return j = i while j < len(buf): c = buf[j] if c not in BYTES_PRINTABLE_SET: break if addr_str == -1: addr_str = addr ascii_str.append(c) j += 1 if c != 0 and j == len(buf): addr += j - i break if c == 0 and len(ascii_str) >= 2: print_no_end(color_addr(addr_str)) print_no_end( color_string("\"" + "".join(map(get_char, ascii_str)) + "\"")) print(", 0") addr += j - i i = j else: print_no_end(color_addr(addr)) print("0x%.2x " % buf[i]) addr += 1 i += 1 addr_str = -1 ascii_str = [] l += 1 if l >= lines: return def dump_data(self, ctx, lines, size_word): _, mode = self.binary.get_arch() if mode & self.capstone.CS_MODE_BIG_ENDIAN: endian = ">" else: endian = "<" if size_word == 1: unpack_str = endian + "B" elif size_word == 2: unpack_str = endian + "H" elif size_word == 4: unpack_str = endian + "L" elif size_word == 8: unpack_str = endian + "Q" N = size_word * 64 addr = ctx.entry_addr s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) l = 0 while l < lines: buf = self.binary.section_stream_read(addr, N) if not buf: break i = 0 while i < len(buf): b = buf[i:i + size_word] if addr > s_end: return if len(b) != size_word: for c in buf: print_no_end(color_addr(addr)) print("0x%.2x" % c) return if addr in self.binary.reverse_symbols: print(color_symbol(self.binary.reverse_symbols[addr])) print_no_end(color_addr(addr)) w = struct.unpack(unpack_str, b)[0] print_no_end("0x%.2x" % w) sec_name, is_data = self.binary.is_address(w) if sec_name is not None: print_no_end(" (") print_no_end(color_section(sec_name)) print_no_end(")") if size_word >= 4 and w in self.binary.reverse_symbols: print_no_end(" ") print_no_end( color_symbol(self.binary.reverse_symbols[w])) print() addr += size_word i += size_word l += 1 if l >= lines: return def print_calls(self, ctx): ARCH = self.load_arch_module() ARCH_UTILS = ARCH.utils ARCH_OUTPUT = ARCH.output s_name, s_start, s_end = self.binary.get_section_meta(ctx.entry_addr) self.print_section_meta(s_name, s_start, s_end) o = ARCH_OUTPUT.Output(ctx) ad = s_start while ad < s_end: i = self.lazy_disasm(ad, s_start) if i is None: ad += 1 else: ad += i.size if ARCH_UTILS.is_call(i): o.print_inst(i) def print_symbols(self, print_sections, sym_filter=None): if sym_filter is not None: sym_filter = sym_filter.lower() for addr in self.binary.reverse_symbols: sy = self.binary.reverse_symbols[addr] if sym_filter is None or sym_filter in sy.lower(): sec_name, _ = self.binary.is_address(addr) if sy: print_no_end(color_addr(addr) + " " + sy) if print_sections and sec_name is not None: print_no_end(" (" + color_section(sec_name) + ")") print() def lazy_disasm(self, addr, stay_in_section=-1): meta = self.binary.get_section_meta(addr) if meta is None: return None _, start, _ = meta if stay_in_section != -1 and start != stay_in_section: return None if addr in self.code: return self.code[addr] # Disassemble by block of N bytes N = 1024 d = self.binary.section_stream_read(addr, N) gen = self.md.disasm(d, addr) first = None try: first = next(gen) self.code[first.address] = first # Max N instructions (N is in bytes) for n in range(N): i = next(gen) if i.address in self.code: return first self.code[i.address] = i except StopIteration: pass return first def __prefetch_inst(self, inst): return self.lazy_disasm(inst.address + inst.size) # Generate a flow graph of the given function (addr) def get_graph(self, entry_addr): from capstone import CS_OP_IMM, CS_ARCH_MIPS ARCH_UTILS = self.load_arch_module().utils curr = self.lazy_disasm(entry_addr) if curr is None: return None gph = Graph(self, entry_addr) rest = [] start = time.clock() prefetch = None # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) while 1: if not gph.exists(curr): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(curr) if ARCH_UTILS.is_uncond_jump(curr) and len(curr.operands) > 0: if curr.operands[-1].type == CS_OP_IMM: addr = curr.operands[-1].value.imm nxt = self.lazy_disasm(addr) if nxt is None: gph.add_node(curr, prefetch) else: gph.set_next(curr, nxt, prefetch) rest.append(nxt.address) else: # Can't interpret jmp ADDR|reg gph.add_node(curr, prefetch) gph.uncond_jumps_set.add(curr.address) elif ARCH_UTILS.is_cond_jump(curr) and len(curr.operands) > 0: if curr.operands[-1].type == CS_OP_IMM: nxt_jump = self.lazy_disasm( curr.operands[-1].value.imm) if self.arch == CS_ARCH_MIPS: direct_nxt = \ self.lazy_disasm(prefetch.address + prefetch.size) else: direct_nxt = \ self.lazy_disasm(curr.address + curr.size) if nxt_jump is not None: rest.append(nxt_jump.address) if direct_nxt is not None: rest.append(direct_nxt.address) gph.set_cond_next(curr, nxt_jump, direct_nxt, prefetch) else: gph.set_next(curr, nxt_jump, prefetch) else: if direct_nxt is not None: rest.append(direct_nxt.address) gph.set_next(curr, direct_nxt, prefetch) else: gph.add_node(curr, prefetch) else: # Can't interpret jmp ADDR|reg gph.add_node(curr, prefetch) gph.cond_jumps_set.add(curr.address) elif ARCH_UTILS.is_ret(curr): gph.add_node(curr, prefetch) else: try: nxt = self.lazy_disasm(curr.address + curr.size) gph.set_next(curr, nxt) rest.append(nxt.address) except: gph.add_node(curr) pass try: curr = self.lazy_disasm(rest.pop()) except IndexError: break if self.binary.type == T_BIN_PE: self.binary.pe_reverse_stripped_symbols(self) elapsed = time.clock() elapsed = elapsed - start debug__("Graph built in %fs" % elapsed) return gph