class Disassembler(): def __init__(self, filename, raw_type, raw_base, raw_big_endian, database): import capstone as CAPSTONE self.capstone_inst = {} # capstone instruction cache 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 database.loaded: self.binary.symbols = database.symbols self.binary.reverse_symbols = database.reverse_symbols self.mem = database.mem else: self.binary.load_symbols() database.symbols = self.binary.symbols database.reverse_symbols = self.binary.reverse_symbols self.mem = Memory() database.mem = self.mem self.jmptables = database.jmptables self.user_inline_comments = database.user_inline_comments self.internal_inline_comments = database.internal_inline_comments self.user_previous_comments = database.user_previous_comments self.internal_previous_comments = database.internal_previous_comments self.functions = database.functions self.end_functions = database.end_functions # TODO: is it a global constant or $gp can change during the execution ? self.mips_gp = database.mips_gp self.binary.load_section_names() self.capstone = CAPSTONE self.md = CAPSTONE.Cs(arch, mode) self.md.detail = True self.arch = arch self.mode = mode for s in self.binary.iter_sections(): s.big_endian = self.mode & self.capstone.CS_MODE_BIG_ENDIAN if not database.loaded: self.mem.add(s.start, s.end, MEM_UNK) 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" else: return None 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, SYM_UNK] self.binary.reverse_symbols[addr] = [name, SYM_UNK] return name # TODO: create a function in SectionAbs def read_array(self, ad, array_max_size, size_word, s=None): unpack_str = self.get_unpack_str(size_word) N = size_word * array_max_size if s is None: s = self.binary.get_section(ad) array = [] l = 0 while l < array_max_size: buf = s.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 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"): try: a = int(opt_addr, 16) except: raise ExcSymNotFound(search[0]) else: a = self.binary.symbols.get(s, -1) if a == -1: a = self.binary.section_names.get(s, -1) else: a = a[0] # it contains [ad, type] if a != -1: return a raise ExcSymNotFound(search[0]) def dump_asm(self, ctx, lines=NB_LINES_TO_DISASM, until=-1): from capstone import CS_OP_IMM ARCH = self.load_arch_module() ARCH_UTILS = ARCH.utils ARCH_OUTPUT = ARCH.output ad = ctx.entry_addr s = self.binary.get_section(ctx.entry_addr) if s is None: # until is != -1 only from the visual mode # It allows to not go before the first section. if until != -1: return None # Get the next section, it's not mandatory that sections # are consecutives ! s = self.binary.get_next_section(ad) if s is None: return None ad = s.start o = ARCH_OUTPUT.Output(ctx) o._new_line() o.section_prefix = True o.curr_section = s l = 0 while 1: if ad == s.start: o._new_line() o._dash() o._section(s.name) o._add(" 0x%x -> 0x%x" % (s.start, s.end)) o._new_line() o._new_line() while ((l < lines and until == -1) or (ad != until and until != -1)) \ and ad <= s.end: if self.mem.is_code(ad): # TODO optimize if ad in self.functions: if not o.is_last_2_line_empty(): o._new_line() o._dash() o._user_comment("; SUBROUTINE") o._new_line() o._dash() i = self.lazy_disasm(ad, s.start) o._asm_inst(i) if ad in self.end_functions: for e in self.end_functions[ad]: sy = self.binary.reverse_symbols[e][0] o._user_comment("; end function %s" % sy) o._new_line() o._new_line() ad += i.size else: if o.is_symbol(ad): o._symbol(ad) o._new_line() o._address(ad) o._db(s.read_byte(ad)) o._new_line() ad += 1 l += 1 if (l >= lines and until == -1) or (ad == until and until != -1): break s = self.binary.get_section(ad) if s is None: # Get the next section, it's not mandatory that sections # are consecutives ! s = self.binary.get_next_section(ad) if s is None: break ad = s.start if ad == until: break o.curr_section = s if until in self.functions: o._new_line() # remove the last empty line o.lines.pop(-1) o.token_lines.pop(-1) o.join_lines() # TODO: move it in the analyzer if self.binary.type == T_BIN_PE: # TODO: if ret != 0 : database is modified self.binary.pe_reverse_stripped_symbols(self, o.addr_line) return o def find_addr_before(self, ad): l = 0 s = self.binary.get_section(ad) while l < NB_LINES_TO_DISASM: if self.mem.is_code(ad): size = self.mem.code[ad][0] l += 1 l -= size else: l += 1 if ad == s.start: s = self.binary.get_prev_section(ad) if s is None: return ad ad = s.end ad -= 1 return ad def dump_data_ascii(self, ctx, lines): N = 128 # read by block of 128 bytes addr = ctx.entry_addr s = self.binary.get_section(ctx.entry_addr) s.print_header() l = 0 ascii_str = [] addr_str = -1 while l < lines: buf = s.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 = self.binary.get_section(ctx.entry_addr) s.print_header() ad = ctx.entry_addr for w in self.read_array(ctx.entry_addr, lines, size_word, s): if ad in self.binary.reverse_symbols: print(color_symbol(self.binary.reverse_symbols[ad][0])) print_no_end(color_addr(ad)) print_no_end("0x%.2x" % w) section = self.binary.get_section(w) if section is not None: print_no_end(" (") print_no_end(color_section(section.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][0])) ad += size_word print() def print_calls(self, ctx): ARCH = self.load_arch_module() ARCH_UTILS = ARCH.utils ARCH_OUTPUT = ARCH.output s = self.binary.get_section(ctx.entry_addr) s.print_header() o = ARCH_OUTPUT.Output(ctx) o._new_line() 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._asm_inst(i) o.print() # # sym_filter : search a symbol, non case-sensitive # if it starts with '-', it prints non-matching symbols # def print_symbols(self, print_sections, sym_filter=None, only_func=False): if sym_filter is not None: sym_filter = sym_filter.lower() if sym_filter[0] == "-": invert_match = True sym_filter = sym_filter[1:] else: invert_match = False total = 0 # TODO: race condition with the analyzer for sy in list(self.binary.symbols): addr, ty = self.binary.symbols[sy] if only_func and ty != SYM_FUNC: continue if sym_filter is None or \ (invert_match and sym_filter not in sy.lower()) or \ (not invert_match and sym_filter in sy.lower()): if sy: section = self.binary.get_section(addr) print_no_end(color_addr(addr) + " " + sy) if print_sections and section is not None: print_no_end(" (" + color_section(section.name) + ")") print() total += 1 print("Total:", total) def lazy_disasm(self, addr, stay_in_section=-1, s=None): s = self.binary.get_section(addr) if s is None: return None # if stay_in_section != -1 and s.start != stay_in_section: # return None, s if addr in self.capstone_inst: return self.capstone_inst[addr] # TODO: remove when it's too big ? if len(self.capstone_inst) > CAPSTONE_CACHE_SIZE: self.capstone_inst.clear() # Disassemble by block of N bytes N = 128 d = s.read(addr, N) gen = self.md.disasm(d, addr) try: first = next(gen) except StopIteration: return None self.capstone_inst[first.address] = first for i in gen: if i.address in self.capstone_inst: break self.capstone_inst[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 ARCH_UTILS = self.load_arch_module().utils gph = Graph(self, entry_addr) stack = [entry_addr] start = time() prefetch = None addresses = set() # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) # Here each instruction is a node. Blocks will be created in the # function __simplify. 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 addresses.add(ad) if ARCH_UTILS.is_ret(inst): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(inst) addresses.add(prefetch.address) gph.new_node(inst, prefetch, None) elif ARCH_UTILS.is_uncond_jump(inst): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(inst) addresses.add(prefetch.address) gph.uncond_jumps_set.add(ad) op = inst.operands[-1] if op.type == CS_OP_IMM: nxt = op.value.imm stack.append(nxt) gph.new_node(inst, prefetch, [nxt]) else: if inst.address in self.jmptables: table = self.jmptables[inst.address].table stack += table gph.new_node(inst, prefetch, table) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) elif ARCH_UTILS.is_cond_jump(inst): if self.arch == CS_ARCH_MIPS: prefetch = self.__prefetch_inst(inst) addresses.add(prefetch.address) 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.new_node(inst, prefetch, [direct_nxt, nxt_jmp]) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) else: nxt = inst.address + inst.size stack.append(nxt) gph.new_node(inst, None, [nxt]) if len(gph.nodes) == 0: return None, 0 if self.binary.type == T_BIN_PE: nb_new_syms = self.binary.pe_reverse_stripped_symbols(self, addresses) else: nb_new_syms = 0 elapsed = time() elapsed = elapsed - start debug__("Graph built in %fs (%d instructions)" % (elapsed, len(gph.nodes))) return gph, nb_new_syms 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.internal_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.internal_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, sym, rev_sym, jmptables, inline_comments, previous_comments, load_symbols=True, mips_gp=-1): import capstone as CAPSTONE self.code = {} self.binary = Binary(filename, raw_type, raw_base, raw_big_endian) # TODO: is it a global constant or $gp can change during the execution ? self.mips_gp = mips_gp 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.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_word(self, ad, size_word): unpack_str = self.get_unpack_str(size_word) b = self.binary.section_stream_read(ad, size_word) if len(b) != size_word: return 0 return struct.unpack(unpack_str, b)[0] 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 = self.binary.get_section(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 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 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 = self.binary.get_section(ctx.entry_addr) s.print_header() # 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) o._new_line() # dump ad = ctx.entry_addr l = 0 if ad in self.binary.reverse_symbols: o._symbol(ad) o._new_line() while l < lines and ad <= s.end: i = self.lazy_disasm(ad, s.start) if i is None: ad += 1 o._bad(ad) else: o._asm_inst(i) ad += i.size l += 1 # empty line o.lines.pop(-1) o.token_lines.pop(-1) return o def dump_data_ascii(self, ctx, lines): N = 128 # read by block of 128 bytes addr = ctx.entry_addr s = self.binary.get_section(ctx.entry_addr) s.print_header() 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 = self.binary.get_section(ctx.entry_addr) s.print_header() 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) section = self.binary.get_section(w) if section is not None: print_no_end(" (") print_no_end(color_section(section.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 = self.binary.get_section(ctx.entry_addr) s.print_header() o = ARCH_OUTPUT.Output(ctx) o._new_line() 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._asm_inst(i) o.print() # # sym_filter : search a symbol, non case-sensitive # if it starts with '-', it prints non-matching symbols # def print_symbols(self, print_sections, sym_filter=None): if sym_filter is not None: sym_filter = sym_filter.lower() if sym_filter[0] == "-": invert_match = True sym_filter = sym_filter[1:] else: invert_match = False for sy in self.binary.symbols: addr = self.binary.symbols[sy] if sym_filter is None or \ (invert_match and sym_filter not in sy.lower()) or \ (not invert_match and sym_filter in sy.lower()): if sy: section = self.binary.get_section(addr) print_no_end(color_addr(addr) + " " + sy) if print_sections and section is not None: print_no_end(" (" + color_section(section.name) + ")") print() def lazy_disasm(self, addr, stay_in_section=-1): s = self.binary.get_section(addr) if s is None: return None if stay_in_section != -1 and s.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 ARCH_UTILS = self.load_arch_module().utils gph = Graph(self, entry_addr) stack = [entry_addr] start = time() prefetch = None # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) # Here each instruction is a node. Blocks will be created in the # function __simplify. 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.new_node(inst, prefetch, None) 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.new_node(inst, prefetch, [nxt]) else: if inst.address in self.jmptables: table = self.jmptables[inst.address].table stack += table gph.new_node(inst, prefetch, table) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) 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.new_node(inst, prefetch, [direct_nxt, nxt_jmp]) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) else: nxt = inst.address + inst.size stack.append(nxt) gph.new_node(inst, None, [nxt]) if len(gph.nodes) == 0: return None, 0 if self.binary.type == T_BIN_PE: nb_new_syms = self.binary.pe_reverse_stripped_symbols(self) else: nb_new_syms = 0 elapsed = time() elapsed = elapsed - start debug__("Graph built in %fs (%d instructions)" % (elapsed, len(gph.nodes))) return gph, nb_new_syms 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, sym, rev_sym, jmptables, inline_comments, previous_comments, load_symbols=True, mips_gp=-1): import capstone as CAPSTONE self.code = {} self.binary = Binary(filename, raw_type, raw_base, raw_big_endian) # TODO: is it a global constant or $gp can change during the execution ? self.mips_gp = mips_gp 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.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_word(self, ad, size_word): unpack_str = self.get_unpack_str(size_word) b = self.binary.section_stream_read(ad, size_word) if len(b) != size_word: return 0 return struct.unpack(unpack_str, b)[0] 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 = self.binary.get_section(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 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 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 = self.binary.get_section(ctx.entry_addr) s.print_header() # 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) o._new_line() # dump ad = ctx.entry_addr l = 0 if ad in self.binary.reverse_symbols: o._symbol(ad) o._new_line() while l < lines and ad <= s.end: i = self.lazy_disasm(ad, s.start) if i is None: ad += 1 o._bad(ad) else: o._asm_inst(i) ad += i.size l += 1 # empty line o.lines.pop(-1) o.token_lines.pop(-1) return o def dump_data_ascii(self, ctx, lines): N = 128 # read by block of 128 bytes addr = ctx.entry_addr s = self.binary.get_section(ctx.entry_addr) s.print_header() 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 = self.binary.get_section(ctx.entry_addr) s.print_header() 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) section = self.binary.get_section(w) if section is not None: print_no_end(" (") print_no_end(color_section(section.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 = self.binary.get_section(ctx.entry_addr) s.print_header() o = ARCH_OUTPUT.Output(ctx) o._new_line() 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._asm_inst(i) o.print() # # sym_filter : search a symbol, non case-sensitive # if it starts with '-', it prints non-matching symbols # def print_symbols(self, print_sections, sym_filter=None): if sym_filter is not None: sym_filter = sym_filter.lower() if sym_filter[0] == "-": invert_match = True sym_filter = sym_filter[1:] else: invert_match = False for sy in self.binary.symbols: addr = self.binary.symbols[sy] if sym_filter is None or \ (invert_match and sym_filter not in sy.lower()) or \ (not invert_match and sym_filter in sy.lower()): if sy: section = self.binary.get_section(addr) print_no_end(color_addr(addr) + " " + sy) if print_sections and section is not None: print_no_end(" (" + color_section(section.name) + ")") print() def lazy_disasm(self, addr, stay_in_section=-1): s = self.binary.get_section(addr) if s is None: return None if stay_in_section != -1 and s.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 ARCH_UTILS = self.load_arch_module().utils gph = Graph(self, entry_addr) stack = [entry_addr] start = time() prefetch = None # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) # Here each instruction is a node. Blocks will be created in the # function __simplify. 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.new_node(inst, prefetch, None) 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.new_node(inst, prefetch, [nxt]) else: if inst.address in self.jmptables: table = self.jmptables[inst.address].table stack += table gph.new_node(inst, prefetch, table) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) 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.new_node(inst, prefetch, [direct_nxt, nxt_jmp]) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) else: nxt = inst.address + inst.size stack.append(nxt) gph.new_node(inst, None, [nxt]) if len(gph.nodes) == 0: return None, 0 if self.binary.type == T_BIN_PE: nb_new_syms = self.binary.pe_reverse_stripped_symbols(self) else: nb_new_syms = 0 elapsed = time() elapsed = elapsed - start debug__("Graph built in %fs (%d instructions)" % (elapsed, len(gph.nodes))) return gph, nb_new_syms 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, database): import capstone as CAPSTONE self.capstone_inst = {} # capstone instruction cache if database.loaded: self.mem = database.mem else: self.mem = Memory() database.mem = self.mem self.binary = Binary(self.mem, filename, raw_type, raw_base, raw_big_endian) self.binary.load_section_names() arch, mode = self.binary.get_arch() if arch is None or mode is None: raise ExcArch(self.binary.get_arch_string()) self.jmptables = database.jmptables self.user_inline_comments = database.user_inline_comments self.internal_inline_comments = database.internal_inline_comments self.user_previous_comments = database.user_previous_comments self.internal_previous_comments = database.internal_previous_comments self.functions = database.functions self.func_id = database.func_id self.end_functions = database.end_functions self.xrefs = database.xrefs # TODO: is it a global constant or $gp can change during the execution ? self.mips_gp = database.mips_gp if database.loaded: self.binary.symbols = database.symbols self.binary.reverse_symbols = database.reverse_symbols self.binary.imports = database.imports else: self.binary.load_symbols() database.symbols = self.binary.symbols database.reverse_symbols = self.binary.reverse_symbols database.imports = self.binary.imports self.capstone = CAPSTONE self.md = CAPSTONE.Cs(arch, mode) self.md.detail = True self.arch = arch self.mode = mode for s in self.binary.iter_sections(): s.big_endian = self.mode & self.capstone.CS_MODE_BIG_ENDIAN # TODO: useful ? if not database.loaded: self.mem.add(s.start, s.end, MEM_UNK) 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" else: return None return unpack_str def add_xref(self, from_ad, to_ad): if isinstance(to_ad, list): for x in to_ad: if x in self.xrefs: if from_ad not in self.xrefs[x]: self.xrefs[x].append(from_ad) else: self.xrefs[x] = [from_ad] else: if to_ad in self.xrefs: if from_ad not in self.xrefs[to_ad]: self.xrefs[to_ad].append(from_ad) else: self.xrefs[to_ad] = [from_ad] def add_symbol(self, ad, name): if name in self.binary.symbols: last = self.binary.symbols[name] del self.binary.reverse_symbols[last] if ad in self.binary.reverse_symbols: last = self.binary.reverse_symbols[ad] del self.binary.symbols[last] self.binary.symbols[name] = ad self.binary.reverse_symbols[ad] = name if not self.mem.exists(ad): self.mem.add(ad, 1, MEM_UNK) return name # TODO: create a function in SectionAbs def read_array(self, ad, array_max_size, size_word, s=None): unpack_str = self.get_unpack_str(size_word) N = size_word * array_max_size if s is None: s = self.binary.get_section(ad) array = [] l = 0 while l < array_max_size: buf = s.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 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 dump_xrefs(self, ctx, ad): ARCH = self.load_arch_module() ARCH_OUTPUT = ARCH.output o = ARCH_OUTPUT.Output(ctx) o._new_line() o.print_labels = False for x in ctx.gctx.dis.xrefs[ad]: s = self.binary.get_section(x) if self.mem.is_code(x): func_id = self.mem.get_func_id(x) if func_id != -1: fad = self.func_id[func_id] o._label(fad) diff = x - fad if diff >= 0: o._add(" + %d " % diff) else: o._add(" - %d " % (-diff)) o._pad_width(20) i = self.lazy_disasm(x, s.start) o._asm_inst(i) else: o._address(x) o._new_line() # remove the last empty line o.lines.pop(-1) o.token_lines.pop(-1) o.join_lines() return o def is_label(self, ad): return ad in self.binary.reverse_symbols or ad in self.xrefs def get_symbol(self, ad): s = self.binary.reverse_symbols.get(ad, None) if s is None: ty = self.mem.get_type(ad) if ty == MEM_FUNC: return "sub_%x" % ad if ty == MEM_CODE: return "loc_%x" % ad if ty == MEM_UNK: return "unk_%x" % ad return s def dump_asm(self, ctx, lines=NB_LINES_TO_DISASM, until=-1): ARCH = self.load_arch_module() ARCH_OUTPUT = ARCH.output ad = ctx.entry s = self.binary.get_section(ad) if s is None: # until is != -1 only from the visual mode # It allows to not go before the first section. if until != -1: return None # Get the next section, it's not mandatory that sections # are consecutives ! s = self.binary.get_next_section(ad) if s is None: return None ad = s.start o = ARCH_OUTPUT.Output(ctx) o._new_line() o.section_prefix = True o.curr_section = s o.mode_dump = True l = 0 while 1: if ad == s.start: o._new_line() o._dash() o._section(s.name) o._add(" 0x%x -> 0x%x" % (s.start, s.end)) o._new_line() o._new_line() while ((l < lines and until == -1) or (ad < until and until != -1)) \ and ad <= s.end: # A PE import should not be displayed as a subroutine if not(self.binary.type == T_BIN_PE and ad in self.binary.imports) \ and self.mem.is_code(ad): is_func = ad in self.functions and self.functions[ad][ 0] != -1 if is_func: if not o.is_last_2_line_empty(): o._new_line() o._dash() o._user_comment("; SUBROUTINE") o._new_line() o._dash() i = self.lazy_disasm(ad, s.start) if not is_func and ad in self.xrefs and \ not o.is_last_2_line_empty(): o._new_line() o._asm_inst(i) if ad in self.end_functions: for fad in self.end_functions[ad]: sy = self.get_symbol(fad) o._user_comment("; end function %s" % sy) o._new_line() o._new_line() ad += i.size else: o._label_and_address(ad) o.set_line(ad) o._db(s.read_byte(ad)) o._new_line() ad += 1 l += 1 if (l >= lines and until == -1) or (ad >= until and until != -1): break s = self.binary.get_section(ad) if s is None: # Get the next section, it's not mandatory that sections # are consecutives ! s = self.binary.get_next_section(ad) if s is None: break ad = s.start if until != -1 and ad >= until: break o.curr_section = s if until in self.functions: o._new_line() # remove the last empty line o.lines.pop(-1) o.token_lines.pop(-1) o.join_lines() return o def find_addr_before(self, ad): l = 0 s = self.binary.get_section(ad) while l < NB_LINES_TO_DISASM: if self.mem.is_code(ad): size = self.mem.mm[ad][0] l += 1 l -= size else: l += 1 if ad == s.start: s = self.binary.get_prev_section(ad) if s is None: return ad ad = s.end ad -= 1 return ad def dump_data_ascii(self, ctx, lines): N = 128 # read by block of 128 bytes ad = ctx.entry s = self.binary.get_section(ad) print(hex(ad)) s.print_header() l = 0 ascii_str = [] ad_str = -1 while l < lines: buf = s.read(ad, N) if not buf: break i = 0 while i < len(buf): if ad > s.end: return j = i while j < len(buf): c = buf[j] if c not in BYTES_PRINTABLE_SET: break if ad_str == -1: ad_str = ad ascii_str.append(c) j += 1 if c != 0 and j == len(buf): ad += j - i break if c == 0 and len(ascii_str) >= 2: if self.is_label(ad_str): print(color_symbol(self.get_symbol(ad_str))) print_no_end(color_addr(ad_str)) print_no_end( color_string("\"" + "".join(map(get_char, ascii_str)) + "\"")) print(", 0") ad += j - i i = j else: if self.is_label(ad): print(color_symbol(self.get_symbol(ad))) print_no_end(color_addr(ad)) print("0x%.2x " % buf[i]) ad += 1 i += 1 ad_str = -1 ascii_str = [] l += 1 if l >= lines: return def dump_data(self, ctx, lines, size_word): ad = ctx.entry s = self.binary.get_section(ad) s.print_header() for w in self.read_array(ad, lines, size_word, s): if self.is_label(ad): print(color_symbol(self.get_symbol(ad))) print_no_end(color_addr(ad)) print_no_end("0x%.2x" % w) section = self.binary.get_section(w) if section is not None: print_no_end(" (") print_no_end(color_section(section.name)) print_no_end(")") if size_word >= 4 and self.is_label(w): print_no_end(" ") print_no_end(color_symbol(self.get_symbol(w))) ad += size_word print() def print_functions(self): total = 0 # TODO: race condition with the analyzer ? for ad in list(self.functions): print(color_addr(ad) + " " + self.get_symbol(ad)) total += 1 print("Total:", total) # # sym_filter : search a symbol, non case-sensitive # if it starts with '-', it prints non-matching symbols # def print_symbols(self, print_sections, sym_filter=None): if sym_filter is not None: sym_filter = sym_filter.lower() if sym_filter[0] == "-": invert_match = True sym_filter = sym_filter[1:] else: invert_match = False total = 0 # TODO: race condition with the analyzer ? for sy in list(self.binary.symbols): ad = self.binary.symbols[sy] if sym_filter is None or \ (invert_match and sym_filter not in sy.lower()) or \ (not invert_match and sym_filter in sy.lower()): if sy: section = self.binary.get_section(ad) print_no_end(color_addr(ad) + " " + sy) if print_sections and section is not None: print_no_end(" (" + color_section(section.name) + ")") print() total += 1 print("Total:", total) def lazy_disasm(self, ad, stay_in_section=-1, s=None): s = self.binary.get_section(ad) if s is None: return None # if stay_in_section != -1 and s.start != stay_in_section: # return None, s if ad in self.capstone_inst: return self.capstone_inst[ad] # TODO: remove when it's too big ? if len(self.capstone_inst) > CAPSTONE_CACHE_SIZE: self.capstone_inst.clear() # Disassemble by block of N bytes N = 128 d = s.read(ad, N) gen = self.md.disasm(d, ad) try: first = next(gen) except StopIteration: return None self.capstone_inst[first.address] = first for i in gen: if i.address in self.capstone_inst: break self.capstone_inst[i.address] = i return first def __add_prefetch(self, addr_set, inst): if self.arch == self.CS_ARCH_MIPS: prefetch = self.lazy_disasm(inst.address + inst.size) addr_set.add(prefetch.address) return prefetch return None def is_noreturn(self, ad): return self.functions[ad][1] & FUNC_FLAG_NORETURN # Generate a flow graph of the given function (addr) def get_graph(self, entry): from capstone import CS_OP_IMM, CS_ARCH_MIPS self.CS_ARCH_MIPS = CS_ARCH_MIPS ARCH_UTILS = self.load_arch_module().utils gph = Graph(self, entry) stack = [entry] start = time() prefetch = None addresses = set() # WARNING: this assume that on every architectures the jump # address is the last operand (operands[-1]) # Here each instruction is a node. Blocks will be created in the # function __simplify. 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 addresses.add(ad) if ARCH_UTILS.is_ret(inst): prefetch = self.__add_prefetch(addresses, inst) gph.new_node(inst, prefetch, None) elif ARCH_UTILS.is_uncond_jump(inst): prefetch = self.__add_prefetch(addresses, inst) gph.uncond_jumps_set.add(ad) op = inst.operands[-1] if op.type == CS_OP_IMM: nxt = op.value.imm if nxt in self.functions: gph.new_node(inst, prefetch, None) else: stack.append(nxt) gph.new_node(inst, prefetch, [nxt]) else: if inst.address in self.jmptables: table = self.jmptables[inst.address].table stack += table gph.new_node(inst, prefetch, table) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) elif ARCH_UTILS.is_cond_jump(inst): prefetch = self.__add_prefetch(addresses, inst) gph.cond_jumps_set.add(ad) op = inst.operands[-1] if op.type == CS_OP_IMM: if prefetch is None: direct_nxt = inst.address + inst.size else: direct_nxt = prefetch.address + prefetch.size nxt_jmp = op.value.imm stack.append(direct_nxt) if nxt_jmp in self.functions: gph.new_node(inst, prefetch, [direct_nxt]) else: stack.append(nxt_jmp) gph.new_node(inst, prefetch, [direct_nxt, nxt_jmp]) else: # Can't interpret jmp ADDR|reg gph.new_node(inst, prefetch, None) else: if ad != entry and ARCH_UTILS.is_call(inst): op = inst.operands[0] if op.type == CS_OP_IMM: imm = op.value.imm if imm in self.functions and self.is_noreturn(imm): prefetch = self.__add_prefetch(addresses, inst) gph.new_node(inst, prefetch, None) continue nxt = inst.address + inst.size stack.append(nxt) gph.new_node(inst, None, [nxt]) if len(gph.nodes) == 0: return None, 0 if self.binary.type == T_BIN_PE: nb_new_syms = self.binary.pe_reverse_stripped_list(self, addresses) else: nb_new_syms = 0 elapsed = time() elapsed = elapsed - start debug__("Graph built in %fs (%d instructions)" % (elapsed, len(gph.nodes))) return gph, nb_new_syms def add_jmptable(self, inst_addr, table_addr, entry_size, nb_entries): name = self.add_symbol(table_addr, "jmptable_%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.internal_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.internal_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