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)
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 reverse.lib.arch.x86 as ARCH elif self.arch == self.capstone.CS_ARCH_ARM: import reverse.lib.arch.arm as ARCH elif self.arch == self.capstone.CS_ARCH_MIPS: import reverse.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, database): import capstone as CAPSTONE self.capstone_inst = {} # capstone instruction cache self.db = database if database.loaded: self.mem = database.mem else: self.mem = Memory() database.mem = self.mem self.binary = Binary(self.db, 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 not database.loaded: self.binary.load_symbols() database.symbols = self.binary.symbols database.reverse_symbols = self.binary.reverse_symbols database.demangled = self.binary.demangled database.reverse_demangled = self.binary.reverse_demangled 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 # `func_ad` is the function address where the variable `name` # is supposed to be. def var_get_offset(self, func_ad, name): if func_ad not in self.functions: return None func_obj = self.functions[func_ad] if func_obj is None: return None for off, val in func_obj[FUNC_VARS].items(): if val[VAR_NAME] == name: return off return None def var_rename(self, func_ad, off, name): if func_ad not in self.functions: return func_obj = self.functions[func_ad] if func_obj is None: return func_obj[FUNC_VARS][off][VAR_NAME] = name def load_arch_module(self): if self.arch == self.capstone.CS_ARCH_X86: import reverse.lib.arch.x86 as ARCH elif self.arch == self.capstone.CS_ARCH_ARM: import reverse.lib.arch.arm as ARCH elif self.arch == self.capstone.CS_ARCH_MIPS: import reverse.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) ty = self.mem.get_type(x) # 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 (ty == MEM_FUNC or ty == MEM_CODE): 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) elif ty == MEM_OFFSET: o._address(x) o.set_line(x) sz = self.mem.get_size(x) off = s.read_int(x, sz) if off is None: continue o._data_prefix(sz) o._add(" ") o._imm(off, sz, True, print_data=False, force_dont_print_data=True) o._new_line() else: o._address(x) o.set_line(x) sz = self.mem.get_size_from_type(ty) o._word(s.read_int(x, sz), sz) 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.db.reverse_symbols or ad in self.xrefs def dump_asm(self, ctx, lines=NB_LINES_TO_DISASM, until=-1): from capstone import CS_OP_IMM ARCH = self.load_arch_module() ARCH_OUTPUT = ARCH.output ARCH_UTILS = ARCH.utils 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 api = ctx.gctx.api while 1: if ad == s.start: if not o.is_last_2_line_empty(): 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: ty = self.mem.get_type(ad) # 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 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 = api.get_symbol(fad) o._user_comment("; end function %s" % sy) o._new_line() o._new_line() elif ARCH_UTILS.is_uncond_jump(i) or ARCH_UTILS.is_ret(i): o._new_line() elif ARCH_UTILS.is_call(i): op = i.operands[0] if op.type == CS_OP_IMM: imm = unsigned(op.value.imm) if imm in self.functions and self.is_noreturn(imm): o._new_line() ad += i.size elif ty == MEM_OFFSET: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size(ad) off = s.read_int(ad, sz) if off is None: continue if ctx.gctx.print_bytes: o._bytes(s.read(ad, sz)) o._data_prefix(sz) o._add(" ") o._imm(off, sz, True, print_data=False, force_dont_print_data=True) o._new_line() ad += sz elif ty == MEM_ASCII: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size(ad) buf = self.binary.get_string(ad, sz) if buf is not None: if ctx.gctx.print_bytes: o._bytes(s.read(ad, sz)) o._string('"' + buf + '"') o._add(", 0") o._new_line() ad += sz else: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size_from_type(ty) if ctx.gctx.print_bytes: o._bytes(s.read(ad, sz)) o._word(s.read_int(ad, sz), sz) o._new_line() ad += sz l += 1 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 o._new_line() ad = s.start if until != -1 and ad >= until: break if (l >= lines and until == -1) or (ad >= until and until != -1): break o.curr_section = s if until == ad: if self.mem.is_code(ad) and ad in self.xrefs or ad == s.start: if not o.is_last_2_line_empty(): 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) # TODO: because we don't know addresses before, it will be # necessary to add in memory.py an offset to tell that there is # a known address at n previous bytes. It will allows to not set # an offset on each byte (the database will increase too much). 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 hexdump(self, ctx, lines): MAX_NB_BYTES = 16 def print_line(ad, line): if not line: return print_no_end(color_addr(ad)) for by in line: print_no_end("%.2x " % by) if len(line) != MAX_NB_BYTES: print_no_end(" " * (MAX_NB_BYTES - len(line))) print_no_end("| ") for by in line: if by in BYTES_PRINTABLE_SET and by != 13 and by != 9 and by != 10: print_no_end("%c" % by) else: print_no_end(".") print() ad = ctx.entry s = self.binary.get_section(ad) off = ad - s.start l = 0 buf = [] first_ad = ad while off < s.real_size and l < lines: buf.append(s.data[off]) if len(buf) == MAX_NB_BYTES: l += 1 print_line(first_ad, buf) buf.clear() first_ad = s.start + off off += 1 print_line(first_ad, buf) def print_functions(self, api): total = 0 lst = list(self.functions) lst.sort() # TODO: race condition with the analyzer ? for ad in lst: print_no_end(color_addr(ad)) sy = api.get_symbol(ad) if ad in self.db.reverse_demangled: print_no_end( " %s (%s) " % (self.db.reverse_demangled[ad], color_comment(sy))) else: print_no_end(" " + sy) print() 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.db.symbols): ad = self.db.symbols[sy] if ad in self.db.reverse_demangled: dem = self.db.reverse_demangled[ad] else: dem = None print_sym = True 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()) or \ (dem is not None and ((invert_match and sym_filter not in dem.lower()) or \ (not invert_match and sym_filter in dem.lower()))): if sy: print_no_end(color_addr(ad)) if dem is not None: print_no_end(" %s (%s) " % (dem, color_comment(sy))) else: print_no_end(" " + sy) section = self.binary.get_section(ad) 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): func_obj = self.functions[ad] if func_obj is None: return False return self.functions[ad][FUNC_FLAGS] & 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 = unsigned(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 = unsigned(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 = unsigned(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
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 rm_xrefs_range(self, start, end): while start < end: if start in self.xrefs: del self.xrefs[start] start += 1 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 def rm_symbol(self, ad): if ad in self.binary.reverse_symbols: name = self.binary.reverse_symbols[ad] del self.binary.reverse_symbols[ad] if name in self.binary.symbols: del self.binary.symbols[name] def has_reserved_prefix(self, name): for n in RESERVED_PREFIX: if name.startswith(n): return True return False # 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 reverse.lib.arch.x86 as ARCH elif self.arch == self.capstone.CS_ARCH_ARM: import reverse.lib.arch.arm as ARCH elif self.arch == self.capstone.CS_ARCH_MIPS: import reverse.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) ty = self.mem.get_type(x) # 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 (ty == MEM_FUNC or ty == MEM_CODE): 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) elif ty == MEM_OFFSET: o._address(x) o.set_line(x) sz = self.mem.get_size(x) off = s.read_int(x, sz) if off is None: continue off_sect = self.binary.get_section(off) o._data_prefix(sz) o._add(" ") if off_sect is None: o._off_not_found(off) else: o._imm(off, sz, True, section=off_sect, print_data=False, force_dont_print_data=True) o._new_line() else: o._address(x) o.set_line(x) sz = self.mem.get_size_from_type(ty) o._word(s.read_int(x, sz), sz) 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_DWORD: return "dword_%x" % ad if ty == MEM_BYTE: return "byte_%x" % ad if ty == MEM_QWORD: return "qword_%x" % ad if ty == MEM_UNK: return "unk_%x" % ad if ty == MEM_WORD: return "word_%x" % ad if ty == MEM_ASCII: return "asc_%x" % ad if ty == MEM_OFFSET: return "off_%x" % ad return s def dump_asm(self, ctx, lines=NB_LINES_TO_DISASM, until=-1): from capstone import CS_OP_IMM ARCH = self.load_arch_module() ARCH_OUTPUT = ARCH.output ARCH_UTILS = ARCH.utils 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: ty = self.mem.get_type(ad) # 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 (ty == MEM_FUNC or ty == MEM_CODE): is_func = ad in self.functions and \ self.functions[ad][FUNC_END] != -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() elif ARCH_UTILS.is_uncond_jump(i) or ARCH_UTILS.is_ret(i): o._new_line() elif ARCH_UTILS.is_call(i): op = i.operands[0] if op.type == CS_OP_IMM and \ op.value.imm in self.functions and \ self.is_noreturn(op.value.imm): o._new_line() ad += i.size elif ty == MEM_OFFSET: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size(ad) off = s.read_int(ad, sz) if off is None: continue off_sect = self.binary.get_section(off) o._data_prefix(sz) o._add(" ") if off_sect is None: o._off_not_found(off) else: o._imm(off, sz, True, section=off_sect, print_data=False, force_dont_print_data=True) o._new_line() ad += sz elif ty == MEM_ASCII: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size(ad) buf = self.binary.get_string(ad, sz + 1) if buf is not None: o._string(buf) o._add(", 0") o._new_line() ad += sz + 1 else: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size_from_type(ty) o._word(s.read_int(ad, sz), sz) o._new_line() ad += sz 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) # TODO: because we don't know known addresses before, it will be # necessary to add in memory.py an offset to tell that there is # a known address at n previous bytes. It will allows to not set # an offset on each byte (the database will increase too much). # # For example if we have a string with 1025 chars, this loop will # not works because it will stop just after the known address, and the # string will be not printed as a string : there will be 1024 lines # instead of 1 line. while l < 1024: 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][FUNC_FLAGS] & 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, database): import capstone as CAPSTONE self.capstone_inst = {} # capstone instruction cache self.db = database if database.loaded: self.mem = database.mem else: self.mem = Memory() database.mem = self.mem self.binary = Binary(self.db, 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 not database.loaded: self.binary.load_symbols() database.symbols = self.binary.symbols database.reverse_symbols = self.binary.reverse_symbols database.demangled = self.binary.demangled database.reverse_demangled = self.binary.reverse_demangled 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 # `func_ad` is the function address where the variable `name` # is supposed to be. def var_get_offset(self, func_ad, name): if func_ad not in self.functions: return None func_obj = self.functions[func_ad] if func_obj is None: return None for off, val in func_obj[FUNC_VARS].items(): if val[VAR_NAME] == name: return off return None def var_rename(self, func_ad, off, name): if func_ad not in self.functions: return func_obj = self.functions[func_ad] if func_obj is None: return func_obj[FUNC_VARS][off][VAR_NAME] = name def load_arch_module(self): if self.arch == self.capstone.CS_ARCH_X86: import reverse.lib.arch.x86 as ARCH elif self.arch == self.capstone.CS_ARCH_ARM: import reverse.lib.arch.arm as ARCH elif self.arch == self.capstone.CS_ARCH_MIPS: import reverse.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) ty = self.mem.get_type(x) # 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 (ty == MEM_FUNC or ty == MEM_CODE): 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) elif ty == MEM_OFFSET: o._address(x) o.set_line(x) sz = self.mem.get_size(x) off = s.read_int(x, sz) if off is None: continue o._data_prefix(sz) o._add(" ") o._imm(off, sz, True, print_data=False, force_dont_print_data=True) o._new_line() else: o._address(x) o.set_line(x) sz = self.mem.get_size_from_type(ty) o._word(s.read_int(x, sz), sz) 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.db.reverse_symbols or ad in self.xrefs def dump_asm(self, ctx, lines=NB_LINES_TO_DISASM, until=-1): from capstone import CS_OP_IMM ARCH = self.load_arch_module() ARCH_OUTPUT = ARCH.output ARCH_UTILS = ARCH.utils 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 api = ctx.gctx.api while 1: if ad == s.start: if not o.is_last_2_line_empty(): 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: ty = self.mem.get_type(ad) # 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 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 = api.get_symbol(fad) o._user_comment("; end function %s" % sy) o._new_line() o._new_line() elif ARCH_UTILS.is_uncond_jump(i) or ARCH_UTILS.is_ret(i): o._new_line() elif ARCH_UTILS.is_call(i): op = i.operands[0] if op.type == CS_OP_IMM: imm = unsigned(op.value.imm) if imm in self.functions and self.is_noreturn(imm): o._new_line() ad += i.size elif ty == MEM_OFFSET: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size(ad) off = s.read_int(ad, sz) if off is None: continue if ctx.gctx.print_bytes: o._bytes(s.read(ad, sz)) o._data_prefix(sz) o._add(" ") o._imm(off, sz, True, print_data=False, force_dont_print_data=True) o._new_line() ad += sz elif ty == MEM_ASCII: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size(ad) buf = self.binary.get_string(ad, sz) if buf is not None: if ctx.gctx.print_bytes: o._bytes(s.read(ad, sz)) o._string('"' + buf + '"') o._add(", 0") o._new_line() ad += sz else: o._label_and_address(ad) o.set_line(ad) sz = self.mem.get_size_from_type(ty) if ctx.gctx.print_bytes: o._bytes(s.read(ad, sz)) o._word(s.read_int(ad, sz), sz) o._new_line() ad += sz l += 1 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 o._new_line() ad = s.start if until != -1 and ad >= until: break if (l >= lines and until == -1) or (ad >= until and until != -1): break o.curr_section = s if until == ad: if self.mem.is_code(ad) and ad in self.xrefs or ad == s.start: if not o.is_last_2_line_empty(): 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) # TODO: because we don't know addresses before, it will be # necessary to add in memory.py an offset to tell that there is # a known address at n previous bytes. It will allows to not set # an offset on each byte (the database will increase too much). 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 hexdump(self, ctx, lines): MAX_NB_BYTES = 16 def print_line(ad, line): if not line: return print_no_end(color_addr(ad)) for by in line: print_no_end("%.2x " % by) if len(line) != MAX_NB_BYTES: print_no_end(" " * (MAX_NB_BYTES - len(line))) print_no_end("| ") for by in line: if by in BYTES_PRINTABLE_SET and by != 13 and by != 9 and by != 10: print_no_end("%c" % by) else: print_no_end(".") print() ad = ctx.entry s = self.binary.get_section(ad) off = ad - s.start l = 0 buf = [] first_ad = ad while off < s.real_size and l < lines: buf.append(s.data[off]) if len(buf) == MAX_NB_BYTES: l += 1 print_line(first_ad, buf) buf.clear() first_ad = s.start + off off += 1 print_line(first_ad, buf) def print_functions(self, api): total = 0 lst = list(self.functions) lst.sort() # TODO: race condition with the analyzer ? for ad in lst: print_no_end(color_addr(ad)) sy = api.get_symbol(ad) if ad in self.db.reverse_demangled: print_no_end(" %s (%s) " % (self.db.reverse_demangled[ad], color_comment(sy))) else: print_no_end(" " + sy) print() 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.db.symbols): ad = self.db.symbols[sy] if ad in self.db.reverse_demangled: dem = self.db.reverse_demangled[ad] else: dem = None print_sym = True 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()) or \ (dem is not None and ((invert_match and sym_filter not in dem.lower()) or \ (not invert_match and sym_filter in dem.lower()))): if sy: print_no_end(color_addr(ad)) if dem is not None: print_no_end(" %s (%s) " % (dem, color_comment(sy))) else: print_no_end(" " + sy) section = self.binary.get_section(ad) 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): func_obj = self.functions[ad] if func_obj is None: return False return self.functions[ad][FUNC_FLAGS] & 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 = unsigned(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 = unsigned(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 = unsigned(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