Хабрахабр

Модернизация IDA Pro. Учимся писать загрузчики на Python

import idaapi
import ida_idp
import ida_fixup import StringIO
import struct HUNK_UNIT = 999
HUNK_NAME = 1000
HUNK_CODE = 1001
HUNK_DATA = 1002
HUNK_BSS = 1003
HUNK_ABSRELOC32 = 1004
HUNK_RELRELOC16 = 1005
HUNK_RELRELOC8 = 1006
HUNK_EXT = 1007
HUNK_SYMBOL = 1008
HUNK_DEBUG = 1009
HUNK_END = 1010
HUNK_HEADER = 1011 HUNK_OVERLAY = 1013
HUNK_BREAK = 1014
HUNK_DREL32 = 1015
HUNK_DREL16 = 1016
HUNK_DREL8 = 1017
HUNK_LIB = 1018
HUNK_INDEX = 1019
HUNK_RELOC32SHORT = 1020
HUNK_RELRELOC32 = 1021
HUNK_ABSRELOC16 = 1022 HUNK_PPC_CODE = 1257
HUNK_RELRELOC26 = 1260 hunk_names = { HUNK_UNIT: "HUNK_UNIT", HUNK_NAME: "HUNK_NAME", HUNK_CODE: "HUNK_CODE", HUNK_DATA: "HUNK_DATA", HUNK_BSS: "HUNK_BSS", HUNK_ABSRELOC32: "HUNK_ABSRELOC32", HUNK_RELRELOC16: "HUNK_RELRELOC16", HUNK_RELRELOC8: "HUNK_RELRELOC8", HUNK_EXT: "HUNK_EXT", HUNK_SYMBOL: "HUNK_SYMBOL", HUNK_DEBUG: "HUNK_DEBUG", HUNK_END: "HUNK_END", HUNK_HEADER: "HUNK_HEADER", HUNK_OVERLAY: "HUNK_OVERLAY", HUNK_BREAK: "HUNK_BREAK", HUNK_DREL32: "HUNK_DREL32", HUNK_DREL16: "HUNK_DREL16", HUNK_DREL8: "HUNK_DREL8", HUNK_LIB: "HUNK_LIB", HUNK_INDEX: "HUNK_INDEX", HUNK_RELOC32SHORT: "HUNK_RELOC32SHORT", HUNK_RELRELOC32: "HUNK_RELRELOC32", HUNK_ABSRELOC16: "HUNK_ABSRELOC16", HUNK_PPC_CODE: "HUNK_PPC_CODE", HUNK_RELRELOC26: "HUNK_RELRELOC26",
} EXT_SYMB = 0
EXT_DEF = 1
EXT_ABS = 2
EXT_RES = 3
EXT_ABSREF32 = 129
EXT_ABSCOMMON = 130
EXT_RELREF16 = 131
EXT_RELREF8 = 132
EXT_DEXT32 = 133
EXT_DEXT16 = 134
EXT_DEXT8 = 135
EXT_RELREF32 = 136
EXT_RELCOMMON = 137
EXT_ABSREF16 = 138
EXT_ABSREF8 = 139
EXT_RELREF26 = 229 TYPE_UNKNOWN = 0
TYPE_LOADSEG = 1
TYPE_UNIT = 2
TYPE_LIB = 3 HUNK_TYPE_MASK = 0xffff SEGMENT_TYPE_CODE = 0
SEGMENT_TYPE_DATA = 1
SEGMENT_TYPE_BSS = 2 BIN_IMAGE_TYPE_HUNK = 0 segment_type_names = [ "CODE", "DATA", "BSS"
] loadseg_valid_begin_hunks = [ HUNK_CODE, HUNK_DATA, HUNK_BSS, HUNK_PPC_CODE
] loadseg_valid_extra_hunks = [ HUNK_ABSRELOC32, HUNK_RELOC32SHORT, HUNK_DEBUG, HUNK_SYMBOL, HUNK_NAME
] class HunkParseError(Exception): def __init__(self, msg): self.msg = msg def __str__(self): return self.msg class HunkBlock: """Base class for all hunk block types""" def __init__(self): pass blk_id = 0xdeadbeef sub_offset = None # used inside LIB @staticmethod def _read_long(f): """read a 4 byte long""" data = f.read(4) if len(data) != 4: raise HunkParseError("read_long failed") return struct.unpack(">I", data)[0] @staticmethod def _read_word(f): """read a 2 byte word""" data = f.read(2) if len(data) != 2: raise HunkParseError("read_word failed") return struct.unpack(">H", data)[0] def _read_name(self, f): """read name stored in longs return size, string """ num_longs = self._read_long(f) if num_longs == 0: return 0, "" else: return self._read_name_size(f, num_longs) @staticmethod def _read_name_size(f, num_longs): size = (num_longs & 0xffffff) * 4 data = f.read(size) if len(data) < size: return -1, None endpos = data.find('\0') if endpos == -1: return size, data elif endpos == 0: return 0, "" else: return size, data[:endpos] @staticmethod def _write_long(f, v): data = struct.pack(">I", v) f.write(data) @staticmethod def _write_word(f, v): data = struct.pack(">H", v) f.write(data) def _write_name(self, f, s, tag=None): n = len(s) num_longs = int((n + 3) / 4) b = bytearray(num_longs * 4) if n > 0: b[0:n] = s if tag is not None: num_longs |= tag << 24 self._write_long(f, num_longs) f.write(b) class HunkHeaderBlock(HunkBlock): """HUNK_HEADER - header block of Load Modules""" blk_id = HUNK_HEADER def __init__(self): HunkBlock.__init__(self) self.reslib_names = [] self.table_size = 0 self.first_hunk = 0 self.last_hunk = 0 self.hunk_table = [] def setup(self, hunk_sizes): # easy setup for given number of hunks n = len(hunk_sizes) if n == 0: raise HunkParseError("No hunks for HUNK_HEADER given") self.table_size = n self.first_hunk = 0 self.last_hunk = n - 1 self.hunk_table = hunk_sizes def parse(self, f): # parse resident library names (AOS 1.x only) while True: l, s = self._read_name(f) if l < 0: raise HunkParseError("Error parsing HUNK_HEADER names") elif l == 0: break self.reslib_names.append(s) # table size and hunk range self.table_size = self._read_long(f) self.first_hunk = self._read_long(f) self.last_hunk = self._read_long(f) if self.table_size < 0 or self.first_hunk < 0 or self.last_hunk < 0: raise HunkParseError("HUNK_HEADER invalid table_size or first_hunk or last_hunk") # determine number of hunks in size table num_hunks = self.last_hunk - self.first_hunk + 1 for a in xrange(num_hunks): hunk_size = self._read_long(f) if hunk_size < 0: raise HunkParseError("HUNK_HEADER contains invalid hunk_size") # note that the upper bits are the target memory type. We only have FAST, # so let's forget about them for a moment. self.hunk_table.append(hunk_size & 0x3fffffff) def write(self, f): # write residents for reslib in self.reslib_names: self._write_name(f, reslib) self._write_long(f, 0) # table size and hunk range self._write_long(f, self.table_size) self._write_long(f, self.first_hunk) self._write_long(f, self.last_hunk) # sizes for hunk_size in self.hunk_table: self._write_long(f, hunk_size) class HunkSegmentBlock(HunkBlock): """HUNK_CODE, HUNK_DATA, HUNK_BSS""" def __init__(self, blk_id=None, data=None, data_offset=0, size_longs=0): HunkBlock.__init__(self) if blk_id is not None: self.blk_id = blk_id self.data = data self.data_offset = data_offset self.size_longs = size_longs def parse(self, f): size = self._read_long(f) self.size_longs = size if self.blk_id != HUNK_BSS: size *= 4 self.data_offset = f.tell() self.data = f.read(size) def write(self, f): self._write_long(f, self.size_longs) if self.data is not None: f.write(self.data) class HunkRelocLongBlock(HunkBlock): """HUNK_ABSRELOC32 - relocations stored in longs""" def __init__(self, blk_id=None, relocs=None): HunkBlock.__init__(self) if blk_id is not None: self.blk_id = blk_id # map hunk number to list of relocations (i.e. byte offsets in long) if relocs is None: self.relocs = [] else: self.relocs = relocs def parse(self, f): while True: num = self._read_long(f) if num == 0: break hunk_num = self._read_long(f) offsets = [] for i in xrange(num): off = self._read_long(f) offsets.append(off) self.relocs.append((hunk_num, offsets)) def write(self, f): for reloc in self.relocs: hunk_num, offsets = reloc self._write_long(f, len(offsets)) self._write_long(f, hunk_num) for off in offsets: self._write_long(f, off) self._write_long(f, 0) class HunkRelocWordBlock(HunkBlock): """HUNK_RELOC32SHORT - relocations stored in words""" def __init__(self, blk_id=None, relocs=None): HunkBlock.__init__(self) if blk_id is not None: self.blk_id = blk_id # list of tuples (hunk_no, [offsets]) if relocs is None: self.relocs = [] else: self.relocs = relocs def parse(self, f): num_words = 0 while True: num_offs = self._read_word(f) num_words += 1 if num_offs == 0: break hunk_num = self._read_word(f) num_words += num_offs + 1 offsets = [] for i in xrange(num_offs): off = self._read_word(f) offsets.append(off) self.relocs.append((hunk_num, offsets)) # pad to long if num_words % 2 == 1: self._read_word(f) def write(self, f): num_words = 0 for hunk_num, offsets in self.relocs: num_offs = len(offsets) self._write_word(f, num_offs) self._write_word(f, hunk_num) for i in xrange(num_offs): self._write_word(f, offsets[i]) num_words += 2 + num_offs # end self._write_word(f, 0) num_words += 1 # padding? if num_words % 2 == 1: self._write_word(f, 0) class HunkEndBlock(HunkBlock): """HUNK_END""" blk_id = HUNK_END def parse(self, f): pass def write(self, f): pass class HunkOverlayBlock(HunkBlock): """HUNK_OVERLAY""" blk_id = HUNK_OVERLAY def __init__(self): HunkBlock.__init__(self) self.data_offset = 0 self.data = None def parse(self, f): num_longs = self._read_long(f) self.data_offset = f.tell() self.data = f.read(num_longs * 4) def write(self, f): self._write_long(f, int(self.data / 4)) f.write(self.data) class HunkBreakBlock(HunkBlock): """HUNK_BREAK""" blk_id = HUNK_BREAK def parse(self, f): pass def write(self, f): pass class HunkDebugBlock(HunkBlock): """HUNK_DEBUG""" blk_id = HUNK_DEBUG def __init__(self, debug_data=None): HunkBlock.__init__(self) self.debug_data = debug_data def parse(self, f): num_longs = self._read_long(f) num_bytes = num_longs * 4 self.debug_data = f.read(num_bytes) def write(self, f): num_longs = int(len(self.debug_data) / 4) self._write_long(f, num_longs) f.write(self.debug_data) class HunkSymbolBlock(HunkBlock): """HUNK_SYMBOL""" blk_id = HUNK_SYMBOL def __init__(self, symbols=None): HunkBlock.__init__(self) if symbols is None: self.symbols = [] else: self.symbols = symbols def parse(self, f): while True: s, n = self._read_name(f) if s == 0: break off = self._read_long(f) self.symbols.append((n, off)) def write(self, f): for sym, off in self.symbols: self._write_name(f, sym) self._write_long(f, off) self._write_long(f, 0) class HunkUnitBlock(HunkBlock): """HUNK_UNIT""" blk_id = HUNK_UNIT def __init__(self): HunkBlock.__init__(self) self.name = None def parse(self, f): _, self.name = self._read_name(f) def write(self, f): self._write_name(f, self.name) class HunkNameBlock(HunkBlock): """HUNK_NAME""" blk_id = HUNK_NAME def __init__(self): HunkBlock.__init__(self) self.name = None def parse(self, f): _, self.name = self._read_name(f) def write(self, f): self._write_name(f, self.name) class HunkExtEntry: """helper class for HUNK_EXT entries""" def __init__(self, name, ext_type, value, bss_size, offsets): self.name = name self.ext_type = ext_type self.def_value = value # defs only self.bss_size = bss_size # ABSCOMMON only self.ref_offsets = offsets # refs only: list of offsets class HunkExtBlock(HunkBlock): """HUNK_EXT""" blk_id = HUNK_EXT def __init__(self): HunkBlock.__init__(self) self.entries = [] def parse(self, f): while True: tag = self._read_long(f) if tag == 0: break ext_type = tag >> 24 name_len = tag & 0xffffff _, name = self._read_name_size(f, name_len) # add on for type bss_size = None offsets = None value = None # ABSCOMMON -> bss size if ext_type == EXT_ABSCOMMON: bss_size = self._read_long(f) # is a reference elif ext_type >= 0x80: num_refs = self._read_long(f) offsets = [] for i in xrange(num_refs): off = self._read_long(f) offsets.append(off) # is a definition else: value = self._read_long(f) e = HunkExtEntry(name, ext_type, value, bss_size, offsets) self.entries.append(e) def write(self, f): for entry in self.entries: ext_type = entry.ext_type self._write_name(f, entry.name, tag=ext_type) # ABSCOMMON if ext_type == EXT_ABSCOMMON: self._write_long(f, entry.bss_size) # is a reference elif ext_type >= 0x80: num_offsets = len(entry.ref_offsets) self._write_long(f, num_offsets) for off in entry.ref_offsets: self._write_long(f, off) # is a definition else: self._write_long(f, entry.def_value) self._write_long(f, 0) class HunkLibBlock(HunkBlock): """HUNK_LIB""" blk_id = HUNK_LIB def __init__(self): HunkBlock.__init__(self) self.blocks = [] self.offsets = [] def parse(self, f, is_load_seg=False): num_longs = self._read_long(f) pos = f.tell() end_pos = pos + num_longs * 4 # first read block id while pos < end_pos: tag = f.read(4) # EOF if len(tag) == 0: break elif len(tag) != 4: raise HunkParseError("Hunk block tag too short!") blk_id = struct.unpack(">I", tag)[0] # mask out mem flags blk_id = blk_id & HUNK_TYPE_MASK # look up block type if blk_id in hunk_block_type_map: blk_type = hunk_block_type_map[blk_id] # create block and parse block = blk_type() block.blk_id = blk_id block.parse(f) self.offsets.append(pos) self.blocks.append(block) else: raise HunkParseError("Unsupported hunk type: %04d" % blk_id) pos = f.tell() def write(self, f): # write dummy length (fill in later) pos = f.tell() start = pos self._write_long(f, 0) self.offsets = [] # write blocks for block in self.blocks: block_id = block.blk_id block_id_raw = struct.pack(">I", block_id) f.write(block_id_raw) # write block itself block.write(f) # update offsets self.offsets.append(pos) pos = f.tell() # fill in size end = f.tell() size = end - start - 4 num_longs = size / 4 f.seek(start, 0) self._write_long(f, num_longs) f.seek(end, 0) class HunkIndexUnitEntry: def __init__(self, name_off, first_hunk_long_off): self.name_off = name_off self.first_hunk_long_off = first_hunk_long_off self.index_hunks = [] class HunkIndexHunkEntry: def __init__(self, name_off, hunk_longs, hunk_ctype): self.name_off = name_off self.hunk_longs = hunk_longs self.hunk_ctype = hunk_ctype self.sym_refs = [] self.sym_defs = [] class HunkIndexSymbolRef: def __init__(self, name_off): self.name_off = name_off class HunkIndexSymbolDef: def __init__(self, name_off, value, sym_ctype): self.name_off = name_off self.value = value self.sym_ctype = sym_ctype class HunkIndexBlock(HunkBlock): """HUNK_INDEX""" blk_id = HUNK_INDEX def __init__(self): HunkBlock.__init__(self) self.strtab = None self.units = [] def parse(self, f): num_longs = self._read_long(f) num_words = num_longs * 2 # string table size strtab_size = self._read_word(f) self.strtab = f.read(strtab_size) num_words = num_words - (strtab_size / 2) - 1 # read index unit blocks while num_words > 1: # unit description name_off = self._read_word(f) first_hunk_long_off = self._read_word(f) num_hunks = self._read_word(f) num_words -= 3 unit_entry = HunkIndexUnitEntry(name_off, first_hunk_long_off) self.units.append(unit_entry) for i in xrange(num_hunks): # hunk description name_off = self._read_word(f) hunk_longs = self._read_word(f) hunk_ctype = self._read_word(f) hunk_entry = HunkIndexHunkEntry(name_off, hunk_longs, hunk_ctype) unit_entry.index_hunks.append(hunk_entry) # refs num_refs = self._read_word(f) for j in xrange(num_refs): name_off = self._read_word(f) hunk_entry.sym_refs.append(HunkIndexSymbolRef(name_off)) # defs num_defs = self._read_word(f) for j in xrange(num_defs): name_off = self._read_word(f) value = self._read_word(f) stype = self._read_word(f) hunk_entry.sym_defs.append(HunkIndexSymbolDef(name_off, value, stype)) # calc word size num_words = num_words - (5 + num_refs + num_defs * 3) # alignment word? if num_words == 1: self._read_word(f) def write(self, f): # write dummy size num_longs_pos = f.tell() self._write_long(f, 0) num_words = 0 # write string table size_strtab = len(self.strtab) self._write_word(f, size_strtab) f.write(self.strtab) num_words += size_strtab / 2 + 1 # write unit blocks for unit in self.units: self._write_word(f, unit.name_off) self._write_word(f, unit.first_hunk_long_off) self._write_word(f, len(unit.index_hunks)) num_words += 3 for index in unit.index_hunks: self._write_word(f, index.name_off) self._write_word(f, index.hunk_longs) self._write_word(f, index.hunk_ctype) # refs num_refs = len(index.sym_refs) self._write_word(f, num_refs) for sym_ref in index.sym_refs: self._write_word(f, sym_ref.name_off) # defs num_defs = len(index.sym_defs) self._write_word(f, num_defs) for sym_def in index.sym_defs: self._write_word(f, sym_def.name_off) self._write_word(f, sym_def.value) self._write_word(f, sym_def.sym_ctype) # count words num_words += 5 + num_refs + num_defs * 3 # alignment word? if num_words % 2 == 1: num_words += 1 self._write_word(f, 0) # fill in real size pos = f.tell() f.seek(num_longs_pos, 0) self._write_long(f, num_words / 2) f.seek(pos, 0) # map the hunk types to the block classes
hunk_block_type_map = { # Load Module HUNK_HEADER: HunkHeaderBlock, HUNK_CODE: HunkSegmentBlock, HUNK_DATA: HunkSegmentBlock, HUNK_BSS: HunkSegmentBlock, HUNK_ABSRELOC32: HunkRelocLongBlock, HUNK_RELOC32SHORT: HunkRelocWordBlock, HUNK_END: HunkEndBlock, HUNK_DEBUG: HunkDebugBlock, HUNK_SYMBOL: HunkSymbolBlock, # Overlays HUNK_OVERLAY: HunkOverlayBlock, HUNK_BREAK: HunkBreakBlock, # Object Module HUNK_UNIT: HunkUnitBlock, HUNK_NAME: HunkNameBlock, HUNK_RELRELOC16: HunkRelocLongBlock, HUNK_RELRELOC8: HunkRelocLongBlock, HUNK_DREL32: HunkRelocLongBlock, HUNK_DREL16: HunkRelocLongBlock, HUNK_DREL8: HunkRelocLongBlock, HUNK_EXT: HunkExtBlock, # New Library HUNK_LIB: HunkLibBlock, HUNK_INDEX: HunkIndexBlock
} class HunkBlockFile: """The HunkBlockFile holds the list of blocks found in a hunk file""" def __init__(self, blocks=None): if blocks is None: self.blocks = [] else: self.blocks = blocks def get_blocks(self): return self.blocks def set_blocks(self, blocks): self.blocks = blocks def read_path(self, path_name, is_load_seg=False): f = open(path_name, "rb") self.read(f, is_load_seg) f.close() def read(self, f, is_load_seg=False): """read a hunk file and fill block list""" while True: # first read block id tag = f.read(4) # EOF if len(tag) == 0: break elif len(tag) != 4: raise HunkParseError("Hunk block tag too short!") blk_id = struct.unpack(">I", tag)[0] # mask out mem flags blk_id = blk_id & HUNK_TYPE_MASK # look up block type if blk_id in hunk_block_type_map: # v37 special case: 1015 is 1020 (HUNK_RELOC32SHORT) # we do this only in LoadSeg() files if is_load_seg and blk_id == HUNK_DREL32: blk_id = HUNK_RELOC32SHORT blk_type = hunk_block_type_map[blk_id] # create block and parse block = blk_type() block.blk_id = blk_id block.parse(f) self.blocks.append(block) else: raise HunkParseError("Unsupported hunk type: %04d" % blk_id) def write_path(self, path_name): f = open(path_name, "wb") self.write(f) f.close() def write(self, f, is_load_seg=False): """write a hunk file back to file object""" for block in self.blocks: # write block id block_id = block.blk_id # convert id if is_load_seg and block_id == HUNK_RELOC32SHORT: block_id = HUNK_DREL32 block_id_raw = struct.pack(">I", block_id) f.write(block_id_raw) # write block itself block.write(f) def detect_type(self): """look at blocks and try to deduce the type of hunk file""" if len(self.blocks) == 0: return TYPE_UNKNOWN first_block = self.blocks[0] blk_id = first_block.blk_id return self._map_blkid_to_type(blk_id) def peek_type(self, f): """look into given file obj stream to determine file format. stream is read and later on seek'ed back.""" pos = f.tell() tag = f.read(4) # EOF if len(tag) == 0: return TYPE_UNKNOWN elif len(tag) != 4: f.seek(pos, 0) return TYPE_UNKNOWN else: blk_id = struct.unpack(">I", tag)[0] f.seek(pos, 0) return self._map_blkid_to_type(blk_id) @staticmethod def _map_blkid_to_type(blk_id): if blk_id == HUNK_HEADER: return TYPE_LOADSEG elif blk_id == HUNK_UNIT: return TYPE_UNIT elif blk_id == HUNK_LIB: return TYPE_LIB else: return TYPE_UNKNOWN def get_block_type_names(self): """return a string array with the names of all block types""" res = [] for blk in self.blocks: blk_id = blk.blk_id name = hunk_names[blk_id] res.append(name) return res class DebugLineEntry: def __init__(self, offset, src_line, flags=0): self.offset = offset self.src_line = src_line self.flags = flags self.file_ = None def get_offset(self): return self.offset def get_src_line(self): return self.src_line def get_flags(self): return self.flags def get_file(self): return self.file_ class DebugLineFile: def __init__(self, src_file, dir_name=None, base_offset=0): self.src_file = src_file self.dir_name = dir_name self.base_offset = base_offset self.entries = [] def get_src_file(self): return self.src_file def get_dir_name(self): return self.dir_name def get_entries(self): return self.entries def get_base_offset(self): return self.base_offset def add_entry(self, e): self.entries.append(e) e.file_ = self class DebugLine: def __init__(self): self.files = [] def add_file(self, src_file): self.files.append(src_file) def get_files(self): return self.files class Symbol: def __init__(self, offset, name, file_name=None): self.offset = offset self.name = name self.file_name = file_name def get_offset(self): return self.offset def get_name(self): return self.name def get_file_name(self): return self.file_name class SymbolTable: def __init__(self): self.symbols = [] def add_symbol(self, symbol): self.symbols.append(symbol) def get_symbols(self): return self.symbols class Reloc: def __init__(self, offset, width=2, addend=0): self.offset = offset self.width = width self.addend = addend def get_offset(self): return self.offset def get_width(self): return self.width def get_addend(self): return self.addend class Relocations: def __init__(self, to_seg): self.to_seg = to_seg self.entries = [] def add_reloc(self, reloc): self.entries.append(reloc) def get_relocs(self): return self.entries class Segment: def __init__(self, seg_type, size, data=None, data_offset=0, flags=0): self.seg_type = seg_type self.size = size self.data_offset = data_offset self.data = data self.flags = flags self.relocs = self.symtab = None self.id = None self.file_data = None self.debug_line = None def __str__(self): # relocs relocs = [] for to_seg in self.relocs: r = self.relocs[to_seg] relocs.append("(#%d:size=%d)" % (to_seg.id, len(r.entries))) # symtab if self.symtab is not None: symtab = "symtab=#%d" % len(self.symtab.symbols) else: symtab = "" # debug_line if self.debug_line is not None: dl_files = self.debug_line.get_files() file_info = [] for dl_file in dl_files: n = len(dl_file.entries) file_info.append("(%s:#%d)" % (dl_file.src_file, n)) debug_line = "debug_line=" + ",".join(file_info) else: debug_line = "" # summary return "[#%d:%s:size=%d,flags=%d,%s,%s,%s]" % (self.id, segment_type_names[self.seg_type], self.size, self.flags, ",".join(relocs), symtab, debug_line) def get_type(self): return self.seg_type def get_type_name(self): return segment_type_names[self.seg_type] def get_size(self): return self.size def get_data(self): return self.data def add_reloc(self, to_seg, relocs): self.relocs[to_seg] = relocs def get_reloc_to_segs(self): keys = self.relocs.keys() return sorted(keys, key=lambda x: x.id) def get_reloc(self, to_seg): if to_seg in self.relocs: return self.relocs[to_seg] else: return None def set_symtab(self, symtab): self.symtab = symtab def get_symtab(self): return self.symtab def set_debug_line(self, debug_line): self.debug_line = debug_line def get_debug_line(self): return self.debug_line def set_file_data(self, file_data): """set associated loaded binary file""" self.file_data = file_data def get_file_data(self): """get associated loaded binary file""" return self.file_data def find_symbol(self, offset): symtab = self.get_symtab() if symtab is None: return None for symbol in symtab.get_symbols(): off = symbol.get_offset() if off == offset: return symbol.get_name() return None def find_reloc(self, offset, size): to_segs = self.get_reloc_to_segs() for to_seg in to_segs: reloc = self.get_reloc(to_seg) for r in reloc.get_relocs(): off = r.get_offset() if offset <= off <= (offset + size): return r, to_seg, off return None def find_debug_line(self, offset): debug_line = self.debug_line if debug_line is None: return None for df in debug_line.get_files(): for e in df.get_entries(): if e.get_offset() == offset: return e return None class BinImage: """A binary image contains all the segments of a program's binary image. """ def __init__(self, file_type): self.segments = [] self.file_data = None self.file_type = file_type def __str__(self): return "<%s>" % ",".join(map(str, self.segments)) def get_size(self): total_size = 0 for seg in self.segments: total_size += seg.get_size() return total_size def add_segment(self, seg): seg.id = len(self.segments) self.segments.append(seg) def get_segments(self): return self.segments def set_file_data(self, file_data): """set associated loaded binary file""" self.file_data = file_data def get_file_data(self): """get associated loaded binary file""" return self.file_data def get_segment_names(self): names = [] for seg in self.segments: names.append(seg.get_type_name()) return names class HunkDebugLineEntry: def __init__(self, offset, src_line): self.offset = offset self.src_line = src_line def __str__(self): return "[+%08x: %d]" % (self.offset, self.src_line) def get_offset(self): return self.offset def get_src_line(self): return self.src_line class HunkDebugLine: """structure to hold source line info""" def __init__(self, src_file, base_offset): self.tag = 'LINE' self.src_file = src_file self.base_offset = base_offset self.entries = [] def add_entry(self, offset, src_line): self.entries.append(HunkDebugLineEntry(offset, src_line)) def __str__(self): prefix = "{%s,%s,@%08x:" % (self.tag, self.src_file, self.base_offset) return prefix + ",".join(map(str, self.entries)) + "}" def get_src_file(self): return self.src_file def get_base_offset(self): return self.base_offset def get_entries(self): return self.entries class HunkDebugAny: def __init__(self, tag, data, base_offset): self.tag = tag self.data = data self.base_offset = base_offset def __str__(self): return "{%s,%d,%s}" % (self.tag, self.base_offset, self.data) class HunkDebug: def encode(self, debug_info): """encode a debug info and return a debug_data chunk""" out = StringIO.StringIO() # +0: base offset self._write_long(out, debug_info.base_offset) # +4: type tag tag = debug_info.tag out.write(tag) if tag == 'LINE': # file name self._write_string(out, debug_info.src_file) # entries for e in debug_info.entries: self._write_long(out, e.src_line) self._write_long(out, e.offset) elif tag == 'HEAD': out.write("DBGV01\0\0") out.write(debug_info.data) else: # any out.write(debug_info.data) # retrieve result res = out.getvalue() out.close() return res def decode(self, debug_data): """decode a data block from a debug hunk""" if len(debug_data) < 12: return None # +0: base_offset for file base_offset = self._read_long(debug_data, 0) # +4: tag tag = debug_data[4:8] if tag == 'LINE': # SAS/C source line info # +8: string file name src_file, src_size = self._read_string(debug_data, 8) dl = HunkDebugLine(src_file, base_offset) off = 12 + src_size num = (len(debug_data) - off) / 8 for i in range(num): src_line = self._read_long(debug_data, off) offset = self._read_long(debug_data, off + 4) off += 8 dl.add_entry(offset, src_line) return dl elif tag == 'HEAD': tag2 = debug_data[8:16] assert tag2 == "DBGV01\0\0" data = debug_data[16:] return HunkDebugAny(tag, data, base_offset) else: data = debug_data[8:] return HunkDebugAny(tag, data, base_offset) def _read_string(self, buf, pos): size = self._read_long(buf, pos) * 4 off = pos + 4 data = buf[off:off + size] pos = data.find('\0') if pos == 0: return "", size elif pos != -1: return data[:pos], size else: return data, size def _write_string(self, f, s): n = len(s) num_longs = int((n + 3) / 4) self._write_long(f, num_longs) add = num_longs * 4 - n if add > 0: s += '\0' * add f.write(s) def _read_long(self, buf, pos): return struct.unpack_from(">I", buf, pos)[0] def _write_long(self, f, v): data = struct.pack(">I", v) f.write(data) class HunkSegment: """holds a code, data, or bss hunk/segment""" def __init__(self): self.blocks = None self.seg_blk = None self.symbol_blk = None self.reloc_blks = None self.debug_blks = None self.debug_infos = None def __repr__(self): return "[seg=%s,symbol=%s,reloc=%s,debug=%s,debug_info=%s]" % \ (self._blk_str(self.seg_blk), self._blk_str(self.symbol_blk), self._blk_str_list(self.reloc_blks), self._blk_str_list(self.debug_blks), self._debug_infos_str()) def setup_code(self, data): data, size_longs = self._pad_data(data) self.seg_blk = HunkSegmentBlock(HUNK_CODE, data, size_longs) def setup_data(self, data): data, size_longs = self._pad_data(data) self.seg_blk = HunkSegmentBlock(HUNK_DATA, data, size_longs) @staticmethod def _pad_data(data): size_bytes = len(data) bytes_mod = size_bytes % 4 if bytes_mod > 0: add = 4 - bytes_mod data = data + '\0' * add size_long = int((size_bytes + 3) / 4) return data, size_long def setup_bss(self, size_bytes): size_longs = int((size_bytes + 3) / 4) self.seg_blk = HunkSegmentBlock(HUNK_BSS, None, size_longs) def setup_relocs(self, relocs, force_long=False): """relocs: ((hunk_num, (off1, off2, ...)), ...)""" if force_long: use_short = False else: use_short = self._are_relocs_short(relocs) if use_short: self.reloc_blks = [HunkRelocWordBlock(HUNK_RELOC32SHORT, relocs)] else: self.reloc_blks = [HunkRelocLongBlock(HUNK_ABSRELOC32, relocs)] def setup_symbols(self, symbols): """symbols: ((name, off), ...)""" self.symbol_blk = HunkSymbolBlock(symbols) def setup_debug(self, debug_info): if self.debug_infos is None: self.debug_infos = [] self.debug_infos.append(debug_info) hd = HunkDebug() debug_data = hd.encode(debug_info) blk = HunkDebugBlock(debug_data) if self.debug_blks is None: self.debug_blks = [] self.debug_blks.append(blk) @staticmethod def _are_relocs_short(relocs): for hunk_num, offsets in relocs: for off in offsets: if off > 65535: return False return True def _debug_infos_str(self): if self.debug_infos is None: return "n/a" else: return ",".join(map(str, self.debug_infos)) @staticmethod def _blk_str(blk): if blk is None: return "n/a" else: return hunk_names[blk.blk_id] @staticmethod def _blk_str_list(blk_list): res = [] if blk_list is None: return "n/a" for blk in blk_list: res.append(hunk_names[blk.blk_id]) return ",".join(res) def parse(self, blocks): hd = HunkDebug() self.blocks = blocks for blk in blocks: blk_id = blk.blk_id if blk_id in loadseg_valid_begin_hunks: self.seg_blk = blk elif blk_id == HUNK_SYMBOL: if self.symbol_blk is None: self.symbol_blk = blk else: raise Exception("duplicate symbols in hunk") elif blk_id == HUNK_DEBUG: if self.debug_blks is None: self.debug_blks = [] self.debug_blks.append(blk) # decode hunk debug info debug_info = hd.decode(blk.debug_data) if debug_info is not None: if self.debug_infos is None: self.debug_infos = [] self.debug_infos.append(debug_info) elif blk_id in (HUNK_ABSRELOC32, HUNK_RELOC32SHORT): if self.reloc_blks is None: self.reloc_blks = [] self.reloc_blks.append(blk) else: raise HunkParseError("invalid hunk block") def create(self, blocks): # already has blocks? if self.blocks is not None: blocks += self.blocks return self.seg_blk.size_longs # start with segment block if self.seg_blk is None: raise HunkParseError("no segment block!") self.blocks = [self.seg_blk] # has relocations if self.reloc_blks is not None: self.blocks += self.reloc_blks # has debug? if self.debug_blks is not None: self.blocks += self.debug_blks # has symbols? if self.symbol_blk is not None: self.blocks.append(self.symbol_blk) # store blocks blocks += self.blocks # return size of segment return self.seg_blk.size_longs class BinFmtHunk: """Handle Amiga's native Hunk file format""" def __init__(self): pass def is_image(self, path): """check if a given file is a hunk LoadSeg file""" with open(path, "rb") as f: return self.is_image_fobj(f) @staticmethod def is_image_fobj(fobj): """check if a given fobj is a hunk LoadSeg file""" bf = HunkBlockFile() bf_type = bf.peek_type(fobj) return bf_type == TYPE_LOADSEG def load_image(self, path): """load a BinImage from a hunk file given via path""" with open(path, "rb") as f: return self.load_image_fobj(f) def load_image_fobj(self, fobj): """load a BinImage from a hunk file given via file obj""" # read the hunk blocks bf = HunkBlockFile() bf.read(fobj, is_load_seg=True) # derive load seg file lsf = HunkLoadSegFile() lsf.parse_block_file(bf) # convert load seg file return self.create_image_from_load_seg_file(lsf) def save_image(self, path, bin_img): """save a BinImage to a hunk file given via path""" with open(path, "wb") as f: self.save_image_fobj(f, bin_img) def save_image_fobj(self, fobj, bin_img): """save a BinImage to a hunk file given via file obj""" lsf = self.create_load_seg_file_from_image(bin_img) bf = lsf.create_block_file() bf.write(fobj, is_load_seg=True) def create_load_seg_file_from_image(self, bin_img): """create a HunkLodSegFile from a BinImage""" lsf = HunkLoadSegFile() for seg in bin_img.segments: seg_type = seg.get_type() # create HunkSegment lseg = HunkSegment() lsf.add_segment(lseg) if seg_type == SEGMENT_TYPE_CODE: lseg.setup_code(seg.data) elif seg_type == SEGMENT_TYPE_DATA: lseg.setup_data(seg.data) elif seg_type == SEGMENT_TYPE_BSS: lseg.setup_bss(seg.size) else: raise HunkParseError("Unknown Segment Type in BinImage: %d" % seg_type) # add relocs self._add_bin_img_relocs(lseg, seg) # add symbols self._add_bin_img_symbols(lseg, seg) # add debug info self._add_bin_img_debug_info(lseg, seg) return lsf @staticmethod def _add_bin_img_relocs(hunk_seg, seg): reloc_segs = seg.get_reloc_to_segs() hunk_relocs = [] for reloc_seg in reloc_segs: seg_id = reloc_seg.id reloc = seg.get_reloc(reloc_seg) relocs = reloc.get_relocs() offsets = [] for r in relocs: if r.get_width() != 2 or r.get_addend() != 0: raise HunkParseError("Invalid reloc: " + r) offsets.append(r.get_offset()) hunk_relocs.append((seg_id, offsets)) if len(hunk_relocs) > 0: hunk_seg.setup_relocs(hunk_relocs) @staticmethod def _add_bin_img_symbols(hunk_seg, seg): sym_tab = seg.get_symtab() if sym_tab is not None: hunk_sym_list = [] for sym in sym_tab.get_symbols(): hunk_sym_list.append((sym.get_name(), sym.get_offset())) hunk_seg.setup_symbols(hunk_sym_list) @staticmethod def _add_bin_img_debug_info(hunk_seg, seg): debug_line = seg.get_debug_line() if debug_line is not None: for file in debug_line.get_files(): src_file = file.get_src_file() base_offset = file.get_base_offset() dl = HunkDebugLine(src_file, base_offset) for e in file.get_entries(): offset = e.get_offset() src_line = e.get_src_line() flags = e.get_flags() hunk_src_line = src_line | (flags << 24) dl.add_entry(offset, hunk_src_line) hunk_seg.setup_debug(dl) def create_image_from_load_seg_file(self, lsf): """create a BinImage from a HunkLoadSegFile object""" bi = BinImage(BIN_IMAGE_TYPE_HUNK) bi.set_file_data(lsf) segs = lsf.get_segments() for seg in segs: # what type of segment to we have? blk_id = seg.seg_blk.blk_id size = seg.size_longs * 4 data_offset = seg.seg_blk.data_offset data = seg.seg_blk.data if blk_id == HUNK_CODE: seg_type = SEGMENT_TYPE_CODE elif blk_id == HUNK_DATA: seg_type = SEGMENT_TYPE_DATA elif blk_id == HUNK_BSS: seg_type = SEGMENT_TYPE_BSS else: raise HunkParseError("Unknown Segment Type for BinImage: %d" % blk_id) # create seg bs = Segment(seg_type, size, data, data_offset) bs.set_file_data(seg) bi.add_segment(bs) # add relocations if any bi_segs = bi.get_segments() for seg in bi_segs: # add relocations? hseg = seg.file_data reloc_blks = hseg.reloc_blks if reloc_blks is not None: self._add_hunk_relocs(reloc_blks, seg, bi_segs) # add symbol table symbol_blk = hseg.symbol_blk if symbol_blk is not None: self._add_hunk_symbols(symbol_blk, seg) # add debug infos debug_infos = hseg.debug_infos if debug_infos is not None: self._add_debug_infos(debug_infos, seg) return bi @staticmethod def _add_hunk_relocs(blks, seg, all_segs): """add relocations to a segment""" for blk in blks: if blk.blk_id not in (HUNK_ABSRELOC32, HUNK_RELOC32SHORT): raise HunkParseError("Invalid Relocations for BinImage: %d" % blk.blk_id) relocs = blk.relocs for r in relocs: hunk_num = r[0] offsets = r[1] to_seg = all_segs[hunk_num] # create reloc for target segment or reuse one. rl = seg.get_reloc(to_seg) if rl is None: rl = Relocations(to_seg) # add offsets for o in offsets: r = Reloc(o) rl.add_reloc(r) seg.add_reloc(to_seg, rl) @staticmethod def _add_hunk_symbols(blk, seg): """add symbols to segment""" syms = blk.symbols if len(syms) == 0: return st = SymbolTable() seg.set_symtab(st) for sym in syms: name = sym[0] offset = sym[1] symbol = Symbol(offset, name) st.add_symbol(symbol) @staticmethod def _add_debug_infos(debug_infos, seg): dl = DebugLine() seg.set_debug_line(dl) for debug_info in debug_infos: # add source line infos if isinstance(debug_info, HunkDebugLine): src_file = debug_info.src_file # abs path? pos = src_file.rfind('/') if pos != -1: dir_name = src_file[:pos] src_file = src_file[pos + 1:] else: dir_name = "" base_offset = debug_info.base_offset df = DebugLineFile(src_file, dir_name, base_offset) dl.add_file(df) for entry in debug_info.get_entries(): off = entry.offset src_line = entry.src_line & 0xffffff flags = (entry.src_line & 0xff000000) >> 24 e = DebugLineEntry(off, src_line, flags) df.add_entry(e) class HunkLoadSegFile: """manage a LoadSeg() hunk file starting with HUNK_HEADER""" def __init__(self): self.hdr_blk = None self.segments = [] def get_segments(self): return self.segments def add_segment(self, seg): self.segments.append(seg) def parse_block_file(self, bf): """assign hunk blocks into segments""" # get file blocks blks = bf.get_blocks() if blks is None or len(blks) == 0: raise HunkParseError("no hunk blocks found!") # ensure its a HUNK_HEADER hdr_blk = blks[0] if hdr_blk.blk_id != HUNK_HEADER: raise HunkParseError("no HEADER block found!") self.hdr_blk = hdr_blk # first round: split block list into sections seperated by END first = [] cur = None for blk in blks[1:]: blk_id = blk.blk_id # split by END block if blk_id == HUNK_END: cur = None # add non end block to list else: # check validity of block if blk_id not in loadseg_valid_begin_hunks and \ blk_id not in loadseg_valid_extra_hunks: raise HunkParseError("invalid block found: %d" % blk_id) if cur is None: cur = [] first.append(cur) cur.append(blk) # second round: split list if two segments are found in a single list # this is only necessary for broken files that lack END blocks second = [] for l in first: pos_seg = [] off = 0 for blk in l: if blk.blk_id in loadseg_valid_begin_hunks: pos_seg.append(off) off += 1 n = len(pos_seg) if n == 1: # list is ok second.append(l) elif n > 1: # list needs split # we can only split if no extra block is before next segment block new_list = None for blk in l: if blk.blk_id in loadseg_valid_begin_hunks: new_list = [blk] second.append(new_list) elif new_list is not None: new_list.append(blk) else: raise HunkParseError("can't split block list") # check size of hunk table if len(hdr_blk.hunk_table) != len(second): raise HunkParseError("can't match hunks to header") # convert block lists into segments for l in second: seg = HunkSegment() seg.parse(l) self.segments.append(seg) # set size in segments n = len(second) for i in xrange(n): self.segments[i].size_longs = hdr_blk.hunk_table[i] self.segments[i].size = self.segments[i].size_longs * 4 def create_block_file(self): """create a HunkBlockFile from the segments given""" # setup header block self.hdr_blk = HunkHeaderBlock() blks = [self.hdr_blk] sizes = [] for seg in self.segments: size = seg.create(blks) sizes.append(size) # add HUNK_END blks.append(HunkEndBlock()) # finally setup header self.hdr_blk.setup(sizes) # create HunkBlockFile return HunkBlockFile(blks) class Relocate: """Relocate a BinImage to given addresses""" def __init__(self, bin_img): self.bin_img = bin_img def get_sizes(self): """return a list of the required sizes for all sections""" sizes = [] for segment in self.bin_img.get_segments(): size = segment.size sizes.append(size) return sizes def get_total_size(self, padding=0): """return the total size of all segments appended. useful for one large blob""" sizes = self.get_sizes() total = 0 for s in sizes: total += s + padding return total def get_seq_addrs(self, base_addr, padding=0): """generate a sequence of addresses for continous segments in one blob""" sizes = self.get_sizes() addrs = [] addr = base_addr for s in sizes: addrs.append(addr) addr += s + padding return addrs def relocate_one_block(self, base_addr, padding=0): total_size = self.get_total_size(padding) data = bytearray(total_size) addrs = self.get_seq_addrs(base_addr, padding) offset = 0 segs = self.bin_img.get_segments() for segment in segs: self._copy_data(data, segment, offset) self._reloc_data(data, segment, addrs, offset) offset += segment.size + padding return data def relocate(self, addrs): """perform relocations on segments and return relocated data""" segs = self.bin_img.get_segments() if len(segs) != len(addrs): raise ValueError("addrs != segments") datas = [] for segment in segs: # allocate new buffer data = bytearray(segment.size) self._copy_data(data, segment) self._reloc_data(data, segment, addrs) datas.append(data) return datas @staticmethod def _copy_data(data, segment, offset=0): # allocate segment data size = segment.size src_data = segment.data if src_data is not None: src_len = len(src_data) data[offset:src_len + offset] = src_data def _reloc_data(self, data, segment, addrs, offset=0): # find relocations to_segs = segment.get_reloc_to_segs() for to_seg in to_segs: # get target segment's address to_id = to_seg.id to_addr = addrs[to_id] # get relocations reloc = segment.get_reloc(to_seg) for r in reloc.get_relocs(): self._reloc(segment.id, data, r, to_addr, to_id, offset) def _reloc(self, my_id, data, reloc, to_addr, to_id, extra_offset): """relocate one entry""" offset = reloc.get_offset() + extra_offset delta = self.read_long(data, offset) + reloc.addend addr = to_addr + delta self.write_long(data, offset, addr) @staticmethod def read_long(data, offset): d = data[offset:offset + 4] return struct.unpack(">i", d)[0] @staticmethod def write_long(data, offset, value): d = struct.pack(">i", value) data[offset:offset + 4] = d def accept_file(li, filename): li.seek(0) bf = BinFmtHunk() tag = li.read(4) tagf = StringIO.StringIO(tag) if bf.is_image_fobj(tagf): return {'format': 'Amiga Hunk executable', 'processor': '68040'} else: return 0 def load_file(li, neflags, format): idaapi.set_processor_type('68040', ida_idp.SETPROC_LOADER) idaapi.cvar.inf.af = idaapi.AF_CODE | idaapi.AF_JUMPTBL | idaapi.AF_USED | idaapi.AF_UNK | \ idaapi.AF_PROC | idaapi.AF_LVAR | idaapi.AF_STKARG | idaapi.AF_REGARG | \ idaapi.AF_TRACE | idaapi.AF_VERSP | idaapi.AF_ANORET | idaapi.AF_MEMFUNC | \ idaapi.AF_TRFUNC | idaapi.AF_FIXUP | idaapi.AF_JFUNC | idaapi.AF_NULLSUB | \ idaapi.AF_NULLSUB | idaapi.AF_IMMOFF | idaapi.AF_STRLIT li.seek(0) data = li.read(li.size()) bf = BinFmtHunk() fobj = StringIO.StringIO(data) bi = bf.load_image_fobj(fobj) rel = Relocate(bi) addrs = rel.get_seq_addrs(0x21F000) datas = rel.relocate(addrs) idaapi.add_entry(addrs[0], addrs[0], "start", 1) for seg in bi.get_segments(): offset = addrs[seg.id] size = seg.size to_segs = seg.get_reloc_to_segs() for to_seg in to_segs: reloc = seg.get_reloc(to_seg) for r in reloc.get_relocs(): offset2 = r.get_offset() rel_off = Relocate.read_long(datas[seg.id], offset2) addr = offset + rel_off + r.addend fd = idaapi.fixup_data_t(idaapi.FIXUP_OFF32) fd.off = addr fd.set(offset + offset2) idaapi.mem2base(str(datas[seg.id]), offset, seg.data_offset) idaapi.add_segm(0, offset, offset + size, 'SEG_%02d' % seg.id, seg.get_type_name()) return 1 def move_segm(frm, to, sz, fileformatname): delta = to xEA = ida_fixup.get_first_fixup_ea() while xEA != idaapi.BADADDR: fd = ida_fixup.fixup_data_t(idaapi.FIXUP_OFF32) ida_fixup.get_fixup(xEA, fd) fd.off += delta if fd.get_type() == ida_fixup.FIXUP_OFF8: idaapi.put_byte(xEA, fd.off) elif fd.get_type() == ida_fixup.FIXUP_OFF16: idaapi.put_word(xEA, fd.off) elif fd.get_type() == ida_fixup.FIXUP_OFF32: idaapi.put_long(xEA, fd.off) fd.set(xEA) xEA = ida_fixup.get_next_fixup_ea(xEA) idaapi.cvar.inf.baseaddr = idaapi.cvar.inf.baseaddr + delta return 1

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