Mercurial > touhou
changeset 261:2876c267be00
Add heuristics to extract character data from the demo .exe.
author | Thibaut Girka <thib@sitedethib.com> |
---|---|
date | Mon, 23 Jan 2012 00:03:06 +0100 |
parents | e22e0d73f614 |
children | 8fa660da5f0c |
files | pytouhou/formats/exe.py |
diffstat | 1 files changed, 41 insertions(+), 15 deletions(-) [+] |
line wrap: on
line diff
--- a/pytouhou/formats/exe.py +++ b/pytouhou/formats/exe.py @@ -95,19 +95,28 @@ class SHT(object): # So far, this character definition seems to be valid. # Now, make sure the shoot function wrappers pass valid addresses - pe_file.seek_to_va(ptr1 + 4) - shtptr1, = unpack('<I', pe_file.file.read(4)) - pe_file.seek_to_va(ptr2 + 4) - shtptr2, = unpack('<I', pe_file.file.read(4)) + + # Search for the “push” instruction + for i in xrange(20): + # Find the “push” instruction + pe_file.seek_to_va(ptr1 + i) + instr1, shtptr1 = unpack('<BI', pe_file.file.read(5)) + pe_file.seek_to_va(ptr2 + i) + instr2, shtptr2 = unpack('<BI', pe_file.file.read(5)) + if instr1 == 0x68 and instr2 == 0x68 and (0 <= shtptr1 - data_va < data_size - 12 + and 0 <= shtptr2 - data_va < data_size - 12): + # It is unlikely this character record is *not* valid, but + # just to be sure, let's check the first SHT definition. + pe_file.seek_to_va(shtptr1) + nb_shots, power, shotsptr = unpack('<III', pe_file.file.read(12)) + if (0 < nb_shots <= 1000 + and 0 <= power < 1000 + and 0 <= shotsptr - data_va < data_size - 36*nb_shots): + break + # Check if everything is fine... if not (0 <= shtptr1 - data_va < data_size - 12 - and 0 <= shtptr2 - data_va < data_size - 12): - break - - # It is unlikely this character record is *not* valid, but - # just to be sure, let's check the first SHT definition. - pe_file.seek_to_va(shtptr1) - nb_shots, power, shotsptr = unpack('<III', pe_file.file.read(12)) - if not (0 < nb_shots <= 1000 + and 0 <= shtptr2 - data_va < data_size - 12 + and 0 < nb_shots <= 1000 and 0 <= power < 1000 and 0 <= shotsptr - data_va < data_size - 36*nb_shots): break @@ -123,6 +132,14 @@ class SHT(object): @classmethod def read(cls, file): pe_file = PEFile(file) + data_section = [section for section in pe_file.sections + if section.Name.startswith('.data')][0] + text_section = [section for section in pe_file.sections + if section.Name.startswith('.text')][0] + data_va = pe_file.image_base + data_section.VirtualAddress + data_size = data_section.SizeOfRawData + text_va = pe_file.image_base + text_section.VirtualAddress + text_size = text_section.SizeOfRawData character_records_va = list(cls.find_character_defs(pe_file))[0] @@ -148,9 +165,18 @@ class SHT(object): characters.append((sht, focused_sht)) for sht, func_offset in ((sht, shots_func_offset), (focused_sht, shots_func_offset_focused)): - # Read from “push” operand - pe_file.seek_to_va(func_offset + 4) - offset, = unpack('<I', file.read(4)) + # Search for the “push” instruction + for i in xrange(20): + # Find the “push” instruction + pe_file.seek_to_va(func_offset + i) + instr, offset = unpack('<BI', file.read(5)) + if instr == 0x68 and 0 <= offset - data_va < data_size - 12: + pe_file.seek_to_va(offset) + nb_shots, power, shotsptr = unpack('<III', pe_file.file.read(12)) + if (0 < nb_shots <= 1000 + and 0 <= power < 1000 + and 0 <= shotsptr - data_va < data_size - 36*nb_shots): + break if offset not in shots_offsets: shots_offsets[offset] = [] shots_offsets[offset].append(sht)