Gen Proto BanG Dream

Gen Proto BanG Dream.md

This is the code rewritten in Python 3 from the original code of esterTion's PHP version. Only works with blobs from Android apk!!!

genProto.py for old versions, genProto.py for new versions with arm64 blobs.

genProto.py

from struct import unpack
import re
import sys

dumpcs = open('dump.cs').read()
prog = open('libil2cpp.so', 'rb')

definedClass = []
targetClass = sys.argv[1] #'SuiteMasterGetResponse'  # change to get different classes
outputPath = './{}.proto'.format(targetClass)
outputFile = open(outputPath, 'w')
# write first line
outputFile.write('syntax = "proto2";\n')

typeMap = {
  'uint': 'uint32',
  'string': 'string',
  'ulong': 'uint64',
  'float': 'float',
  'int': 'int32',
  'double': 'double',
  'bool': 'bool',
  'long': 'int64'
}

def getTag(address):
  offset = address & 0xFFFFFFFF

  prog.seek(offset)
  inst = prog.read(4)
  inst = int.from_bytes(inst, byteorder='little', signed=False)
  if inst == 0xe5900004: #0x080440f9:
    prog.seek(offset + 4)
    retnum = int.from_bytes(prog.read(2), 'little', signed=False)
    rotate_flag = int.from_bytes(prog.read(1), 'little', signed=False)
    if rotate_flag == 0xA0:
      # rotate tag number
      rotate_num = (retnum >> 8) & 0xF
      tag = retnum & 0xFF
      for i in range(rotate_num * 2):
        tag = rotr(tag, 32)
      return tag
    return retnum & 0xfff
  elif inst == 0xe92d4c10:
    prog.seek(offset + 12)
    return int.from_bytes(prog.read(2), 'little', signed=False) & 0xfff
  else:
    print(hex(inst), hex(address))

def rotr(num, bits):
    num &= (2**bits-1)
    bit = num & 1
    num >>= 1
    if(bit):
        num |= (1 << (bits-1))

    return num

def writeMessage(target, message):
  outputFile.write('message {} {{\n'.format(target))
  for item, info in message.items():
    typ = info[0]
    if type(info[1]).__name__ == 'str':
      tag = getTag(int(info[1], 16))
    else:
      tag = info[1]
    hint = info[2]
    comment = info[3]
    if hint == 'map':
      outputFile.write('  {}{} {} = {};\n'.format(hint, typ, item, tag))
    else:
      outputFile.write('  {} {} {} = {};\n'.format(hint, typ, item, tag))
  outputFile.write('}\n')

def readClass(level, target):
  try:
    definedClass.index(target)
    shownClass = True
  except ValueError:
    definedClass.append(target)
    shownClass = False

  message = {}
  classDef = re.search('\[ProtoContractAttribute\].*?\n.*?class ' + target + ' [^\{\}]*?\{((.*\n)*?)?\s+(//\s+Properties(.*\n)*?)?\s+(//\s+Methods(.*\n)*?)?\}\s*?', dumpcs)
  if not classDef:
    print('{} not found'.format(target))
  else:
    propList = re.findall('(\[ProtoMemberAttribute\] //.*Offset: 0x([0-9A-F]+)\n	\w+ ([^\ \<]+(\<(.*?)\>)?) ([^\ ;]+))', classDef[0])
    for prop in propList:
      typ = jumpTyp(level, prop[2], prop[5])
      message[typ[0]] = [typ[1], prop[1], typ[2], typ[3]]
    if not shownClass:
      # print('{} \n'.format(target))
      writeMessage(target, message)

def jumpTyp(level, typ, name):
  if typ[-2:] == '[]':
    sub = jumpTyp(level + 2, typ[0:-2], 'entry')
    return [name, sub[1], 'repeated', 'array']
  elif typ[0:11] == 'Dictionary`':
    subType = re.search('<(\w+), (\w+)>', typ)
    readClass(level + 1, subType[2])
    # prefix = '{}_{}'.format(subType[1], subType[2])
    
    # try:
    #   definedClass.index(prefix)
    #   shownClass = True
    # except ValueError:
    #   definedClass.append(prefix)
    #   shownClass = False
    # message = {}
    # sub = jumpTyp(level + 1, subType[1], '{}_key'.format(prefix))
    # message[sub[0]] = [sub[1], 1, sub[2], sub[3]]
    # sub = jumpTyp(level + 1, subType[2], '{}_value'.format(prefix))
    # message[sub[0]] = [sub[1], 2, sub[2], sub[3]]
    # if not shownClass:
    #   writeMessage(prefix, message)
    return [name, '<{}, {}>'.format(typeMap.get(subType[1], subType[1]), typeMap.get(subType[2], subType[2])), 'map', 'dictionary']
  elif typ[0:5] == 'List`':
    subType = re.search('<(\w+)>', typ)
    sub = jumpTyp(level + 1, subType[1], 'entry')
    return [name, sub[1], 'repeated', 'list']
  elif typ[0:9] == 'Nullable`':
    subType = re.search('<(\w+)>', typ)
    sub = jumpTyp(level, subType[1], name)
    sub[3] = 'nullable'
    return sub
  else:
    expectTyp = ['uint','string','ulong','float','int','double', 'bool','long']
    try:
      expectTyp.index(typ)
      isType = True
    except ValueError:
      expectTyp.append(typ)
      isType = False

    if isType:
      return [name, typeMap[typ], 'optional', 'normal type']
    else:
      readClass(level + 1, typ)
      return [name, typ, 'optional', 'sub class']

readClass(0, targetClass)

genProto_arm64.py

from struct import unpack
import re
import sys

dumpcs = open('dump.cs', encoding="utf8").read()
prog = open('libil2cpp.so', 'rb')

definedClass = []
targetClass = sys.argv[1] #'SuiteMasterGetResponse'  # change to get different classes
outputPath = './{}.proto'.format(targetClass)
outputFile = open(outputPath, 'w')
# write first line
outputFile.write('syntax = "proto2";\n')
# outputFile.write('package bang;\n')

typeMap = {
  'uint': 'uint32',
  'string': 'string',
  'ulong': 'uint32',
  'float': 'float',
  'int': 'int32',
  'double': 'double',
  'bool': 'bool',
  'long': 'int32'
}

def getTag(address):
  offset = address & 0xFFFFFFFF

  prog.seek(offset)
  inst = prog.read(4)
  inst = int.from_bytes(inst, byteorder='little', signed=False)
  if inst == 0xf9400408:
    prog.seek(offset + 4)
    inst = int.from_bytes(prog.read(4), 'little', signed=False)
  elif inst == 0xf81e0ff3:
    prog.seek(offset + 16)
    inst = int.from_bytes(prog.read(4), 'little', signed=False)
  else:
    print(hex(inst), hex(address))
    return None
  if inst >> 24 == 0x52:
    return (inst >> 5) & 0xFFFF
  elif inst >> 24 == 0x32:
    retnum = (inst >> 8) & 0xFFFF
    immr = (retnum >> 8) & 0x3F
    imms = (retnum >> 2) & 0x3F
    clz = lambda x: "{:032b}".format(x).index("1")
    _len = 31 - clz((0 << 6) | (~imms & 0x3F))
    _size = 1 << _len
    R = immr & (_size - 1)
    S = imms & (_size - 1)
    ret = (1 << (S+1)) - 1
    for i in range(immr):
      ret = rotr(ret, 32)
    return ret


def rotr(num, bits):
    num &= (2**bits-1)
    bit = num & 1
    num >>= 1
    if(bit):
        num |= (1 << (bits-1))

    return num

def writeMessage(target, message):
  outputFile.write('message {} {{\n'.format(target))
  for item, info in message.items():
    typ = info[0]
    if type(info[1]).__name__ == 'str':
      tag = getTag(int(info[1], 16))
    else:
      tag = info[1]
    hint = info[2]
    comment = info[3]
    if hint == 'map':
      outputFile.write('  {}{} {} = {};\n'.format(hint, typ, item, tag))
    else:
      outputFile.write('  {} {} {} = {};\n'.format(hint, typ, item, tag))
  outputFile.write('}\n')

def readClass(level, target):
  try:
    definedClass.index(target)
    shownClass = True
  except ValueError:
    definedClass.append(target)
    shownClass = False

  message = {}
  classDef = re.search('\[ProtoContractAttribute\].*?\n.*?class ' + target + ' [^\{\}]*?\{((.*\n)*?)?\s+(//\s+Properties(.*\n)*?)?\s+(//\s+Methods(.*\n)*?)?\}\s*?', dumpcs)
  if not classDef:
    print('{} not found'.format(target))
  else:
    propList = re.findall('(\[ProtoMemberAttribute\] //.*Offset: 0x([0-9A-F]+).+?\n	\w+ ([^\ \<]+(\<(.*?)\>)?) ([^\ ;]+))', classDef[0])
    for prop in propList:
      typ = jumpTyp(level, prop[2], prop[5])
      message[typ[0]] = [typ[1], prop[1], typ[2], typ[3]]
    if not shownClass:
      # print('{} \n'.format(target))
      writeMessage(target, message)

def jumpTyp(level, typ, name):
  if typ[-2:] == '[]':
    sub = jumpTyp(level + 2, typ[0:-2], 'entry')
    return [name, sub[1], 'repeated', 'array']
  elif typ[0:10] == 'Dictionary':
    subType = re.search('<(\w+), (\w+)>', typ)
    readClass(level + 1, subType[2])
    return [name, '<{}, {}>'.format(typeMap.get(subType[1], subType[1]), typeMap.get(subType[2], subType[2])), 'map', 'dictionary']
  elif typ[0:4] == 'List':
    subType = re.search('<(\w+)>', typ)
    sub = jumpTyp(level + 1, subType[1], 'entry')
    return [name, sub[1], 'repeated', 'list']
  elif typ[0:8] == 'Nullable':
    subType = re.search('<(\w+)>', typ)
    sub = jumpTyp(level, subType[1], name)
    sub[3] = 'nullable'
    return sub
  else:
    expectTyp = ['uint','string','ulong','float','int','double', 'bool','long']
    try:
      expectTyp.index(typ)
      isType = True
    except ValueError:
      expectTyp.append(typ)
      isType = False

    if isType:
      return [name, typeMap[typ], 'optional', 'normal type']
    else:
      readClass(level + 1, typ)
      return [name, typ, 'optional', 'sub class']

readClass(0, targetClass)

You can read the output dump.cs to know how the structure was defined and use disassembler to know how to get tag id from binary.

I have example code like this. When write manually, proto would be. But I don't know the regex to find and extract field from this. Can you please help me?
proto

message ResGetPlayerInfos{
 UserPlayerInfo userPlayerInfos_=1;
 bool isLinkUUID_=2;
 repeated int32 chargeGoldList_=3;
}

This is from dump.cs

public sealed class ResGetPlayerInfos : IMessage<ResGetPlayerInfos>, IMessage, IEquatable<ResGetPlayerInfos>, IDeepCloneable<ResGetPlayerInfos> // TypeDefIndex: 10759
{
	// Fields
	private static readonly MessageParser<ResGetPlayerInfos> _parser; // 0x0
	private UnknownFieldSet _unknownFields; // 0x10
	public const int UserPlayerInfosFieldNumber = 1;
	private static readonly FieldCodec<UserPlayerInfo> _repeated_userPlayerInfos_codec; // 0x8
	private readonly RepeatedField<UserPlayerInfo> userPlayerInfos_; // 0x18
	public const int IsLinkUUIDFieldNumber = 2;
	private bool isLinkUUID_; // 0x20
	public const int ChargeGoldListFieldNumber = 3;
	private static readonly FieldCodec<int> _repeated_chargeGoldList_codec; // 0x10
	private readonly RepeatedField<int> chargeGoldList_; // 0x28

You can learn and test regex with regex101. It won't be much different with protobuf-net ones.