SARCExtract.py

from struct import pack, unpack
from os import mkdir, makedirs
from os.path import exists
import sys

def half(f, en):
    return unpack("%sH" % en, f.read(2))[0]

def full(f, en):
    return unpack("%sI" % en, f.read(4))[0]

def getstr(f):
    ret = b"";char = f.read(1)
    while char != b"\x00":
        ret += char
        char = f.read(1)
    return ret.decode("UTF-8")

def gethash(name, multiplier):
    result = 0
    for i in range(len(name)):
        result  = ord(name[i]) + (result * multiplier)
        result &= 0xFFFFFFFF
    return result

if __name__ == "__main__":
    with open(sys.argv[1], "rb") as f:
        assert f.read(4) == b"SARC" #magic
        f.seek(6) #need to read endian before 0x14
        en = ["<", ">"][half(f, ">") & 1]
        f.seek(4) #now we can check it with endian
        assert half(f, en) == 0x14 #header size
        f.seek(0, 2) #end of file, verify correct size
        size = f.tell()
        f.seek(8) #expected size
        assert full(f, en) == size #filesize
        start = full(f, en) #of raw data
        assert full(f, en) == 0x100 #???
        assert f.read(4) == b"SFAT"
        assert half(f, en) == 12 #header size
        count = half(f, en)
        multi = full(f, en)
        if multi != 0x65:
            print("WARNING: odd hash multiplier, may not be supp.")
        attr = [];count1 = count #backup for below
        while count: #may be giant, do a decrement
            attr.append(unpack("%s4I" % en, f.read(16)))
            count -= 1
        assert f.read(4) == b"SFNT"
        assert half(f, en) == 8 #SFNT header size
        assert half(f, en) == 0 #????
        SFNT = f.tell()
        base = ".".join(sys.argv[1].split(".")[:-1])
        if not exists(base):
            mkdir(base)
        print("%s%s      %s" % ("NAME".ljust(80), "SIZE", "HASH"))
        unknown = 0;i = 0;count = count1
        while count:
            if attr[i][1] & 0x01000000: #file has name
                f.seek(SFNT + ((attr[i][1] & 0xFFFF) * 4))
                name = getstr(f)
                assert gethash(name, multi) == attr[i][0]
            else:
                f.seek(start + attr[i][2])
                name = b"UNKNOWN%d.%s" % (unknown, getext(f.read(4)))
                unknown += 1
            if len(name) < 80:
                print("%s%08X  %08X" % (name.ljust(80), attr[i][3]\
                                          - attr[i][2], attr[i][0]))
            else:
                trun = "..." + name[-76:] + " "
                print("%s%08X  %08X" % (trun, attr[i][3]-attr[i][2],\
                                                         attr[i][0]))
            if "/" in name: #assume all are encoded this way
                path = base + "/" + "/".join(name.split("/")[:-1])
            else:
                path = base
            if not exists(path): makedirs(path)
            with open(base + "/" + name, "wb") as o:
                f.seek(start + attr[i][2])
                o.write(f.read(attr[i][3]-attr[i][2]))
            count -= 1;i += 1