NCCHInfo PadGen (Requires KeyXs)

from Crypto.Cipher import AES
from Crypto.Util import Counter
from ctypes import *
import hashlib
import struct

# TODO:
#   -Parse NCCH data directly from the ROM
#   -Decrypt NCCH directly
#   -Use command-line based handling

#http://www.falatic.com/index.php/108/python-and-bitwise-rotation
rol = lambda val, r_bits, max_bits: \
    (val << r_bits%max_bits) & (2**max_bits-1) | \
    ((val & (2**max_bits-1)) >> (max_bits-(r_bits%max_bits)))

ror = lambda val, r_bits, max_bits: \
    ((val & (2**max_bits-1)) >> r_bits%max_bits) | \
    (val << (max_bits-(r_bits%max_bits)) & (2**max_bits-1))

def to_bytes(num):
    numstr = ''
    tmp = num
    while len(numstr) < 16:
        numstr += chr(tmp & 0xFF)
        tmp >>= 8
    return numstr[::-1]

class ncchinfo_hdr(Structure):
    _fields_ = [
        ('FFFFFFFF', c_uint32),
        ('Ver', c_uint32),
        ('Entries', c_uint32),
        ('Reserved', c_uint32)
    ]

class ncchinfo_entry(Structure):
    _fields_ = [
        ('Counter', c_uint8 * 0x10),
        ('KeyY', c_uint8 * 0x10),
        ('Size', c_uint32),
        ('Reserved', c_uint32),
        ('Reserved', c_uint32),
        ('CryptoFlag', c_uint32),
        ('TitleID', c_uint32 * 2),
        ('Name', c_char * 112)
    ]

#https://github.com/archshift/Decrypt9/blob/master/scripts/ncchinfo_gen.py
def ArrayToString(ctypeArray):
    return ''.join('%02X' % x for x in ctypeArray[::+1])

def ReverseArrayToString(ctypeArray):
    return ''.join('%02X' % x for x in ctypeArray[::-1])

with open('ncchinfo.bin', 'rb') as f:
    info = ncchinfo_hdr()
    f.readinto(info)
    f.read(16)
    f.seek(16)

    for x in xrange(0, info.Entries):
        entry = ncchinfo_entry()
        f.readinto(entry)
        f.seek(168*x+16)
        f.read(168)

        KeyX = 0

        if (entry.CryptoFlag == 0):
            KeyX = 0x00000000000000000000000000000000 #KeyX 0x2C
            if not hashlib.sha1(to_bytes(KeyX)).hexdigest().upper() == '54701686283A18CA54FF76B6910C49DEC2D6CF13':
                KeyX = 0
        elif (entry.CryptoFlag == 0x01):
            KeyX = 0x00000000000000000000000000000000 #KeyX 0x25
            if not hashlib.sha1(to_bytes(KeyX)).hexdigest().upper() == '4231F2B435EC7A456C0ACC5FAFCD4CB949F83BC0':
                KeyX = 0
        elif (entry.CryptoFlag == 0x0A):
            KeyX = 0x00000000000000000000000000000000 #KeyX 0x18
            if not hashlib.sha1(to_bytes(KeyX)).hexdigest().upper() == 'FBEAA933DC7D4997463E8973AD1867C0B245E0BD':
                KeyX = 0
        elif (entry.CryptoFlag == 0x0B):
            KeyX = 0x00000000000000000000000000000000 #KeyX 0x1B
            if not hashlib.sha1(to_bytes(KeyX)).hexdigest().upper() == '1E96BE527AC64E6F6929B38760B1A4873D051B96':
                KeyX = 0

        ctr = Counter.new(128, initial_value=long(ArrayToString(entry.Counter),16))
        KeyY = long(ArrayToString(entry.KeyY), 16)
        NormalKey = rol((rol(KeyX, 2, 128) ^ KeyY) + 0x1FF9E9AAC5FE0408024591DC5D52768A, 87, 128)
        ctrmode = AES.new(to_bytes(NormalKey), AES.MODE_CTR, counter = ctr)

        filename = entry.Name.encode('ascii','ignore')
        print(filename[1:])
        print(ArrayToString(entry.Counter))
        print(ArrayToString(entry.KeyY))
        print '%X' % (NormalKey)

        if (KeyX != 0):
            with open(filename[1:], 'w+b') as p:
                l = 0

                for i in xrange(0, entry.Size*0x10):
                    out = ctrmode.decrypt("00000000000000000000000000000000".decode("hex"))
                    for c in xrange(0, 4095): #0x10000 byte chunks seem to work the fastest
                        out += ctrmode.decrypt("00000000000000000000000000000000".decode("hex"))
                    p.write(out)

                    percent = 100 * float(i)/float(entry.Size*0x10)
                    if (percent >= l):
                        print 'Generating XORpad... %d%%\r' % percent,
                        l = l+1
                print 'Generating XORpad... 100%'

                print("Done!")
        else:
            print("Invalid KeyX!")

        print