String Decryptor for RDR2 Companion App

###
### RDR2 Companion App "Super String Decryptor PRO ((ULTIMATE EDITION)) v1.2" Script Utility (IDA Pro)
### © 2018 Fireboyd78
###
### If this script helps you in any way, please give credit where it's due ;)
###

def get_decrypt_key(ea):
    name = Name(ea)

    if not name.startswith("_ZTS"):
        print("**** Can't get decrypt key! ****")
        return

    str = name[4:]
    buffer = [ord(c) for c in str] + [0]

    index = 0
    count = len(buffer)

    #print('"%s"(%02d):' % (str, count))

    key = []

    while index < count:
        b = Byte(ea + index)
        v = buffer[index]
        k = (b ^ v)

        key.append(k)

        #print('%02x\t\t%02x\t\t^%02x' % (v, b, k))

        index += 1

    #print(''.join(["%02x " % k for k in key]))

    return key

# 82 characters!
# TODO: Find the actual key
DECRYPT_KEY = get_decrypt_key(0x2A91C10)

def get_decrypt_buffer(ea):
    index = 0
    buffer = []
    while index < 256:
        b = Byte(ea + index)
        buffer.append(b)

        index += 1
    return buffer

# TODO: Wrong key?!
# uses 's_FromBase64LUT' buffer
# (sorry folks, not posting the key here)
#DECRYPT_KEY = get_decrypt_buffer(0x2B18C68)

def decrypt_string(ea, makeCmt = True):
    index = 0
    max_len = len(DECRYPT_KEY)

    buffer = []
    eos = False

    while index < max_len:
        b = Byte(ea + index)
        k = DECRYPT_KEY[index]
        v = (b ^ k)

        # read up until null-terminator
        if v == 0:
            eos = True
            break

        buffer.append(v)

        index += 1

    str = ''.join([chr(b) for b in buffer])

    # string longer than decryption buffer?
    if not eos:
        print("**** Couldn't decrypt entire string (only up to %d bytes) ****" % max_len)

    if makeCmt:
        MakeRptCmt(ea, 'decrypted: "%s"' % str)

    return str

def decrypt_string_ptr(ea, makeCmt = True):
    ptr = Qword(ea)
    return decrypt_string(ptr, makeCmt)

def decrypt_string_ptr_list(ea, count = 1, makeCmt = True):
    index = 0
    list = []
    while index < count:
        str = decrypt_string_ptr(ea + (index * 8), makeCmt)
        list.append(str)

        index += 1
    return list