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+ 33671E1F41334901B94EC0FC991EFA42F52C1619B332ABBC0CED336E9AD15BA270E116BDDE43185A80394D31BBBF498549A88F6AF2E064DE367A8D90D0E3ED07
makepgp.py

(0 . 0)(1 . 148)
import struct
import time
import sys
import base64
import math

openpgp_publickey_format = ">BIB"
mpi_format = ">H"
packet_length_format = ">I"
crc_format = ">I"

# determine the index of the highest bit set to 1
def count_bits(B):
  R = 0
  i = 0
  while B > 0:
    i += 1
    if B & 0x1:
      R = i
    B >>= 1
  return R

# convert a number to an array of bytes
# the bytes in the array are stored in big-endian order. 
# the most significant byte is stored as the first item 
# in the array
def number_to_bytes(B):
  R = []
  bits = 0
  while B > 0xff:
    bits += 8
    R.append(B & 0xff)
    B >>= 8
  R.append(B)
  bits += count_bits(B)
  return bits, ''.join(map(chr, reversed(R)))
  
# An MPI is a byte array that starts with a two byte
# length header. The length is given in bits
def number_to_mpi(B):
  C, A = number_to_bytes(B)
  return struct.pack(mpi_format, C) + A

# A PGP public key header consists of a byte "4", 
# an integer (4 byte) timestamp and a byte "1" (RSA)
def public_key_header(T):
  return struct.pack(openpgp_publickey_format, 4, T, 1)

# A public key packet is the public key header 
# plus 2 MPI numbers, the RSA modulus N and
# the RSA exponent e.
def public_key_packet(t, n, e):
  return ''.join((public_key_header(t), number_to_mpi(n), number_to_mpi(e),))

# A comment or userid packet is a string encoded as utf-8
def userid_packet(s):
  return s.encode('utf8')

# The PGP format is a stream of "packets".
# Each packet has a header. This header consists of a tag
# and a length field. The tag has flags to determine if it is a 
# "new" or "old" packet. The only supported encoding is "new".
def encode_packet(packet_bytes, tag = 6):
  # 0x80, 8th bit always set, 7th bit set --> new packet
  h = 0x80 | 0x40
  # 0-5 bits -> the tag
  h |= tag 
  header = chr(h)
  
  # dude, this is totally how you may save 2 or 3 bytes with minimal complexity 
  l = len(packet_bytes)
  if l < 192:
    header += chr(l)
  elif l < 8384:
    l -= 192
    o1 = l >> 0xff
    o2 = l & 0xff
    header += chr(o1 + 192) + chr(o2)
  else:
    header += chr(0xff) + struct.pack(packet_length_format, l)
    
  return header + packet_bytes

# When you encode binary data as an ascii text with base64
# this data becomes fragile. So a CRC code is needed to 
# fix this. 
def crc24(s):
  R = 0xB704CE
  for char in s:
    B = ord(char)
    R ^=  B << 16
    for i in range(8):
      R <<= 1;
      if R & 0x1000000:
        R ^= 0x1864CFB
  return R & 0xFFFFFF

# Create a public key for consumption by Phuctor.
# The public key needs to contain 2 packets
# one for the key data (n, e)
# one for the comment
# It must be in the armor / ascii format.
def enarmored_public_key(n, e, comment, t):
  R = []
  # the header
  R.append("-----BEGIN PGP PUBLIC KEY BLOCK-----")
  R.append("")
  
  # the packets in bytes
  A = encode_packet(public_key_packet(t, n, e), 6)
  A += encode_packet(userid_packet(comment), 13)
  
  # the packets in base64 encoding with line length max 76
  s=base64.b64encode(A)
  i = 0
  while i < len(s):
    R.append(s[i:i+76])
    i += 76
  
  # the CRC
  R.append("="+base64.b64encode(struct.pack(crc_format, crc24(A))[1:]))
  
  # the footer
  R.append("")
  R.append("-----END PGP PUBLIC KEY BLOCK-----")
  
  return '\n'.join(R)

# read a file with comma separated lines
# each line is in the TMSR format: e,n,comment
if __name__ == "__main__":
  ser = 1
  for x in sys.stdin:
    x = x.strip()
    
    # ignore empty lines
    if len(x) == 0 or x.startswith('#'):
      continue
      
    # the comment may contain comma's so split on the first 2
    e,n,comment = x.split(',', 2)
    
    t0 = int(time.time())
    with open("{0}.txt".format(ser), "wb") as stream:
      stream.write(enarmored_public_key(int(n), int(e), comment, t0))
      
    ser += 1