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tmsr-pgp-genesis        1 import struct
tmsr-pgp-genesis        2 import time
tmsr-pgp-genesis        3 import sys
tmsr-pgp-genesis        4 import base64
tmsr-pgp-genesis        5 import math
tmsr-pgp-genesis        6 
tmsr-pgp-genesis        7 openpgp_publickey_format = ">BIB"
tmsr-pgp-genesis        8 mpi_format = ">H"
tmsr-pgp-genesis        9 packet_length_format = ">I"
tmsr-pgp-genesis       10 crc_format = ">I"
tmsr-pgp-genesis       11 
tmsr-pgp-genesis       12 # determine the index of the highest bit set to 1
tmsr-pgp-genesis       13 def count_bits(B):
tmsr-pgp-genesis       14   R = 0
tmsr-pgp-genesis       15   i = 0
tmsr-pgp-genesis       16   while B > 0:
tmsr-pgp-genesis       17     i += 1
tmsr-pgp-genesis       18     if B & 0x1:
tmsr-pgp-genesis       19       R = i
tmsr-pgp-genesis       20     B >>= 1
tmsr-pgp-genesis       21   return R
tmsr-pgp-genesis       22 
tmsr-pgp-genesis       23 # convert a number to an array of bytes
tmsr-pgp-genesis       24 # the bytes in the array are stored in big-endian order. 
tmsr-pgp-genesis       25 # the most significant byte is stored as the first item 
tmsr-pgp-genesis       26 # in the array
tmsr-pgp-genesis       27 def number_to_bytes(B):
tmsr-pgp-genesis       28   R = []
tmsr-pgp-genesis       29   bits = 0
tmsr-pgp-genesis       30   while B > 0xff:
tmsr-pgp-genesis       31     bits += 8
tmsr-pgp-genesis       32     R.append(B & 0xff)
tmsr-pgp-genesis       33     B >>= 8
tmsr-pgp-genesis       34   R.append(B)
tmsr-pgp-genesis       35   bits += count_bits(B)
tmsr-pgp-genesis       36   return bits, ''.join(map(chr, reversed(R)))
tmsr-pgp-genesis       37   
tmsr-pgp-genesis       38 # An MPI is a byte array that starts with a two byte
tmsr-pgp-genesis       39 # length header. The length is given in bits
tmsr-pgp-genesis       40 def number_to_mpi(B):
tmsr-pgp-genesis       41   C, A = number_to_bytes(B)
tmsr-pgp-genesis       42   return struct.pack(mpi_format, C) + A
tmsr-pgp-genesis       43 
tmsr-pgp-genesis       44 # A PGP public key header consists of a byte "4", 
tmsr-pgp-genesis       45 # an integer (4 byte) timestamp and a byte "1" (RSA)
tmsr-pgp-genesis       46 def public_key_header(T):
tmsr-pgp-genesis       47   return struct.pack(openpgp_publickey_format, 4, T, 1)
tmsr-pgp-genesis       48 
tmsr-pgp-genesis       49 # A public key packet is the public key header 
tmsr-pgp-genesis       50 # plus 2 MPI numbers, the RSA modulus N and
tmsr-pgp-genesis       51 # the RSA exponent e.
tmsr-pgp-genesis       52 def public_key_packet(t, n, e):
tmsr-pgp-genesis       53   return ''.join((public_key_header(t), number_to_mpi(n), number_to_mpi(e),))
tmsr-pgp-genesis       54 
tmsr-pgp-genesis       55 # A comment or userid packet is a string encoded as utf-8
tmsr-pgp-genesis       56 def userid_packet(s):
tmsr-pgp-genesis       57   return s.encode('utf8')
tmsr-pgp-genesis       58 
tmsr-pgp-genesis       59 # The PGP format is a stream of "packets".
tmsr-pgp-genesis       60 # Each packet has a header. This header consists of a tag
tmsr-pgp-genesis       61 # and a length field. The tag has flags to determine if it is a 
tmsr-pgp-genesis       62 # "new" or "old" packet. The only supported encoding is "new".
tmsr-pgp-genesis       63 def encode_packet(packet_bytes, tag = 6):
tmsr-pgp-genesis       64   # 0x80, 8th bit always set, 7th bit set --> new packet
tmsr-pgp-genesis       65   h = 0x80 | 0x40
tmsr-pgp-genesis       66   # 0-5 bits -> the tag
tmsr-pgp-genesis       67   h |= tag 
tmsr-pgp-genesis       68   header = chr(h)
tmsr-pgp-genesis       69   
tmsr-pgp-genesis       70   # dude, this is totally how you may save 2 or 3 bytes with minimal complexity 
tmsr-pgp-genesis       71   l = len(packet_bytes)
tmsr-pgp-genesis       72   if l < 192:
tmsr-pgp-genesis       73     header += chr(l)
tmsr-pgp-genesis       74   elif l < 8384:
tmsr-pgp-genesis       75     l -= 192
tmsr-pgp-genesis       76     o1 = l >> 0xff
tmsr-pgp-genesis       77     o2 = l & 0xff
tmsr-pgp-genesis       78     header += chr(o1 + 192) + chr(o2)
tmsr-pgp-genesis       79   else:
tmsr-pgp-genesis       80     header += chr(0xff) + struct.pack(packet_length_format, l)
tmsr-pgp-genesis       81     
tmsr-pgp-genesis       82   return header + packet_bytes
tmsr-pgp-genesis       83 
tmsr-pgp-genesis       84 # When you encode binary data as an ascii text with base64
tmsr-pgp-genesis       85 # this data becomes fragile. So a CRC code is needed to 
tmsr-pgp-genesis       86 # fix this. 
tmsr-pgp-genesis       87 def crc24(s):
tmsr-pgp-genesis       88   R = 0xB704CE
tmsr-pgp-genesis       89   for char in s:
tmsr-pgp-genesis       90     B = ord(char)
tmsr-pgp-genesis       91     R ^=  B << 16
tmsr-pgp-genesis       92     for i in range(8):
tmsr-pgp-genesis       93       R <<= 1;
tmsr-pgp-genesis       94       if R & 0x1000000:
tmsr-pgp-genesis       95         R ^= 0x1864CFB
tmsr-pgp-genesis       96   return R & 0xFFFFFF
tmsr-pgp-genesis       97 
tmsr-pgp-genesis       98 # Create a public key for consumption by Phuctor.
tmsr-pgp-genesis       99 # The public key needs to contain 2 packets
tmsr-pgp-genesis      100 # one for the key data (n, e)
tmsr-pgp-genesis      101 # one for the comment
tmsr-pgp-genesis      102 # It must be in the armor / ascii format.
tmsr-pgp-genesis      103 def enarmored_public_key(n, e, comment, t):
tmsr-pgp-genesis      104   R = []
tmsr-pgp-genesis      105   # the header
tmsr-pgp-genesis      106   R.append("-----BEGIN PGP PUBLIC KEY BLOCK-----")
tmsr-pgp-genesis      107   R.append("")
tmsr-pgp-genesis      108   
tmsr-pgp-genesis      109   # the packets in bytes
tmsr-pgp-genesis      110   A = encode_packet(public_key_packet(t, n, e), 6)
tmsr-pgp-genesis      111   A += encode_packet(userid_packet(comment), 13)
tmsr-pgp-genesis      112   
tmsr-pgp-genesis      113   # the packets in base64 encoding with line length max 76
tmsr-pgp-genesis      114   s=base64.b64encode(A)
tmsr-pgp-genesis      115   i = 0
tmsr-pgp-genesis      116   while i < len(s):
tmsr-pgp-genesis      117     R.append(s[i:i+76])
tmsr-pgp-genesis      118     i += 76
tmsr-pgp-genesis      119   
tmsr-pgp-genesis      120   # the CRC
tmsr-pgp-genesis      121   R.append("="+base64.b64encode(struct.pack(crc_format, crc24(A))[1:]))
tmsr-pgp-genesis      122   
tmsr-pgp-genesis      123   # the footer
tmsr-pgp-genesis      124   R.append("")
tmsr-pgp-genesis      125   R.append("-----END PGP PUBLIC KEY BLOCK-----")
tmsr-pgp-genesis      126   
tmsr-pgp-genesis      127   return '\n'.join(R)
tmsr-pgp-genesis      128 
tmsr-pgp-genesis      129 # read a file with comma separated lines
tmsr-pgp-genesis      130 # each line is in the TMSR format: e,n,comment
tmsr-pgp-genesis      131 if __name__ == "__main__":
tmsr-pgp-genesis      132   ser = 1
tmsr-pgp-genesis      133   for x in sys.stdin:
tmsr-pgp-genesis      134     x = x.strip()
tmsr-pgp-genesis      135     
tmsr-pgp-genesis      136     # ignore empty lines
tmsr-pgp-genesis      137     if len(x) == 0 or x.startswith('#'):
tmsr-pgp-genesis      138       continue
tmsr-pgp-genesis      139       
tmsr-pgp-genesis      140     # the comment may contain comma's so split on the first 2
tmsr-pgp-genesis      141     e,n,comment = x.split(',', 2)
tmsr-pgp-genesis      142     
tmsr-pgp-genesis      143     t0 = int(time.time())
tmsr-pgp-genesis      144     with open("{0}.txt".format(ser), "wb") as stream:
tmsr-pgp-genesis      145       stream.write(enarmored_public_key(int(n), int(e), comment, t0))
tmsr-pgp-genesis      146       
tmsr-pgp-genesis      147     ser += 1
tmsr-pgp-genesis      148