gajim-otrplugin/potr/utils.py

67 lines
1.8 KiB
Python

# Copyright 2012 Kjell Braden <afflux@pentabarf.de>
#
# This file is part of the python-potr library.
#
# python-potr is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# any later version.
#
# python-potr is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library. If not, see <http://www.gnu.org/licenses/>.
# some python3 compatibilty
from __future__ import unicode_literals
import struct
def pack_mpi(n):
return pack_data(long_to_bytes(n))
def read_mpi(data):
n, data = read_data(data)
return bytes_to_long(n), data
def pack_data(data):
return struct.pack(b'!I', len(data)) + data
def read_data(data):
datalen, data = unpack(b'!I', data)
return data[:datalen], data[datalen:]
def unpack(fmt, buf):
s = struct.Struct(fmt)
return s.unpack(buf[:s.size]) + (buf[s.size:],)
def bytes_to_long(b):
l = len(b)
s = 0
for i in range(l):
s += byte_to_long(b[i:i+1]) << 8*(l-i-1)
return s
def long_to_bytes(l, n=0):
b = b''
while l != 0 or n > 0:
b = long_to_byte(l & 0xff) + b
l >>= 8
n -= 1
return b
def byte_to_long(b):
return struct.unpack(b'B', b)[0]
def long_to_byte(l):
return struct.pack(b'B', l)
def human_hash(fp):
fp = fp.upper()
fplen = len(fp)
wordsize = fplen//5
buf = ''
for w in range(0, fplen, wordsize):
buf += '{0} '.format(fp[w:w+wordsize])
return buf.rstrip()