X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=base91.py;h=f407d44c44db856250c53cd5489837ea84e1a602;hb=49b56eafcd147185c28848a7c04e31a32c49a82e;hp=d6541314f61ff97009b5ba8b88a5180603dba39a;hpb=56d9f9ae8cd036c0ad6771131236d049f046422a;p=secnet.git diff --git a/base91.py b/base91.py deleted file mode 100644 index d654131..0000000 --- a/base91.py +++ /dev/null @@ -1,94 +0,0 @@ -# Base91 encode/decode for Python 2 and Python 3 -# -# Copyright (c) 2012 Adrien Beraud -# Copyright (c) 2015 Guillaume Jacquenot -# All rights reserved. -# -# Redistribution and use in source and binary forms, with or without -# modification, are permitted provided that the following conditions are met: -# -# * Redistributions of source code must retain the above copyright notice, -# this list of conditions and the following disclaimer. -# * Redistributions in binary form must reproduce the above copyright notice, -# this list of conditions and the following disclaimer in the documentation -# and/or other materials provided with the distribution. -# * Neither the name of Adrien Beraud, Wisdom Vibes Pte. Ltd., nor the names -# of its contributors may be used to endorse or promote products derived -# from this software without specific prior written permission. -# -# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" -# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE -# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE -# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL -# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR -# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, -# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -# -import struct - -base91_alphabet = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', - 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', - 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', - 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', - '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '!', '#', '$', - '%', '&', '(', ')', '*', '+', ',', '.', '/', ':', ';', '<', '=', - '>', '?', '@', '[', ']', '^', '_', '`', '{', '|', '}', '~', '"'] - -decode_table = dict((v, k) for k, v in enumerate(base91_alphabet)) - - -def decode(encoded_str): - ''' Decode Base91 string to a bytearray ''' - v = -1 - b = 0 - n = 0 - out = bytearray() - for strletter in encoded_str: - if not strletter in decode_table: - continue - c = decode_table[strletter] - if (v < 0): - v = c - else: - v += c * 91 - b |= v << n - n += 13 if (v & 8191) > 88 else 14 - while True: - out += struct.pack('B', b & 255) - b >>= 8 - n -= 8 - if not n > 7: - break - v = -1 - if v + 1: - out += struct.pack('B', (b | v << n) & 255) - return out - - -def encode(bindata): - ''' Encode a bytearray to a Base91 string ''' - b = 0 - n = 0 - out = '' - for count in range(len(bindata)): - byte = bindata[count:count + 1] - b |= struct.unpack('B', byte)[0] << n - n += 8 - if n > 13: - v = b & 8191 - if v > 88: - b >>= 13 - n -= 13 - else: - v = b & 16383 - b >>= 14 - n -= 14 - out += base91_alphabet[v % 91] + base91_alphabet[v // 91] - if n: - out += base91_alphabet[b % 91] - if n > 7 or b > 90: - out += base91_alphabet[b // 91] - return out diff --git a/base91.py b/base91.py new file mode 120000 index 0000000..f407d44 --- /dev/null +++ b/base91.py @@ -0,0 +1 @@ +base91-python/base91/__init__.py \ No newline at end of file