# vim: sw=4:expandtab:foldmethod=marker
#
# Copyright (c) 2006, Mathieu Fenniak
# 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.
# * The name of the author may not 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.
"""
Utility functions for PDF library.
"""
__author__ = "Mathieu Fenniak"
__author_email__ = "biziqe@mathieu.fenniak.net"
#ENABLE_PSYCO = False
#if ENABLE_PSYCO:
# try:
# import psyco
# except ImportError:
# ENABLE_PSYCO = False
#
#if not ENABLE_PSYCO:
# class psyco:
# def proxy(func):
# return func
# proxy = staticmethod(proxy)
def readUntilWhitespace(stream, maxchars=None):
txt = ""
while True:
tok = stream.read(1)
if tok.isspace() or not tok:
break
txt += tok
if len(txt) == maxchars:
break
return txt
def readNonWhitespace(stream):
tok = ' '
while tok == '\n' or tok == '\r' or tok == ' ' or tok == '\t':
tok = stream.read(1)
return tok
class ConvertFunctionsToVirtualList(object):
def __init__(self, lengthFunction, getFunction):
self.lengthFunction = lengthFunction
self.getFunction = getFunction
def __len__(self):
return self.lengthFunction()
def __getitem__(self, index):
if not isinstance(index, int):
raise TypeError, "sequence indices must be integers"
len_self = len(self)
if index < 0:
# support negative indexes
index = len_self + index
if index < 0 or index >= len_self:
raise IndexError, "sequence index out of range"
return self.getFunction(index)
def RC4_encrypt(key, plaintext):
S = [i for i in range(256)]
j = 0
for i in range(256):
j = (j + S[i] + ord(key[i % len(key)])) % 256
S[i], S[j] = S[j], S[i]
i, j = 0, 0
retval = ""
for x in range(len(plaintext)):
i = (i + 1) % 256
j = (j + S[i]) % 256
S[i], S[j] = S[j], S[i]
t = S[(S[i] + S[j]) % 256]
retval += chr(ord(plaintext[x]) ^ t)
return retval
class PdfReadError(Exception):
pass
if __name__ == "__main__":
# test RC4
out = RC4_encrypt("Key", "Plaintext")
print repr(out)
pt = RC4_encrypt("Key", out)
print repr(pt)
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