rex-text/lib/rex/text/base32.rb

88 lines
2.9 KiB
Ruby

# -*- coding: binary -*-
module Rex
module Text
# We are re-opening the module to add these module methods.
# Breaking them up this way allows us to maintain a little higher
# degree of organisation and make it easier to find what you're looking for
# without hanging the underlying calls that we historically rely upon.
#
# Base32 code
#
# Based on --> https://github.com/stesla/base32
# Copyright (c) 2007-2011 Samuel Tesla
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# Base32 encoder
#
def self.b32encode(bytes_in)
n = (bytes_in.length * 8.0 / 5.0).ceil
p = n < 8 ? 5 - (bytes_in.length * 8) % 5 : 0
c = bytes_in.inject(0) {|m,o| (m << 8) + o} << p
[(0..n-1).to_a.reverse.collect {|i| Base32[(c >> i * 5) & 0x1f].chr},
("=" * (8-n))]
end
def self.encode_base32(str)
bytes = str.bytes
result = ''
size= 5
while bytes.any? do
bytes.each_slice(size) do |a|
bytes_out = b32encode(a).flatten.join
result << bytes_out
bytes = bytes.drop(size)
end
end
return result
end
#
# Base32 decoder
#
def self.b32decode(bytes_in)
bytes = bytes_in.take_while {|c| c != 61} # strip padding
n = (bytes.length * 5.0 / 8.0).floor
p = bytes.length < 8 ? 5 - (n * 8) % 5 : 0
c = bytes.inject(0) {|m,o| (m << 5) + Base32.index(o.chr)} >> p
(0..n-1).to_a.reverse.collect {|i| ((c >> i * 8) & 0xff).chr}
end
def self.decode_base32(str)
bytes = str.bytes
result = ''
size= 8
while bytes.any? do
bytes.each_slice(size) do |a|
bytes_out = b32decode(a).flatten.join
result << bytes_out
bytes = bytes.drop(size)
end
end
return result
end
end
end