--- /dev/null
+-- The MIT License (MIT)
+--
+-- Copyright (c) 2013 aiq
+--
+-- 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.
+--
+--
+--
+--------------------------------------------------------------------------------
+-- util functions
+--------------------------------------------------------------------------------
+
+local function divide_string( str, max, fillChar )
+ fillChar = fillChar or ""
+ local result = {}
+
+ local start = 1
+ for i = 1, #str do
+ if i % max == 0 then
+ table.insert( result, str:sub( start, i ) )
+ start = i + 1
+ elseif i == #str then
+ table.insert( result, str:sub( start, i ) )
+ end
+ end
+
+ return result
+end
+
+local function number_to_bit( num, length )
+ local bits = {}
+
+ while num > 0 do
+ local rest = math.floor( math.fmod( num, 2 ) )
+ table.insert( bits, rest )
+ num = ( num - rest ) / 2
+ end
+
+ while #bits < length do
+ table.insert( bits, "0" )
+ end
+
+ return string.reverse( table.concat( bits ) )
+end
+
+local function ignore_set( str, set )
+ if set then
+ str = str:gsub( "["..set.."]", "" )
+ end
+ return str
+end
+
+local function pure_from_bit( str )
+ return ( str:gsub( '........', function ( cc )
+ return string.char( tonumber( cc, 2 ) )
+ end ) )
+end
+
+local function unexpected_char_error( str, pos )
+ local c = string.sub( str, pos, pos )
+ return string.format( "unexpected character at position %d: '%s'", pos, c )
+end
+
+--------------------------------------------------------------------------------
+
+local basexx = {}
+
+--------------------------------------------------------------------------------
+-- base2(bitfield) decode and encode function
+--------------------------------------------------------------------------------
+
+local bitMap = { o = "0", i = "1", l = "1" }
+
+function basexx.from_bit( str, ignore )
+ str = ignore_set( str, ignore )
+ str = string.lower( str )
+ str = str:gsub( '[ilo]', function( c ) return bitMap[ c ] end )
+ local pos = string.find( str, "[^01]" )
+ if pos then return nil, unexpected_char_error( str, pos ) end
+
+ return pure_from_bit( str )
+end
+
+function basexx.to_bit( str )
+ return ( str:gsub( '.', function ( c )
+ local byte = string.byte( c )
+ local bits = {}
+ for i = 1,8 do
+ table.insert( bits, byte % 2 )
+ byte = math.floor( byte / 2 )
+ end
+ return table.concat( bits ):reverse()
+ end ) )
+end
+
+--------------------------------------------------------------------------------
+-- base16(hex) decode and encode function
+--------------------------------------------------------------------------------
+
+function basexx.from_hex( str, ignore )
+ str = ignore_set( str, ignore )
+ local pos = string.find( str, "[^%x]" )
+ if pos then return nil, unexpected_char_error( str, pos ) end
+
+ return ( str:gsub( '..', function ( cc )
+ return string.char( tonumber( cc, 16 ) )
+ end ) )
+end
+
+function basexx.to_hex( str )
+ return ( str:gsub( '.', function ( c )
+ return string.format('%02X', string.byte( c ) )
+ end ) )
+end
+
+--------------------------------------------------------------------------------
+-- generic function to decode and encode base32/base64
+--------------------------------------------------------------------------------
+
+local function from_basexx( str, alphabet, bits )
+ local result = {}
+ for i = 1, #str do
+ local c = string.sub( str, i, i )
+ if c ~= '=' then
+ local index = string.find( alphabet, c, 1, true )
+ if not index then
+ return nil, unexpected_char_error( str, i )
+ end
+ table.insert( result, number_to_bit( index - 1, bits ) )
+ end
+ end
+
+ local value = table.concat( result )
+ local pad = #value % 8
+ return pure_from_bit( string.sub( value, 1, #value - pad ) )
+end
+
+local function to_basexx( str, alphabet, bits, pad )
+ local bitString = basexx.to_bit( str )
+
+ local chunks = divide_string( bitString, bits )
+ local result = {}
+ for key,value in ipairs( chunks ) do
+ if ( #value < bits ) then
+ value = value .. string.rep( '0', bits - #value )
+ end
+ local pos = tonumber( value, 2 ) + 1
+ table.insert( result, alphabet:sub( pos, pos ) )
+ end
+
+ table.insert( result, pad )
+ return table.concat( result )
+end
+
+--------------------------------------------------------------------------------
+-- rfc 3548: http://www.rfc-editor.org/rfc/rfc3548.txt
+--------------------------------------------------------------------------------
+
+local base32Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"
+local base32PadMap = { "", "======", "====", "===", "=" }
+
+function basexx.from_base32( str, ignore )
+ str = ignore_set( str, ignore )
+ return from_basexx( string.upper( str ), base32Alphabet, 5 )
+end
+
+function basexx.to_base32( str )
+ return to_basexx( str, base32Alphabet, 5, base32PadMap[ #str % 5 + 1 ] )
+end
+
+--------------------------------------------------------------------------------
+-- crockford: http://www.crockford.com/wrmg/base32.html
+--------------------------------------------------------------------------------
+
+local crockfordAlphabet = "0123456789ABCDEFGHJKMNPQRSTVWXYZ"
+local crockfordMap = { O = "0", I = "1", L = "1" }
+
+function basexx.from_crockford( str, ignore )
+ str = ignore_set( str, ignore )
+ str = string.upper( str )
+ str = str:gsub( '[ILOU]', function( c ) return crockfordMap[ c ] end )
+ return from_basexx( str, crockfordAlphabet, 5 )
+end
+
+function basexx.to_crockford( str )
+ return to_basexx( str, crockfordAlphabet, 5, "" )
+end
+
+--------------------------------------------------------------------------------
+-- base64 decode and encode function
+--------------------------------------------------------------------------------
+
+local base64Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"..
+ "abcdefghijklmnopqrstuvwxyz"..
+ "0123456789+/"
+local base64PadMap = { "", "==", "=" }
+
+function basexx.from_base64( str, ignore )
+ str = ignore_set( str, ignore )
+ return from_basexx( str, base64Alphabet, 6 )
+end
+
+function basexx.to_base64( str )
+ return to_basexx( str, base64Alphabet, 6, base64PadMap[ #str % 3 + 1 ] )
+end
+
+--------------------------------------------------------------------------------
+-- URL safe base64 decode and encode function
+--------------------------------------------------------------------------------
+
+local url64Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"..
+ "abcdefghijklmnopqrstuvwxyz"..
+ "0123456789-_"
+
+function basexx.from_url64( str, ignore )
+ str = ignore_set( str, ignore )
+ return from_basexx( str, url64Alphabet, 6 )
+end
+
+function basexx.to_url64( str )
+ return to_basexx( str, url64Alphabet, 6, "" )
+end
+
+--------------------------------------------------------------------------------
+--
+--------------------------------------------------------------------------------
+
+local function length_error( len, d )
+ return string.format( "invalid length: %d - must be a multiple of %d", len, d )
+end
+
+local z85Decoder = { 0x00, 0x44, 0x00, 0x54, 0x53, 0x52, 0x48, 0x00,
+ 0x4B, 0x4C, 0x46, 0x41, 0x00, 0x3F, 0x3E, 0x45,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+ 0x08, 0x09, 0x40, 0x00, 0x49, 0x42, 0x4A, 0x47,
+ 0x51, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A,
+ 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32,
+ 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
+ 0x3B, 0x3C, 0x3D, 0x4D, 0x00, 0x4E, 0x43, 0x00,
+ 0x00, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,
+ 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
+ 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
+ 0x21, 0x22, 0x23, 0x4F, 0x00, 0x50, 0x00, 0x00 }
+
+function basexx.from_z85( str, ignore )
+ str = ignore_set( str, ignore )
+ if ( #str % 5 ) ~= 0 then
+ return nil, length_error( #str, 5 )
+ end
+
+ local result = {}
+
+ local value = 0
+ for i = 1, #str do
+ local index = string.byte( str, i ) - 31
+ if index < 1 or index >= #z85Decoder then
+ return nil, unexpected_char_error( str, i )
+ end
+ value = ( value * 85 ) + z85Decoder[ index ]
+ if ( i % 5 ) == 0 then
+ local divisor = 256 * 256 * 256
+ while divisor ~= 0 do
+ local b = math.floor( value / divisor ) % 256
+ table.insert( result, string.char( b ) )
+ divisor = math.floor( divisor / 256 )
+ end
+ value = 0
+ end
+ end
+
+ return table.concat( result )
+end
+
+local z85Encoder = "0123456789"..
+ "abcdefghijklmnopqrstuvwxyz"..
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ"..
+ ".-:+=^!/*?&<>()[]{}@%$#"
+
+function basexx.to_z85( str )
+ if ( #str % 4 ) ~= 0 then
+ return nil, length_error( #str, 4 )
+ end
+
+ local result = {}
+
+ local value = 0
+ for i = 1, #str do
+ local b = string.byte( str, i )
+ value = ( value * 256 ) + b
+ if ( i % 4 ) == 0 then
+ local divisor = 85 * 85 * 85 * 85
+ while divisor ~= 0 do
+ local index = ( math.floor( value / divisor ) % 85 ) + 1
+ table.insert( result, z85Encoder:sub( index, index ) )
+ divisor = math.floor( divisor / 85 )
+ end
+ value = 0
+ end
+ end
+
+ return table.concat( result )
+end
+
+--------------------------------------------------------------------------------
+
+return basexx
projects / thirdparty / knot-resolver.git / commitdiff
