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Function for Base64 decoding, needed for luatool.py binary uploads

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Marcos Kirsch 2015-02-07 12:30:03 -06:00
parent b1f87f3ffa
commit 4dffc7009d
1 changed files with 15 additions and 194 deletions
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b64.lua
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@ -1,217 +1,51 @@
#!/usr/local/bin/lua #!/usr/local/bin/lua
-- http://lua-users.org/wiki/BaseSixtyFour -- Based on http://lua-users.org/wiki/BaseSixtyFour by Alex Kloss
-- working lua base64 codec (c) 2006-2008 by Alex Kloss
-- compatible with lua 5.1 -- compatible with lua 5.1
-- http://www.it-rfc.de -- http://www.it-rfc.de
-- licensed under the terms of the LGPL2 -- licensed under the terms of the LGPL2
-- bitshift functions (<<, >> equivalent) -- bitshift functions (<<, >> equivalent)
-- shift left -- shift left
function lsh(value,shift) local function lsh(value,shift)
return (value*(2^shift)) % 256 return (value*(2^shift)) % 256
end end
-- shift right -- shift right
function rsh(value,shift) local function rsh(value,shift)
return math.floor(value/2^shift) % 256 return math.floor(value/2^shift) % 256
end end
-- return single bit (for OR) -- return single bit (for OR)
function bit(x,b) local function bit(x,b)
return (x % 2^b - x % 2^(b-1) > 0) return (x % 2^b - x % 2^(b-1) > 0)
end end
-- logic OR for number values -- logic OR for number values
function lor(x,y) local function lor(x,y)
result = 0 result = 0
for p=1,8 do result = result + (((bit(x,p) or bit(y,p)) == true) and 2^(p-1) or 0) end for p=1,8 do result = result + (((bit(x,p) or bit(y,p)) == true) and 2^(p-1) or 0) end
return result return result
end end
-- encryption table -- Character decoding table
local base64chars = {
[0]='A',
[1]='B',
[2]='C',
[3]='D',
[4]='E',
[5]='F',
[6]='G',
[7]='H',
[8]='I',
[9]='J',
[10]='K',
[11]='L',
[12]='M',
[13]='N',
[14]='O',
[15]='P',
[16]='Q',
[17]='R',
[18]='S',
[19]='T',
[20]='U',
[21]='V',
[22]='W',
[23]='X',
[24]='Y',
[25]='Z',
[26]='a',
[27]='b',
[28]='c',
[29]='d',
[30]='e',
[31]='f',
[32]='g',
[33]='h',
[34]='i',
[35]='j',
[36]='k',
[37]='l',
[38]='m',
[39]='n',
[40]='o',
[41]='p',
[42]='q',
[43]='r',
[44]='s',
[45]='t',
[46]='u',
[47]='v',
[48]='w',
[49]='x',
[50]='y',
[51]='z',
[52]='0',
[53]='1',
[54]='2',
[55]='3',
[56]='4',
[57]='5',
[58]='6',
[59]='7',
[60]='8',
[61]='9',
[62]='-',
[63]='_'
}
-- function encode
-- encodes input string to base64.
function enc(data)
local bytes = {}
local result = ""
for spos=0,string.len(data)-1,3 do
for byte=1,3 do bytes[byte] = string.byte(string.sub(data,(spos+byte))) or 0 end
result = string.format('%s%s%s%s%s',result,base64chars[rsh(bytes[1],2)],base64chars[lor(lsh((bytes[1] % 4),4), rsh(bytes[2],4))] or "=",((#data-spos) > 1) and base64chars[lor(lsh(bytes[2] % 16,2), rsh(bytes[3],6))] or "=",((#data-spos) > 2) and base64chars[(bytes[3] % 64)] or "=")
end
return result
end
local function toBase64Byte(char) local function toBase64Byte(char)
ascii = string.byte(char, 1) ascii = string.byte(char, 1)
if ascii >= string.byte('A', 1) and ascii <= string.byte('Z', 1) then if ascii >= string.byte('A', 1) and ascii <= string.byte('Z', 1) then return ascii - string.byte('A', 1)
return ascii - string.byte('A', 1) elseif ascii >= string.byte('a', 1) and ascii <= string.byte('z', 1) then return ascii - string.byte('a', 1) + 26
elseif ascii >= string.byte('a', 1) and ascii <= string.byte('z', 1) then elseif ascii >= string.byte('0', 1) and ascii <= string.byte('9', 1) then return ascii + 4
return ascii - string.byte('a', 1) + 26 elseif ascii == string.byte('-', 1) then return 62
elseif ascii >= string.byte('0', 1) and ascii <= string.byte('9', 1) then elseif ascii == string.byte('_', 1) then return 63
return ascii + 4 elseif ascii == string.byte('=', 1) then return nil
elseif ascii == string.byte('-', 1) then else return nil, "ERROR! Char is invalid for Base64 encoding: "..char end
return 62
elseif ascii == string.byte('_', 1) then
return 63
elseif ascii == string.byte('=', 1) then
return nil
else
return "ERROR! Char is invalid for Base64 encoding: "..char
end
end end
print(toBase64Byte('A'))
print(toBase64Byte('B'))
print(toBase64Byte('C'))
print(toBase64Byte('D'))
print(toBase64Byte('a'))
print(toBase64Byte('b'))
print(toBase64Byte('c'))
print(toBase64Byte('d'))
-- decryption table
local base64bytes = {
['A']=0,
['B']=1,
['C']=2,
['D']=3,
['E']=4,
['F']=5,
['G']=6,
['H']=7,
['I']=8,
['J']=9,
['K']=10,
['L']=11,
['M']=12,
['N']=13,
['O']=14,
['P']=15,
['Q']=16,
['R']=17,
['S']=18,
['T']=19,
['U']=20,
['V']=21,
['W']=22,
['X']=23,
['Y']=24,
['Z']=25,
['a']=26,
['b']=27,
['c']=28,
['d']=29,
['e']=30,
['f']=31,
['g']=32,
['h']=33,
['i']=34,
['j']=35,
['k']=36,
['l']=37,
['m']=38,
['n']=39,
['o']=40,
['p']=41,
['q']=42,
['r']=43,
['s']=44,
['t']=45,
['u']=46,
['v']=47,
['w']=48,
['x']=49,
['y']=50,
['z']=51,
['0']=52,
['1']=53,
['2']=54,
['3']=55,
['4']=56,
['5']=57,
['6']=58,
['7']=59,
['8']=60,
['9']=61,
['-']=62,
['_']=63,
['=']=nil
}
-- function decode -- function decode
-- decode base64 input to string -- decode base64 input to string
function dec(data) function decode(data)
local chars = {} local chars = {}
local result="" local result=""
for dpos=0,string.len(data)-1,4 do for dpos=0,string.len(data)-1,4 do
-- for char=1,4 do chars[char] = base64bytes[(string.sub(data,(dpos+char),(dpos+char)) or "=")] end
for char=1,4 do chars[char] = toBase64Byte((string.sub(data,(dpos+char),(dpos+char)) or "=")) end for char=1,4 do chars[char] = toBase64Byte((string.sub(data,(dpos+char),(dpos+char)) or "=")) end
result = string.format( result = string.format(
'%s%s%s%s', '%s%s%s%s',
@ -226,17 +60,4 @@ function dec(data)
return result return result
end end
-- command line if not called as library module('b64',package.seeall)
if (arg ~= nil) then
local func = 'enc'
for n,v in ipairs(arg) do
if (n > 0) then
if (v == "-h") then print "base64.lua [-e] [-d] text/data" break
elseif (v == "-e") then func = 'enc'
elseif (v == "-d") then func = 'dec'
else print(_G[func](v)) end
end
end
else
module('base64',package.seeall)
end