Encoding/decoding

[Orange]

There are few implentations of encodings into MTA:

Base64 Encoding

function base64_enc(data)
   return ((data:gsub('.', function(x) 
       local r,b='',x:byte()
       for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
       return r;
   end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
       if (#x < 6) then return '' end
       local c=0
       for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
       return b:sub(c+1,c+1)
   end)..({ '', '==', '=' })[#data%3+1])
end

USAGE: base64_enc('string') encodes 'string'

Base64 Decoding

function base64_dec(data)
   data = string.gsub(data, '[^'..b..'=]', '')
   return (data:gsub('.', function(x)
       if (x == '=') then return '' end
       local r,f='',(b:find(x)-1)
       for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end
       return r;
   end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)
       if (#x ~=  then return '' end
       local c=0
       for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end
       return string.char(c)
   end))
end

USAGE: base64_dec('KDFHSKJ87987KJSHAKJD9') decodes 'KDFHSKJ87987KJSHAKJD9'

Edited January 15, 2010 by Guest

[Orange]

There are few implentations of encodings into MTA:

Base64 Encoding

function base64_enc(data)    return ((data:gsub('.', function(x)         local r,b='',x:byte()        for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end        return r;    end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)        if (#x < 6) then return '' end        local c=0        for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end        return b:sub(c+1,c+1)    end)..({ '', '==', '=' })[#data%3+1])end

USAGE: base64_enc('string') encodes 'string'

Base64 Decoding

function base64_dec(data)    data = string.gsub(data, '[^'..b..'=]', '')    return (data:gsub('.', function(x)        if (x == '=') then return '' end        local r,f='',(b:find(x)-1)        for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end        return r;    end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)        if (#x ~=  then return '' end        local c=0        for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end        return string.char(c)    end))end

USAGE: base64_dec('KDFHSKJ87987KJSHAKJD9') decodes 'KDFHSKJ87987KJSHAKJD9'

Edited January 15, 2010 by Guest

[eAi]

Base 64 clearly isn't encryption. It's encoding, don't expect this to fool any but the most amateur hacker. Base 64 encoded text also tends to be fairly distinctive, if nothing else than it's tendency to have = or == at the end.

[eAi]

Base 64 clearly isn't encryption. It's encoding, don't expect this to fool any but the most amateur hacker. Base 64 encoded text also tends to be fairly distinctive, if nothing else than it's tendency to have = or == at the end.

[robhol]

eAi is right, as encryption this isn't of much use. In cryptography, base64 is commonly used to "stringify" byte arrays that have been ran through some other form of crypto algorithm, not by itself. Also, as eAi said, it is pretty easy to identify and decode.

[robhol]

eAi is right, as encryption this isn't of much use. In cryptography, base64 is commonly used to "stringify" byte arrays that have been ran through some other form of crypto algorithm, not by itself. Also, as eAi said, it is pretty easy to identify and decode.

[Orange]

Sorry, wrong word used Btw. can someone fix this code?

[Orange]

Sorry, wrong word used Btw. can someone fix this code?

[robhol]

You called it GUIDE and there's something wrong with it?? That just doesn't make any sense...

[robhol]

You called it GUIDE and there's something wrong with it?? That just doesn't make any sense...

[Orange]

I'm crazy today Ofc, it's not guide.

Found a new one:

-- encryption 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
 
-- 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
-- decode base64 input to string
function dec(data)
local chars = {}
local result=""
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
	result = string.format('%s%s%s%s',result,string.char(lor(lsh(chars[1],2), rsh(chars[2],4))),(chars[3] ~= nil) and string.char(lor(lsh(chars[2],4), rsh(chars[3],2))) or "",(chars[4] ~= nil) and string.char(lor(lsh(chars[3],6) % 192, (chars[4]))) or "")
end
return result
end

[Orange]

I'm crazy today Ofc, it's not guide.

Found a new one:

-- encryption tablelocal 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 resultend -- decryption tablelocal 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-- decode base64 input to stringfunction dec(data)	local chars = {}	local result=""	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		result = string.format('%s%s%s%s',result,string.char(lor(lsh(chars[1],2), rsh(chars[2],4))),(chars[3] ~= nil) and string.char(lor(lsh(chars[2],4), rsh(chars[3],2))) or "",(chars[4] ~= nil) and string.char(lor(lsh(chars[3],6) % 192, (chars[4]))) or "")	end	return resultend