Merge pull request #742 from FIr3baL/FB_FixBase64Decode

base64 decode fix for missing =

LuaMenu/Addons/base64.lua

@@ -13,59 +13,82 @@
 
 Spring.Utilities = Spring.Utilities or {}
 
-local function lsh(value,shift)
-	return (value*(2^shift)) % 256
+local function lsh(value, shift)
+	return (value * (2 ^ shift)) % 256
 end
 
 -- shift right
-local function rsh(value,shift)
-	return math.floor(value/2^shift) % 256
+local function rsh(value, shift)
+	return math.floor(value / 2 ^ shift) % 256
 end
 
 -- return single bit (for OR)
-local function bit(x,b)
-	return (x % 2^b - x % 2^(b-1) > 0)
+local function bit(x, b)
+	return (x % 2 ^ b - x % 2 ^ (b - 1) > 0)
 end
 
 -- logic OR for number values
-local function lor(x,y)
+local function lor(x, y)
 	local 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
 end
 
--- 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]='_'}
+-- encoding 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 Spring.Utilities.Base64Encode(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),(spos+byte))) or 0
+	for spos = 0, string.len(data) - 1, 3 do
+		for byte = 1, 3 do
+			bytes[byte] = string.byte(string.sub(data, (spos + byte), (spos + byte))) or 0
 		end
-		result[#result + 1] = string.format('%s%s%s%s',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 "=")
+		result[#result + 1] = 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
 	result = table.concat(result)
 	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}
+-- decoding 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 Spring.Utilities.Base64Decode(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 "=")] 
+	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[#result + 1]  = string.format('%s%s%s',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 "")
+		result[#result + 1] = 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), (chars[4]))) or "")
 	end
 	result = table.concat(result)
 	return result