Mercurial > yubikey-lua / file comparison
comparison: aeslua/util.lua
aeslua/util.lua
- changeset 0
- 598d09faf89c
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| -1:000000000000 | 0:598d09faf89c |
|---|---|
| 1 local bit = require("bit"); | |
| 2 | |
| 3 local public = {}; | |
| 4 local private = {}; | |
| 5 | |
| 6 local aeslua = require("aeslua"); | |
| 7 aeslua.util = public; | |
| 8 | |
| 9 -- | |
| 10 -- calculate the parity of one byte | |
| 11 -- | |
| 12 function public.byteParity(byte) | |
| 13 byte = bit.bxor(byte, bit.rshift(byte, 4)); | |
| 14 byte = bit.bxor(byte, bit.rshift(byte, 2)); | |
| 15 byte = bit.bxor(byte, bit.rshift(byte, 1)); | |
| 16 return bit.band(byte, 1); | |
| 17 end | |
| 18 | |
| 19 -- | |
| 20 -- get byte at position index | |
| 21 -- | |
| 22 function public.getByte(number, index) | |
| 23 if (index == 0) then | |
| 24 return bit.band(number,0xff); | |
| 25 else | |
| 26 return bit.band(bit.rshift(number, index*8),0xff); | |
| 27 end | |
| 28 end | |
| 29 | |
| 30 | |
| 31 -- | |
| 32 -- put number into int at position index | |
| 33 -- | |
| 34 function public.putByte(number, index) | |
| 35 if (index == 0) then | |
| 36 return bit.band(number,0xff); | |
| 37 else | |
| 38 return bit.lshift(bit.band(number,0xff),index*8); | |
| 39 end | |
| 40 end | |
| 41 | |
| 42 -- | |
| 43 -- convert byte array to int array | |
| 44 -- | |
| 45 function public.bytesToInts(bytes, start, n) | |
| 46 local ints = {}; | |
| 47 for i = 0, n - 1 do | |
| 48 ints[i] = public.putByte(bytes[start + (i*4) ], 3) | |
| 49 + public.putByte(bytes[start + (i*4) + 1], 2) | |
| 50 + public.putByte(bytes[start + (i*4) + 2], 1) | |
| 51 + public.putByte(bytes[start + (i*4) + 3], 0); | |
| 52 end | |
| 53 return ints; | |
| 54 end | |
| 55 | |
| 56 -- | |
| 57 -- convert int array to byte array | |
| 58 -- | |
| 59 function public.intsToBytes(ints, output, outputOffset, n) | |
| 60 n = n or #ints; | |
| 61 for i = 0, n do | |
| 62 for j = 0,3 do | |
| 63 output[outputOffset + i*4 + (3 - j)] = public.getByte(ints[i], j); | |
| 64 end | |
| 65 end | |
| 66 return output; | |
| 67 end | |
| 68 | |
| 69 -- | |
| 70 -- convert bytes to hexString | |
| 71 -- | |
| 72 function private.bytesToHex(bytes) | |
| 73 local hexBytes = ""; | |
| 74 | |
| 75 for i,byte in ipairs(bytes) do | |
| 76 hexBytes = hexBytes .. string.format("%02x ", byte); | |
| 77 end | |
| 78 | |
| 79 return hexBytes; | |
| 80 end | |
| 81 | |
| 82 -- | |
| 83 -- convert data to hex string | |
| 84 -- | |
| 85 function public.toHexString(data) | |
| 86 local type = type(data); | |
| 87 if (type == "number") then | |
| 88 return string.format("%08x",data); | |
| 89 elseif (type == "table") then | |
| 90 return private.bytesToHex(data); | |
| 91 elseif (type == "string") then | |
| 92 local bytes = {string.byte(data, 1, #data)}; | |
| 93 | |
| 94 return private.bytesToHex(bytes); | |
| 95 else | |
| 96 return data; | |
| 97 end | |
| 98 end | |
| 99 | |
| 100 function public.padByteString(data) | |
| 101 local dataLength = #data; | |
| 102 | |
| 103 local random1 = math.random(0,255); | |
| 104 local random2 = math.random(0,255); | |
| 105 | |
| 106 local prefix = string.char(random1, | |
| 107 random2, | |
| 108 random1, | |
| 109 random2, | |
| 110 public.getByte(dataLength, 3), | |
| 111 public.getByte(dataLength, 2), | |
| 112 public.getByte(dataLength, 1), | |
| 113 public.getByte(dataLength, 0)); | |
| 114 | |
| 115 data = prefix .. data; | |
| 116 | |
| 117 local paddingLength = math.ceil(#data/16)*16 - #data; | |
| 118 local padding = ""; | |
| 119 for i=1,paddingLength do | |
| 120 padding = padding .. string.char(math.random(0,255)); | |
| 121 end | |
| 122 | |
| 123 return data .. padding; | |
| 124 end | |
| 125 | |
| 126 function private.properlyDecrypted(data) | |
| 127 local random = {string.byte(data,1,4)}; | |
| 128 | |
| 129 if (random[1] == random[3] and random[2] == random[4]) then | |
| 130 return true; | |
| 131 end | |
| 132 | |
| 133 return false; | |
| 134 end | |
| 135 | |
| 136 function public.unpadByteString(data) | |
| 137 if (not private.properlyDecrypted(data)) then | |
| 138 return nil; | |
| 139 end | |
| 140 | |
| 141 local dataLength = public.putByte(string.byte(data,5), 3) | |
| 142 + public.putByte(string.byte(data,6), 2) | |
| 143 + public.putByte(string.byte(data,7), 1) | |
| 144 + public.putByte(string.byte(data,8), 0); | |
| 145 | |
| 146 return string.sub(data,9,8+dataLength); | |
| 147 end | |
| 148 | |
| 149 function public.xorIV(data, iv) | |
| 150 for i = 1,16 do | |
| 151 data[i] = bit.bxor(data[i], iv[i]); | |
| 152 end | |
| 153 end | |
| 154 | |
| 155 return public; |
