AES(Rijndael) 算法的 JavaScript 实现
引用:下面的内容来自 Rijndael in JavaScript。下面的代码是 Rijndael 算法的 JavaScript 实现。它可以在 IE4+、NS4+ 以及任何兼容 ECMAScript 第一版的浏览器中运行。这个实现没有进行优化，也就是说它不适合处理大量的数据（比如多于几 KB）和需要高速运行的应用程序中。
// Rijndael parameters -- Valid values are 128, 192, or 256
var keySizeInBits = 128;
var blockSizeInBits = 128;
/////// You shouldn't have to modify anything below this line except for
/////// the function getRandomBytes().
//
// Note: in the following code the two dimensional arrays are indexed as
// you would probably expect, as array[row][column]. The state arrays
// are 2d arrays of the form state[4][Nb].
// The number of rounds for the cipher, indexed by [Nk][Nb]
var roundsArray = [ ,,,,[,,,,10,, 12,, 14],,
[,,,,12,, 12,, 14],,
[,,,,14,, 14,, 14] ];
// The number of bytes to shift by in shiftRow, indexed by [Nb][row]
var shiftOffsets = [ ,,,,[,1, 2, 3],,[,1, 2, 3],,[,1, 3, 4] ];
// The round constants used in subkey expansion
var Rcon = [
0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc,
0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4,
0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91 ];
// Precomputed lookup table for the SBox
var SBox = [
99, 124, 119, 123, 242, 107, 111, 197, 48, 1, 103, 43, 254, 215, 171,
118, 202, 130, 201, 125, 250, 89, 71, 240, 173, 212, 162, 175, 156, 164,
114, 192, 183, 253, 147, 38, 54, 63, 247, 204, 52, 165, 229, 241, 113,
216, 49, 21, 4, 199, 35, 195, 24, 150, 5, 154, 7, 18, 128, 226,
235, 39, 178, 117, 9, 131, 44, 26, 27, 110, 90, 160, 82, 59, 214,
179, 41, 227, 47, 132, 83, 209, 0, 237, 32, 252, 177, 91, 106, 203,
190, 57, 74, 76, 88, 207, 208, 239, 170, 251, 67, 77, 51, 133, 69,
249, 2, 127, 80, 60, 159, 168, 81, 163, 64, 143, 146, 157, 56, 245,
188, 182, 218, 33, 16, 255, 243, 210, 205, 12, 19, 236, 95, 151, 68,
23, 196, 167, 126, 61, 100, 93, 25, 115, 96, 129, 79, 220, 34, 42,
144, 136, 70, 238, 184, 20, 222, 94, 11, 219, 224, 50, 58, 10, 73,
6, 36, 92, 194, 211, 172, 98, 145, 149, 228, 121, 231, 200, 55, 109,
141, 213, 78, 169, 108, 86, 244, 234, 101, 122, 174, 8, 186, 120, 37,
46, 28, 166, 180, 198, 232, 221, 116, 31, 75, 189, 139, 138, 112, 62,
181, 102, 72, 3, 246, 14, 97, 53, 87, 185, 134, 193, 29, 158, 225,
248, 152, 17, 105, 217, 142, 148, 155, 30, 135, 233, 206, 85, 40, 223,
140, 161, 137, 13, 191, 230, 66, 104, 65, 153, 45, 15, 176, 84, 187,
22 ];
// Precomputed lookup table for the inverse SBox
var SBoxInverse = [
82, 9, 106, 213, 48, 54, 165, 56, 191, 64, 163, 158, 129, 243, 215,
251, 124, 227, 57, 130, 155, 47, 255, 135, 52, 142, 67, 68, 196, 222,
233, 203, 84, 123, 148, 50, 166, 194, 35, 61, 238, 76, 149, 11, 66,
250, 195, 78, 8, 46, 161, 102, 40, 217, 36, 178, 118, 91, 162, 73,
109, 139, 209, 37, 114, 248, 246, 100, 134, 104, 152, 22, 212, 164, 92,
204, 93, 101, 182, 146, 108, 112, 72, 80, 253, 237, 185, 218, 94, 21,
70, 87, 167, 141, 157, 132, 144, 216, 171, 0, 140, 188, 211, 10, 247,
228, 88, 5, 184, 179, 69, 6, 208, 44, 30, 143, 202, 63, 15, 2,
193, 175, 189, 3, 1, 19, 138, 107, 58, 145, 17, 65, 79, 103, 220,
234, 151, 242, 207, 206, 240, 180, 230, 115, 150, 172, 116, 34, 231, 173,
53, 133, 226, 249, 55, 232, 28, 117, 223, 110, 71, 241, 26, 113, 29,
41, 197, 137, 111, 183, 98, 14, 170, 24, 190, 27, 252, 86, 62, 75,
198, 210, 121, 32, 154, 219, 192, 254, 120, 205, 90, 244, 31, 221, 168,
51, 136, 7, 199, 49, 177, 18, 16, 89, 39, 128, 236, 95, 96, 81,
127, 169, 25, 181, 74, 13, 45, 229, 122, 159, 147, 201, 156, 239, 160,
224, 59, 77, 174, 42, 245, 176, 200, 235, 187, 60, 131, 83, 153, 97,
23, 43, 4, 126, 186, 119, 214, 38, 225, 105, 20, 99, 85, 33, 12,
125 ];
// This method circularly shifts the array left by the number of elements
// given in its parameter. It returns the resulting array and is used for
// the ShiftRow step. Note that shift() and push() could be used for a more
// elegant solution, but they require IE5.5+, so I chose to do it manually.
function cyclicShiftLeft(theArray, positions) {
var temp = theArray.slice(0, positions);
theArray = theArray.slice(positions).concat(temp);
return theArray;
}
// Cipher parameters ... do not change these
var Nk = keySizeInBits / 32;
var Nb = blockSizeInBits / 32;
var Nr = roundsArray[Nk][Nb];
// Multiplies the element "poly" of GF(2^8) by x. See the Rijndael spec.
function xtime(poly) {
poly <<= 1;
return ((poly & 0x100) ? (poly ^ 0x11B) : (poly));
}
// Multiplies the two elements of GF(2^8) together and returns the result.
// See the Rijndael spec, but should be straightforward: for each power of
// the indeterminant that has a 1 coefficient in x, add y times that power
// to the result. x and y should be bytes representing elements of GF(2^8)
function mult_GF256(x, y) {
var bit, result = 0;
for (bit = 1; bit < 256; bit *= 2, y = xtime(y)) {
if (x & bit)
result ^= y;
}
return result;
}
// Performs the substitution step of the cipher. State is the 2d array of
// state information (see spec) and direction is string indicating whether
// we are performing the forward substitution ("encrypt") or inverse
// substitution (anything else)
function byteSub(state, direction) {
var S;
if (direction == "encrypt") // Point S to the SBox we're using
S = SBox;
else
S = SBoxInverse;
for (var i = 0; i < 4; i++) // Substitute for every byte in state
for (var j = 0; j < Nb; j++)
state[i][j] = S[state[i][j]];
}
// Performs the row shifting step of the cipher.
function shiftRow(state, direction) {
for (var i=1; i<4; i++) // Row 0 never shifts
if (direction == "encrypt")
state[i] = cyclicShiftLeft(state[i], shiftOffsets[Nb][i]);
else
state[i] = cyclicShiftLeft(state[i], Nb - shiftOffsets[Nb][i]);
}
