
/*
 	Taken from http://www.movable-type.co.uk/scripts/aes.html
	Chris Veness under LGPL
*/

/* Change Notes:
    This library now relies on Base64.js (the embedded one is buggy)
    8/18/08 Will Wagner
*/

(function() {



function _CreateAESManager() {

    /*
    * AES Cipher function: encrypt 'input' with Rijndael algorithm
    *
    *   takes   byte-array 'input' (16 bytes)
    *           2D byte-array key schedule 'w' (Nr+1 x Nb bytes)
    *
    *   applies Nr rounds (10/12/14) using key schedule w for 'add round key' stage
    *
    *   returns byte-array encrypted value (16 bytes)
    */
    function Cipher(input, w) {    // main Cipher function [§5.1]
    var Nb = 4;               // block size (in words): no of columns in state (fixed at 4 for AES)
    var Nr = w.length/Nb - 1; // no of rounds: 10/12/14 for 128/192/256-bit keys

    var state = [[],[],[],[]];  // initialise 4xNb byte-array 'state' with input [§3.4]
    for (var i=0; i<4*Nb; i++) state[i%4][Math.floor(i/4)] = input[i];

    state = AddRoundKey(state, w, 0, Nb);

    for (var round=1; round<Nr; round++) {
        state = SubBytes(state, Nb);
        state = ShiftRows(state, Nb);
        state = MixColumns(state, Nb);
        state = AddRoundKey(state, w, round, Nb);
    }

    state = SubBytes(state, Nb);
    state = ShiftRows(state, Nb);
    state = AddRoundKey(state, w, Nr, Nb);

    var output = new Array(4*Nb);  // convert state to 1-d array before returning [§3.4]
    for (var i=0; i<4*Nb; i++) output[i] = state[i%4][Math.floor(i/4)];
    return output;
    }


    function SubBytes(s, Nb) {    // apply SBox to state S [§5.1.1]
    for (var r=0; r<4; r++) {
        for (var c=0; c<Nb; c++) s[r][c] = Sbox[s[r][c]];
    }
    return s;
    }


    function ShiftRows(s, Nb) {    // shift row r of state S left by r bytes [§5.1.2]
    var t = new Array(4);
    for (var r=1; r<4; r++) {
        for (var c=0; c<4; c++) t[c] = s[r][(c+r)%Nb];  // shift into temp copy
        for (var c=0; c<4; c++) s[r][c] = t[c];         // and copy back
    }          // note that this will work for Nb=4,5,6, but not 7,8 (always 4 for AES):
    return s;  // see fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.311.pdf 
    }


    function MixColumns(s, Nb) {   // combine bytes of each col of state S [§5.1.3]
    for (var c=0; c<4; c++) {
        var a = new Array(4);  // 'a' is a copy of the current column from 's'
        var b = new Array(4);  // 'b' is a•{02} in GF(2^8)
        for (var i=0; i<4; i++) {
        a[i] = s[i][c];
        b[i] = s[i][c]&0x80 ? s[i][c]<<1 ^ 0x011b : s[i][c]<<1;
        }
        // a[n] ^ b[n] is a•{03} in GF(2^8)
        s[0][c] = b[0] ^ a[1] ^ b[1] ^ a[2] ^ a[3]; // 2*a0 + 3*a1 + a2 + a3
        s[1][c] = a[0] ^ b[1] ^ a[2] ^ b[2] ^ a[3]; // a0 * 2*a1 + 3*a2 + a3
        s[2][c] = a[0] ^ a[1] ^ b[2] ^ a[3] ^ b[3]; // a0 + a1 + 2*a2 + 3*a3
        s[3][c] = a[0] ^ b[0] ^ a[1] ^ a[2] ^ b[3]; // 3*a0 + a1 + a2 + 2*a3
    }
    return s;
    }


    function AddRoundKey(state, w, rnd, Nb) {  // xor Round Key into state S [§5.1.4]
    for (var r=0; r<4; r++) {
        for (var c=0; c<Nb; c++) state[r][c] ^= w[rnd*4+c][r];
    }
    return state;
    }


    function KeyExpansion(key) {  // generate Key Schedule (byte-array Nr+1 x Nb) from Key [§5.2]
    var Nb = 4;            // block size (in words): no of columns in state (fixed at 4 for AES)
    var Nk = key.length/4  // key length (in words): 4/6/8 for 128/192/256-bit keys
    var Nr = Nk + 6;       // no of rounds: 10/12/14 for 128/192/256-bit keys

    var w = new Array(Nb*(Nr+1));
    var temp = new Array(4);

    for (var i=0; i<Nk; i++) {
        var r = [key[4*i], key[4*i+1], key[4*i+2], key[4*i+3]];
        w[i] = r;
    }

    for (var i=Nk; i<(Nb*(Nr+1)); i++) {
        w[i] = new Array(4);
        for (var t=0; t<4; t++) temp[t] = w[i-1][t];
        if (i % Nk == 0) {
        temp = SubWord(RotWord(temp));
        for (var t=0; t<4; t++) temp[t] ^= Rcon[i/Nk][t];
        } else if (Nk > 6 && i%Nk == 4) {
        temp = SubWord(temp);
        }
        for (var t=0; t<4; t++) w[i][t] = w[i-Nk][t] ^ temp[t];
    }

    return w;
    }

    function SubWord(w) {    // apply SBox to 4-byte word w
    for (var i=0; i<4; i++) w[i] = Sbox[w[i]];
    return w;
    }

    function RotWord(w) {    // rotate 4-byte word w left by one byte
    var tmp = w[0];
    for (var i=0; i<4; i++) w[i] = w[i+1];
    w[3] = tmp;
    return w;
    }


    // Sbox is pre-computed multiplicative inverse in GF(2^8) used in SubBytes and KeyExpansion [§5.1.1]
    var Sbox =  [0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76,
                0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0,
                0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15,
                0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75,
                0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84,
                0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf,
                0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8,
                0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2,
                0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73,
                0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb,
                0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79,
                0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08,
                0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a,
                0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e,
                0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf,
                0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16];

    // Rcon is Round Constant used for the Key Expansion [1st col is 2^(r-1) in GF(2^8)] [§5.2]
    var Rcon = [ [0x00, 0x00, 0x00, 0x00],
                [0x01, 0x00, 0x00, 0x00],
                [0x02, 0x00, 0x00, 0x00],
                [0x04, 0x00, 0x00, 0x00],
                [0x08, 0x00, 0x00, 0x00],
                [0x10, 0x00, 0x00, 0x00],
                [0x20, 0x00, 0x00, 0x00],
                [0x40, 0x00, 0x00, 0x00],
                [0x80, 0x00, 0x00, 0x00],
                [0x1b, 0x00, 0x00, 0x00],
                [0x36, 0x00, 0x00, 0x00] ];


    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

    /* 
    * Use AES to encrypt 'plaintext' with 'password' using 'nBits' key, in 'Counter' mode of operation
    *                           - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
    *   for each block
    *   - outputblock = cipher(counter, key)
    *   - cipherblock = plaintext xor outputblock
    */
    function AESEncryptCtr(plaintext, password, nBits) {
    if (!(nBits==128 || nBits==192 || nBits==256)) return '';  // standard allows 128/192/256 bit keys

    // use AES itself to encrypt password to get cipher key (using plain password as source for key 
    // expansion) - gives us well encrypted key to use
    var nBytes = nBits/8;  // no bytes in key
    var pwBytes = new Array(nBytes);
    for (var i=0; i<nBytes; i++) pwBytes[i] = password.charCodeAt(i) & 0xff;
    var key = Cipher(pwBytes, KeyExpansion(pwBytes));  // gives us 16-byte key
    key = key.concat(key.slice(0, nBytes-16));  // key is now 16/24/32 bytes long

    // initialise counter block (NIST SP800-38A §B.2): millisecond time-stamp for nonce in 1st 8 bytes,
    // block counter in 2nd 8 bytes
    var blockSize = 16;  // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    var counterBlock = new Array(blockSize);  // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    var nonce = (new Date()).getTime();  // milliseconds since 1-Jan-1970

    // encode nonce in two stages to cater for JavaScript 32-bit limit on bitwise ops
    for (var i=0; i<4; i++) counterBlock[i] = (nonce >>> i*8) & 0xff;
    for (var i=0; i<4; i++) counterBlock[i+4] = (nonce/0x100000000 >>> i*8) & 0xff; 

    // generate key schedule - an expansion of the key into distinct Key Rounds for each round
    var keySchedule = KeyExpansion(key);

    var blockCount = Math.ceil(plaintext.length/blockSize);
    var ciphertext = new Array(blockCount);  // ciphertext as array of strings
    
    for (var b=0; b<blockCount; b++) {
        // set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
        // done in two stages for 32-bit ops: using two words allows us to go past 2^32 blocks (68GB)
        for (var c=0; c<4; c++) counterBlock[15-c] = (b >>> c*8) & 0xff;
        for (var c=0; c<4; c++) counterBlock[15-c-4] = (b/0x100000000 >>> c*8)

        var cipherCntr = Cipher(counterBlock, keySchedule);  // -- encrypt counter block --
        
        // calculate length of final block:
        var blockLength = b<blockCount-1 ? blockSize : (plaintext.length-1)%blockSize+1;

        var ct = [];
        for (var i=0; i<blockLength; i++) {  // -- xor plaintext with ciphered counter byte-by-byte --
        var plaintextByte = plaintext.charCodeAt(b*blockSize+i);
        var cipherByte = plaintextByte ^ cipherCntr[i];
        ct.push( String.fromCharCode(cipherByte));
        }
        // ct is now ciphertext for this block

        ciphertext[b] = escCtrlChars(ct.join(""));  // escape troublesome characters in ciphertext
    }

    // convert the nonce to a string to go on the front of the ciphertext
    var ctrTxt = [];
    for (var i=0; i<8; i++) ctrTxt.push( String.fromCharCode(counterBlock[i]));

    // use '-' to separate blocks, use Array.join to concatenate arrays of strings for efficiency
    return escCtrlChars(ctrTxt.join("")).concat('-', ciphertext.join('-'));
    }


    /* 
    * Use AES to decrypt 'ciphertext' with 'password' using 'nBits' key, in Counter mode of operation
    *
    *   for each block
    *   - outputblock = cipher(counter, key)
    *   - cipherblock = plaintext xor outputblock
    */
    function AESDecryptCtr(ciphertext, password, nBits) {
    if (!(nBits==128 || nBits==192 || nBits==256)) return '';  // standard allows 128/192/256 bit keys

    var nBytes = nBits/8;  // no bytes in key
    var pwBytes = new Array(nBytes);
    for (var i=0; i<nBytes; i++) pwBytes[i] = password.charCodeAt(i) & 0xff;
    var pwKeySchedule = KeyExpansion(pwBytes);
    var key = Cipher(pwBytes, pwKeySchedule);
    key = key.concat(key.slice(0, nBytes-16));  // key is now 16/24/32 bytes long

    var keySchedule = KeyExpansion(key);

    ciphertext = ciphertext.split('-');  // split ciphertext into array of block-length strings 

    // recover nonce from 1st element of ciphertext
    var blockSize = 16;  // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    var counterBlock = new Array(blockSize);
    var ctrTxt = unescCtrlChars(ciphertext[0]);
    for (var i=0; i<8; i++) counterBlock[i] = ctrTxt.charCodeAt(i);

    var plaintext = new Array(ciphertext.length-1);

    for (var b=1; b<ciphertext.length; b++) {
        // set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
        for (var c=0; c<4; c++) counterBlock[15-c] = ((b-1) >>> c*8) & 0xff;
        for (var c=0; c<4; c++) counterBlock[15-c-4] = ((b/0x100000000-1) >>> c*8) & 0xff;

        var cipherCntr = Cipher(counterBlock, keySchedule);  // encrypt counter block

        ciphertext[b] = unescCtrlChars(ciphertext[b]);

        var pt = [];
        for (var i=0; i<ciphertext[b].length; i++) {
        // -- xor plaintext with ciphered counter byte-by-byte --
        var ciphertextByte = ciphertext[b].charCodeAt(i);
        var plaintextByte = ciphertextByte ^ cipherCntr[i];
        pt.push( String.fromCharCode(plaintextByte));
        }
        // pt is now plaintext for this block

        plaintext[b-1] = pt.join("");  // b-1 'cos no initial nonce block in plaintext
    }

    return plaintext.join('');
    }

    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

    function escCtrlChars(str) {  // escape control chars which might cause problems handling ciphertext
    return str.replace(/[\0\t\n\v\f\r\xa0'"!-]/g, function(c) { return '!' + c.charCodeAt(0) + '!'; });
    }  // \xa0 to cater for bug in Firefox; include '-' to leave it free for use as a block marker

    function unescCtrlChars(str) {  // unescape potentially problematic control characters
    return str.replace(/!\d\d?\d?!/g, function(c) { return String.fromCharCode(c.slice(1,-1)); });
    }

    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

    /*
    * if escCtrlChars()/unescCtrlChars() still gives problems, use encodeBase64()/decodeBase64() instead
    */
    var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    function encodeBase64(str) {  // http://tools.ietf.org/html/rfc4648
    var o1, o2, o3, h1, h2, h3, h4, bits, i=0, enc='';
    
    str = encodeUTF8(str);  // encode multi-byte chars into UTF-8 for byte-array

    do {  // pack three octets into four hexets
        o1 = str.charCodeAt(i++);
        o2 = str.charCodeAt(i++);
        o3 = str.charCodeAt(i++);
        
        bits = o1<<16 | o2<<8 | o3;
        
        h1 = bits>>18 & 0x3f;
        h2 = bits>>12 & 0x3f;
        h3 = bits>>6 & 0x3f;
        h4 = bits & 0x3f;
        
        // end of string? index to '=' in b64
        if (isNaN(o3)) h4 = 64;
        if (isNaN(o2)) h3 = 64;
        
        // use hexets to index into b64, and append result to encoded string
        enc += b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
    } while (i < str.length);
    
    return enc;
    }

    function decodeBase64(str) {
    var o1, o2, o3, h1, h2, h3, h4, bits, i=0, enc='';

    do {  // unpack four hexets into three octets using index points in b64
        h1 = b64.indexOf(str.charAt(i++));
        h2 = b64.indexOf(str.charAt(i++));
        h3 = b64.indexOf(str.charAt(i++));
        h4 = b64.indexOf(str.charAt(i++));
        
        bits = h1<<18 | h2<<12 | h3<<6 | h4;
        
        o1 = bits>>16 & 0xff;
        o2 = bits>>8 & 0xff;
        o3 = bits & 0xff;
        
        if (h3 == 64)      enc += String.fromCharCode(o1);
        else if (h4 == 64) enc += String.fromCharCode(o1, o2);
        else               enc += String.fromCharCode(o1, o2, o3);
    } while (i < str.length);

    return decodeUTF8(enc);  // decode UTF-8 byte-array back to Unicode
    }

    function encodeUTF8(str) {  // encode multi-byte string into utf-8 multiple single-byte characters 
    str = str.replace(
        /[\u0080-\u07ff]/g,  // U+0080 - U+07FF = 2-byte chars
        function(c) { 
            var cc = c.charCodeAt(0);
            return String.fromCharCode(0xc0 | cc>>6, 0x80 | cc&0x3f); }
        );
    str = str.replace(
        /[\u0800-\uffff]/g,  // U+0800 - U+FFFF = 3-byte chars
        function(c) { 
            var cc = c.charCodeAt(0); 
            return String.fromCharCode(0xe0 | cc>>12, 0x80 | cc>>6&0x3F, 0x80 | cc&0x3f); }
        );
    return str;
    }

    function decodeUTF8(str) {  // decode utf-8 encoded string back into multi-byte characters
    str = str.replace(
        /[\u00c0-\u00df][\u0080-\u00bf]/g,                 // 2-byte chars
        function(c) { 
            var cc = (c.charCodeAt(0)&0x1f)<<6 | c.charCodeAt(1)&0x3f;
            return String.fromCharCode(cc); }
        );
    str = str.replace(
        /[\u00e0-\u00ef][\u0080-\u00bf][\u0080-\u00bf]/g,  // 3-byte chars
        function(c) { 
            var cc = (c.charCodeAt(0)&0x0f)<<12 | (c.charCodeAt(1)&0x3f<<6) | c.charCodeAt(2)&0x3f; 
            return String.fromCharCode(cc); }
        );
    return str;
    }


    function byteArrayToHexStr(b) {  // convert byte array to hex string for displaying test vectors
    var s = '';
    for (var i=0; i<b.length; i++) s += b[i].toString(16) + ' ';
    return s;
    }

    return {
        encrypt: function(password, text){
            if(typeof(window) != 'undefined' && window.Foxmarks){
                return Foxmarks.ThirdParty.Base64.encode(
                    AESEncryptCtr(text, password, 256), false);
            }
            else {
                return Base64.encode(AESEncryptCtr(text, password, 256), false);
            }
        },
        decrypt: function(password, text){
            if(typeof(window) != 'undefined' && window.Foxmarks){
                return AESDecryptCtr(
                    Foxmarks.ThirdParty.Base64.decode(text),
                    password, 256);
            }
            else {
                return AESDecryptCtr(Base64.decode(text), password, 256);
            }
        },
        utEncryption: function(numloops, strlength, callback, callback_error){
            var password = "opensesame";
            numloops = numloops || 1000;
            strlength = strlength || 255;
            
            while(numloops--){
                var txt = "";
                var ct = strlength;
                var charrange = 255 -32;
                while(ct--){
                    var ascii = Math.floor(charrange * Math.random()) + 32;
                    txt += String.fromCharCode(ascii);
                }

                callback("Loop #" + numloops + "\n");
                callback("String: " + txt + "\n");
               
                var s = this.encrypt(password, txt);
                var d = this.decrypt(password, s);
                callback("DString: " + d + "\n");
                if(d != txt){
                    callback_error("Error in encryptor.");
                    break;
                }
            }
        }
     };
}

if (typeof(window) != 'undefined' && window.Foxmarks) {
	Foxmarks.provide('Foxmarks.ThirdParty.CreateAESManager');
	Foxmarks.ThirdParty.CreateAESManager = _CreateAESManager;
} else {
	CreateAESManager = _CreateAESManager;
}

})();
