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chrisns/aes.class.php

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Revisions

  1. chrisns revised this gist Feb 26, 2013. 1 changed file with 0 additions and 2 deletions.
    2 changes: 0 additions & 2 deletions aes.class.php
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    Original file line number Diff line number Diff line change
    @@ -164,9 +164,7 @@ private static function rotWord($w) { // rotate 4-byte word w left by one byt
    }

    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    ?>

    <?php
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* AES counter (CTR) mode implementation in PHP */
    /* (c) Chris Veness 2005-2011 www.movable-type.co.uk/scripts */
  2. chrisns revised this gist Feb 26, 2013. 1 changed file with 1 addition and 2 deletions.
    3 changes: 1 addition & 2 deletions aes.class.php
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    Original file line number Diff line number Diff line change
    @@ -329,5 +329,4 @@ private static function urs($a, $b) {
    }

    }
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    ?>
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  3. chrisns revised this gist Nov 1, 2012. 1 changed file with 463 additions and 0 deletions.
    463 changes: 463 additions & 0 deletions aes.js
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,463 @@
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* AES implementation in JavaScript (c) Chris Veness 2005-2012 */
    /* - see http://csrc.nist.gov/publications/PubsFIPS.html#197 */
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    var Aes = {}; // Aes namespace

    /**
    * AES Cipher function: encrypt 'input' state with Rijndael algorithm
    * applies Nr rounds (10/12/14) using key schedule w for 'add round key' stage
    *
    * @param {Number[]} input 16-byte (128-bit) input state array
    * @param {Number[][]} w Key schedule as 2D byte-array (Nr+1 x Nb bytes)
    * @returns {Number[]} Encrypted output state array
    */
    Aes.cipher = function(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 = Aes.addRoundKey(state, w, 0, Nb);

    for (var round=1; round<Nr; round++) {
    state = Aes.subBytes(state, Nb);
    state = Aes.shiftRows(state, Nb);
    state = Aes.mixColumns(state, Nb);
    state = Aes.addRoundKey(state, w, round, Nb);
    }

    state = Aes.subBytes(state, Nb);
    state = Aes.shiftRows(state, Nb);
    state = Aes.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;
    }

    /**
    * Perform Key Expansion to generate a Key Schedule
    *
    * @param {Number[]} key Key as 16/24/32-byte array
    * @returns {Number[][]} Expanded key schedule as 2D byte-array (Nr+1 x Nb bytes)
    */
    Aes.keyExpansion = function(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 = Aes.subWord(Aes.rotWord(temp));
    for (var t=0; t<4; t++) temp[t] ^= Aes.rCon[i/Nk][t];
    } else if (Nk > 6 && i%Nk == 4) {
    temp = Aes.subWord(temp);
    }
    for (var t=0; t<4; t++) w[i][t] = w[i-Nk][t] ^ temp[t];
    }

    return w;
    }

    /*
    * ---- remaining routines are private, not called externally ----
    */

    Aes.subBytes = function(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] = Aes.sBox[s[r][c]];
    }
    return s;
    }

    Aes.shiftRows = function(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 asmaes.sourceforge.net/rijndael/rijndaelImplementation.pdf
    }

    Aes.mixColumns = function(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;
    }

    Aes.addRoundKey = function(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;
    }

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

    Aes.rotWord = function(w) { // rotate 4-byte word w left by one byte
    var tmp = w[0];
    for (var i=0; i<3; 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]
    Aes.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]
    Aes.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] ];


    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* AES Counter-mode implementation in JavaScript (c) Chris Veness 2005-2012 */
    /* - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf */
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    Aes.Ctr = {}; // Aes.Ctr namespace: a subclass or extension of Aes

    /**
    * Encrypt a text using AES encryption in Counter mode of operation
    *
    * Unicode multi-byte character safe
    *
    * @param {String} plaintext Source text to be encrypted
    * @param {String} password The password to use to generate a key
    * @param {Number} nBits Number of bits to be used in the key (128, 192, or 256)
    * @returns {string} Encrypted text
    */
    Aes.Ctr.encrypt = function(plaintext, password, nBits) {
    var blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    if (!(nBits==128 || nBits==192 || nBits==256)) return ''; // standard allows 128/192/256 bit keys
    plaintext = Utf8.encode(plaintext);
    password = Utf8.encode(password);
    //var t = new Date(); // timer

    // use AES itself to encrypt password to get cipher key (using plain password as source for key
    // expansion) - gives us well encrypted key (though hashed key might be preferred for prod'n use)
    var nBytes = nBits/8; // no bytes in key (16/24/32)
    var pwBytes = new Array(nBytes);
    for (var i=0; i<nBytes; i++) { // use 1st 16/24/32 chars of password for key
    pwBytes[i] = isNaN(password.charCodeAt(i)) ? 0 : password.charCodeAt(i);
    }
    var key = Aes.cipher(pwBytes, Aes.keyExpansion(pwBytes)); // gives us 16-byte key
    key = key.concat(key.slice(0, nBytes-16)); // expand key to 16/24/32 bytes long

    // initialise 1st 8 bytes of counter block with nonce (NIST SP800-38A §B.2): [0-1] = millisec,
    // [2-3] = random, [4-7] = seconds, together giving full sub-millisec uniqueness up to Feb 2106
    var counterBlock = new Array(blockSize);

    var nonce = (new Date()).getTime(); // timestamp: milliseconds since 1-Jan-1970
    var nonceMs = nonce%1000;
    var nonceSec = Math.floor(nonce/1000);
    var nonceRnd = Math.floor(Math.random()*0xffff);

    for (var i=0; i<2; i++) counterBlock[i] = (nonceMs >>> i*8) & 0xff;
    for (var i=0; i<2; i++) counterBlock[i+2] = (nonceRnd >>> i*8) & 0xff;
    for (var i=0; i<4; i++) counterBlock[i+4] = (nonceSec >>> i*8) & 0xff;

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

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

    var blockCount = Math.ceil(plaintext.length/blockSize);
    var ciphertxt = 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 = Aes.cipher(counterBlock, keySchedule); // -- encrypt counter block --

    // block size is reduced on final block
    var blockLength = b<blockCount-1 ? blockSize : (plaintext.length-1)%blockSize+1;
    var cipherChar = new Array(blockLength);

    for (var i=0; i<blockLength; i++) { // -- xor plaintext with ciphered counter char-by-char --
    cipherChar[i] = cipherCntr[i] ^ plaintext.charCodeAt(b*blockSize+i);
    cipherChar[i] = String.fromCharCode(cipherChar[i]);
    }
    ciphertxt[b] = cipherChar.join('');
    }

    // Array.join is more efficient than repeated string concatenation in IE
    var ciphertext = ctrTxt + ciphertxt.join('');
    ciphertext = Base64.encode(ciphertext); // encode in base64

    //alert((new Date()) - t);
    return ciphertext;
    }

    /**
    * Decrypt a text encrypted by AES in counter mode of operation
    *
    * @param {String} ciphertext Source text to be encrypted
    * @param {String} password The password to use to generate a key
    * @param {Number} nBits Number of bits to be used in the key (128, 192, or 256)
    * @returns {String} Decrypted text
    */
    Aes.Ctr.decrypt = function(ciphertext, password, nBits) {
    var blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    if (!(nBits==128 || nBits==192 || nBits==256)) return ''; // standard allows 128/192/256 bit keys
    ciphertext = Base64.decode(ciphertext);
    password = Utf8.encode(password);
    //var t = new Date(); // timer

    // use AES to encrypt password (mirroring encrypt routine)
    var nBytes = nBits/8; // no bytes in key
    var pwBytes = new Array(nBytes);
    for (var i=0; i<nBytes; i++) {
    pwBytes[i] = isNaN(password.charCodeAt(i)) ? 0 : password.charCodeAt(i);
    }
    var key = Aes.cipher(pwBytes, Aes.keyExpansion(pwBytes));
    key = key.concat(key.slice(0, nBytes-16)); // expand key to 16/24/32 bytes long

    // recover nonce from 1st 8 bytes of ciphertext
    var counterBlock = new Array(8);
    ctrTxt = ciphertext.slice(0, 8);
    for (var i=0; i<8; i++) counterBlock[i] = ctrTxt.charCodeAt(i);

    // generate key schedule
    var keySchedule = Aes.keyExpansion(key);

    // separate ciphertext into blocks (skipping past initial 8 bytes)
    var nBlocks = Math.ceil((ciphertext.length-8) / blockSize);
    var ct = new Array(nBlocks);
    for (var b=0; b<nBlocks; b++) ct[b] = ciphertext.slice(8+b*blockSize, 8+b*blockSize+blockSize);
    ciphertext = ct; // ciphertext is now array of block-length strings

    // plaintext will get generated block-by-block into array of block-length strings
    var plaintxt = new Array(ciphertext.length);

    for (var b=0; b<nBlocks; 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) >>> c*8) & 0xff;
    for (var c=0; c<4; c++) counterBlock[15-c-4] = (((b+1)/0x100000000-1) >>> c*8) & 0xff;

    var cipherCntr = Aes.cipher(counterBlock, keySchedule); // encrypt counter block

    var plaintxtByte = new Array(ciphertext[b].length);
    for (var i=0; i<ciphertext[b].length; i++) {
    // -- xor plaintxt with ciphered counter byte-by-byte --
    plaintxtByte[i] = cipherCntr[i] ^ ciphertext[b].charCodeAt(i);
    plaintxtByte[i] = String.fromCharCode(plaintxtByte[i]);
    }
    plaintxt[b] = plaintxtByte.join('');
    }

    // join array of blocks into single plaintext string
    var plaintext = plaintxt.join('');
    plaintext = Utf8.decode(plaintext); // decode from UTF8 back to Unicode multi-byte chars

    //alert((new Date()) - t);
    return plaintext;
    }


    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* Base64 class: Base 64 encoding / decoding (c) Chris Veness 2002-2012 */
    /* note: depends on Utf8 class */
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    var Base64 = {}; // Base64 namespace

    Base64.code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    /**
    * Encode string into Base64, as defined by RFC 4648 [http://tools.ietf.org/html/rfc4648]
    * (instance method extending String object). As per RFC 4648, no newlines are added.
    *
    * @param {String} str The string to be encoded as base-64
    * @param {Boolean} [utf8encode=false] Flag to indicate whether str is Unicode string to be encoded
    * to UTF8 before conversion to base64; otherwise string is assumed to be 8-bit characters
    * @returns {String} Base64-encoded string
    */
    Base64.encode = function(str, utf8encode) { // http://tools.ietf.org/html/rfc4648
    utf8encode = (typeof utf8encode == 'undefined') ? false : utf8encode;
    var o1, o2, o3, bits, h1, h2, h3, h4, e=[], pad = '', c, plain, coded;
    var b64 = Base64.code;

    plain = utf8encode ? str.encodeUTF8() : str;

    c = plain.length % 3; // pad string to length of multiple of 3
    if (c > 0) { while (c++ < 3) { pad += '='; plain += '\0'; } }
    // note: doing padding here saves us doing special-case packing for trailing 1 or 2 chars

    for (c=0; c<plain.length; c+=3) { // pack three octets into four hexets
    o1 = plain.charCodeAt(c);
    o2 = plain.charCodeAt(c+1);
    o3 = plain.charCodeAt(c+2);

    bits = o1<<16 | o2<<8 | o3;

    h1 = bits>>18 & 0x3f;
    h2 = bits>>12 & 0x3f;
    h3 = bits>>6 & 0x3f;
    h4 = bits & 0x3f;

    // use hextets to index into code string
    e[c/3] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
    }
    coded = e.join(''); // join() is far faster than repeated string concatenation in IE

    // replace 'A's from padded nulls with '='s
    coded = coded.slice(0, coded.length-pad.length) + pad;

    return coded;
    }

    /**
    * Decode string from Base64, as defined by RFC 4648 [http://tools.ietf.org/html/rfc4648]
    * (instance method extending String object). As per RFC 4648, newlines are not catered for.
    *
    * @param {String} str The string to be decoded from base-64
    * @param {Boolean} [utf8decode=false] Flag to indicate whether str is Unicode string to be decoded
    * from UTF8 after conversion from base64
    * @returns {String} decoded string
    */
    Base64.decode = function(str, utf8decode) {
    utf8decode = (typeof utf8decode == 'undefined') ? false : utf8decode;
    var o1, o2, o3, h1, h2, h3, h4, bits, d=[], plain, coded;
    var b64 = Base64.code;

    coded = utf8decode ? str.decodeUTF8() : str;


    for (var c=0; c<coded.length; c+=4) { // unpack four hexets into three octets
    h1 = b64.indexOf(coded.charAt(c));
    h2 = b64.indexOf(coded.charAt(c+1));
    h3 = b64.indexOf(coded.charAt(c+2));
    h4 = b64.indexOf(coded.charAt(c+3));

    bits = h1<<18 | h2<<12 | h3<<6 | h4;

    o1 = bits>>>16 & 0xff;
    o2 = bits>>>8 & 0xff;
    o3 = bits & 0xff;

    d[c/4] = String.fromCharCode(o1, o2, o3);
    // check for padding
    if (h4 == 0x40) d[c/4] = String.fromCharCode(o1, o2);
    if (h3 == 0x40) d[c/4] = String.fromCharCode(o1);
    }
    plain = d.join(''); // join() is far faster than repeated string concatenation in IE

    return utf8decode ? plain.decodeUTF8() : plain;
    }


    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* Utf8 class: encode / decode between multi-byte Unicode characters and UTF-8 multiple */
    /* single-byte character encoding (c) Chris Veness 2002-2012 */
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    var Utf8 = {}; // Utf8 namespace

    /**
    * Encode multi-byte Unicode string into utf-8 multiple single-byte characters
    * (BMP / basic multilingual plane only)
    *
    * Chars in range U+0080 - U+07FF are encoded in 2 chars, U+0800 - U+FFFF in 3 chars
    *
    * @param {String} strUni Unicode string to be encoded as UTF-8
    * @returns {String} encoded string
    */
    Utf8.encode = function(strUni) {
    // use regular expressions & String.replace callback function for better efficiency
    // than procedural approaches
    var strUtf = strUni.replace(
    /[\u0080-\u07ff]/g, // U+0080 - U+07FF => 2 bytes 110yyyyy, 10zzzzzz
    function(c) {
    var cc = c.charCodeAt(0);
    return String.fromCharCode(0xc0 | cc>>6, 0x80 | cc&0x3f); }
    );
    strUtf = strUtf.replace(
    /[\u0800-\uffff]/g, // U+0800 - U+FFFF => 3 bytes 1110xxxx, 10yyyyyy, 10zzzzzz
    function(c) {
    var cc = c.charCodeAt(0);
    return String.fromCharCode(0xe0 | cc>>12, 0x80 | cc>>6&0x3F, 0x80 | cc&0x3f); }
    );
    return strUtf;
    }

    /**
    * Decode utf-8 encoded string back into multi-byte Unicode characters
    *
    * @param {String} strUtf UTF-8 string to be decoded back to Unicode
    * @returns {String} decoded string
    */
    Utf8.decode = function(strUtf) {
    // note: decode 3-byte chars first as decoded 2-byte strings could appear to be 3-byte char!
    var strUni = strUtf.replace(
    /[\u00e0-\u00ef][\u0080-\u00bf][\u0080-\u00bf]/g, // 3-byte chars
    function(c) { // (note parentheses for precence)
    var cc = ((c.charCodeAt(0)&0x0f)<<12) | ((c.charCodeAt(1)&0x3f)<<6) | ( c.charCodeAt(2)&0x3f);
    return String.fromCharCode(cc); }
    );
    strUni = strUni.replace(
    /[\u00c0-\u00df][\u0080-\u00bf]/g, // 2-byte chars
    function(c) { // (note parentheses for precence)
    var cc = (c.charCodeAt(0)&0x1f)<<6 | c.charCodeAt(1)&0x3f;
    return String.fromCharCode(cc); }
    );
    return strUni;
    }

    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  4. chrisns created this gist Nov 1, 2012.
    333 changes: 333 additions & 0 deletions aes.class.php
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,333 @@
    <?php
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* AES implementation in PHP */
    /* (c) Chris Veness 2005-2011 www.movable-type.co.uk/scripts */
    /* Right of free use is granted for all commercial or non-commercial use providing this */
    /* copyright notice is retainded. No warranty of any form is offered. */
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    class Aes {

    /**
    * AES Cipher function: encrypt 'input' with Rijndael algorithm
    *
    * @param input message as byte-array (16 bytes)
    * @param w key schedule as 2D byte-array (Nr+1 x Nb bytes) -
    * generated from the cipher key by keyExpansion()
    * @return ciphertext as byte-array (16 bytes)
    */
    public static function cipher($input, $w) { // main cipher function [§5.1]
    $Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES)
    $Nr = count($w)/$Nb - 1; // no of rounds: 10/12/14 for 128/192/256-bit keys

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

    $state = self::addRoundKey($state, $w, 0, $Nb);

    for ($round=1; $round<$Nr; $round++) { // apply Nr rounds
    $state = self::subBytes($state, $Nb);
    $state = self::shiftRows($state, $Nb);
    $state = self::mixColumns($state, $Nb);
    $state = self::addRoundKey($state, $w, $round, $Nb);
    }

    $state = self::subBytes($state, $Nb);
    $state = self::shiftRows($state, $Nb);
    $state = self::addRoundKey($state, $w, $Nr, $Nb);

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


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

    private static function subBytes($s, $Nb) { // apply SBox to state S [§5.1.1]
    for ($r=0; $r<4; $r++) {
    for ($c=0; $c<$Nb; $c++) $s[$r][$c] = self::$sBox[$s[$r][$c]];
    }
    return $s;
    }

    private static function shiftRows($s, $Nb) { // shift row r of state S left by r bytes [§5.1.2]
    $t = array(4);
    for ($r=1; $r<4; $r++) {
    for ($c=0; $c<4; $c++) $t[$c] = $s[$r][($c+$r)%$Nb]; // shift into temp copy
    for ($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
    }

    private static function mixColumns($s, $Nb) { // combine bytes of each col of state S [§5.1.3]
    for ($c=0; $c<4; $c++) {
    $a = array(4); // 'a' is a copy of the current column from 's'
    $b = array(4); // 'b' is a•{02} in GF(2^8)
    for ($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;
    }

    /**
    * Key expansion for Rijndael cipher(): performs key expansion on cipher key
    * to generate a key schedule
    *
    * @param key cipher key byte-array (16 bytes)
    * @return key schedule as 2D byte-array (Nr+1 x Nb bytes)
    */
    public static function keyExpansion($key) { // generate Key Schedule from Cipher Key [§5.2]
    $Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES)
    $Nk = count($key)/4; // key length (in words): 4/6/8 for 128/192/256-bit keys
    $Nr = $Nk + 6; // no of rounds: 10/12/14 for 128/192/256-bit keys

    $w = array();
    $temp = array();

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

    for ($i=$Nk; $i<($Nb*($Nr+1)); $i++) {
    $w[$i] = array();
    for ($t=0; $t<4; $t++) $temp[$t] = $w[$i-1][$t];
    if ($i % $Nk == 0) {
    $temp = self::subWord(self::rotWord($temp));
    for ($t=0; $t<4; $t++) $temp[$t] ^= self::$rCon[$i/$Nk][$t];
    } else if ($Nk > 6 && $i%$Nk == 4) {
    $temp = self::subWord($temp);
    }
    for ($t=0; $t<4; $t++) $w[$i][$t] = $w[$i-$Nk][$t] ^ $temp[$t];
    }
    return $w;
    }

    private static function subWord($w) { // apply SBox to 4-byte word w
    for ($i=0; $i<4; $i++) $w[$i] = self::$sBox[$w[$i]];
    return $w;
    }

    private static function rotWord($w) { // rotate 4-byte word w left by one byte
    $tmp = $w[0];
    for ($i=0; $i<3; $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]
    private static $sBox = array(
    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]
    private static $rCon = array(
    array(0x00, 0x00, 0x00, 0x00),
    array(0x01, 0x00, 0x00, 0x00),
    array(0x02, 0x00, 0x00, 0x00),
    array(0x04, 0x00, 0x00, 0x00),
    array(0x08, 0x00, 0x00, 0x00),
    array(0x10, 0x00, 0x00, 0x00),
    array(0x20, 0x00, 0x00, 0x00),
    array(0x40, 0x00, 0x00, 0x00),
    array(0x80, 0x00, 0x00, 0x00),
    array(0x1b, 0x00, 0x00, 0x00),
    array(0x36, 0x00, 0x00, 0x00) );

    }

    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    ?>

    <?php
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    /* AES counter (CTR) mode implementation in PHP */
    /* (c) Chris Veness 2005-2011 www.movable-type.co.uk/scripts */
    /* Right of free use is granted for all commercial or non-commercial use providing this */
    /* copyright notice is retainded. No warranty of any form is offered. */
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    class AesCtr extends Aes {

    /**
    * Encrypt a text using AES encryption in Counter mode of operation
    * - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
    *
    * Unicode multi-byte character safe
    *
    * @param plaintext source text to be encrypted
    * @param password the password to use to generate a key
    * @param nBits number of bits to be used in the key (128, 192, or 256)
    * @return encrypted text
    */
    public static function encrypt($plaintext, $password, $nBits) {
    $blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    if (!($nBits==128 || $nBits==192 || $nBits==256)) return ''; // standard allows 128/192/256 bit keys
    // note PHP (5) gives us plaintext and password in UTF8 encoding!

    // use AES itself to encrypt password to get cipher key (using plain password as source for
    // key expansion) - gives us well encrypted key
    $nBytes = $nBits/8; // no bytes in key
    $pwBytes = array();
    for ($i=0; $i<$nBytes; $i++) $pwBytes[$i] = ord(substr($password,$i,1)) & 0xff;
    $key = Aes::cipher($pwBytes, Aes::keyExpansion($pwBytes));
    $key = array_merge($key, array_slice($key, 0, $nBytes-16)); // expand key to 16/24/32 bytes long

    // initialise 1st 8 bytes of counter block with nonce (NIST SP800-38A §B.2): [0-1] = millisec,
    // [2-3] = random, [4-7] = seconds, giving guaranteed sub-ms uniqueness up to Feb 2106
    $counterBlock = array();
    $nonce = floor(microtime(true)*1000); // timestamp: milliseconds since 1-Jan-1970
    $nonceMs = $nonce%1000;
    $nonceSec = floor($nonce/1000);
    $nonceRnd = floor(rand(0, 0xffff));

    for ($i=0; $i<2; $i++) $counterBlock[$i] = self::urs($nonceMs, $i*8) & 0xff;
    for ($i=0; $i<2; $i++) $counterBlock[$i+2] = self::urs($nonceRnd, $i*8) & 0xff;
    for ($i=0; $i<4; $i++) $counterBlock[$i+4] = self::urs($nonceSec, $i*8) & 0xff;

    // and convert it to a string to go on the front of the ciphertext
    $ctrTxt = '';
    for ($i=0; $i<8; $i++) $ctrTxt .= chr($counterBlock[$i]);

    // generate key schedule - an expansion of the key into distinct Key Rounds for each round
    $keySchedule = Aes::keyExpansion($key);
    //print_r($keySchedule);

    $blockCount = ceil(strlen($plaintext)/$blockSize);
    $ciphertxt = array(); // ciphertext as array of strings

    for ($b=0; $b<$blockCount; $b++) {
    // set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
    // done in two stages for 32-bit ops: using two words allows us to go past 2^32 blocks (68GB)
    for ($c=0; $c<4; $c++) $counterBlock[15-$c] = self::urs($b, $c*8) & 0xff;
    for ($c=0; $c<4; $c++) $counterBlock[15-$c-4] = self::urs($b/0x100000000, $c*8);

    $cipherCntr = Aes::cipher($counterBlock, $keySchedule); // -- encrypt counter block --

    // block size is reduced on final block
    $blockLength = $b<$blockCount-1 ? $blockSize : (strlen($plaintext)-1)%$blockSize+1;
    $cipherByte = array();

    for ($i=0; $i<$blockLength; $i++) { // -- xor plaintext with ciphered counter byte-by-byte --
    $cipherByte[$i] = $cipherCntr[$i] ^ ord(substr($plaintext, $b*$blockSize+$i, 1));
    $cipherByte[$i] = chr($cipherByte[$i]);
    }
    $ciphertxt[$b] = implode('', $cipherByte); // escape troublesome characters in ciphertext
    }

    // implode is more efficient than repeated string concatenation
    $ciphertext = $ctrTxt . implode('', $ciphertxt);
    $ciphertext = base64_encode($ciphertext);
    return $ciphertext;
    }


    /**
    * Decrypt a text encrypted by AES in counter mode of operation
    *
    * @param ciphertext source text to be decrypted
    * @param password the password to use to generate a key
    * @param nBits number of bits to be used in the key (128, 192, or 256)
    * @return decrypted text
    */
    public static function decrypt($ciphertext, $password, $nBits) {
    $blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
    if (!($nBits==128 || $nBits==192 || $nBits==256)) return ''; // standard allows 128/192/256 bit keys
    $ciphertext = base64_decode($ciphertext);

    // use AES to encrypt password (mirroring encrypt routine)
    $nBytes = $nBits/8; // no bytes in key
    $pwBytes = array();
    for ($i=0; $i<$nBytes; $i++) $pwBytes[$i] = ord(substr($password,$i,1)) & 0xff;
    $key = Aes::cipher($pwBytes, Aes::keyExpansion($pwBytes));
    $key = array_merge($key, array_slice($key, 0, $nBytes-16)); // expand key to 16/24/32 bytes long

    // recover nonce from 1st element of ciphertext
    $counterBlock = array();
    $ctrTxt = substr($ciphertext, 0, 8);
    for ($i=0; $i<8; $i++) $counterBlock[$i] = ord(substr($ctrTxt,$i,1));

    // generate key schedule
    $keySchedule = Aes::keyExpansion($key);

    // separate ciphertext into blocks (skipping past initial 8 bytes)
    $nBlocks = ceil((strlen($ciphertext)-8) / $blockSize);
    $ct = array();
    for ($b=0; $b<$nBlocks; $b++) $ct[$b] = substr($ciphertext, 8+$b*$blockSize, 16);
    $ciphertext = $ct; // ciphertext is now array of block-length strings

    // plaintext will get generated block-by-block into array of block-length strings
    $plaintxt = array();

    for ($b=0; $b<$nBlocks; $b++) {
    // set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
    for ($c=0; $c<4; $c++) $counterBlock[15-$c] = self::urs($b, $c*8) & 0xff;
    for ($c=0; $c<4; $c++) $counterBlock[15-$c-4] = self::urs(($b+1)/0x100000000-1, $c*8) & 0xff;

    $cipherCntr = Aes::cipher($counterBlock, $keySchedule); // encrypt counter block

    $plaintxtByte = array();
    for ($i=0; $i<strlen($ciphertext[$b]); $i++) {
    // -- xor plaintext with ciphered counter byte-by-byte --
    $plaintxtByte[$i] = $cipherCntr[$i] ^ ord(substr($ciphertext[$b],$i,1));
    $plaintxtByte[$i] = chr($plaintxtByte[$i]);

    }
    $plaintxt[$b] = implode('', $plaintxtByte);
    }

    // join array of blocks into single plaintext string
    $plaintext = implode('',$plaintxt);

    return $plaintext;
    }


    /*
    * Unsigned right shift function, since PHP has neither >>> operator nor unsigned ints
    *
    * @param a number to be shifted (32-bit integer)
    * @param b number of bits to shift a to the right (0..31)
    * @return a right-shifted and zero-filled by b bits
    */
    private static function urs($a, $b) {
    $a &= 0xffffffff; $b &= 0x1f; // (bounds check)
    if ($a&0x80000000 && $b>0) { // if left-most bit set
    $a = ($a>>1) & 0x7fffffff; // right-shift one bit & clear left-most bit
    $a = $a >> ($b-1); // remaining right-shifts
    } else { // otherwise
    $a = ($a>>$b); // use normal right-shift
    }
    return $a;
    }

    }
    /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    ?>