/*!
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* Crypto-JS v1.1.0
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* http://code.google.com/p/crypto-js/
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* Copyright (c) 2009, Jeff Mott. All rights reserved.
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* http://code.google.com/p/crypto-js/wiki/License
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*/
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(function(){
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// Shortcut
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var util = Crypto.util;
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var MARC4 = Crypto.MARC4 = {
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/**
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* Public API
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*/
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encrypt: function (message, password) {
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var
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// Convert to bytes
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m = util.stringToBytes(message),
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// Generate random IV
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iv = util.randomBytes(16),
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// Generate key
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k = Crypto.PBKDF2(password, util.bytesToString(iv), 32, { asBytes: true });
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// Encrypt
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MARC4._marc4(m, k, 1536);
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// Return ciphertext
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return util.bytesToBase64(iv.concat(m));
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},
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decrypt: function (ciphertext, password) {
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var
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// Convert to bytes
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c = util.base64ToBytes(ciphertext),
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// Separate IV and message
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iv = c.splice(0, 16),
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// Generate key
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k = Crypto.PBKDF2(password, util.bytesToString(iv), 32, { asBytes: true });
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// Decrypt
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MARC4._marc4(c, k, 1536);
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// Return plaintext
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return util.bytesToString(c);
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},
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/**
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* Internal methods
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*/
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// The core
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_marc4: function (m, k, drop) {
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// State variables
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var i, j, s, temp;
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// Key setup
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for (i = 0, s = []; i < 256; i++) s[i] = i;
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for (i = 0, j = 0; i < 256; i++) {
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j = (j + s[i] + k[i % k.length]) % 256;
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// Swap
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temp = s[i];
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s[i] = s[j];
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s[j] = temp;
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}
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// Clear counters
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i = j = 0;
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// Encryption
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for (var k = 0 - drop; k < m.length; k++) {
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i = (i + 1) % 256;
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j = (j + s[i]) % 256;
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// Swap
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temp = s[i];
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s[i] = s[j];
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s[j] = temp;
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// Stop here if we're still dropping keystream
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if (k < 0) continue;
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// Encrypt
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m[k] ^= s[(s[i] + s[j]) % 256];
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}
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}
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};
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})();
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