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46 lines
1.1 KiB
46 lines
1.1 KiB
var base64 = require('./base64');
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var bytesToStr = require('./bytesToStr');
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var strToBytes = require('./strToBytes');
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exports = {
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encrypt: function(key, str) {
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return rc4(key, str, false);
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},
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decrypt: function(key, str) {
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return rc4(key, str, true);
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}
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};
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function rc4(key, str, decrypt) {
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key = strToBytes(key);
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if (!decrypt) {
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str = strToBytes(str);
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} else {
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str = base64.decode(str);
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}
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var result = [];
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var s = [];
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var j = 0;
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var i = 0;
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var x;
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for (i = 0; i < 256; i++) {
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s[i] = i;
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}
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for (i = 0; i < 256; i++) {
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j = (j + s[i] + key[i % key.length]) % 256;
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x = s[i];
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s[i] = s[j];
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s[j] = x;
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}
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i = 0;
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j = 0;
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for (var y = 0, len = str.length; y < len; y++) {
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i = (i + 1) % 256;
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j = (j + s[i]) % 256;
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x = s[i];
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s[i] = s[j];
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s[j] = x;
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result.push(str[y] ^ s[(s[i] + s[j]) % 256]);
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}
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return !decrypt ? base64.encode(result) : bytesToStr(result);
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}
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module.exports = exports;
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