mirror of https://github.com/gchq/CyberChef.git
35 lines
966 B
JavaScript
35 lines
966 B
JavaScript
/**
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* @author n1073645 [n1073645@gmail.com]
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* @copyright Crown Copyright 2020
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* @license Apache-2.0
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*/
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export function encode(tempIVP, key, rounds, input) {
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const ivp = new Uint8Array(key.concat(tempIVP));
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const state = new Array(256).fill(0);
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let j = 0, i = 0;
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const result = [];
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// Mixing states based off of IV.
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for (let i = 0; i < 256; i++)
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state[i] = i;
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const ivpLength = ivp.length;
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for (let r = 0; r < rounds; r ++) {
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for (let k = 0; k < 256; k++) {
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j = (j + state[k] + ivp[k % ivpLength]) % 256;
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[state[k], state[j]] = [state[j], state[k]];
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}
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}
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j = 0;
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i = 0;
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// XOR cipher with key.
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for (let x = 0; x < input.length; x++) {
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i = (++i) % 256;
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j = (j + state[i]) % 256;
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[state[i], state[j]] = [state[j], state[i]];
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const n = (state[i] + state[j]) % 256;
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result.push(state[n] ^ input[x]);
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}
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return result;
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}
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