CyberChef/src/core/operations/BitShiftRight.mjs

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/**
* @author n1474335 [n1474335@gmail.com]
* @copyright Crown Copyright 2016
* @license Apache-2.0
*/
import Operation from "../Operation";
/**
* Bit shift right operation
*/
class BitShiftRight extends Operation {
/**
* BitShiftRight constructor
*/
constructor() {
super();
this.name = "Bit shift right";
this.module = "Default";
this.description = "Shifts the bits in each byte towards the right by the specified amount.<br><br><i>Logical shifts</i> replace the leftmost bits with zeros.<br><i>Arithmetic shifts</i> preserve the most significant bit (MSB) of the original byte keeping the sign the same (positive or negative).";
this.infoURL = "https://wikipedia.org/wiki/Bitwise_operation#Bit_shifts";
this.inputType = "byteArray";
this.outputType = "byteArray";
this.args = [
{
"name": "Amount",
"type": "number",
"value": 1
},
{
"name": "Type",
"type": "option",
"value": ["Logical shift", "Arithmetic shift"]
}
];
}
/**
* @param {byteArray} input
* @param {Object[]} args
* @returns {byteArray}
*/
run(input, args) {
const amount = args[0],
type = args[1],
mask = type === "Logical shift" ? 0 : 0x80;
return input.map(b => {
return (b >>> amount) ^ (b & mask);
});
}
/**
* Highlight Bit shift right
*
* @param {Object[]} pos
* @param {number} pos[].start
* @param {number} pos[].end
* @param {Object[]} args
* @returns {Object[]} pos
*/
highlight(pos, args) {
return pos;
}
/**
* Highlight Bit shift right in reverse
*
* @param {Object[]} pos
* @param {number} pos[].start
* @param {number} pos[].end
* @param {Object[]} args
* @returns {Object[]} pos
*/
highlightReverse(pos, args) {
return pos;
}
}
export default BitShiftRight;