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Adds Rolling, Rolling cumulative, and Rolling cumulative (self) XOR options. Not in love with those names though, tbh

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Spencer Walden 2023-03-30 23:51:19 -07:00
parent 1bc88728f0
commit 4847b45f7d
1 changed files with 28 additions and 3 deletions
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31
src/core/operations/XOR.mjs
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@ -6,7 +6,7 @@
import Operation from "../Operation.mjs";
import Utils from "../Utils.mjs";
import { bitOp, xor, BITWISE_OP_DELIMS } from "../lib/BitwiseOp.mjs";
import { bitOp, xor, add, BITWISE_OP_DELIMS } from "../lib/BitwiseOp.mjs";
/**
* XOR operation
@ -21,7 +21,7 @@ class XOR extends Operation {
this.name = "XOR";
this.module = "Default";
this.description = "XOR the input with the given key.<br>e.g. <code>fe023da5</code><br><br><strong>Options</strong><br><u>Null preserving:</u> If the current byte is 0x00 or the same as the key, skip it.<br><br><u>Scheme:</u><ul><li>Standard - key is unchanged after each round</li><li>Input differential - key is set to the value of the previous unprocessed byte</li><li>Output differential - key is set to the value of the previous processed byte</li><li>Cascade - key is set to the input byte shifted by one</li></ul>";
this.description = "XOR the input with the given key.<br>e.g. <code>fe023da5</code><br><br><strong>Options</strong><br><u>Null preserving:</u> If the current byte is 0x00 or the same as the key, skip it.<br><br><u>Scheme:</u><ul><li>Standard - key is unchanged after each round</li><li>Input differential - key is set to the value of the previous unprocessed byte</li><li>Output differential - key is set to the value of the previous processed byte</li><li>Cascade - key is set to the input byte shifted by one</li><li>Rolling - key is set to the value of itself added with the current position in the bytes</li>Rolling cumulative - key is set to the value of itself added with a cumulative addition of the position in the bytes<li></li><li>Rolling cumulative (self) - key is set to the value of itself XOR'd with the previous chunk of bytes (where the chunk size is equal to key size)</li></ul>";
this.infoURL = "https://wikipedia.org/wiki/XOR";
this.inputType = "ArrayBuffer";
this.outputType = "byteArray";
@ -35,7 +35,7 @@ class XOR extends Operation {
{
"name": "Scheme",
"type": "option",
"value": ["Standard", "Input differential", "Output differential", "Cascade"]
"value": ["Standard", "Input differential", "Output differential", "Cascade", "Rolling", "Rolling cumulative", "Rolling cumulative (self)"]
},
{
"name": "Null preserving",
@ -55,6 +55,31 @@ class XOR extends Operation {
const key = Utils.convertToByteArray(args[0].string || "", args[0].option),
[, scheme, nullPreserving] = args;
if (scheme.startswith("Rolling") && key.length) {
const inputChunks = Utils.chunked(input, key.length);
let runningIndex = 0;
let runningKey = key;
let xorred = null;
return inputChunks.reduce((result, current, index) => {
runningIndex += index;
switch (scheme) {
case "Rolling": // key = key + index
return result.concat(bitOp(current, key.map(x => add(x, index)), xor, nullPreserving, scheme));
case "Rolling cumulative": // key = key + index + previous
return result.concat(bitOp(current, key.map(x => add(x, runningIndex)), xor, nullPreserving, scheme));
case "Rolling cumulative (self)": // key = key XOR previous chunk
// Xor this chunk
xorred = bitOp(current, runningKey, xor, nullPreserving, scheme));
// Update the running key for next part of loop
runningKey = bitOp(runningKey, current, xor, nullPreserving, scheme));
// Return the result with the newest xor'd chunk
return result.concat(xorred);
}
}, Utils.strToByteArray(""));
}
return bitOp(input, key, xor, nullPreserving, scheme);
}