node-decipher/cipher.js at main · ClementPF/node-decipher · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
const { decypher } = require("./utils");

const getRandomMapping = () => {
  let i = 0;
  const map = {};
  const a = "a".charCodeAt(0);
  while (i < 26) {
    const charCode = Math.floor(Math.random() * 26);
    const char = String.fromCharCode(a + charCode);
    if (Object.values(map).includes(char)) continue;

    map[String.fromCharCode(a + i)] = char;
    i++;
  }
  return map;
};

const offsetMap = (offset) => {
  let i = 0;
  const map = {};
  const a = "a".charCodeAt(0);
  while (i < 26) {
    const charCode = (i + offset) % 26;
    const char = String.fromCharCode(a + charCode);
    map[String.fromCharCode(a + i)] = char;
    i++;
  }
  return map;
};

cipherString = (string) => {
  const map = getRandomMapping();
  return { map, cipher: decypher(string, map) };
};

cipherCeasarString = (string) => {
  const map = offsetMap(1);
  return { map, cipher: decypher(string, map) };
};
module.exports = cipherString;