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function convertStringToFixedNumber(input: string): number {
let hash = 0;
for (let i = 0; i < input.length; i++) {
const char = input.charCodeAt(i);
hash = (hash * 31 + char) % 1000000007; // Hashing by a large prime number
}
return hash;
}
const chars = `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-1234567890`;
const shuffled = shuffle(
chars.split(""),
convertStringToFixedNumber(process.env.BACKEND_SECURITY_KEY),
);
function random(seed: number) {
const x = Math.sin(seed++) * 10000;
return x - Math.floor(x);
}
function shuffle(array: string[], seed: number) {
let m = array.length,
t,
i;
while (m) {
i = Math.floor(random(seed) * m--);
t = array[m];
array[m] = array[i]!;
array[i] = t!;
++seed;
}
return array;
}
export const cipher = (text: string) => {
let returned_text = "";
for (let i = 0; i < text.length; i++) {
returned_text += shuffled[chars.indexOf(text[i]!)];
}
return extend(returned_text);
};
export const decipher = (text: string) => {
let returned_text = "";
const index = Math.floor(
random(convertStringToFixedNumber(process.env.BACKEND_SECURITY_KEY)) *
(text.length / 2),
);
for (let i = 0; i < text.length; i++) {
returned_text += chars[shuffled.indexOf(text[i]!)];
}
const total = parseInt(text[index]!);
const str = parseInt(text.slice(index + 1, index + total + 1));
return returned_text.slice(text.length - str);
};
const extend = (text: string, length = 60) => {
const extra = length - text.length;
if (extra < 0) {
return text;
}
// Random index to store the length of the string
const index = Math.floor(
random(convertStringToFixedNumber(process.env.BACKEND_SECURITY_KEY)) *
(length / 2),
);
const storage_string =
text.length.toString().length.toString() + text.length.toString();
let returned = "";
let total = storage_string.length + text.length;
for (let i = 0; i < extra; i++) {
if (i == index) {
returned += storage_string;
} else {
if (total >= length) {
break;
}
// Add a random character
returned += shuffled[Math.floor(random(Math.random()) * shuffled.length)];
total++;
}
}
returned += text;
return returned;
};
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