Riskless/static/js/modules/crypto/rsa.js
2023-03-13 14:52:14 +00:00

59 lines
1.3 KiB
JavaScript

import { generate_prime } from "./random_primes.js";
import { mod_exp, mod_inv } from "./math.js";
export class RsaPubKey {
constructor(n, e) {
this.n = n;
this.e = e;
}
encrypt(m) {
return mod_exp(m, this.e, this.n);
}
toJSON() {
return {
n: "0x" + this.n.toString(16),
e: "0x" + this.e.toString(16),
};
}
static fromJSON(data) {
return new RsaPubKey(BigInt(data.n), BigInt(data.e));
}
}
class RsaPrivKey {
constructor(p, q) {
this.n = p * q;
this.d = mod_inv(65537n, (q - 1n) * (p - 1n));
}
decrypt(c) {
return mod_exp(c, this.d, this.n);
}
}
export function generate_rsa_keypair() {
let p, q, pubKey, privKey;
if (window.sessionStorage.getItem("rsa_p") === null) {
p = generate_prime();
window.sessionStorage.setItem("rsa_p", p);
} else {
p = BigInt(window.sessionStorage.getItem("rsa_p"));
}
if (window.sessionStorage.getItem("rsa_q") === null) {
q = generate_prime();
window.sessionStorage.setItem("rsa_q", q);
} else {
q = BigInt(window.sessionStorage.getItem("rsa_q"));
}
pubKey = new RsaPubKey(p * q, 65537n);
privKey = new RsaPrivKey(p, q);
return { pubKey, privKey };
}