Secret key doesn't match about crystals-kyber-ts HOT 4 CLOSED

Apologies for not getting back to you sooner. If you haven't been able to resolve what's happening, I'll take a look this week.

from crystals-kyber-ts.

To revisit, each Handshake has two cipher text and secret key pairs that are generated by 2 different methods.

generateCipherTextAndSharedSecret -> Takes the remote public key and generates the "local" cipher text and secret key

When that user sends their cipher text back to the remote user, the remote user would run:

generateRemoteSharedSecret - > Take the remote user's generated cipher text and generates the "remote" cipher text and secret key.

Match ups are: Local cipher text to remote cipher text and local shared secret to remote shared secret. They will match.

Between 2 parties you could generate one pair and use one secret key, OR you could have both parties send their public keys to each other, and each party generates their local cipher and secret, then sends their cipher to the other party, who then generates the remote secret key for that cipher text.

In that case, you now have 2 separate cipher text/secret key pairs. You could always encrypt outgoing messages with your
"local" secret and decode the incoming messages with your "remote" secret. Your comms are still using a symmetric key, however you are using 2 separate keys for the traffic flow.

from crystals-kyber-ts.

I'll be posting up a repo with what I mean soon. In the meantime, here's an example using crypto-js:

import {Component} from '@angular/core';
import {Kyber1024Handshake} from "crystals-kyber-ts";
import * as CryptoJS from 'crypto-js';

@component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'kyber-ts-example';
public bobHandshake: Kyber1024Handshake;
public aliceHandshake: Kyber1024Handshake;
public alicePrivateKey: number[];
public alicePublicKey: number[];
public aliceCipherText: number[];
public bobPrivateKey: number[];
public bobPublicKey: number[];
public bobCipherText: number[] = [];
public bobRemoteCipherText: number[] = [];
bobRemoteSharedSecret: number[];
public aliceRemoteCipherText: number[] = [];
aliceRemoteSharedSecret: number[];
aliceSharedSecret: number[] = [];
bobSharedSecret: number[] = [];
bobClearText: string = "Testing encrypt and decrypt from Bob";
aliceClearText: string = "Testing encrypt and decrypt from Alice";
bobEncryptedText: string = "";
aliceEncryptedText: string = "";
bobDecryptedText: string = "";
aliceDecryptedText: string = "";
bobCipher: any;
aliceCipher: any;
bobDecipher: any;
aliceDecipher: any;

constructor() {

this.bobHandshake = new Kyber1024Handshake();
this.bobPublicKey = this.bobHandshake.publicKey;
this.bobPrivateKey = this.bobHandshake.privateKey;

this.aliceHandshake = new Kyber1024Handshake();
this.alicePublicKey = this.aliceHandshake.publicKey;
this.alicePrivateKey = this.aliceHandshake.privateKey;

// Bob sent Alice his public key and Alice generates a secret key and cipher text
this.aliceCipherText = this.aliceHandshake.generateCipherTextAndSharedSecret(this.bobPublicKey);
this.aliceSharedSecret = this.aliceHandshake.sharedSecret;
// Alice sends her generated Cipher text to Bob so that Bob can generate the same Secret Key that Alice now has
this.bobRemoteSharedSecret = this.bobHandshake.generateRemoteSharedSecret(this.aliceCipherText);
this.bobRemoteCipherText = this.bobHandshake.remoteCipherText;
// Bob wants to send Alice his message so he encrypts it with the shared secret he generated from Alice's cipher text (which was from his public key)
this.bobEncryptedText = CryptoJS.AES.encrypt(this.bobClearText, this.bobRemoteSharedSecret.toString()).toString();

// Use Alice's hex string secret to decrypt the message received from Bob
const base64String = CryptoJS.AES.decrypt(this.bobEncryptedText, this.aliceHandshake.sharedSecret.toString()).toString(CryptoJS.enc.Utf8);
this.aliceDecryptedText = Buffer.from(base64String).toString('utf-8');
// ==================================================================
// Can use the one shared secret for further comms going back and forth.. or:

// Alice sent Bob her public key and Bob generates a secret key and cipher text
this.bobCipherText = this.bobHandshake.generateCipherTextAndSharedSecret(this.alicePublicKey);
this.bobSharedSecret = this.bobHandshake.sharedSecret;
// Bob sends his generated Cipher text to Alice so that Alice can generate the same Secret Key that Bob now has
this.aliceRemoteSharedSecret = this.aliceHandshake.generateRemoteSharedSecret(this.bobCipherText);
this.aliceRemoteCipherText = this.aliceHandshake.remoteCipherText;
// Alice wants to send Bob her message so she encrypts it with the shared secret she generated from Bob's cipher text (which was from her public key)
this.aliceEncryptedText = CryptoJS.AES.encrypt(this.aliceClearText, this.aliceRemoteSharedSecret.toString()).toString();

// Use Bob's hex string secret to decrypt the message received from Alice
const base64String2 = CryptoJS.AES.decrypt(this.aliceEncryptedText, this.bobHandshake.sharedSecret.toString()).toString(CryptoJS.enc.Utf8);
this.bobDecryptedText = Buffer.from(base64String2).toString('utf-8');

}
}

from crystals-kyber-ts.

It is unclear what caused the problem last time, but I couldn't reproduce the issue anymore. Works fine now.

from crystals-kyber-ts.