DiffieHellman - crypto - Node

class DiffieHellman

Usage in Deno

import { DiffieHellman } from "node:crypto";

The DiffieHellman class is a utility for creating Diffie-Hellman key exchanges.

Instances of the DiffieHellman class can be created using the createDiffieHellman function.

import assert from 'node:assert';

const {
  createDiffieHellman,
} = await import('node:crypto');

// Generate Alice's keys...
const alice = createDiffieHellman(2048);
const aliceKey = alice.generateKeys();

// Generate Bob's keys...
const bob = createDiffieHellman(alice.getPrime(), alice.getGenerator());
const bobKey = bob.generateKeys();

// Exchange and generate the secret...
const aliceSecret = alice.computeSecret(bobKey);
const bobSecret = bob.computeSecret(aliceKey);

// OK
assert.strictEqual(aliceSecret.toString('hex'), bobSecret.toString('hex'));

Constructors

new



DiffieHellman()

Properties



verifyError: number

A bit field containing any warnings and/or errors resulting from a check performed during initialization of the DiffieHellman object.

The following values are valid for this property (as defined in node:constants module):

DH_CHECK_P_NOT_SAFE_PRIME
DH_CHECK_P_NOT_PRIME
DH_UNABLE_TO_CHECK_GENERATOR
DH_NOT_SUITABLE_GENERATOR

Methods



computeSecret(otherPublicKey: ArrayBufferView,
inputEncoding?: null,
outputEncoding?: null,
): Buffer

Computes the shared secret using otherPublicKey as the other party's public key and returns the computed shared secret. The supplied key is interpreted using the specified inputEncoding, and secret is encoded using specified outputEncoding. If the inputEncoding is not provided, otherPublicKey is expected to be a Buffer, TypedArray, or DataView.

If outputEncoding is given a string is returned; otherwise, a Buffer is returned.



computeSecret(otherPublicKey: string,
inputEncoding: BinaryToTextEncoding,
outputEncoding?: null,
): Buffer



computeSecret(otherPublicKey: ArrayBufferView,
inputEncoding: null,
outputEncoding: BinaryToTextEncoding,
): string



computeSecret(otherPublicKey: string,
inputEncoding: BinaryToTextEncoding,
outputEncoding: BinaryToTextEncoding,
): string



generateKeys(): Buffer

Generates private and public Diffie-Hellman key values unless they have been generated or computed already, and returns the public key in the specified encoding. This key should be transferred to the other party. If encoding is provided a string is returned; otherwise a Buffer is returned.

This function is a thin wrapper around DH_generate_key(). In particular, once a private key has been generated or set, calling this function only updates the public key but does not generate a new private key.



generateKeys(encoding: BinaryToTextEncoding): string



getGenerator(): Buffer

Returns the Diffie-Hellman generator in the specified encoding. If encoding is provided a string is returned; otherwise a Buffer is returned.



getGenerator(encoding: BinaryToTextEncoding): string



getPrime(): Buffer

Returns the Diffie-Hellman prime in the specified encoding. If encoding is provided a string is returned; otherwise a Buffer is returned.



getPrime(encoding: BinaryToTextEncoding): string



getPrivateKey(): Buffer

Returns the Diffie-Hellman private key in the specified encoding. If encoding is provided a string is returned; otherwise a Buffer is returned.



getPrivateKey(encoding: BinaryToTextEncoding): string



getPublicKey(): Buffer

Returns the Diffie-Hellman public key in the specified encoding. If encoding is provided a string is returned; otherwise a Buffer is returned.



getPublicKey(encoding: BinaryToTextEncoding): string



setPrivateKey(privateKey: ArrayBufferView): void

Sets the Diffie-Hellman private key. If the encoding argument is provided,privateKey is expected to be a string. If no encoding is provided, privateKey is expected to be a Buffer, TypedArray, or DataView.

This function does not automatically compute the associated public key. Either diffieHellman.setPublicKey() or diffieHellman.generateKeys() can be used to manually provide the public key or to automatically derive it.



setPrivateKey(privateKey: string,
encoding: BufferEncoding,
): void



setPublicKey(publicKey: ArrayBufferView): void

Sets the Diffie-Hellman public key. If the encoding argument is provided, publicKey is expected to be a string. If no encoding is provided, publicKey is expected to be a Buffer, TypedArray, or DataView.



setPublicKey(publicKey: string,
encoding: BufferEncoding,
): void