X25519 class abstract

X25519 (RFC 7748) KeyExchangeAlgorithm.

X25519 is an elliptic curve Diffie-Hellman key exchange algorithm that uses Curve25519.

By default, DartX25519 will be used. If you use Flutter, you can enable cryptography_flutter. It can improve performance in many cases.

Things to know

• Private key is any 32 bytes (SimpleKeyPair).
• Public key is 32 bytes (SimplePublicKey).
• Output is 32 bytes.
• You can use package:jwk to encode/decode JSON Web Key (JWK) data.

Example

import 'package:cryptography/cryptography.dart';

Future<void> main() async {
  final algorithm = X25519();

  // We need the private key pair of Alice.
  final aliceKeyPair = await algorithm.newKeyPair();

  // We need only public key of Bob.
  final bobKeyPair = await algorithm.newKeyPair();
  final bobPublicKey = await bobKeyPair.extractPublicKey();

  // We can now calculate a 32-byte shared secret key.
  final sharedSecretKey = await algorithm.sharedSecretKey(
    keyPair: aliceKeyPair,
    remotePublicKey: bobPublicKey,
  );
}

## In need of synchronous APIs?

If you need to perform operations synchronously, use [DartX25519] in
_package:cryptography/dart.dart_.

Inheritance

• Object
• KeyExchangeAlgorithm
• X25519

Implementers

• DartX25519

Constructors

X25519()

factory

X25519.constructor({Random? random})

Constructor for classes that extend this class.

const

Properties

hashCode → int

The hash code for this object.

no setter, inherited

keyPairType → KeyPairType<KeyPairData, PublicKey>

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

newKeyExchangeWand() → Future<KeyExchangeWand>

Returns a new KeyExchangeWand that has a random KeyPair.

inherited

newKeyExchangeWandFromKeyPair(KeyPair keyPair) → Future<KeyExchangeWand>

Returns a new KeyExchangeWand that uses the given KeyPair.

inherited

newKeyPair() → Future<SimpleKeyPair>

Generates a new KeyPair that can be used with this algorithm.

override

newKeyPairFromSeed(List<int> seed) → Future<SimpleKeyPair>

Generates a key pair from the seed.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

sharedSecretKey({required KeyPair keyPair, required PublicKey remotePublicKey}) → Future<SecretKey>

Calculates a shared SecretKey.

inherited

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited