CryptoFunction (Exonum Java Binding: Common 0.6.0 API)

All Known Implementing Classes:

Ed25519CryptoFunction
```
public interface CryptoFunction
```
A crypto function that provides several signature system crypto methods. All method arguments can't be null otherwise NullPointerException will be thrown.

Method Summary

Modifier and Type	Method	Description
`KeyPair`	`generateKeyPair()`	Generates a private key and a corresponding public key using a random seed.
`KeyPair`	`generateKeyPair(byte[] seed)`	Generates a private key and a corresponding public key using a `seed` byte array.
`byte[]`	`signMessage(byte[] message, PrivateKey privateKey)`	Given a `privateKey`, computes and returns a signature for the supplied `message`.
`boolean`	`verify(byte[] message, byte[] signature, PublicKey publicKey)`	Given a `publicKey`, verifies that `signature` is a valid signature for the supplied `message`.

- Method Detail
  - generateKeyPair
```
KeyPair generateKeyPair(byte[] seed)
```
    Generates a private key and a corresponding public key using a seed byte array.
    
    Throws:
    
    IllegalArgumentException - if the specified seed is not valid
  - generateKeyPair
```
KeyPair generateKeyPair()
```
    Generates a private key and a corresponding public key using a random seed.
  - signMessage
```
byte[] signMessage(byte[] message,
                   PrivateKey privateKey)
```
    Given a privateKey, computes and returns a signature for the supplied message.
    
    Returns:
    
    signature as a byte array
    
    Throws:
    
    IllegalArgumentException - if the private key is not valid for this cryptographic function
  - verify
```
boolean verify(byte[] message,
               byte[] signature,
               PublicKey publicKey)
```
    Given a publicKey, verifies that signature is a valid signature for the supplied message.
    
    Returns:
    
    true if signature is valid, false otherwise