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package org.eclipse.jgit.transport;

import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.transport.PushCertificate.NonceStatus;

A NonceGenerator is used to create a nonce to be sent out to the pusher who
will sign the nonce to prove it is not a replay attack on the push
certificate.
Since:
4.0/**
 * A NonceGenerator is used to create a nonce to be sent out to the pusher who
 * will sign the nonce to prove it is not a replay attack on the push
 * certificate.
 *
 * @since 4.0
 */
public interface NonceGenerator {

	
Create nonce to be signed by the pusher
Params:
db – 
           The repository which should be used to obtain a unique String
           such that the pusher cannot forge nonces by pushing to another
           repository at the same time as well and reusing the nonce.
timestamp – 
           The current time in seconds.
Throws:
IllegalStateException – 
Returns:
The nonce to be signed by the pusher/**
	 * Create nonce to be signed by the pusher
	 *
	 * @param db
	 *            The repository which should be used to obtain a unique String
	 *            such that the pusher cannot forge nonces by pushing to another
	 *            repository at the same time as well and reusing the nonce.
	 * @param timestamp
	 *            The current time in seconds.
	 * @return The nonce to be signed by the pusher
	 * @throws java.lang.IllegalStateException
	 */
	String createNonce(Repository db, long timestamp)
			throws IllegalStateException;

	
Verify trustworthiness of the received nonce.
Params:
received – 
           The nonce which was received from the server
sent – 
           The nonce which was originally sent out to the client.
db – 
           The repository which should be used to obtain a unique String
           such that the pusher cannot forge nonces by pushing to another
           repository at the same time as well and reusing the nonce.
allowSlop – 
           If the receiving backend is able to generate slop. This is
           the case for serving via http protocol using more than one
           http frontend. The client would talk to different http
           frontends, which may have a slight difference of time due to
slop – 
           If `allowSlop` is true, this specifies the number of seconds
           which we allow as slop.
Returns:
a NonceStatus indicating the trustworthiness of the received
        nonce./**
	 * Verify trustworthiness of the received nonce.
	 *
	 * @param received
	 *            The nonce which was received from the server
	 * @param sent
	 *            The nonce which was originally sent out to the client.
	 * @param db
	 *            The repository which should be used to obtain a unique String
	 *            such that the pusher cannot forge nonces by pushing to another
	 *            repository at the same time as well and reusing the nonce.
	 * @param allowSlop
	 *            If the receiving backend is able to generate slop. This is
	 *            the case for serving via http protocol using more than one
	 *            http frontend. The client would talk to different http
	 *            frontends, which may have a slight difference of time due to
	 * @param slop
	 *            If `allowSlop` is true, this specifies the number of seconds
	 *            which we allow as slop.
	 * @return a NonceStatus indicating the trustworthiness of the received
	 *         nonce.
	 */
	NonceStatus verify(String received, String sent,
			Repository db, boolean allowSlop, int slop);
}