net.oauth.jsontoken.crypto.Signer Maven / Gradle / Ivy
/**
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package net.oauth.jsontoken.crypto;
import java.security.SignatureException;
/**
* Interface that a token signer has to implement. A Signer represents a specific
* signing key, and knows the id of this key. (The key id is an identifier by
* which a verifier can find this particular key. It does not need to be
* globally unique, but must be unique for per token issuer.) A Signer also
* belongs to a certain issuer: An issuer is the entity that issues tokens, and
* uses signers to sign them.
*/
public interface Signer {
/**
* Returns the id of this signing key. If not null, this will be included in
* the JSON Token's envelope as the key_id parameter.
*/
public String getKeyId();
/**
* The issuer of the JSON Token. Each signer belongs to an issuer, and an issuer
* may have one or more signers, each with a distinct key id.
*/
public String getIssuer();
/**
* Returns the signature algorithm used by this signer.
*/
public SignatureAlgorithm getSignatureAlgorithm();
/**
* Signs an array of bytes.
* @param source The bytes that should be signed.
* @return The signature on the bytes.
* @throws SignatureException if the signer could not create the signature.
*/
public byte[] sign(byte[] source) throws SignatureException;
}