org.apache.sshd.common.signature.Signature Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.common.signature;
import java.security.PrivateKey;
import java.security.PublicKey;
import org.apache.sshd.common.AlgorithmNameProvider;
import org.apache.sshd.common.session.SessionContext;
import org.apache.sshd.common.util.NumberUtils;
/**
* Signature interface for SSH used to sign or verify packets. Usually wraps a {@code javax.crypto.Signature} object.
* The reported algorithm name refers to the signature type being applied.
*
* @author Apache MINA SSHD Project
*/
public interface Signature extends AlgorithmNameProvider {
/**
* @param session The {@link SessionContext} for calling this method - may be {@code null} if not called within a
* session context
* @param key The {@link PublicKey} to be used for verifying signatures
* @throws Exception If failed to initialize
*/
void initVerifier(SessionContext session, PublicKey key) throws Exception;
/**
* @param session The {@link SessionContext} for calling this method - may be {@code null} if not called within a
* session context
* @param key The {@link PrivateKey} to be used for signing
* @throws Exception If failed to initialize
*/
void initSigner(SessionContext session, PrivateKey key) throws Exception;
/**
* Update the computed signature with the given data
*
* @param session The {@link SessionContext} for calling this method - may be {@code null} if not called within a
* session context
* @param hash The hash data buffer
* @throws Exception If failed to update
* @see #update(SessionContext, byte[], int, int)
*/
default void update(SessionContext session, byte[] hash) throws Exception {
update(session, hash, 0, NumberUtils.length(hash));
}
/**
* Update the computed signature with the given data
*
* @param session The {@link SessionContext} for calling this method - may be {@code null} if not called within a
* session context
* @param hash The hash data buffer
* @param off Offset of hash data in buffer
* @param len Length of hash data
* @throws Exception If failed to update
*/
void update(SessionContext session, byte[] hash, int off, int len) throws Exception;
/**
* Verify against the given signature
*
* @param session The {@link SessionContext} for calling this method - may be {@code null} if not called within a
* session context
* @param sig The signed data
* @return {@code true} if signature is valid
* @throws Exception If failed to extract signed data for validation
*/
boolean verify(SessionContext session, byte[] sig) throws Exception;
/**
* Compute the signature
*
* @param session The {@link SessionContext} for calling this method - may be {@code null} if not called within a
* session context
* @return The signature value
* @throws Exception If failed to calculate the signature
*/
byte[] sign(SessionContext session) throws Exception;
/**
* @param algo - the negotiated value
* @return The original ssh name of the signature algorithm
*/
default String getSshAlgorithmName(String algo) {
return algo;
}
}