org.kercoin.magrit.sshd.auth.GitPublickeyAuthenticator.java Source code

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Here is the source code for org.kercoin.magrit.sshd.auth.GitPublickeyAuthenticator.java

Source

/*
Copyright 2011 Frederic Menou
    
This file is part of Magrit.
    
Magrit is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of
the License, or (at your option) any later version.
    
Magrit is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.
    
You should have received a copy of the GNU Affero General Public
License along with Magrit.
If not, see <http://www.gnu.org/licenses/>.
*/
package org.kercoin.magrit.sshd.auth;

import java.io.IOException;
import java.security.PublicKey;

import org.apache.sshd.server.PublickeyAuthenticator;
import org.apache.sshd.server.session.ServerSession;
import org.bouncycastle.util.Arrays;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.errors.AmbiguousObjectException;
import org.eclipse.jgit.lib.Repository;
import org.kercoin.magrit.core.Context;
import org.kercoin.magrit.core.utils.GitUtils;

import com.google.inject.Inject;

public class GitPublickeyAuthenticator implements PublickeyAuthenticator {

    private final Context context;
    private final GitUtils gitUtils;

    private Repository datasource;

    @Inject
    public GitPublickeyAuthenticator(Context context, GitUtils gitUtils) {
        this.context = context;
        this.gitUtils = gitUtils;
    }

    private void open() throws IOException {
        if (this.datasource == null) {
            this.datasource = Git.open(context.configuration().getPublickeyRepositoryDir()).getRepository();
        }
    }

    @Override
    public boolean authenticate(String username, PublicKey authKey, ServerSession session) {
        try {
            open();
            PublicKey targetKey = readKeyFromRepository(username);
            return targetKey != null && areEqual(targetKey, authKey);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    boolean areEqual(PublicKey ref, PublicKey candidate) {
        return Arrays.areEqual(ref.getEncoded(), candidate.getEncoded());
    }

    private PublicKey readKeyFromRepository(String username) throws AmbiguousObjectException, Exception {
        String revstr = String.format("HEAD:keys/%s.pub", username);
        String encoded = gitUtils.show(datasource, revstr);
        if (encoded == null)
            return null;

        return new AuthorizedKeysDecoder().decodePublicKey(encoded);
    }

}