/*
* Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of 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.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project 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
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* <http://www.gnu.org/licenses/> or <http://www.apache.org/licenses/LICENSE-2.0>.
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.nutsnbolts.security.ssh;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import org.smallmind.nutsnbolts.http.Base64Codec;
public class PKCS8KeyReader implements SSHKeyReader {
@Override
public SSHKeyFactors extractFactors (String raw)
throws IOException, NoSuchAlgorithmException, InvalidKeySpecException, SSHParseException {
try (DataInputStream dataInputStream = new DataInputStream(new ByteArrayInputStream(Base64Codec.decode(raw)))) {
if (!"ssh-rsa".equals(new String(readBytes(dataInputStream)))) {
throw new SSHParseException("Missing RFC-416 'ssh-rsa' prologue");
}
byte[] exponentBytes = readBytes(dataInputStream);
byte[] modulusBytes = readBytes(dataInputStream);
return new SSHKeyFactors(new BigInteger(modulusBytes), new BigInteger(exponentBytes));
}
}
private byte[] readBytes (DataInputStream dataInputStream)
throws IOException {
byte[] bytes = new byte[dataInputStream.readInt()];
dataInputStream.readFully(bytes);
return bytes;
}
}