/* Certificate.java -- SSL Certificate message.
   Copyright (C) 2003  Casey Marshall <rsdio@metastatic.org>

This file is a part of Jessie.

Jessie is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.

Jessie 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
for more details.

You should have received a copy of the GNU General Public License along
with Jessie; if not, write to the

   Free Software Foundation, Inc.,
   59 Temple Place, Suite 330,
   Boston, MA  02111-1307
   USA

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under terms
of your choice, provided that you also meet, for each linked independent
module, the terms and conditions of the license of that module.  An
independent module is a module which is not derived from or based on
this library.  If you modify this library, you may extend this exception
to your version of the library, but you are not obligated to do so.  If
you do not wish to do so, delete this exception statement from your
version.  */


package org.metastatic.jessie.provider;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.StringReader;
import java.io.StringWriter;

import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import java.util.LinkedList;

import javax.net.ssl.SSLProtocolException;

final class Certificate implements Handshake.Body
{

  // Fields.
  // -------------------------------------------------------------------------

  private final X509Certificate[] certs;

  // Constructors.
  // -------------------------------------------------------------------------

  Certificate(X509Certificate[] certs)
  {
    if (certs == null)
      {
        throw new NullPointerException();
      }
    this.certs = certs;
  }

  // Class methods.
  // -------------------------------------------------------------------------

  static Certificate read(InputStream in, CertificateType type)
    throws IOException
  {
    if (type == CertificateType.X509)
      {
        int len = (in.read() & 0xFF) << 16 | (in.read() & 0xFF) << 8
                | (in.read() & 0xFF);
        byte[] buf = new byte[len];
        int count = 0;
        while (count < len)
          {
            int l = in.read(buf, count, len - count);
            if (l == -1)
              {
                throw new EOFException("unexpected end of stream");
              }
            count += l;
          }
        try
          {
            LinkedList certs = new LinkedList();
            CertificateFactory fact = CertificateFactory.getInstance("X.509");
            ByteArrayInputStream bin = new ByteArrayInputStream(buf);
            count = 0;
            while (count < len)
              {
                int len2 = (bin.read() & 0xFF) << 16 | (bin.read() & 0xFF) << 8
                         | (bin.read() & 0xFF);
                certs.add(fact.generateCertificate(bin));
                count += len2 + 3;
              }
            return new Certificate((X509Certificate[])
              certs.toArray(new X509Certificate[certs.size()]));
          }
        catch (CertificateException ce)
          {
            SSLProtocolException sslpe = new SSLProtocolException(ce.getMessage());
            sslpe.initCause (ce);
            throw sslpe;
          }
      }
    else if (type == CertificateType.OPEN_PGP)
      {
        throw new UnsupportedOperationException("not yet implemented");
      }
    else
      throw new Error("unsupported certificate type "+type);
  }

  // Instance methods.
  // -------------------------------------------------------------------------

  public void write(OutputStream out) throws IOException
  {
    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    try
      {
        for (int i = 0; i < certs.length; i++)
          {
            byte[] enc = certs[i].getEncoded();
            bout.write((enc.length >>> 16) & 0xFF);
            bout.write((enc.length >>>  8) & 0xFF);
            bout.write( enc.length & 0xFF);
            bout.write(enc);
          }
      }
    catch (CertificateEncodingException cee)
      {
        throw new Error("cannot encode certificates");
      }
    catch (IOException ignored)
      {
      }
    out.write(bout.size() >>> 16 & 0xFF);
    out.write(bout.size() >>>  8 & 0xFF);
    out.write(bout.size() & 0xFF);
    bout.writeTo(out);
  }

  X509Certificate[] getCertificates()
  {
    return certs;
  }

  public String toString()
  {
    StringWriter str = new StringWriter();
    PrintWriter out = new PrintWriter(str);
    out.println("struct {");
    out.println("  certificateList =");
    for (int i = 0; i < certs.length; i++)
      {
        BufferedReader r =
          new BufferedReader(new StringReader(certs[i].toString()));
        String s;
        try
          {
            while ((s = r.readLine()) != null)
              {
                out.print("    ");
                out.println(s);
              }
          }
        catch (IOException ignored)
          {
          }
      }
    out.println("} Certificate;");
    return str.toString();
  }
}