KeyPairDSA.java

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/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/*
Copyright (c) 2002-2011 ymnk, JCraft,Inc. All rights reserved.

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modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.

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     notice, this list of conditions and the following disclaimer in 
     the documentation and/or other materials provided with the distribution.

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     derived from this software without specific prior written permission.

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*/

package com.jcraft.jsch;

public class KeyPairDSA extends KeyPair{
  private byte[] P_array;
  private byte[] Q_array;
  private byte[] G_array;
  private byte[] pub_array;
  private byte[] prv_array;

  //private int key_size=0;
  private int key_size=1024;

  public KeyPairDSA(JSch jsch){
    super(jsch);
  }

  void generate(int key_size) throws JSchException{
    this.key_size=key_size;
    try{
      Class c=Class.forName(jsch.getConfig("keypairgen.dsa"));
      KeyPairGenDSA keypairgen=(KeyPairGenDSA)(c.newInstance());
      keypairgen.init(key_size);
      P_array=keypairgen.getP();
      Q_array=keypairgen.getQ();
      G_array=keypairgen.getG();
      pub_array=keypairgen.getY();
      prv_array=keypairgen.getX();

      keypairgen=null;
    }
    catch(Exception e){
      //System.err.println("KeyPairDSA: "+e); 
      if(e instanceof Throwable)
        throw new JSchException(e.toString(), (Throwable)e);
      throw new JSchException(e.toString());
    }
  }

  private static final byte[] begin=Util.str2byte("-----BEGIN DSA PRIVATE KEY-----");
  private static final byte[] end=Util.str2byte("-----END DSA PRIVATE KEY-----");

  byte[] getBegin(){ return begin; }
  byte[] getEnd(){ return end; }

  byte[] getPrivateKey(){
    int content=
      1+countLength(1) + 1 +                           // INTEGER
      1+countLength(P_array.length) + P_array.length + // INTEGER  P
      1+countLength(Q_array.length) + Q_array.length + // INTEGER  Q
      1+countLength(G_array.length) + G_array.length + // INTEGER  G
      1+countLength(pub_array.length) + pub_array.length + // INTEGER  pub
      1+countLength(prv_array.length) + prv_array.length;  // INTEGER  prv

    int total=
      1+countLength(content)+content;   // SEQUENCE

    byte[] plain=new byte[total];
    int index=0;
    index=writeSEQUENCE(plain, index, content);
    index=writeINTEGER(plain, index, new byte[1]);  // 0
    index=writeINTEGER(plain, index, P_array);
    index=writeINTEGER(plain, index, Q_array);
    index=writeINTEGER(plain, index, G_array);
    index=writeINTEGER(plain, index, pub_array);
    index=writeINTEGER(plain, index, prv_array);
    return plain;
  }

  boolean parse(byte[] plain){
    try{

      if(vendor==VENDOR_FSECURE){
    if(plain[0]!=0x30){              // FSecure
      Buffer buf=new Buffer(plain);
      buf.getInt();
      P_array=buf.getMPIntBits();
      G_array=buf.getMPIntBits();
      Q_array=buf.getMPIntBits();
      pub_array=buf.getMPIntBits();
      prv_array=buf.getMPIntBits();
      return true;
    }
    return false;
      }

      int index=0;
      int length=0;

      if(plain[index]!=0x30)return false;
      index++; // SEQUENCE
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }

      if(plain[index]!=0x02)return false;
      index++; // INTEGER
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }
      index+=length;

      index++;
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }
      P_array=new byte[length];
      System.arraycopy(plain, index, P_array, 0, length);
      index+=length;

      index++;
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }
      Q_array=new byte[length];
      System.arraycopy(plain, index, Q_array, 0, length);
      index+=length;

      index++;
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }
      G_array=new byte[length];
      System.arraycopy(plain, index, G_array, 0, length);
      index+=length;

      index++;
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }
      pub_array=new byte[length];
      System.arraycopy(plain, index, pub_array, 0, length);
      index+=length;

      index++;
      length=plain[index++]&0xff;
      if((length&0x80)!=0){
        int foo=length&0x7f; length=0;
        while(foo-->0){ length=(length<<8)+(plain[index++]&0xff); }
      }
      prv_array=new byte[length];
      System.arraycopy(plain, index, prv_array, 0, length);
      index+=length;
    }
    catch(Exception e){
      //System.err.println(e);
      //e.printStackTrace();
      return false;
    }
    return true;
  }

  public byte[] getPublicKeyBlob(){
    byte[] foo=super.getPublicKeyBlob();
    if(foo!=null) return foo;

    if(P_array==null) return null;

    Buffer buf=new Buffer(sshdss.length+4+
              P_array.length+4+ 
              Q_array.length+4+ 
              G_array.length+4+ 
              pub_array.length+4);
    buf.putString(sshdss);
    buf.putString(P_array);
    buf.putString(Q_array);
    buf.putString(G_array);
    buf.putString(pub_array);
    return buf.buffer;
  }

  private static final byte[] sshdss=Util.str2byte("ssh-dss");
  byte[] getKeyTypeName(){return sshdss;}
  public int getKeyType(){return DSA;}

  public int getKeySize(){return key_size; }
  public void dispose(){
    super.dispose();
    Util.bzero(prv_array);
  }
}