DHG1.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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  1. Redistributions of source code must retain the above copyright notice,
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package com.jcraft.jsch;

public class DHG1 extends KeyExchange{

  static final byte[] g={ 2 };
  static final byte[] p={
(byte)0x00,
(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF, 
(byte)0xC9,(byte)0x0F,(byte)0xDA,(byte)0xA2,(byte)0x21,(byte)0x68,(byte)0xC2,(byte)0x34,
(byte)0xC4,(byte)0xC6,(byte)0x62,(byte)0x8B,(byte)0x80,(byte)0xDC,(byte)0x1C,(byte)0xD1,
(byte)0x29,(byte)0x02,(byte)0x4E,(byte)0x08,(byte)0x8A,(byte)0x67,(byte)0xCC,(byte)0x74,
(byte)0x02,(byte)0x0B,(byte)0xBE,(byte)0xA6,(byte)0x3B,(byte)0x13,(byte)0x9B,(byte)0x22,
(byte)0x51,(byte)0x4A,(byte)0x08,(byte)0x79,(byte)0x8E,(byte)0x34,(byte)0x04,(byte)0xDD,
(byte)0xEF,(byte)0x95,(byte)0x19,(byte)0xB3,(byte)0xCD,(byte)0x3A,(byte)0x43,(byte)0x1B,
(byte)0x30,(byte)0x2B,(byte)0x0A,(byte)0x6D,(byte)0xF2,(byte)0x5F,(byte)0x14,(byte)0x37,
(byte)0x4F,(byte)0xE1,(byte)0x35,(byte)0x6D,(byte)0x6D,(byte)0x51,(byte)0xC2,(byte)0x45,
(byte)0xE4,(byte)0x85,(byte)0xB5,(byte)0x76,(byte)0x62,(byte)0x5E,(byte)0x7E,(byte)0xC6,
(byte)0xF4,(byte)0x4C,(byte)0x42,(byte)0xE9,(byte)0xA6,(byte)0x37,(byte)0xED,(byte)0x6B,
(byte)0x0B,(byte)0xFF,(byte)0x5C,(byte)0xB6,(byte)0xF4,(byte)0x06,(byte)0xB7,(byte)0xED,
(byte)0xEE,(byte)0x38,(byte)0x6B,(byte)0xFB,(byte)0x5A,(byte)0x89,(byte)0x9F,(byte)0xA5,
(byte)0xAE,(byte)0x9F,(byte)0x24,(byte)0x11,(byte)0x7C,(byte)0x4B,(byte)0x1F,(byte)0xE6,
(byte)0x49,(byte)0x28,(byte)0x66,(byte)0x51,(byte)0xEC,(byte)0xE6,(byte)0x53,(byte)0x81,
(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF,(byte)0xFF
};

  private static final int SSH_MSG_KEXDH_INIT=                     30;
  private static final int SSH_MSG_KEXDH_REPLY=                    31;

  static final int RSA=0;
  static final int DSS=1;
  private int type=0;

  private int state;

  DH dh;
//  HASH sha;

//  byte[] K;
//  byte[] H;

  byte[] V_S;
  byte[] V_C;
  byte[] I_S;
  byte[] I_C;

//  byte[] K_S;

  byte[] e;

  private Buffer buf;
  private Packet packet;

  public void init(Session session,
           byte[] V_S, byte[] V_C, byte[] I_S, byte[] I_C) throws Exception{
    this.session=session;
    this.V_S=V_S;      
    this.V_C=V_C;      
    this.I_S=I_S;      
    this.I_C=I_C;      

//    sha=new SHA1();
//    sha.init();
    try{
      Class c=Class.forName(session.getConfig("sha-1"));
      sha=(HASH)(c.newInstance());
      sha.init();
    }
    catch(Exception e){
      System.err.println(e);
    }

    buf=new Buffer();
    packet=new Packet(buf);

    try{
      Class c=Class.forName(session.getConfig("dh"));
      dh=(DH)(c.newInstance());
      dh.init();
    }
    catch(Exception e){
      //System.err.println(e);
      throw e;
    }

    dh.setP(p);
    dh.setG(g);

    // The client responds with:
    // byte  SSH_MSG_KEXDH_INIT(30)
    // mpint e <- g^x mod p
    //         x is a random number (1 < x < (p-1)/2)

    e=dh.getE();

    packet.reset();
    buf.putByte((byte)SSH_MSG_KEXDH_INIT);
    buf.putMPInt(e);
    session.write(packet);

    if(JSch.getLogger().isEnabled(Logger.INFO)){
      JSch.getLogger().log(Logger.INFO, 
                           "SSH_MSG_KEXDH_INIT sent");
      JSch.getLogger().log(Logger.INFO, 
                           "expecting SSH_MSG_KEXDH_REPLY");
    }

    state=SSH_MSG_KEXDH_REPLY;
  }

  public boolean next(Buffer _buf) throws Exception{
    int i,j;

    switch(state){
    case SSH_MSG_KEXDH_REPLY:
      // The server responds with:
      // byte      SSH_MSG_KEXDH_REPLY(31)
      // string    server public host key and certificates (K_S)
      // mpint     f
      // string    signature of H
      j=_buf.getInt();
      j=_buf.getByte();
      j=_buf.getByte();
      if(j!=31){
    System.err.println("type: must be 31 "+j);
    return false;
      }

      K_S=_buf.getString();
      // K_S is server_key_blob, which includes ....
      // string ssh-dss
      // impint p of dsa
      // impint q of dsa
      // impint g of dsa
      // impint pub_key of dsa
      //System.err.print("K_S: "); //dump(K_S, 0, K_S.length);
      byte[] f=_buf.getMPInt();
      byte[] sig_of_H=_buf.getString();
      /*
for(int ii=0; ii<sig_of_H.length;ii++){
  System.err.print(Integer.toHexString(sig_of_H[ii]&0xff));
  System.err.print(": ");
}
System.err.println("");
      */

      dh.setF(f);
      K=dh.getK();

      //The hash H is computed as the HASH hash of the concatenation of the
      //following:
      // string    V_C, the client's version string (CR and NL excluded)
      // string    V_S, the server's version string (CR and NL excluded)
      // string    I_C, the payload of the client's SSH_MSG_KEXINIT
      // string    I_S, the payload of the server's SSH_MSG_KEXINIT
      // string    K_S, the host key
      // mpint     e, exchange value sent by the client
      // mpint     f, exchange value sent by the server
      // mpint     K, the shared secret
      // This value is called the exchange hash, and it is used to authenti-
      // cate the key exchange.
      buf.reset();
      buf.putString(V_C); buf.putString(V_S);
      buf.putString(I_C); buf.putString(I_S);
      buf.putString(K_S);
      buf.putMPInt(e); buf.putMPInt(f);
      buf.putMPInt(K);
      byte[] foo=new byte[buf.getLength()];
      buf.getByte(foo);
      sha.update(foo, 0, foo.length);
      H=sha.digest();
      //System.err.print("H -> "); //dump(H, 0, H.length);

      i=0;
      j=0;
      j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
    ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
      String alg=Util.byte2str(K_S, i, j);
      i+=j;

      boolean result=false;

      if(alg.equals("ssh-rsa")){
    byte[] tmp;
    byte[] ee;
    byte[] n;

    type=RSA;

    j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
      ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
    tmp=new byte[j]; System.arraycopy(K_S, i, tmp, 0, j); i+=j;
    ee=tmp;
    j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
      ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
    tmp=new byte[j]; System.arraycopy(K_S, i, tmp, 0, j); i+=j;
    n=tmp;
    
//  SignatureRSA sig=new SignatureRSA();
//  sig.init();

    SignatureRSA sig=null;
    try{
      Class c=Class.forName(session.getConfig("signature.rsa"));
      sig=(SignatureRSA)(c.newInstance());
      sig.init();
    }
    catch(Exception e){
      System.err.println(e);
    }

    sig.setPubKey(ee, n);   
    sig.update(H);
    result=sig.verify(sig_of_H);

        if(JSch.getLogger().isEnabled(Logger.INFO)){
          JSch.getLogger().log(Logger.INFO, 
                               "ssh_rsa_verify: signature "+result);
        }

      }
      else if(alg.equals("ssh-dss")){
    byte[] q=null;
    byte[] tmp;
    byte[] p;
    byte[] g;
      
    type=DSS;

    j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
      ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
    tmp=new byte[j]; System.arraycopy(K_S, i, tmp, 0, j); i+=j;
    p=tmp;
    j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
      ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
    tmp=new byte[j]; System.arraycopy(K_S, i, tmp, 0, j); i+=j;
    q=tmp;
    j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
      ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
    tmp=new byte[j]; System.arraycopy(K_S, i, tmp, 0, j); i+=j;
    g=tmp;
    j=((K_S[i++]<<24)&0xff000000)|((K_S[i++]<<16)&0x00ff0000)|
      ((K_S[i++]<<8)&0x0000ff00)|((K_S[i++])&0x000000ff);
    tmp=new byte[j]; System.arraycopy(K_S, i, tmp, 0, j); i+=j;
    f=tmp;
//  SignatureDSA sig=new SignatureDSA();
//  sig.init();
    SignatureDSA sig=null;
    try{
      Class c=Class.forName(session.getConfig("signature.dss"));
      sig=(SignatureDSA)(c.newInstance());
      sig.init();
    }
    catch(Exception e){
      System.err.println(e);
    }
    sig.setPubKey(f, p, q, g);   
    sig.update(H);
    result=sig.verify(sig_of_H);

        if(JSch.getLogger().isEnabled(Logger.INFO)){
          JSch.getLogger().log(Logger.INFO, 
                               "ssh_dss_verify: signature "+result);
        }

      }
      else{
    System.err.println("unknown alg");
      }     
      state=STATE_END;
      return result;
    }
    return false;
  }

  public String getKeyType(){
    if(type==DSS) return "DSA";
    return "RSA";
  }

  public int getState(){return state; }
}