Java 类com.jcraft.jsch.Buffer 实例源码

public byte[] sign() throws Exception{
  byte[] sig=signature.sign();

  // It seems that the output from SunEC is in ASN.1,
  // so we have to convert it.
  if(sig[0]==0x30 &&                                      // in ASN.1
     ((sig[1]+2 == sig.length) ||
      ((sig[1]&0x80)!=0 && (sig[2]&0xff)+3==sig.length))){// 2bytes for len

    int index=3;
    if((sig[1]&0x80)!=0 && (sig[2]&0xff)+3==sig.length)
      index=4;

    byte[] r = new byte[sig[index]];
    byte[] s = new byte[sig[index+2+sig[index]]];
    System.arraycopy(sig, index+1, r, 0, r.length);
    System.arraycopy(sig, index+3+sig[index], s, 0, s.length);

    r = chop0(r);
    s = chop0(s);

    Buffer buf = new Buffer();
    buf.putMPInt(r);
    buf.putMPInt(s);

    sig=new byte[buf.getLength()];
    buf.setOffSet(0);
    buf.getByte(sig);
  }

  return sig;
}

public byte[] sign() throws Exception{
  byte[] sig=signature.sign();

  // It seems that the output from SunEC is in ASN.1,
  // so we have to convert it.
  if(sig[0]==0x30 &&                                      // in ASN.1
     ((sig[1]+2 == sig.length) ||
      ((sig[1]&0x80)!=0 && (sig[2]&0xff)+3==sig.length))){// 2bytes for len

    int index=3;
    if((sig[1]&0x80)!=0 && (sig[2]&0xff)+3==sig.length)
      index=4;

    byte[] r = new byte[sig[index]];
    byte[] s = new byte[sig[index+2+sig[index]]];
    System.arraycopy(sig, index+1, r, 0, r.length);
    System.arraycopy(sig, index+3+sig[index], s, 0, s.length);

    r = chop0(r);
    s = chop0(s);

    Buffer buf = new Buffer();
    buf.putMPInt(r);
    buf.putMPInt(s);

    sig=new byte[buf.getLength()];
    buf.setOffSet(0);
    buf.getByte(sig);
  }

  return sig;
}

public boolean verify(byte[] sig) throws Exception{

    // It seems that SunEC expects ASN.1 data,
    // so we have to convert it.
    if(!(sig[0]==0x30 &&                                    // not in ASN.1
         ((sig[1]+2 == sig.length) ||
          ((sig[1]&0x80)!=0 && (sig[2]&0xff)+3==sig.length)))) {
      Buffer b = new Buffer(sig);

      b.getString();  // ecdsa-sha2-nistp256
      b.getInt();

      byte[] r = b.getMPInt();
      byte[] s = b.getMPInt();

      r=insert0(r);
      s=insert0(s);

      byte[] asn1 = null;
      if(r.length<64){
        asn1 = new byte[6+r.length+s.length];
        asn1[0] = (byte)0x30;
        asn1[1] = (byte)(4+r.length+s.length);
        asn1[2] = (byte)0x02;
        asn1[3] = (byte)r.length;
        System.arraycopy(r, 0, asn1, 4, r.length);
        asn1[r.length+4] = (byte)0x02;
        asn1[r.length+5] = (byte)s.length;
        System.arraycopy(s, 0, asn1, (6+r.length), s.length);
      }
      else {
        asn1 = new byte[6+r.length+s.length+1];
        asn1[0] = (byte)0x30;
        asn1[1] = (byte)0x81;
        asn1[2] = (byte)(4+r.length+s.length);
        asn1[3] = (byte)0x02;
        asn1[4] = (byte)r.length;
        System.arraycopy(r, 0, asn1, 5, r.length);
        asn1[r.length+5] = (byte)0x02;
        asn1[r.length+6] = (byte)s.length;
        System.arraycopy(s, 0, asn1, (7+r.length), s.length);
      }
      sig=asn1;
    }

    return signature.verify(sig); 
  }

public boolean verify(byte[] sig) throws Exception{

    // It seems that SunEC expects ASN.1 data,
    // so we have to convert it.
    if(!(sig[0]==0x30 &&                                    // not in ASN.1
         ((sig[1]+2 == sig.length) ||
          ((sig[1]&0x80)!=0 && (sig[2]&0xff)+3==sig.length)))) {
      Buffer b = new Buffer(sig);

      b.getString();  // ecdsa-sha2-nistp256
      b.getInt();

      byte[] r = b.getMPInt();
      byte[] s = b.getMPInt();

      r=insert0(r);
      s=insert0(s);

      byte[] asn1 = null;
      if(r.length<64){
        asn1 = new byte[6+r.length+s.length];
        asn1[0] = (byte)0x30;
        asn1[1] = (byte)(4+r.length+s.length);
        asn1[2] = (byte)0x02;
        asn1[3] = (byte)r.length;
        System.arraycopy(r, 0, asn1, 4, r.length);
        asn1[r.length+4] = (byte)0x02;
        asn1[r.length+5] = (byte)s.length;
        System.arraycopy(s, 0, asn1, (6+r.length), s.length);
      }
      else {
        asn1 = new byte[6+r.length+s.length+1];
        asn1[0] = (byte)0x30;
        asn1[1] = (byte)0x81;
        asn1[2] = (byte)(4+r.length+s.length);
        asn1[3] = (byte)0x02;
        asn1[4] = (byte)r.length;
        System.arraycopy(r, 0, asn1, 5, r.length);
        asn1[r.length+5] = (byte)0x02;
        asn1[r.length+6] = (byte)s.length;
        System.arraycopy(s, 0, asn1, (7+r.length), s.length);
      }
      sig=asn1;
    }

    return signature.verify(sig); 
  }