com.jcraft.jsch

Interface SignatureDSA

All Superinterfaces:

Signature

public interface SignatureDSA
extends Signature

Usually not to be used by applications. A DSA signing or signature checking algorithm.

This interface is a slimmed down and specialized (on DSA) version of Signature.

It will be used by the library to check the server's signature during key exchange, and to prove our own possession of the private key for public-key authentication in the default Identity implementation.

The library will choose the implementation class by the configuration option signature.dsa, and instantiate it using the no-argument constructor. For signature checking, the usage would look like this:

  sig = class.newInstance();
  sig.init();
  sig.setPubKey(y, p, q, g);
  sig.update(H); // maybe more than once
  boolean ok = sig.verify(sig_of_H);

For signing, the usage would look like this:

  sig = class.newInstance();
  sig.init();
  sig.setPrvKey(x, p, q, g);
  sig.update(H); // maybe more than once
  byte[] sig_of_H = sig.sign();

The library contains a default implementation based on Signature.

See Also:

SignatureRSA

Method Summary

Modifier and Type	Method and Description
void	setPrvKey(byte[] x, byte[] p, byte[] q, byte[] g) Sets the private key and prepares this signature object for signing.
void	setPubKey(byte[] y, byte[] p, byte[] q, byte[] g) Sets the public key and prepares this signature object for signature verifying.

Methods inherited from interface com.jcraft.jsch.Signature

init, sign, update, verify

Method Detail

setPubKey

void setPubKey(byte[] y,
               byte[] p,
               byte[] q,
               byte[] g)
        throws Exception

Sets the public key and prepares this signature object for signature verifying.

Parameters:

y - the public key y = g^x mod p.

p - the big prime

q - the small prime

g - the generator

Throws:

Exception

See Also:

KeyPairGenDSA

setPrvKey

void setPrvKey(byte[] x,
               byte[] p,
               byte[] q,
               byte[] g)
        throws Exception

Sets the private key and prepares this signature object for signing.

Parameters:

x - the private key

p - the big prime

q - the small prime

g - the generator

Throws:

Exception

See Also:

KeyPairGenDSA