edu.vt.middleware.crypt.signature
Class AbstractDSASignature

java.lang.Object
  edu.vt.middleware.crypt.AbstractAlgorithm
      edu.vt.middleware.crypt.signature.SignatureAlgorithm
          edu.vt.middleware.crypt.signature.AbstractDSASignature

All Implemented Interfaces:

Algorithm

Direct Known Subclasses:

DSASignature, ECDSASignature

public abstract class AbstractDSASignature
extends SignatureAlgorithm

Base class for all signatures that implement the DSA scheme.

Version:

$Revision: 2744 $

Author:

Middleware Services

Field Summary

protected org.bouncycastle.crypto.DSA

signer Signer that implements DSA algorithm.

Fields inherited from class edu.vt.middleware.crypt.signature.SignatureAlgorithm

digest, signKey, verifyKey

Fields inherited from class edu.vt.middleware.crypt.AbstractAlgorithm

algorithm, logger, randomByteSize, randomProvider

Constructor Summary

protected

AbstractDSASignature(String alg) Creates a new instance of a the given signature algorithm.

Method Summary

protected void	init(boolean forSigning, org.bouncycastle.crypto.CipherParameters params) Initialize the signer.
byte[]	sign(byte[] data) Signs the given data and returns the signature as a byte array.
byte[]	sign(InputStream in) Computes the signature of the data in the given input stream by processing in chunks.
boolean	verify(byte[] data, byte[] signature) Verifies the signature of the given data matches the given signature.
boolean	verify(InputStream in, byte[] signature) Verifies the signature of the given data matches the given signature.

Methods inherited from class edu.vt.middleware.crypt.signature.SignatureAlgorithm

clone, initSign, initVerify, newInstance, newInstance, setSignKey, setVerifyKey, sign, sign, verify, verify

Methods inherited from class edu.vt.middleware.crypt.AbstractAlgorithm

getAlgorithm, getRandomData, setRandomProvider, toString

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

signer

protected org.bouncycastle.crypto.DSA signer

Signer that implements DSA algorithm.

Constructor Detail

AbstractDSASignature

protected AbstractDSASignature(String alg)

Creates a new instance of a the given signature algorithm.

Parameters:

alg - Signature algorithm name, e.g. DSA, RSA.

Method Detail

sign

public byte[] sign(byte[] data)
            throws CryptException

Signs the given data and returns the signature as a byte array.

Overrides:

sign in class SignatureAlgorithm

Parameters:

data - Data to be signed.

Returns:

Signature of given data as byte array.

Throws:

CryptException - On signature failure.

sign

public byte[] sign(InputStream in)
            throws CryptException,
                   IOException

Computes the signature of the data in the given input stream by processing in chunks.

Overrides:

sign in class SignatureAlgorithm

Parameters:

in - Input stream containing data to be signed.

Returns:

Signature of given data as byte array.

Throws:

CryptException - On signature failure.

IOException - On input stream read errors.

verify

public boolean verify(byte[] data,
                      byte[] signature)
               throws CryptException

Verifies the signature of the given data matches the given signature.

Overrides:

verify in class SignatureAlgorithm

Parameters:

data - Data to be verified.

signature - Signature to be used for comparison.

Returns:

True if the signed data matches the given signature, false otherwise.

Throws:

CryptException - On verification failure.

verify

public boolean verify(InputStream in,
                      byte[] signature)
               throws CryptException,
                      IOException

Verifies the signature of the given data matches the given signature.

Overrides:

verify in class SignatureAlgorithm

Parameters:

in - Input stream containing data to be verified.

signature - Signature to be used for comparison.

Returns:

True if the signed data matches the given signature, false otherwise.

Throws:

CryptException - On verification failure.

IOException - On input stream read errors.

init

protected void init(boolean forSigning,
                    org.bouncycastle.crypto.CipherParameters params)

Initialize the signer.

Parameters:

forSigning - Whether to initialize signer for the sign operation.

params - BC cipher parameters.