iaik.xml.crypto.alg.signature

Class DSASHA1ProxySignature

java.lang.Object

java.security.SignatureSpi

iaik.xml.crypto.alg.signature.ProxySignature

iaik.xml.crypto.alg.signature.DSASHA1ProxySignature

public class DSASHA1ProxySignature
extends ProxySignature

This Signature implements the DSA signature method as specified in XML-Signature Syntax and Processing, Section 6.4.1.

Field Summary

Fields inherited from class iaik.xml.crypto.alg.signature.ProxySignature

signature_

Fields inherited from class java.security.SignatureSpi

appRandom

Constructor Summary

Constructors

Constructor and Description
DSASHA1ProxySignature() Creates a new instance of this DSAProxySignatureEngine.

Method Summary

Modifier and Type	Method and Description
protected byte[]	engineSign()
protected boolean	engineVerify(byte[] sigBytes)
protected String	getSignatureName() Returns an instance of the signature engine used to delegate all cryptographic operations to.
protected byte[]	removeSignumAndAlign20(byte[] signedInteger) Receives the byte representation of a POSITIVE integer value as two's-complement representation.

Methods inherited from class iaik.xml.crypto.alg.signature.ProxySignature

engineGetParameter, engineGetParameters, engineInitSign, engineInitSign, engineInitVerify, engineSetParameter, engineSetParameter, engineSign, engineUpdate, engineUpdate, engineUpdate, engineVerify, getInstance, getInstanceUncaught

Methods inherited from class java.security.SignatureSpi

clone

Methods inherited from class java.lang.Object

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

Constructor Detail

DSASHA1ProxySignature

public DSASHA1ProxySignature()
                      throws NoSuchAlgorithmException,
                             NoSuchProviderException

Creates a new instance of this DSAProxySignatureEngine.

Throws:

NoSuchAlgorithmException

NoSuchProviderException

Method Detail

getSignatureName

protected String getSignatureName()

Description copied from class: ProxySignature

Returns an instance of the signature engine used to delegate all cryptographic operations to.

Specified by:

getSignatureName in class ProxySignature

Returns:

an instance of the signature engine

See Also:

ProxySignature.getSignatureName()

engineVerify

protected boolean engineVerify(byte[] sigBytes)
                        throws SignatureException

Overrides:

engineVerify in class ProxySignature

Throws:

SignatureException

See Also:

SignatureSpi.engineVerify(byte[])

engineSign

protected byte[] engineSign()
                     throws SignatureException

Overrides:

engineSign in class ProxySignature

Throws:

SignatureException

See Also:

SignatureSpi.engineSign()

removeSignumAndAlign20

protected byte[] removeSignumAndAlign20(byte[] signedInteger)

Receives the byte representation of a POSITIVE integer value as two's-complement representation. If the sign bit occupies a whole byte of its own (the least significant byte of the array), this byte is removed. Finally bytes with value 0 are added until the length of the byte array reaches a value of 20. For instance, the hex value "001B" is firstly changed to "1B", finally it will be expanded to "000000000000000000000000000000000000001B".
Please note:

• Parameter signedInteger must not contain more than 21 bytes.
• Parameter signedInteger must not represent a negative integer.

Parameters:

signedInteger - The two's-complement byte representation of a POSITIVE integer value.

Returns:

the expanded representation as shown above.