iaik.security.dsa

Class DetSigDSAParameterSpec

java.lang.Object

java.security.spec.DSAParameterSpec

iaik.security.dsa.DetSigDSAParameterSpec

All Implemented Interfaces:

java.security.interfaces.DSAParams, java.security.spec.AlgorithmParameterSpec

public final class DetSigDSAParameterSpec
extends java.security.spec.DSAParameterSpec

Algorithm parameter to enable deterministic DSA signing following RFC 6979.

By default every time when calculating a DSA signature a new random value ("k") is required. In some environments (e.g. embedded systems) the generation of strong secure random numbers might be an extensive task. Especially for such environments RFC 6979 provides an alternative by specifying a deterministic method for calculating the value k.

To enable deterministic signing create an instance of this class and then call Signature.setParameter(AlgorithmParameterSpec):

 Signature dsa = Signature.getInstance("SHA256withDSA", IAIK.getInstance());
 dsa.setParameter(new DetSigDSAParameterSpec());
 dsa.initSign(...);
 ...
 

When using a raw DSA signature engine ("NONEwithDSA") it is necessary to announce the hash algorithm to be used for calculation of the k value, e.g. (using SHA256):

 Signature dsa = Signature.getInstance("NONEwithDSA", IAIK.getInstance());
 DetSigDSAParameterSpec paramSpec = new DetSigDSAParameterSpec("SHA256");
 dsa.setParameter(paramSpec);
 dsa.initSign(...);
 ...
 

The hash algorithm shall be the same as used for calculating the hash from the data to be signed.

References:

[1] T. Pornin, "Deterministic Usage of the Digital Signature Algorithm (DSA) and Elliptic Curve Digital Signature Algorithm (ECDSA)", https://tools.ietf.org/html/rfc6979

Constructor Summary

Constructors

Constructor and Description
DetSigDSAParameterSpec() Default constructor for enabling deterministic signing.
DetSigDSAParameterSpec(AlgorithmID hashAlg) Creates a new DetSigDSAParameterSpec for enabling deterministic signing by using the given hash algorithm when calculating the k value.
DetSigDSAParameterSpec(java.math.BigInteger p, java.math.BigInteger q, java.math.BigInteger g, boolean enableDeterministic) Creates a new DSAParameterSpec for deterministic signing with the specified parameter values.
DetSigDSAParameterSpec(java.math.BigInteger p, java.math.BigInteger q, java.math.BigInteger g, boolean enableDeterministic, AlgorithmID hashAlg) Creates a new DSAParameterSpec for deterministic signing with the specified parameter values.
DetSigDSAParameterSpec(java.math.BigInteger p, java.math.BigInteger q, java.math.BigInteger g, boolean enableDeterministic, java.lang.String hashAlg) Creates a new DSAParameterSpec for deterministic signing with the specified parameter values.
DetSigDSAParameterSpec(boolean enableDeterministic) Creates a new DetSigDSAParameterSpec for en/disabling deterministic signing.
DetSigDSAParameterSpec(boolean enableDeterministic, AlgorithmID hashAlg) Creates a new DetSigDSAParameterSpec for en/disabling deterministic signing by using the given hash algorithm when calculating the k value.
DetSigDSAParameterSpec(boolean enableDeterministic, java.lang.String hashAlg) Creates a new DetSigDSAParameterSpec for en/disabling deterministic signing by using the given hash algorithm when calculating the k value.
DetSigDSAParameterSpec(java.lang.String hashAlg) Creates a new DetSigDSAParameterSpec for enabling deterministic signing by using the given hash algorithm when calculating the k value.

Method Summary

Methods inherited from class java.security.spec.DSAParameterSpec

getG, getP, getQ

Methods inherited from class java.lang.Object

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

Constructor Detail

DetSigDSAParameterSpec

public DetSigDSAParameterSpec()

Default constructor for enabling deterministic signing.

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(java.lang.String hashAlg)

Creates a new DetSigDSAParameterSpec for enabling deterministic signing by using the given hash algorithm when calculating the k value.

Parameters:

hashAlg - the name of the hash algorithm to be used

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(AlgorithmID hashAlg)

Creates a new DetSigDSAParameterSpec for enabling deterministic signing by using the given hash algorithm when calculating the k value.

Parameters:

hashAlg - the hash algorithm to be used as AlgorithmID

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(boolean enableDeterministic)

Creates a new DetSigDSAParameterSpec for en/disabling deterministic signing.

Parameters:

enableDeterministic - flag indicating whether deterministic signing should be enabled

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(boolean enableDeterministic,
                      java.lang.String hashAlg)

Creates a new DetSigDSAParameterSpec for en/disabling deterministic signing by using the given hash algorithm when calculating the k value.

Parameters:

enableDeterministic - flag indicating whether deterministic signing should be enabled

hashAlg - the name of the hash algorithm to be used

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(boolean enableDeterministic,
                      AlgorithmID hashAlg)

Creates a new DetSigDSAParameterSpec for en/disabling deterministic signing by using the given hash algorithm when calculating the k value.

Parameters:

enableDeterministic - flag indicating whether deterministic signing should be enabled

hashAlg - the hash algorithm to be used as AlgorithmID

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(java.math.BigInteger p,
                      java.math.BigInteger q,
                      java.math.BigInteger g,
                      boolean enableDeterministic)

Creates a new DSAParameterSpec for deterministic signing with the specified parameter values.

Parameters:

p - the prime

q - the sub-prime

g - the base

enableDeterministic - flag indicating whether deterministic signing should be enabled

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(java.math.BigInteger p,
                      java.math.BigInteger q,
                      java.math.BigInteger g,
                      boolean enableDeterministic,
                      java.lang.String hashAlg)

Creates a new DSAParameterSpec for deterministic signing with the specified parameter values.

Parameters:

p - the prime

q - the sub-prime

g - the base

enableDeterministic - flag indicating whether deterministic signing should be enabled

hashAlg - the name of the hash algorithm to be used

DetSigDSAParameterSpec

public DetSigDSAParameterSpec(java.math.BigInteger p,
                      java.math.BigInteger q,
                      java.math.BigInteger g,
                      boolean enableDeterministic,
                      AlgorithmID hashAlg)

Creates a new DSAParameterSpec for deterministic signing with the specified parameter values.

Parameters:

p - the prime

q - the sub-prime

g - the base

enableDeterministic - flag indicating whether deterministic signing should be enabled

hashAlg - the hash algorithm to be used as AlgorithmID