de.flexiprovider.core.dsa
Class DSASignature

java.lang.Object
  |
  +--java.security.SignatureSpi
        |
        +--de.flexiprovider.api.Signature
              |
              +--de.flexiprovider.core.dsa.interfaces.DSASignature
                    |
                    +--de.flexiprovider.core.dsa.DSASignature

Direct Known Subclasses:

DSASignature.Raw, DSASignature.SHA1, DSASignature.SHA224, DSASignature.SHA256, DSASignature.SHA384, DSASignature.SHA512

public abstract class DSASignature

extends DSASignature

Inner Class Summary

static class	DSASignature.Raw Inner class providing DSA without message digest
static class	DSASignature.SHA1 DSA with SHA1.
static class	DSASignature.SHA224 DSA with SHA224.
static class	DSASignature.SHA256 DSA with SHA256.
static class	DSASignature.SHA384 DSA with SHA384.
static class	DSASignature.SHA512 DSA with SHA512.

Fields inherited from class java.security.SignatureSpi

appRandom

Constructor Summary

protected

DSASignature(MessageDigest md) Constructor.

Method Summary

void	initSign(PrivateKey privKey, SecureRandom random) Initialize the signature algorithm for signing a message.
void	initVerify(PublicKey pubKey) Initialize the signature algorithm for verifying a signature.
void	setParameters(AlgorithmParameterSpec params) Initialize this signature engine with the specified parameter set.
byte[]	sign() Signs a message.
void	update(byte b) Pass a message byte to the message digest.
void	update(byte[] b, int offset, int length) Pass message bytes to the message digest.
boolean	verify(byte[] sigBytes) Verifies a signature.

Methods inherited from class de.flexiprovider.core.dsa.interfaces.DSASignature

engineSetParameter

Methods inherited from class de.flexiprovider.api.Signature

engineGetParameter, engineInitSign, engineInitSign, engineInitVerify, engineSetParameter, engineSign, engineUpdate, engineUpdate, engineVerify, engineVerify, initSign, sign, update, verify, verify, verify

Methods inherited from class java.security.SignatureSpi

clone, engineSign

Methods inherited from class java.lang.Object

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

Constructor Detail

DSASignature

protected DSASignature(MessageDigest md)

Constructor.

Parameters:

md - the message digest to use

Method Detail

initSign

public void initSign(PrivateKey privKey,
                     SecureRandom random)
              throws InvalidKeyException

Initialize the signature algorithm for signing a message.

Overrides:

initSign in class Signature

Parameters:

privKey - the private key of the signer

random - the source of randomness

Throws:

InvalidKeyException - if the key is not an instance of DSAPrivKey.

initVerify

public void initVerify(PublicKey pubKey)
                throws InvalidKeyException

Initialize the signature algorithm for verifying a signature.

Overrides:

initVerify in class Signature

Parameters:

pubKey - the public key of the signer.

Throws:

InvalidKeyException - if the public key is not an instance of DSAPubKey.

setParameters

public void setParameters(AlgorithmParameterSpec params)
                   throws InvalidAlgorithmParameterException

Initialize this signature engine with the specified parameter set.

Overrides:

setParameters in class Signature

Parameters:

params - the parameters

Throws:

InvalidAlgorithmParameterException - if the given parameters are inappropriate for this signature engine

update

public void update(byte b)

Pass a message byte to the message digest.

Overrides:

update in class Signature

Parameters:

b - the message byte

update

public void update(byte[] b,
                   int offset,
                   int length)

Pass message bytes to the message digest.

Overrides:

update in class Signature

Parameters:

b - the message byte

offset - the index where the message bytes starts

length - the number of message bytes

sign

public byte[] sign()
            throws SignatureException

Signs a message. The result is an ASN1 Sequence containing the Integers r and s. With r = (g^k mod p) mod q and s = (k^-1 (SHA(M) + x*r)) mod q.

Overrides:

sign in class Signature

Returns:

the signature (an ASN1 Sequence containing the Integers r and s).

Throws:

SignatureException - if the signature is not initialized properly.

verify

public boolean verify(byte[] sigBytes)

Verifies a signature.

Overrides:

verify in class Signature

Parameters:

sigBytes - the signature to be verified

Returns:

true if the signature is correct, false otherwise