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cryptix.jce.provider.dsa
Class DSASignature  

java.lang.Object
  java.security.SignatureSpi
      cryptix.jce.provider.dsa.DSASignature

All Implemented Interfaces:

java.lang.Cloneable

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public final class DSASignature

extends java.security.SignatureSpi

implements java.lang.Cloneable

Implementation of the Digital Signature Algorithm (DSA) conformant with FIPS 186-2, Digital Signature Standard (DSS), February 2000. Tested and interoperable with the DSA implementation in the Sun JDKs.

Version:

$Revision: 1.4 $

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Field Summary
private  java.math.BigInteger	_exp           Either public or private exponent, depending on our mode.
private static java.security.SecureRandom	_fallbackRng           RNG used when none is specified by our callers.
private  java.math.BigInteger	_g
private  java.security.MessageDigest	_md
private  java.math.BigInteger	_p
private  java.math.BigInteger	_q
private static boolean	MODE_SIGN
private static boolean	MODE_VERIFY

 

Fields inherited from class java.security.SignatureSpi

appRandom

 

Constructor Summary
	DSASignature()
private	DSASignature(DSASignature srcSig)           Copy constructor.

 

Method Summary
private  void	_clear()           Clear all sensitive state.
private  boolean	_isValid(boolean mode)           Invariants hold?
java.lang.Object	clone()           Returns a clone of this instance.
protected  java.lang.Object	engineGetParameter(java.lang.String param)           Returns the value for the specified algorithm parameter.
protected  void	engineInitSign(java.security.PrivateKey privateKey)           Init for signing with private key and a default RNG.
protected  void	engineInitSign(java.security.PrivateKey privKey, java.security.SecureRandom random)           Init for signing with private key and RNG.
protected  void	engineInitVerify(java.security.PublicKey pubKey)           Init for verification with a public key.
protected  void	engineSetParameter(java.security.spec.AlgorithmParameterSpec params)           Sets the signature engine with the specified java.security.spec.AlgorithmParameterSpec.
protected  void	engineSetParameter(java.lang.String param, java.lang.Object value)           Sets the specified algorithm parameter to the specified value.
protected  byte[]	engineSign()           Calculate the signature over the accumulated data and reset (keeping the key information, resetting the hash).
protected  int	engineSign(byte[] outbuf, int offset, int len)           Calculate the signature over the accumulated data and reset (keeping the key information, resetting the hash).
protected  void	engineUpdate(byte b)           Updates the data to be signed or verified with the specified byte.
protected  void	engineUpdate(byte[] b, int off, int len)           Updates the data to be signed or verified with the specified bytes.
protected  boolean	engineVerify(byte[] sigBytes)           Calculate signature over the accumulated data and compare the result to the passed in signature.
boolean	equals(java.lang.Object o)           Determine whether this Object is semantically equal to another Object.
int	hashCode()           Get a value that represents this Object, as uniquely as possible within the confines of an int.

 

Methods inherited from class java.security.SignatureSpi

engineGetParameters, engineVerify

 

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

 

Field Detail

_fallbackRng

private static final java.security.SecureRandom _fallbackRng

RNG used when none is specified by our callers.

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_md

private final java.security.MessageDigest _md

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_g

private java.math.BigInteger _g

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_p

private java.math.BigInteger _p

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_q

private java.math.BigInteger _q

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_exp

private java.math.BigInteger _exp

Either public or private exponent, depending on our mode.

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MODE_SIGN

private static final boolean MODE_SIGN

See Also:

Constant Field Values

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MODE_VERIFY

private static final boolean MODE_VERIFY

See Also:

Constant Field Values

Constructor Detail

DSASignature

public DSASignature()

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DSASignature

private DSASignature(DSASignature srcSig)
              throws java.lang.CloneNotSupportedException

Copy constructor.

Method Detail

clone

public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Description copied from class: java.security.SignatureSpi

Returns a clone of this instance.

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equals

public boolean equals(java.lang.Object o)

Description copied from class: java.lang.Object

Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

• It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
• It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
• It must be reflexive. a.equals(a) must always be true.
• It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
• a.equals(null) must be false.
• It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a java.lang.ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a java.lang.NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, java.util.IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

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hashCode

public int hashCode()

Description copied from class: java.lang.Object

Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

• Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
• It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in java.util.Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

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engineGetParameter

protected java.lang.Object engineGetParameter(java.lang.String param)
                                       throws java.security.InvalidParameterException

Description copied from class: java.security.SignatureSpi

Returns the value for the specified algorithm parameter.

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engineInitSign

protected void engineInitSign(java.security.PrivateKey privateKey)
                       throws java.security.InvalidKeyException

Init for signing with private key and a default RNG.

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engineInitSign

protected void engineInitSign(java.security.PrivateKey privKey,
                              java.security.SecureRandom random)
                       throws java.security.InvalidKeyException

Init for signing with private key and RNG.

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engineSign

protected byte[] engineSign()
                     throws java.security.SignatureException

Calculate the signature over the accumulated data and reset (keeping the key information, resetting the hash).

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engineSign

protected int engineSign(byte[] outbuf,
                         int offset,
                         int len)
                  throws java.security.SignatureException

Calculate the signature over the accumulated data and reset (keeping the key information, resetting the hash).

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engineUpdate

protected void engineUpdate(byte b)
                     throws java.security.SignatureException

Description copied from class: java.security.SignatureSpi

Updates the data to be signed or verified with the specified byte.

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engineUpdate

protected void engineUpdate(byte[] b,
                            int off,
                            int len)
                     throws java.security.SignatureException

Description copied from class: java.security.SignatureSpi

Updates the data to be signed or verified with the specified bytes.

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engineInitVerify

protected void engineInitVerify(java.security.PublicKey pubKey)
                         throws java.security.InvalidKeyException

Init for verification with a public key.

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engineVerify

protected boolean engineVerify(byte[] sigBytes)
                        throws java.security.SignatureException

Calculate signature over the accumulated data and compare the result to the passed in signature.

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engineSetParameter

protected void engineSetParameter(java.security.spec.AlgorithmParameterSpec params)
                           throws java.security.InvalidAlgorithmParameterException

Description copied from class: java.security.SignatureSpi

Sets the signature engine with the specified java.security.spec.AlgorithmParameterSpec.

This method cannot be abstract for backward compatibility reasons. By default it always throws java.lang.UnsupportedOperationException unless overridden.

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engineSetParameter

protected void engineSetParameter(java.lang.String param,
                                  java.lang.Object value)
                           throws java.security.InvalidParameterException

Description copied from class: java.security.SignatureSpi

Sets the specified algorithm parameter to the specified value.

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_clear

private void _clear()

Clear all sensitive state.

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_isValid

private boolean _isValid(boolean mode)

Invariants hold?

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> cryptix >> jce >> provider >> [ dsa overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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