Skip navigation links

oracle.security.crypto.core
Class DSAPublicKey

java.lang.Object
oracle.security.crypto.core.DSAPublicKey

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Cloneable, ASN1Object, Key, PublicKey, Streamable

public class DSAPublicKey

extends java.lang.Object

implements PublicKey, ASN1Object

A DSA public key.

The OID used to identify the key algorithm may be set via setKeyAlgOID. The encoding used for keys of this class is based on the SubjectPublicKeyInfo structure of X.509, and is compatible with that used in JDK 1.2.

See Also:

DSA, Serialized Form

Constructor Summary

DSAPublicKey()
Makes a new, uninitialized instance.

DSAPublicKey(ASN1Sequence s)
Deprecated. Use DSAPublicKey(InputStream is) instead.

DSAPublicKey(java.math.BigInteger y, DSAParams params)
Makes a new instance with the given set of parameters and value of y.

DSAPublicKey(byte[] data)
Makes a new instance by reading its encoding from the given byte array.

DSAPublicKey(java.io.InputStream is)
Makes a new instance by reading its encoding from the given input stream.

Method Summary

java.lang.Object	clone() Creates a deep copy of this DSAPublicKey instance.
void	erase() Erases the sensitive key material of a private or symmetric key, making the key un-usable.
void	finalize() Erases this object prior to being reclaimed by the garbage collector.
AlgorithmIdentifier	getAlgID() Returns the algorithm identifier for this key.
java.lang.String	getAlgorithm() Gets the algorithm name for this key.
boolean	getAllowExport() Always returns true.
int	getBitLength() Returns the number of bits needed to represent the DSAPublicKey's public component P.
ASN1Object	getContents() Returns the contents of this key.
byte[]	getEncoded() Returns the encoded form of this key.
java.lang.String	getFormat() Returns a string which indicates the format of this object's encoding.
ASN1ObjectID	getKeyAlgOID() Returns the key algorithm OID.
DSAParams	getParams() Returns the DSA algorithm parameters for this public key.
java.math.BigInteger	getY() Gets y.
void	initialize(AlgorithmIdentifier algID, ASN1Object contents) Initializes this instance from the given algorithm paramters and key contents.
void	input(ASN1Sequence s) Deprecated. use input(InputStream is) instead.
void	input(java.io.InputStream is) Inputs a DSAPublicKey object by reading its encoding from the given input stream.
int	length() Gets the length of the encoding of this object.
void	output(java.io.OutputStream os) Outputs encoding of this object to a given output stream.
void	readExternal(java.io.ObjectInput is) Reads the input stream and initializes the DSA public key.
void	setKeyAlgOID(ASN1ObjectID oid) Sets the key algorithm OID.
void	setParams(DSAParams params) Sets the DSA algorithm parameters for this public key.
java.lang.String	toString() Returns a string which describes this object.
void	writeExternal(java.io.ObjectOutput os) Writes to the output stream the DER encoding of this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

DSAPublicKey

public DSAPublicKey()

Makes a new, uninitialized instance.

DSAPublicKey

public DSAPublicKey(java.math.BigInteger y,
                    DSAParams params)

Makes a new instance with the given set of parameters and value of y.

Parameters:

y - The value of y.

params - The DSAParams of this DSAPublicKey.

DSAPublicKey

public DSAPublicKey(byte[] data)
             throws java.io.IOException

Makes a new instance by reading its encoding from the given byte array.

Parameters:

data - The byte array from which this object will be read.

Throws:

java.io.IOException - If an input exception occured.

DSAPublicKey

public DSAPublicKey(java.io.InputStream is)
             throws java.io.IOException

Makes a new instance by reading its encoding from the given input stream.

Parameters:

is - The input stream from from which this object will be read.

Throws:

java.io.IOException - If an input exception occured.

DSAPublicKey

public DSAPublicKey(ASN1Sequence s)
             throws java.io.IOException

Deprecated. Use DSAPublicKey(InputStream is) instead.

Throws:

java.io.IOException

Method Detail

getEncoded

public byte[] getEncoded()

Description copied from interface: Key

Returns the encoded form of this key.

Specified by:

getEncoded in interface Key

getAlgorithm

public java.lang.String getAlgorithm()

Gets the algorithm name for this key.

Specified by:

getAlgorithm in interface Key

Returns:

"DSA"

getBitLength

public int getBitLength()

Returns the number of bits needed to represent the DSAPublicKey's public component P.

0 will be returned if the key has not been initialized.

Specified by:

getBitLength in interface Key

getFormat

public java.lang.String getFormat()

Returns a string which indicates the format of this object's encoding.

Specified by:

getFormat in interface Key

Returns:

"X.509"

erase

public void erase()

Description copied from interface: Key

Erases the sensitive key material of a private or symmetric key, making the key un-usable. Keys may be erased multiple times with no consequences.

Note: After erase() has been invoked, no other methods of the Key object are guaranteed to function correctly. In particular, invoking another method after erase() may result in a NullPointerException being thrown.

Specified by:

erase in interface Key

finalize

public void finalize()

Erases this object prior to being reclaimed by the garbage collector.

Note: There is no guarantee of when, if ever, finalize will be invoked by the Java runtime.

Overrides:

finalize in class java.lang.Object

clone

public java.lang.Object clone()

Creates a deep copy of this DSAPublicKey instance.

Specified by:

clone in interface Key

Overrides:

clone in class java.lang.Object

Returns:

A deep clone of the Key instance.

getAllowExport

public boolean getAllowExport()

Always returns true.

Specified by:

getAllowExport in interface Key

Returns:

Whether or not this key's material may be exported in plaintext.

Since:

3.0

See Also:

FIPS_140_2.getAllowKeyExport()

initialize

public void initialize(AlgorithmIdentifier algID,
                       ASN1Object contents)
                throws AlgorithmIdentifierException,
                       InvalidInputException

Description copied from interface: PublicKey

Initializes this instance from the given algorithm paramters and key contents.

Specified by:

initialize in interface PublicKey

Throws:

AlgorithmIdentifierException

InvalidInputException

getAlgID

public AlgorithmIdentifier getAlgID()

Description copied from interface: PublicKey

Returns the algorithm identifier for this key.

Specified by:

getAlgID in interface PublicKey

getContents

public ASN1Object getContents()

Description copied from interface: PublicKey

Returns the contents of this key.

Specified by:

getContents in interface PublicKey

getKeyAlgOID

public ASN1ObjectID getKeyAlgOID()

Returns the key algorithm OID. If no key algorithm OID has been set, then the default, DSA.dsaKeyOID, is returned.

Returns:

the key algorithm OID

See Also:

DSA.dsaKeyOID

setKeyAlgOID

public void setKeyAlgOID(ASN1ObjectID oid)

Sets the key algorithm OID.

Parameters:

oid - the key algorithm OID

getY

public java.math.BigInteger getY()

Gets y.

Returns:

y

setParams

public void setParams(DSAParams params)

Sets the DSA algorithm parameters for this public key.

getParams

public DSAParams getParams()

Returns the DSA algorithm parameters for this public key.

Returns:

the algorithm parameters

toString

public java.lang.String toString()

Returns a string which describes this object.

Overrides:

toString in class java.lang.Object

input

public void input(java.io.InputStream is)
           throws java.io.IOException

Inputs a DSAPublicKey object by reading its encoding from the given input stream.

Specified by:

input in interface Streamable

Parameters:

is - The input stream from which this object will be read.

Throws:

java.io.IOException - If an input exception occured.

input

public void input(ASN1Sequence s)
           throws java.io.IOException

Deprecated. use input(InputStream is) instead.

Throws:

java.io.IOException

output

public void output(java.io.OutputStream os)
            throws java.io.IOException

Outputs encoding of this object to a given output stream.

Specified by:

output in interface Streamable

Parameters:

os - The output stream to which the encoding of this object will be written.

Throws:

java.io.IOException - If an output exception occured.

length

public int length()

Gets the length of the encoding of this object.

Specified by:

length in interface Streamable

Returns:

The length of the encoding of this object.

writeExternal

public void writeExternal(java.io.ObjectOutput os)
                   throws java.io.IOException

Writes to the output stream the DER encoding of this object.

Specified by:

writeExternal in interface java.io.Externalizable

Parameters:

os - The output stream to write the encoding to.

Throws:

java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput is)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Reads the input stream and initializes the DSA public key.

Specified by:

readExternal in interface java.io.Externalizable

Parameters:

is - The stream to read from.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

Skip navigation links