oracle.security.crypto.core
Class DSAParams

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

All Implemented Interfaces:

ASN1Object, Streamable

public class DSAParams

extends java.lang.Object

implements ASN1Object

Parameters used for the Digital Signature Standard, as described in FIPS 186. The parameter names used here match that reference.

The necessary parameters to implement DSA are:

• p -- the large prime.
• q -- the small prime.
• g -- the generator.

The following ASN.1 encoding is used, defined in the PKIX draft standard:

                Dss-Parms  ::=  SEQUENCE  {
                        p                        INTEGER,
                        q                        INTEGER,
                        g                        INTEGER  }
        

A DSAParams may also store the seed and counter used to generate p and q.

Warning: The serialization capability of this class should only be used for short-term storage and RMI between applications running the same version of this product. It should not be relied on for long-term perisistence, as future versions of this class may use an incompatible serialization format. For now, applications requiring long-term persistence should use the ASN.1 encodings provided by the input(InputStream) and output(OutputStream) methods directly, instead of serialization.

Constructor Summary

DSAParams()
Creates a new, noninitialized DSAParams object.

DSAParams(ASN1Sequence s)
Creates a new DSAParams object by parsing the given ASN.1 sequence.

DSAParams(java.math.BigInteger p, java.math.BigInteger q, java.math.BigInteger g)
Creates a new DSAParams object with the given values of p, q, and g.

DSAParams(java.math.BigInteger p, java.math.BigInteger q, java.math.BigInteger g, byte[] seed, int counter)
Creates a new DSAParams object with the given values of p, q, g, seed and counter.

DSAParams(java.io.InputStream is)
Creates a new DSAParams object by reading its encoding from the given input stream.

Method Summary

int	getCounter() Get the counter that was used generate these parameters.
java.math.BigInteger	getG() Gets g.
java.math.BigInteger	getP() Gets p.
java.math.BigInteger	getQ() Gets q.
byte[]	getSeed() Gets the seed that was used generate these parameters.
void	input(ASN1Sequence s) parses a DSAParams object from given ASN1Sequence.
void	input(java.io.InputStream is) reads the encoding of a DSAParams object from given InputStream.
int	length() Returns the length of this object's encoding.
void	output(java.io.OutputStream os) Outputs the encoding of this DSAParams object to the given OutputStream.
ASN1Sequence	outputASN1() Outputs this DSAParams object to the given ASN1Sequence.
java.lang.String	toString() Transforms this DSAParams object into a readable string.

Methods inherited from class java.lang.Object

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

Constructor Detail

DSAParams

public DSAParams()

Creates a new, noninitialized DSAParams object.

DSAParams

public DSAParams(java.math.BigInteger p,
                 java.math.BigInteger q,
                 java.math.BigInteger g)

Creates a new DSAParams object with the given values of p, q, and g. The seed and counter used to generate p and q are not stored.

Parameters:

p - the large prime p

q - the small prime q

g - the generator g

DSAParams

public DSAParams(java.math.BigInteger p,
                 java.math.BigInteger q,
                 java.math.BigInteger g,
                 byte[] seed,
                 int counter)

Creates a new DSAParams object with the given values of p, q, g, seed and counter.

Parameters:

p - the large prime p

q - the small prime q

g - the generator g

seed - the seed used to generate p and q.

counter - the counter used to generate p and q.

DSAParams

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

Creates a new DSAParams object by reading its encoding from the given input stream.

Parameters:

is - the inputStream where the DSAParam comes from

Throws:

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

DSAParams

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

Creates a new DSAParams object by parsing the given ASN.1 sequence.

Parameters:

s - the ASN1Sequence representing the DSAParams.

Throws:

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

Method Detail

getP

public java.math.BigInteger getP()

Gets p.

Returns:

the large prime p; or null if p is not initialized

getQ

public java.math.BigInteger getQ()

Gets q.

Returns:

the small prime q; or null if q is not initialized

getG

public java.math.BigInteger getG()

Gets g.

Returns:

the generator g; or null if g is not initialized

getSeed

public byte[] getSeed()

Gets the seed that was used generate these parameters. The seed is not saved or restored on I/O, so it will only be set in an object output by DSAKeyPairGenerator.generateParameters().

Returns:

the seed used to generate p and q; or null if seed is not initialized

getCounter

public int getCounter()

Get the counter that was used generate these parameters. The counter is not saved or restored on I/O, so it will only be set in an object output by DSAKeyPairGenerator.generateParameters().

Returns:

the count used to generate p and q. or null if the count is not initialized

input

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

reads the encoding of a DSAParams object from given InputStream.

Specified by:

input in interface Streamable

Parameters:

is - the inputStream where the DSAParam comes from

Throws:

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

See Also:

output(java.io.OutputStream)

input

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

parses a DSAParams object from given ASN1Sequence.

Parameters:

s - the ASN1Sequence representing the DSAParams.

Throws:

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

See Also:

outputASN1()

output

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

Outputs the encoding of this DSAParams object to the given OutputStream.

Specified by:

output in interface Streamable

Parameters:

os - the OutputStream where this DSAParams will go

Throws:

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

See Also:

input(InputStream)

outputASN1

public ASN1Sequence outputASN1()

Outputs this DSAParams object to the given ASN1Sequence.

Returns:

the ASN1Sequence representing this DSAParams will go

See Also:

input(ASN1Sequence)

length

public int length()

Returns the length of this object's encoding.

Specified by:

length in interface Streamable

Returns:

the length of this object's encoding.

toString

public java.lang.String toString()

Transforms this DSAParams object into a readable string.

Returns:

a string in readable form representing this DSAParams object