DSAParams (Oracle Fusion Middleware Java API Reference for Oracle Security Developer Tools Crypto)

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

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.security.interfaces.DSAParams, ASN1Object, Streamable
```
public class DSAParams
extends java.lang.Object
implements ASN1Object, java.io.Externalizable, java.security.interfaces.DSAParams
```
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.
See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description
`DSAParams()` Creates a new empty instance.
`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, java.math.BigInteger h)` Creates a new DSAParams object with the given values of p, q, g, seed, counter and h.
`DSAParams(java.io.InputStream is)` Creates a new DSAParams object by reading its encoding from the given input stream.

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`getCounter()` Get the counter that was used generate these parameters.
`java.math.BigInteger`	`getG()` Gets g.
`java.math.BigInteger`	`getH()` Gets h.
`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.
`boolean`	`isValidParams()` Checks if this `DSAParams` contains DSA domain parameters generated by the FIPs-approved method as specified in FIPS 186-2.
`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.
`void`	`readExternal(java.io.ObjectInput is)` Reads the input stream and initializes the DSA parameters.
`java.lang.String`	`toString()` Transforms this `DSAParams` object into a readable string.
`void`	`writeExternal(java.io.ObjectOutput os)` Writes to the output stream the DER encoding of this object.

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 empty instance. This constructor is to be used with serialization or with the input method.
  - 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,
         java.math.BigInteger h)
```
    Creates a new DSAParams object with the given values of p, q, g, seed, counter and h.
    
    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.
    
    h - the value used to generate g.
  - 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.
    
    Specified by:
    
    getP in interface java.security.interfaces.DSAParams
    
    Returns:
    
    the large prime p; or null if p is not initialized
  - getQ
```
public java.math.BigInteger getQ()
```
    Gets q.
    
    Specified by:
    
    getQ in interface java.security.interfaces.DSAParams
    
    Returns:
    
    the small prime q; or null if q is not initialized
  - getG
```
public java.math.BigInteger getG()
```
    Gets g.
    
    Specified by:
    
    getG in interface java.security.interfaces.DSAParams
    
    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
  - getH
```
public java.math.BigInteger getH()
```
    Gets h.
    
    Returns:
    
    the generator h; or null if h is not initialized
  - isValidParams
```
public boolean isValidParams()
```
    Checks if this DSAParams contains DSA domain parameters generated by the FIPs-approved method as specified in FIPS 186-2.
  - 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.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string in readable form representing this DSAParams 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 parameters.
    
    Specified by:
    
    readExternal in interface java.io.Externalizable
    
    Parameters:
    
    is - The stream to read from.
    
    Throws:
    
    java.io.IOException
    
    java.lang.ClassNotFoundException

Class DSAParams

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DSAParams

DSAParams

DSAParams

DSAParams

DSAParams

Method Detail

getP

getQ

getG

getSeed

getCounter

getH

isValidParams

input

input

output

outputASN1

length

toString

writeExternal

readExternal