PSSParameterSpec

public class PSSParameterSpec extends Object
implements AlgorithmParameterSpec

This class specifies a parameter spec for RSA-PSS signature scheme, as defined in the PKCS#1 v2.1 standard.

Its ASN.1 definition in PKCS#1 standard is described below:

 RSASSA-PSS-params ::= SEQUENCE {
   hashAlgorithm      [0] OAEP-PSSDigestAlgorithms  DEFAULT sha1,
   maskGenAlgorithm   [1] PKCS1MGFAlgorithms  DEFAULT mgf1SHA1,
   saltLength         [2] INTEGER  DEFAULT 20,
   trailerField       [3] INTEGER  DEFAULT 1
 }
 

where

 OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {
   { OID id-sha1 PARAMETERS NULL   }|
   { OID id-sha224 PARAMETERS NULL   }|
   { OID id-sha256 PARAMETERS NULL }|
   { OID id-sha384 PARAMETERS NULL }|
   { OID id-sha512 PARAMETERS NULL },
   ...  -- Allows for future expansion --
 }

 PKCS1MGFAlgorithms    ALGORITHM-IDENTIFIER ::= {
   { OID id-mgf1 PARAMETERS OAEP-PSSDigestAlgorithms },
   ...  -- Allows for future expansion --
 }
 

Note: the PSSParameterSpec.DEFAULT uses the following: message digest -- "SHA-1" mask generation function (mgf) -- "MGF1" parameters for mgf -- MGF1ParameterSpec.SHA1 SaltLength -- 20 TrailerField -- 1

See Also

• MGF1ParameterSpec
• AlgorithmParameterSpec
• Signature

Field Summary

public static final PSSParameterSpec

DEFAULT

The PSS parameter set with all default values.

Public Constructor Summary

	PSSParameterSpec(String mdName, String mgfName, AlgorithmParameterSpec mgfSpec, int saltLen, int trailerField) Creates a new PSSParameterSpec as defined in the PKCS #1 standard using the specified message digest, mask generation function, parameters for mask generation function, salt length, and trailer field values.
	PSSParameterSpec(int saltLen) Creates a new PSSParameterSpec using the specified salt length and other default values as defined in PKCS#1.

Public Method Summary

String	getDigestAlgorithm() Returns the message digest algorithm name.
String	getMGFAlgorithm() Returns the mask generation function algorithm name.
AlgorithmParameterSpec	getMGFParameters() Returns the parameters for the mask generation function.
int	getSaltLength() Returns the salt length in bits.
int	getTrailerField() Returns the value for the trailer field, i.e.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Fields

public static final PSSParameterSpec DEFAULT

The PSS parameter set with all default values.

Public Constructors

public PSSParameterSpec (String mdName, String mgfName, AlgorithmParameterSpec mgfSpec, int saltLen, int trailerField)

Creates a new PSSParameterSpec as defined in the PKCS #1 standard using the specified message digest, mask generation function, parameters for mask generation function, salt length, and trailer field values.

Parameters

mdName	the algorithm name of the hash function.
mgfName	the algorithm name of the mask generation function.
mgfSpec	the parameters for the mask generation function. If null is specified, null will be returned by getMGFParameters().
saltLen	the length of salt.
trailerField	the value of the trailer field.

Throws

NullPointerException	if mdName, or mgfName is null.
IllegalArgumentException	if saltLen or trailerField is less than 0.

public PSSParameterSpec (int saltLen)

Creates a new PSSParameterSpec using the specified salt length and other default values as defined in PKCS#1.

Parameters

saltLen	the length of salt in bits to be used in PKCS#1 PSS encoding.

Throws

IllegalArgumentException	if saltLen is less than 0.

Public Methods

public String getDigestAlgorithm ()

Returns the message digest algorithm name.

Returns

• the message digest algorithm name.

public String getMGFAlgorithm ()

Returns the mask generation function algorithm name.

Returns

• the mask generation function algorithm name.

public AlgorithmParameterSpec getMGFParameters ()

Returns the parameters for the mask generation function.

Returns

• the parameters for the mask generation function.

public int getSaltLength ()

Returns the salt length in bits.

Returns

• the salt length.

public int getTrailerField ()

Returns the value for the trailer field, i.e. bc in PKCS#1 v2.1.

Returns

• the value for the trailer field, i.e. bc in PKCS#1 v2.1.