java.security.spec
class PSSParameterSpec

java.lang.Object java.security.spec.PSSParameterSpec

All Implemented Interfaces:

AlgorithmParameterSpec

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
 }
 

 OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {
   { OID id-sha1 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

DEFAULT

public static final PSSParameterSpec DEFAULT

The PSS parameter set with all default values.

PSSParameterSpec

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.

PSSParameterSpec

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.

getDigestAlgorithm

public String getDigestAlgorithm()

Returns the message digest algorithm name.

Returns:

the message digest algorithm name.

getMGFAlgorithm

public String getMGFAlgorithm()

Returns the mask generation function algorithm name.

Returns:

the mask generation function algorithm name.

getMGFParameters

public AlgorithmParameterSpec getMGFParameters()

Returns the parameters for the mask generation function.

Returns:

the parameters for the mask generation function.

getSaltLength

public int getSaltLength()

Returns the salt length in bits.

Returns:

the salt length.

getTrailerField

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.