Class PSSParameterSpec

All Implemented Interfaces:
AlgorithmParameterSpec
public class PSSParameterSpec
extends Object
implements AlgorithmParameterSpec

This class specifies a parameter spec for RSASSA-PSS signature scheme, as defined in the PKCS#1 v2.2 standard.

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

RSASSA-PSS-params ::= SEQUENCE {
   hashAlgorithm      [0] HashAlgorithm      DEFAULT sha1,
   maskGenAlgorithm   [1] MaskGenAlgorithm   DEFAULT mgf1SHA1,
   saltLength         [2] INTEGER            DEFAULT 20,
   trailerField       [3] TrailerField       DEFAULT trailerFieldBC(1)
 }
where 
HashAlgorithm ::= AlgorithmIdentifier {
   {OAEP-PSSDigestAlgorithms}
 }
 MaskGenAlgorithm ::= AlgorithmIdentifier { {PKCS1MGFAlgorithms} }
 TrailerField ::= INTEGER { trailerFieldBC(1) }

 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 }|
   { OID id-sha512-224 PARAMETERS NULL }|
   { OID id-sha512-256 PARAMETERS NULL },
   ...  -- Allows for future expansion --
 }
 PKCS1MGFAlgorithms    ALGORITHM-IDENTIFIER ::= {
   { OID id-mgf1 PARAMETERS HashAlgorithm },
   ...  -- 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

Since:
1.4
See Also:
MGF1ParameterSpec, AlgorithmParameterSpec, Signature

Field Summary

Fields
Modifier and Type Field Description
static PSSParameterSpec DEFAULT

The PSS parameter set with all default values
static int TRAILER_FIELD_BC

The TrailerFieldBC constant as defined in PKCS#1

Constructor Summary

Constructors
Constructor Description
PSSParameterSpec​(int saltLen)

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

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description
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 bytes.
int getTrailerField()

Returns the value for the trailer field.

Methods declared in class java.lang.Object

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

Field Detail

TRAILER_FIELD_BC

public static final int TRAILER_FIELD_BC

The TrailerFieldBC constant as defined in PKCS#1

Since:
11
See Also:
Constant Field Values

DEFAULT

public static final PSSParameterSpec DEFAULT

The PSS parameter set with all default values

Since:
1.5

Constructor Detail

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
Throws:
NullPointerException - if mdName, or mgfName is null
IllegalArgumentException - if saltLen or trailerField is less than 0
Since:
1.5

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 bytes to be used in PKCS#1 PSS encoding
Throws:
IllegalArgumentException - if saltLen is less than 0

Method Detail

getDigestAlgorithm

public String getDigestAlgorithm()

Returns the message digest algorithm name.

Returns:
the message digest algorithm name
Since:
1.5

getMGFAlgorithm

public String getMGFAlgorithm()

Returns the mask generation function algorithm name.

Returns:
the mask generation function algorithm name
Since:
1.5

getMGFParameters

public AlgorithmParameterSpec getMGFParameters()

Returns the parameters for the mask generation function.

Returns:
the parameters for the mask generation function
Since:
1.5

getSaltLength

public int getSaltLength()

Returns the salt length in bytes.

Returns:
the salt length

getTrailerField

public int getTrailerField()

Returns the value for the trailer field.

Returns:
the value for the trailer field
Since:
1.5