Class PSSParameterSpec

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)
 }

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

Fields

TRAILER_FIELD_BC

public static final int TRAILER_FIELD_BC

The TrailerFieldBC constant as defined in PKCS#1

Since:

8

See Also:

Constant Field Values

DEFAULT

public static final PSSParameterSpec DEFAULT

The PSS parameter set with all default values

Since:

1.5

Constructors

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

Methods

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

toString

public String toString()

Description copied from class: Object

getClass().getName() + '@' + Integer.toHexString(hashCode())

Overrides:

toString in class Object

Returns:

a string representation of the object.