se.swedenconnect.opensaml.xmlsec.signature.support.provider.padding

Class SCPSSPadding

java.lang.Object

se.swedenconnect.opensaml.xmlsec.signature.support.provider.padding.SCPSSPadding

public class SCPSSPadding
extends Object

Implements the RSA-PSS padding algorithm in accordance with PKCS#1 v2.1.

Author:

Stefan Santesson (stefan@idsec.se), Martin Lindström (martin@idsec.se)

Constructor Summary

Constructors

Constructor and Description
SCPSSPadding(MessageDigest messageDigest, int modulusBits) Constructor for the PSS padding generator.

Method Summary

Modifier and Type	Method and Description
byte[]	getPadding(byte[] messageHash) Calculates the padding for a message hash.
byte[]	getPaddingFromMessage(byte[] message) Generates RSA-PSS encoded message (EM) for a given message.
void	setSalt(byte[] salt) Inject a predefined salt value

Methods inherited from class java.lang.Object

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

Constructor Detail

SCPSSPadding

public SCPSSPadding(MessageDigest messageDigest,
                    int modulusBits)

Constructor for the PSS padding generator. This padding generator uses the default parameter structure of RSA-PSS where message digest equals MGF hash function and where salt length equals hash length and finally where the final byte is set to 0xBC.

Parameters:

messageDigest - Message digest function

modulusBits - number of modulus bits of the RSA key

Method Detail

setSalt

public void setSalt(byte[] salt)

Inject a predefined salt value

Parameters:

salt - predefined salt value;

getPaddingFromMessage

public byte[] getPaddingFromMessage(byte[] message)

Generates RSA-PSS encoded message (EM) for a given message.

Parameters:

message - message

Returns:

encoded message (EM) for RSA PSS

getPadding

public byte[] getPadding(byte[] messageHash)
                  throws IllegalArgumentException

Calculates the padding for a message hash.

Parameters:

messageHash - message hash

Returns:

encoded message (EM) for RSA PSS

Throws:

IllegalArgumentException - if specified modulus is to short