demo.cms.signedData
Class SignedDataStreamDemoWithAdditionalSignerInfo

java.lang.Object
  demo.cms.signedData.SignedDataStreamDemoWithAdditionalSignerInfo

public class SignedDataStreamDemoWithAdditionalSignerInfo
extends java.lang.Object

This class demonstrates the usage of an SDSEncodeListener to add a new SignerInfo to an existing, parsed SignedDataStream object.

A SDSEncodeListener allows an application to update a SignedDataStream during the encoding phase.

In some situations it may be useful to supply information to a SignedDataStream actually during encoding is performed. When implementing an SignedDataStream encode listener an application has the chance to update the SignedDataStream at two points during the encoding process: AFTER the content data has been processed and any digest has been calulated (= BEFORE any signature value is computed) and AFTER the signature values have been calculated. When doing so an application has to implement two abstract methods: beforeComputeSignature and afterComputeSignature (of course, an application may implement any of the two methods in a way to do actually nothing (if no functionality is required)).

This demo uses the IAIK-CMS DefaultSDSEncodeListener for adding a new SignerInfo to an already existing SignedDataStream "on the fly".

See Also:

SignedDataStream, SDSEncodeListener

Constructor Summary

SignedDataStreamDemoWithAdditionalSignerInfo()
Constructor.

Method Summary

byte[]	createSignedDataStream(byte[] message, int mode) Creates a CMS SignedData object.
byte[]	getSignedDataStream(byte[] signedData, byte[] message, boolean writeAgain) Parses a CMS SignedData object and verifies the signatures for all participated signers.
static void	main(java.lang.String[] argv) The main method.
void	start() Starts the test.

Methods inherited from class java.lang.Object

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

Constructor Detail

SignedDataStreamDemoWithAdditionalSignerInfo

public SignedDataStreamDemoWithAdditionalSignerInfo()

Constructor. Reads required keys/certs from the demo keystore.

Method Detail

createSignedDataStream

public byte[] createSignedDataStream(byte[] message,
                                     int mode)
                              throws iaik.cms.CMSException,
                                     java.io.IOException

Creates a CMS SignedData object.

Parameters:

message - the message to be signed, as byte representation

mode - the mode indicating whether to include the content (SignedDataStream.IMPLICIT) or not (SignedDataStream.EXPLICIT)

Returns:

the encoding of the SignedData object just created

Throws:

iaik.cms.CMSException - if the SignedData object cannot be created

java.io.IOException - if an I/O error occurs

getSignedDataStream

public byte[] getSignedDataStream(byte[] signedData,
                                  byte[] message,
                                  boolean writeAgain)
                           throws iaik.cms.CMSException,
                                  java.io.IOException,
                                  java.security.NoSuchAlgorithmException

Parses a CMS SignedData object and verifies the signatures for all participated signers.

Parameters:

signedData - the SignedData, as BER encoded byte array

message - the the message which was transmitted out-of-band (explicit signed)

writeAgain - whether to use a SDSEncodeListener to add a SignerInfo and encode the SignedData again

Returns:

the inherent message as byte array, or the BER encoded SignedData if it shall be encoded again

Throws:

iaik.cms.CMSException - if any signature does not verify

java.io.IOException - if an I/O error occurs

java.security.NoSuchAlgorithmException

start

public void start()

Starts the test.

main

public static void main(java.lang.String[] argv)
                 throws java.io.IOException

The main method.

Throws:

java.io.IOException - if an I/O error occurs when reading required keys and certificates from files