demo.cms.envelopedData

Class EncryptedContentInfoDemo

java.lang.Object

demo.cms.envelopedData.EncryptedContentInfoDemo

public class EncryptedContentInfoDemo
extends java.lang.Object

This class demonstrates the EnvelopedDataStream/EncryptedContentInfoStream usages for algorithms that require a specific parameter handling.

All keys and certificates are read from a keystore created by the SetupCMSKeyStore program.

The following algorithms are demonstrated:

• ARCFOUR: Variable-key-size stream cipher; no parameters to be sent
• RC2_CBC: Variable-key-size block cipher; parameters as used by S/MIME: rc2ParamterVersion and IV; encoded as SEQUENCE:

                 RC2-CBC parameter ::=  SEQUENCE {
                   rc2ParameterVersion  INTEGER,
                   iv                   OCTET STRING (8)}
  
                 For the effective-key-bits of 40, 64, and 128, the
                  rc2ParameterVersion values are 160, 120, 58 respectively.
                

• CAST5_CBC: Feistel type block cipher with key sizes of 40-128 bit in 8 bit increments; parameters (RFC 2144):

                 Parameters ::=  SEQUENCE {
                   iv         OCTET STRING DEFAULT 0,
                   keyLength  INTEGER }
  
                

This class shows how an EncryptedContentInfo is explicit created for encrypting the content and supplying it to an EnvelopedDataStream object. Note that IAIK-CMS also allows to use EnvelopedData(Stream) for algorithms like RC2, ARCFOUR or CAST without having the necessity of explicit key/parameter handling, see RC2EnvelopedDataDemo for an example. Note that the usage of algorithms like RC2 is deprecated but used here for this demo since it requires a specific parameter handling.

Constructor Summary

Constructors

Constructor and Description
EncryptedContentInfoDemo() Setup the demo certificate chains.

Method Summary

Modifier and Type	Method and Description
byte[]	createEnvelopedDataStream(byte[] message, iaik.asn1.structures.AlgorithmID contentEA, int keyLength) Creates a CMS EnvelopedDataStream message.
byte[]	getEnvelopedDataStream(byte[] encoding, java.security.PrivateKey privateKey, int recipientInfoIndex) Decrypts the encrypted content of the given CMS EnvelopedData object for the specified recipient and returns the decrypted (= original) message.
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

EncryptedContentInfoDemo

public EncryptedContentInfoDemo()
                         throws java.io.IOException

Setup the demo certificate chains. Keys and certificate are retrieved from the demo KeyStore.

Throws:

java.io.IOException - if an file read error occurs

Method Detail

createEnvelopedDataStream

public byte[] createEnvelopedDataStream(byte[] message,
                                        iaik.asn1.structures.AlgorithmID contentEA,
                                        int keyLength)
                                 throws java.lang.Exception

Creates a CMS EnvelopedDataStream message.

Parameters:

message - the message to be enveloped, as byte representation

contentEA - the content encryption algorithm

keyLength - the key length for the symmetric key

Returns:

the DER encoding of the EnvelopedData object just created

Throws:

java.lang.Exception - if the EnvelopedData object cannot be created

getEnvelopedDataStream

public byte[] getEnvelopedDataStream(byte[] encoding,
                                     java.security.PrivateKey privateKey,
                                     int recipientInfoIndex)
                              throws java.lang.Exception

Decrypts the encrypted content of the given CMS EnvelopedData object for the specified recipient and returns the decrypted (= original) message.

Parameters:

encoding - the EnvelopedData object as DER encoded byte array

privateKey - the private key to decrypt the message

recipientInfoIndex - the index into the RecipientInfo array to which the specified private key belongs

Returns:

the recovered message, as byte array

Throws:

java.lang.Exception - if the message cannot be recovered

start

public void start()

Starts the test.

main

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

The main method.

Throws:

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

java.lang.Exception