Package org.bouncycastle.cms

Class CMSAuthenticatedDataParser

java.lang.Object

org.bouncycastle.cms.CMSContentInfoParser

org.bouncycastle.cms.CMSAuthenticatedDataParser

public class CMSAuthenticatedDataParser
extends CMSContentInfoParser

Parsing class for an CMS Authenticated Data object from an input stream.

Note: that because we are in a streaming mode only one recipient can be tried and it is important that the methods on the parser are called in the appropriate order.

Example of use - assuming the first recipient matches the private key we have.

      CMSAuthenticatedDataParser     ad = new CMSAuthenticatedDataParser(inputStream);

      RecipientInformationStore  recipients = ad.getRecipientInfos();

      Collection  c = recipients.getRecipients();
      Iterator    it = c.iterator();

      if (it.hasNext())
      {
          RecipientInformation   recipient = (RecipientInformation)it.next();

          CMSTypedStream recData = recipient.getContentStream(new JceKeyTransAuthenticatedRecipient(privateKey).setProvider("BC"));

          processDataStream(recData.getContentStream());

          if (!Arrays.constantTimeAreEqual(ad.getMac(), recipient.getMac()))
          {
              System.err.println("Data corrupted!!!!");
          }
      }
  

Note: this class does not introduce buffering - if you are processing large files you should create the parser with:

          CMSAuthenticatedDataParser     ep = new CMSAuthenticatedDataParser(new BufferedInputStream(inputStream, bufSize));
  

where bufSize is a suitably large buffer size.

Stream handling note:

• The constructor reads only enough of the supplied InputStream to expose the CMS structure metadata (originator info, recipient infos, MAC algorithm). The encapsulated content is drained lazily by the caller via RecipientInformation.getContentStream(org.bouncycastle.cms.Recipient); the MAC is available from getMac() once the content stream has been read to EOF.
• The supplied InputStream is not closed automatically. Call CMSContentInfoParser.close() on this parser (inherited from CMSContentInfoParser) to close the underlying InputStream, or close it yourself.

Field Summary

Fields inherited from class org.bouncycastle.cms.CMSContentInfoParser

_contentInfo, _data

Constructor Summary

Constructors

Constructor	Description
CMSAuthenticatedDataParser(byte[] envelopedData)
CMSAuthenticatedDataParser(byte[] envelopedData, DigestCalculatorProvider digestCalculatorProvider)
CMSAuthenticatedDataParser(java.io.InputStream envelopedData)
CMSAuthenticatedDataParser(java.io.InputStream envelopedData, DigestCalculatorProvider digestCalculatorProvider)

Method Summary

Modifier and Type	Method	Description
org.bouncycastle.asn1.cms.AttributeTable	getAuthAttrs()	return a table of the unauthenticated attributes indexed by the OID of the attribute.
byte[]	getContentDigest()	This will only be valid after the content has been read.
byte[]	getMac()
java.lang.String	getMacAlgOID()	return the object identifier for the mac algorithm.
org.bouncycastle.asn1.x509.AlgorithmIdentifier	getMacAlgorithm()	Return the MAC algorithm details for the MAC associated with the data in this object.
byte[]	getMacAlgParams()	return the ASN.1 encoded encryption algorithm parameters, or null if there aren't any.
OriginatorInformation	getOriginatorInfo()	Return the originator information associated with this message if present.
RecipientInformationStore	getRecipientInfos()	return a store of the intended recipients for this message
org.bouncycastle.asn1.cms.AttributeTable	getUnauthAttrs()	return a table of the unauthenticated attributes indexed by the OID of the attribute.

Methods inherited from class org.bouncycastle.cms.CMSContentInfoParser

close, isBEREncoded

Methods inherited from class java.lang.Object

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

Constructor Detail

CMSAuthenticatedDataParser

public CMSAuthenticatedDataParser(byte[] envelopedData)
                           throws CMSException,
                                  java.io.IOException

Throws:

CMSException

java.io.IOException

CMSAuthenticatedDataParser

public CMSAuthenticatedDataParser(byte[] envelopedData,
                                  DigestCalculatorProvider digestCalculatorProvider)
                           throws CMSException,
                                  java.io.IOException

Throws:

CMSException

java.io.IOException

CMSAuthenticatedDataParser

public CMSAuthenticatedDataParser(java.io.InputStream envelopedData)
                           throws CMSException,
                                  java.io.IOException

Throws:

CMSException

java.io.IOException

CMSAuthenticatedDataParser

public CMSAuthenticatedDataParser(java.io.InputStream envelopedData,
                                  DigestCalculatorProvider digestCalculatorProvider)
                           throws CMSException,
                                  java.io.IOException

Throws:

CMSException

java.io.IOException

Method Detail

getOriginatorInfo

public OriginatorInformation getOriginatorInfo()

Return the originator information associated with this message if present.

Returns:

OriginatorInformation, null if not present.

getMacAlgorithm

public org.bouncycastle.asn1.x509.AlgorithmIdentifier getMacAlgorithm()

Return the MAC algorithm details for the MAC associated with the data in this object.

Returns:

AlgorithmIdentifier representing the MAC algorithm.

getMacAlgOID

public java.lang.String getMacAlgOID()

return the object identifier for the mac algorithm.

getMacAlgParams

public byte[] getMacAlgParams()

return the ASN.1 encoded encryption algorithm parameters, or null if there aren't any.

getRecipientInfos

public RecipientInformationStore getRecipientInfos()

return a store of the intended recipients for this message

getMac

public byte[] getMac()
              throws java.io.IOException

Throws:

java.io.IOException

getAuthAttrs

public org.bouncycastle.asn1.cms.AttributeTable getAuthAttrs()
                                                      throws java.io.IOException

return a table of the unauthenticated attributes indexed by the OID of the attribute.

Throws:

java.io.IOException

getUnauthAttrs

public org.bouncycastle.asn1.cms.AttributeTable getUnauthAttrs()
                                                        throws java.io.IOException

return a table of the unauthenticated attributes indexed by the OID of the attribute.

Throws:

java.io.IOException

getContentDigest

public byte[] getContentDigest()

This will only be valid after the content has been read.

Returns:

the contents of the messageDigest attribute, if available. Null if not present.