org.bouncycastle.cms

Class CMSEnvelopedDataParser

public class CMSEnvelopedDataParser extends CMSContentInfoParser

Parsing class for an CMS Enveloped 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.

      CMSEnvelopedDataParser     ep = new CMSEnvelopedDataParser(inputStream);

      RecipientInformationStore  recipients = ep.getRecipientInfos();

      Collection  c = recipients.getRecipients();
      Iterator    it = c.iterator();
      
      if (it.hasNext())
      {
          RecipientInformation   recipient = (RecipientInformation)it.next();

          CMSTypedStream recData = recipient.getContentStream(privateKey, "BC");
          
          processDataStream(recData.getContentStream());
      }
  
Note: this class does not introduce buffering - if you are processing large files you should create the parser with:
          CMSEnvelopedDataParser     ep = new CMSEnvelopedDataParser(new BufferedInputStream(inputStream, bufSize));
  
where bufSize is a suitably large buffer size.
Constructor Summary
CMSEnvelopedDataParser(byte[] envelopedData)
CMSEnvelopedDataParser(InputStream envelopedData)
Method Summary
AlgorithmParametersgetEncryptionAlgorithmParameters(String provider)
Return an AlgorithmParameters object giving the encryption parameters used to encrypt the message content.
StringgetEncryptionAlgOID()
return the object identifier for the content encryption algorithm.
byte[]getEncryptionAlgParams()
return the ASN.1 encoded encryption algorithm parameters, or null if there aren't any.
RecipientInformationStoregetRecipientInfos()
return a store of the intended recipients for this message
AttributeTablegetUnprotectedAttributes()
return a table of the unprotected attributes indexed by the OID of the attribute.

Constructor Detail

CMSEnvelopedDataParser

public CMSEnvelopedDataParser(byte[] envelopedData)

CMSEnvelopedDataParser

public CMSEnvelopedDataParser(InputStream envelopedData)

Method Detail

getEncryptionAlgorithmParameters

public AlgorithmParameters getEncryptionAlgorithmParameters(String provider)
Return an AlgorithmParameters object giving the encryption parameters used to encrypt the message content.

Parameters: provider the provider to generate the parameters for.

Returns: the parameters object, null if there is not one.

Throws: CMSException if the algorithm cannot be found, or the parameters can't be parsed. NoSuchProviderException if the provider cannot be found.

getEncryptionAlgOID

public String getEncryptionAlgOID()
return the object identifier for the content encryption algorithm.

getEncryptionAlgParams

public byte[] getEncryptionAlgParams()
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

getUnprotectedAttributes

public AttributeTable getUnprotectedAttributes()
return a table of the unprotected attributes indexed by the OID of the attribute.

Throws: IOException