codec.pkcs7
Class EncryptedContentInfo

java.lang.Object
  |
  +--java.util.AbstractCollection
        |
        +--java.util.AbstractList
              |
              +--java.util.ArrayList
                    |
                    +--codec.asn1.ASN1AbstractCollection
                          |
                          +--codec.asn1.ASN1Sequence
                                |
                                +--codec.pkcs7.EncryptedContentInfo

All Implemented Interfaces:

ASN1Collection, ASN1Type, Cloneable, Collection, Externalizable, List, Serializable

public class EncryptedContentInfo

extends ASN1Sequence

This class represents a EncryptedContentInfo as defined in PKCS#7. The ASN.1 definition of this structure is

 EncryptedContentInfo ::= SEQUENCE {
   contentType ContentType,
   contentEncryptionAlgorithm ContentEncryptionAlgorithmIdentifier,
   encryptedContent [0] IMPLICIT EncryptedContent OPTIONAL
 }
 EncryptedContent ::= OCTET STRING
 ContentEncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
 

contentType indicates the type of content embedded in the EncryptedContent. The encryptedContent is optional; if it is not included in this structure then it must be provided by other means (such as a detached file).

PKCS#7 specifies six content types, of which five are supported: data, signedData, envelopedData, signedAndEnvelopedData, and encryptedData. All of these content types have registered OIDs.

Version:

"$Id: EncryptedContentInfo.java,v 1.9 2007/08/30 08:45:05 pebinger Exp $"

Author:

Volker Roth, Markus Tak

See Also:

Serialized Form

Field Summary

protected String	bea_ The bulk encryption algorithm.
static int	BUFFER_SIZE The size of the buffer allocated for encrypting.
protected AlgorithmIdentifier	cAlg_ The ContentEncryptionAlgorithmIdentifier
protected ASN1ObjectIdentifier	contentType_ The OID defining the contents of this structure.
protected ASN1TaggedType	econtent_ The encrypted content, if present in this structure.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

EncryptedContentInfo()
Creates an instance ready for parsing.

EncryptedContentInfo(String bea, SecretKey bek, AlgorithmParameters params)
Initializes an instance with the given secret key, algorithm, and parameters.

Method Summary

byte[]	crypt(byte[] in, int offset, int length, int opmode) Crypts or decrypts the given input bytes and returns the resulting cipher text or clear text.
void	crypt(byte[] in, OutputStream out, int opmode) Crypts or decrypts the given input bytes and writes the resulting cipher text or clear text tp the given output stream.
void	crypt(InputStream in, OutputStream out, int opmode) Pipes the input to the output while encrypting or decrypting the piped data with the BEK.
void	decode(Decoder dec) Decodes this instance with the given decoder.
String	getAlgorithm() Returns the name of the bulk encryption algorithm name.
ASN1ObjectIdentifier	getContentType() Returns the contentType of this structure.
byte[]	getData() This method decrypts and returns the decrypted data contained in this instance or null if there is no contained data.
byte[]	getEncryptedContent() This method returns the actual content of this structure.
AlgorithmParameters	getParameters() Returns the algorithm parameters of the bulk encryption algorithm identifier.
SecretKey	getSecretKey() Returns the secret bulk encryption key.
protected void	init() Basic initialization.
void	init(PrivateKey kdk, RecipientInfo info) Initializes this instance for encryption/decryption with the BEK that is stored in the given RecipientInfo.
void	init(SecretKey key) Initializes this instance for encryption/decryption with the given secret key.
boolean	isReady() This method returns true if this instance is ready for encryption/decryption without further initialization.
RecipientInfo	newRecipient(X509Certificate cert) This method initializes and returns a new RecipientInfo based on the given certificate.
RecipientInfo	newRecipient(X509Certificate cert, int encType) This method initializes and returns a new RecipientInfo based on the given certificate and encoding type.
void	setContentType(ASN1ObjectIdentifier oid) Sets the content type to the given OID.
void	setData(InputStream in) Encrypts the given data and inserts it as Data content.
void	setEncryptedContent(ASN1ObjectIdentifier oid, InputStream in) Encrypts the given data and embeds it into this instance.

Methods inherited from class codec.asn1.ASN1Sequence

getTag

Methods inherited from class codec.asn1.ASN1AbstractCollection

checkConstraints, encode, getCollection, getConstraint, getTagClass, getValue, isExplicit, isOptional, isType, readExternal, setConstraint, setExplicit, setOptional, toString, writeExternal

Methods inherited from class java.util.ArrayList

add, add, addAll, addAll, clear, clone, contains, ensureCapacity, get, indexOf, isEmpty, lastIndexOf, remove, removeRange, set, size, toArray, toArray, trimToSize

Methods inherited from class java.util.AbstractList

equals, hashCode, iterator, listIterator, listIterator, subList

Methods inherited from class java.util.AbstractCollection

containsAll, remove, removeAll, retainAll

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray

Methods inherited from interface java.util.List

containsAll, equals, hashCode, iterator, listIterator, listIterator, remove, removeAll, retainAll, subList

Field Detail

BUFFER_SIZE

public static final int BUFFER_SIZE

The size of the buffer allocated for encrypting.

contentType_

protected ASN1ObjectIdentifier contentType_

The OID defining the contents of this structure.

cAlg_

protected AlgorithmIdentifier cAlg_

The ContentEncryptionAlgorithmIdentifier

econtent_

protected ASN1TaggedType econtent_

The encrypted content, if present in this structure.

bea_

protected String bea_

The bulk encryption algorithm.

Constructor Detail

EncryptedContentInfo

public EncryptedContentInfo()

Creates an instance ready for parsing. After decoding of this instance, it must be initialized with one of the init methods, before encryption or decryption operation can commence.

EncryptedContentInfo

public EncryptedContentInfo(String bea,
                            SecretKey bek,
                            AlgorithmParameters params)
                     throws InvalidAlgorithmParameterException

Initializes an instance with the given secret key, algorithm, and parameters. The content type is set to Data. Instances created with this constructor are ready for encryption and decryption operations by means of the crypt methods.

Parameters:

bea - The bulk encryption algorithm name.

bek - The secret bulk encryption key.

params - The bulk encryption algorithm parameters.

Method Detail

getContentType

public ASN1ObjectIdentifier getContentType()

Returns the contentType of this structure. This value is defined only if the structure has been decoded successfully, or the content has been set previously.

Returns:

The OID describing the contentType of this structure.

getEncryptedContent

public byte[] getEncryptedContent()

This method returns the actual content of this structure.

Returns:

The content or null if no content is available.

getAlgorithm

public String getAlgorithm()

Returns the name of the bulk encryption algorithm name.

Returns:

The algorithm name.

Throws:

IllegalStateException - if this instance is not yet initialized.

getParameters

public AlgorithmParameters getParameters()

Returns the algorithm parameters of the bulk encryption algorithm identifier.

Returns:

The algorithm parameters.

getSecretKey

public SecretKey getSecretKey()

Returns the secret bulk encryption key.

Returns:

The BEK or null.

Throws:

IllegalStateException - if this instance is not yet initialized.

init

public void init(PrivateKey kdk,
                 RecipientInfo info)
          throws GeneralSecurityException

Initializes this instance for encryption/decryption with the BEK that is stored in the given RecipientInfo. The BEK is decrypted with the given private key and initialized according to the algorithm specified in this instance's contentEncryptionAlgorithmIdentifier.

Parameters:

kdk - The private Key Decryption Key required to decrypt the BEK.

info - The RecipientInfo that holds the BEK.

Throws:

GeneralSecurityException - if some cipher related exception is thrown by the underlying engines.

init

public void init(SecretKey key)
          throws GeneralSecurityException

Initializes this instance for encryption/decryption with the given secret key.

Parameters:

key - The secret key that is used to decrypt. The key must match the algorithm defined in the contentEncryptionAlgorithmIdentifier.

Throws:

GeneralSecurityException - if some cipher related exception is thrown by the underlying engines.

init

protected void init()
             throws GeneralSecurityException

Basic initialization.

isReady

public boolean isReady()

This method returns true if this instance is ready for encryption/decryption without further initialization.

Returns:

true if it is ready.

newRecipient

public RecipientInfo newRecipient(X509Certificate cert)
                           throws GeneralSecurityException,
                                  BadNameException

This method initializes and returns a new RecipientInfo based on the given certificate. The BEK must already be initialized, otherwise an exception is thrown.

Parameters:

cert - the certificate

Returns:

the created RecipientInfo

Throws:

GeneralSecurityException - if some cipher operation fails.

BadNameException - if the issuer name in the given certificate cannot be parsed.

IllegalStateException - if the BEK is not yet initialized.

newRecipient

public RecipientInfo newRecipient(X509Certificate cert,
                                  int encType)
                           throws GeneralSecurityException,
                                  BadNameException

This method initializes and returns a new RecipientInfo based on the given certificate and encoding type. The BEK must already be initialized, otherwise an exception is thrown.

Parameters:

cert - the certificate

encType - the encoding type

Returns:

the created RecipientInfo

Throws:

GeneralSecurityException - if some cipher operation fails.

BadNameException - if the issuer name in the given certificate cannot be parsed.

IllegalStateException - if the BEK is not yet initialized.

setData

public void setData(InputStream in)
             throws IOException,
                    GeneralSecurityException

Encrypts the given data and inserts it as Data content. The input stream is not closed.

Throws:

IllegalStateException - if the DEK is not initialized.

GeneralSecurityException - if something nasty happens while encrypting such as algorithms not found, bad paddings et cetera.

getData

public byte[] getData()
               throws GeneralSecurityException,
                      NoSuchElementException

This method decrypts and returns the decrypted data contained in this instance or null if there is no contained data.

Throws:

InconsistentStateException - in case of an unexpected internal exception. This should never happen.

IllegalStateException - if the DEK is not initialized.

NoSuchElementException - if the content type is not Data.

GeneralSecurityException - if a cipher operation fails.

crypt

public void crypt(InputStream in,
                  OutputStream out,
                  int opmode)
           throws IOException,
                  GeneralSecurityException

Pipes the input to the output while encrypting or decrypting the piped data with the BEK. The output stream is not closed by this method but the input stream is.

Parameters:

in - The stream from which data is read.

out - The stream to which data is written.

opmode - The operation mode of the cipher, either Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE.

Throws:

GeneralSecurityException - if the some cipher operation caused an exception.

IllegalStateException - if the BEK is not initialized.

IOException - if some I/O error is detected.

crypt

public void crypt(byte[] in,
                  OutputStream out,
                  int opmode)
           throws IOException,
                  GeneralSecurityException

Crypts or decrypts the given input bytes and writes the resulting cipher text or clear text tp the given output stream. The output stream is flushed but not closed by this method.

Parameters:

in - The byte array from which data is taken.

out - The stream to which data is written.

opmode - The operation mode of the cipher, either Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE.

Throws:

GeneralSecurityException - if the some cipher operation caused an exception.

IllegalStateException - if the BEK is not initialized.

IOException - if some I/O error is detected.

crypt

public byte[] crypt(byte[] in,
                    int offset,
                    int length,
                    int opmode)
             throws GeneralSecurityException

Crypts or decrypts the given input bytes and returns the resulting cipher text or clear text.

Parameters:

in - The byte array from which data is taken.

offset - The offset in the byte array at which the data starts.

length - The number of bytes to operate on starting at the given offset.

opmode - The operation mode of the cipher, either Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE.

Returns:

The resulting cipher text or clear text depending on the operation mode.

Throws:

GeneralSecurityException - if the some cipher operation caused an exception.

IllegalStateException - if the BEK is not initialized.

decode

public void decode(Decoder dec)
            throws IOException,
                   ASN1Exception

Decodes this instance with the given decoder. After decoding, an attempt is made to resolve the algorithm name and parameters.

Overrides:

decode in class ASN1AbstractCollection

Parameters:

dec - The decoder to use.

setEncryptedContent

public void setEncryptedContent(ASN1ObjectIdentifier oid,
                                InputStream in)
                         throws IOException,
                                GeneralSecurityException

Encrypts the given data and embeds it into this instance. The content type is set to the specified OID.

Parameters:

oid - The OID that identifies the content type.

in - The stream from which the data is read.

Throws:

IllegalStateException - if this instance is not properly initialized for encryption.

GeneralSecurityException - if something nasty happens while encrypting such as algorithms not found, bad paddings et cetera.

setContentType

public void setContentType(ASN1ObjectIdentifier oid)

Sets the content type to the given OID. The OID is copied by reference. Modifying it afterwards causes side effects.

Parameters:

oid - The OID that identifies the content type.