codec.pkcs7
Class ContentInfo

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

All Implemented Interfaces:

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

public class ContentInfo

extends ASN1Sequence

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

 ContentInfo ::= SEQUENCE {
   contentType ContentType,
   content [0] EXPLICIT ANY DEFINED BY contentType OPTIONAL
 }
 ContentType ::= OBJECT IDENTIFIER
 

contentType indicates the type of content. 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.

The ContentInfo is also the general syntax of a complete PKCS#7 structure.

Version:

"$Id: ContentInfo.java,v 1.4 2000/12/07 13:21:52 vroth Exp $"

Author:

Volker Roth

See Also:

Serialized Form

Field Summary

protected ASN1TaggedType	content_ The actual content of this structure.
protected ASN1ObjectIdentifier	contentType_ The OID defining the contents of this structure.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

ContentInfo()
This method creates an instance which is initialized for parsing.

ContentInfo(ASN1ObjectIdentifier o)
This constructor sets the content type to the given OID but leaves the actual content empty.

ContentInfo(ASN1RegisteredType o)
This method calls setContent with the given ASN.1 type, which builds the tree of ASN.1 objects used for decoding this structure.

ContentInfo(OIDRegistry registry)
Creates an instance ready for decoding.

Method Summary

void	decode(Decoder decoder) Decodes this instance.
ASN1Type	getContent() This method returns the actual content of this structure.
ASN1ObjectIdentifier	getContentType() Returns the contentType of this structure.
void	setContent(ASN1ObjectIdentifier oid) Sets the content type to the given OID and clears the actual content.
void	setContent(ASN1ObjectIdentifier oid, ASN1Type type) This method sets the OID and content of this structure.
void	setContent(ASN1RegisteredType type) This method sets the content of this structure.

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

contentType_

protected ASN1ObjectIdentifier contentType_

The OID defining the contents of this structure.

content_

protected ASN1TaggedType content_

The actual content of this structure.

Constructor Detail

ContentInfo

public ContentInfo()

This method creates an instance which is initialized for parsing. The PKCSRegistry is used for resolving OIDs to PKCS7 structures.

ContentInfo

public ContentInfo(OIDRegistry registry)

Creates an instance ready for decoding. The given OIDRegistry is used to resolve content types. By default the PKCSRegistry is used.

Parameters:

registry - The Object Identifier registry that is used to resolve content types, or null if a default registry shall be used.

ContentInfo

public ContentInfo(ASN1ObjectIdentifier o)

This constructor sets the content type to the given OID but leaves the actual content empty. This is a constructor required for instance by the SignedData type in the case of signing detached signatures. Such signatures require the content type to be Data, but the actual data must be empty (no identifier, length and contents octets).

This method calls {link #setContent(codec.asn1,ASN1ObjectIdentifier) setContent(oid)}.

Parameters:

o - The OID denoting the content type, most probably the Data content OID.

ContentInfo

public ContentInfo(ASN1RegisteredType o)

This method calls setContent with the given ASN.1 type, which builds the tree of ASN.1 objects used for decoding this structure.

Parameters:

o - The PKCS#7 content type to embed in this structure.

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.

getContent

public ASN1Type getContent()

This method returns the actual content of this structure.

Returns:

The content or null if no content is available.

setContent

public void setContent(ASN1ObjectIdentifier oid)

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

Parameters:

oid - The OID that identifies the (empty) content type.

setContent

public void setContent(ASN1RegisteredType type)

This method sets the content of this structure. This method calls setContent(ASN1ObjectIdentifier, ASN1Type) with the OID returned by ASN1RegisteredType.getOID().

Parameters:

type - The content that shall be set.

setContent

public void setContent(ASN1ObjectIdentifier oid,
                       ASN1Type type)

This method sets the OID and content of this structure. The OID is cloned and the type is stored by reference. Subsequent modification of the type has side effects.

Parameters:

oid - The OID that identifies the content type.

type - The content.

decode

public void decode(Decoder decoder)
            throws ASN1Exception,
                   IOException

Decodes this instance. This method extracts the actual content type from the ASN1OpenType.

Overrides:

decode in class ASN1AbstractCollection

Parameters:

decoder - The Decoder to use.