iaik.cms.attributes

Class CMSAlgorithmProtection

java.lang.Object

iaik.asn1.structures.AttributeValue

iaik.cms.attributes.CMSAlgorithmProtection

All Implemented Interfaces:

iaik.asn1.ASN1Type

public class CMSAlgorithmProtection
extends iaik.asn1.structures.AttributeValue

The CMS Algorithm Identifier Protection Attribute (CMSAlgorithmProtection) attribute.

The CMSAlgorithmProtection attribute is specified to protect the digest algorithm and mac or signature algorithm identifiers of CMS AuthenticatedData or CMS SignedData/SignerInfo structures by including them into the signed attributes. Depending of used with AuthenticatedData or SignedData/SignerInfo either mac algorithm identifier or signature algorithm identifier (but not both together) must be present (see RFC 6211):

  CMSAlgorithmProtection ::= SEQUENCE {
        digestAlgorithm         DigestAlgorithmIdentifier,
        signatureAlgorithm  [1] SignatureAlgorithmIdentifier OPTIONAL,
        macAlgorithm        [2] MessageAuthenticationCodeAlgorithm
                                          OPTIONAL
     }
     (WITH COMPONENTS { signatureAlgorithm PRESENT,
                        macAlgorithm ABSENT } |
      WITH COMPONENTS { signatureAlgorithm ABSENT,
                        macAlgorithm PRESENT })
 

When creating a CMSAlgorithmProtection attribute digest and mac/signature algorithm may be set manually or directly got from the AuthenticatedData or SignerInfo object (e.g. for SignerInfo):

  SignerInfo signerInfo = ...;
  Attribute[] attributes = new Attribute[..];
  ..
  CMSAlgorithmProtection cmsAlgorithmProtection = new CMSAlgorithmProtection(signerInfo);
  attributes[..] = new Attribute(cmsAlgorithmProtection);
  ...
  // set the attributes
  signerInfo.setSignedAttributes(attributes);
 

When parsing an AuthernticatedData/SignerInfo the CMSAlgorithmProtection attribute may be queried for validating the AuthernticatedData/SignerInfo digest and mac/signature algorithms, e.g.:

 SignerInfo signerInfo = ...;
 CMSAlgorithmProtection cmsAlgorithmProtection = (CMSAlgorithmProtection)signerInfo.getSignedAttributeValue(CMSAlgorithmProtection.oid);
 if (cmsAlgorithmProtection != null) {
   cmsAlgorithmProtection.validateSignerInfo(signerInfo);
 } 
 

See Also:

SignerInfo, AuthenticatedData

Field Summary

Fields

Modifier and Type	Field and Description
static iaik.asn1.ObjectID	oid The attributeType object identifier of the CMS ContentType attribute.

Constructor Summary

Constructors

Constructor and Description
CMSAlgorithmProtection() Empty default constructor.
CMSAlgorithmProtection(iaik.asn1.structures.AlgorithmID digestAlgorithm) Creates a CMSAlgorithmProtection attribute from the given digest algorithm.
CMSAlgorithmProtection(iaik.asn1.ASN1Object obj) Creates an CMS CMSAlgorithmProtection from its ASN.1 representation.
CMSAlgorithmProtection(AuthenticatedDataStream authenticatedData) Creates a CMSAlgorithmProtection attribute for the given CMS AuthenticatedData.
CMSAlgorithmProtection(SignerInfo signerInfo) Creates a CMSAlgorithmProtection attribute for the given CMS SignerInfo.

Method Summary

Modifier and Type	Method and Description
void	decode(iaik.asn1.ASN1Object obj) Decodes the given ASN.1 CMAlgorihmProtecion object for parsing the internal structure.
boolean	equals(java.lang.Object obj) Compares this CMSAlgorithmProtection to the specified object.
iaik.asn1.ObjectID	getAttributeType() Returns the OID identifying the CMAlgorihmProtecion attribute type.
iaik.asn1.structures.AlgorithmID	getDigestAlgorithm() Gets the digest algorithm.
iaik.asn1.structures.AlgorithmID	getMacAlgorithm() Gets the AuthenticatedData mac algorithm.
iaik.asn1.structures.AlgorithmID	getSignatureAlgorithm() Gets the SignerInfo signature algorithm.
int	hashCode() Returns a hashcode for this object.
boolean	multipleAllowed() Returns false since only one AttributeValue is allowed in the SET OF AttributeValue of an CMAlgorihmProtecion attribute.
void	setMacAlgorithm(iaik.asn1.structures.AlgorithmID macAlgorithm) Sets the AuthenticatedData mac algorithm.
void	setSignatureAlgorithm(iaik.asn1.structures.AlgorithmID signatureAlgorithm) Sets the SignerInfo signature algorithm.
iaik.asn1.ASN1Object	toASN1Object() Returns this CMAlgorihmProtecion as ASN1Object.
java.lang.String	toString() Returns a string representation of this CMAlgorihmProtecion.
void	validateAuthenticatedData(AuthenticatedDataStream authenticatedData) Validates the given AuthenticatedData against this CMSAlgorithmProtection attribute.
void	validateSignerInfo(SignerInfo signerInfo) Validates the given SignerInfo against this CMSAlgorithmProtection attribute.

Methods inherited from class iaik.asn1.structures.AttributeValue

getName

Methods inherited from class java.lang.Object

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

Field Detail

oid

public static final iaik.asn1.ObjectID oid

The attributeType object identifier of the CMS ContentType attribute. The corresponding OID string is "1.2.840.113549.1.9.52".

Constructor Detail

CMSAlgorithmProtection

public CMSAlgorithmProtection()

Empty default constructor. Required for dynamic object creation. Shall NOT be used by an application.

CMSAlgorithmProtection

public CMSAlgorithmProtection(iaik.asn1.structures.AlgorithmID digestAlgorithm)

Creates a CMSAlgorithmProtection attribute from the given digest algorithm.

Parameters:

digestAlgorithm - the digest algorithm

CMSAlgorithmProtection

public CMSAlgorithmProtection(SignerInfo signerInfo)

Creates a CMSAlgorithmProtection attribute for the given CMS SignerInfo.

Parameters:

signerInfo - the CMS SignerInfo

CMSAlgorithmProtection

public CMSAlgorithmProtection(AuthenticatedDataStream authenticatedData)

Creates a CMSAlgorithmProtection attribute for the given CMS AuthenticatedData.

Parameters:

authenticatedData - the CMS AuthenticatedData

CMSAlgorithmProtection

public CMSAlgorithmProtection(iaik.asn1.ASN1Object obj)
                       throws iaik.asn1.CodingException

Creates an CMS CMSAlgorithmProtection from its ASN.1 representation.

Parameters:

obj - the CMS CMSAlgorithmProtection as ASN1Object

Throws:

iaik.asn1.CodingException - if an error occurs when parsing the ASN.1 object

Method Detail

getDigestAlgorithm

public iaik.asn1.structures.AlgorithmID getDigestAlgorithm()

Gets the digest algorithm.

Returns:

the digest algorithm

setSignatureAlgorithm

public void setSignatureAlgorithm(iaik.asn1.structures.AlgorithmID signatureAlgorithm)

Sets the SignerInfo signature algorithm.

Parameters:

signatureAlgorithm - the SignerInfo signature algorithm

Throws:

java.lang.IllegalArgumentException - if the mac algorithm has been already set

getSignatureAlgorithm

public iaik.asn1.structures.AlgorithmID getSignatureAlgorithm()

Gets the SignerInfo signature algorithm.

Returns:

the signature algorithm or null if the signature algorithm has not been set

setMacAlgorithm

public void setMacAlgorithm(iaik.asn1.structures.AlgorithmID macAlgorithm)

Sets the AuthenticatedData mac algorithm.

Parameters:

macAlgorithm - the AuthenticatedData mac algorithm

Throws:

java.lang.IllegalArgumentException - if the signature algorithm has been already set

getMacAlgorithm

public iaik.asn1.structures.AlgorithmID getMacAlgorithm()

Gets the AuthenticatedData mac algorithm.

Returns:

the mac algorithm or null if the mac algorithm has not been set

decode

public void decode(iaik.asn1.ASN1Object obj)
            throws iaik.asn1.CodingException

Decodes the given ASN.1 CMAlgorihmProtecion object for parsing the internal structure.

Parameters:

obj - the CMAlgorihmProtecion as ASN1Object

Throws:

iaik.asn1.CodingException - if an error occurs when parsing the ASN.1 CMAlgorihmProtecion

toASN1Object

public iaik.asn1.ASN1Object toASN1Object()
                                  throws iaik.asn1.CodingException

Returns this CMAlgorihmProtecion as ASN1Object.

Returns:

this CMAlgorihmProtecion as ASN1Object

Throws:

iaik.asn1.CodingException - if the ASN1Object cannot be built

getAttributeType

public iaik.asn1.ObjectID getAttributeType()

Returns the OID identifying the CMAlgorihmProtecion attribute type.

Specified by:

getAttributeType in class iaik.asn1.structures.AttributeValue

Returns:

the OID identifying the CMAlgorihmProtecion attribute type.

multipleAllowed

public boolean multipleAllowed()

Returns false since only one AttributeValue is allowed in the SET OF AttributeValue of an CMAlgorihmProtecion attribute.

Overrides:

multipleAllowed in class iaik.asn1.structures.AttributeValue

Returns:

false since only one attribute value is allowed

validateSignerInfo

public void validateSignerInfo(SignerInfo signerInfo)
                        throws CMSException

Validates the given SignerInfo against this CMSAlgorithmProtection attribute.

This method checks if digest and signature algorithm of the given SignerInfo comply with digest and signature algorithm of this CMSAlgorithmProtection attribute. This method does NOT check if this CMSAlgorithmProtection attribute is actually included in the given SignerInfo. It is assumed that the attribute first is got from the SignerInfo:

 SignerInfo signerInfo = ...;
 CMSAlgorithmProtection cmsAlgorithmProtection = (CMSAlgorithmProtection)ad.getSigneddAttributeVaue(CMSAlgorithmProtection.oid);
 if (cmsAlgorithmProtection != null) {
   cmsAlgorithmProtection.validated(signerInfo);
 }
 

Parameters:

signerInfo - the SignerInfo to be validated

Throws:

CMSException - if the validation fails for some reason

validateAuthenticatedData

public void validateAuthenticatedData(AuthenticatedDataStream authenticatedData)
                               throws CMSException

Validates the given AuthenticatedData against this CMSAlgorithmProtection attribute.

This method checks if digest and mac algorithm of the given AuthenticatedData comply with digest and mac algorithm of this CMSAlgorithmProtection attribute. This method does NOT check if this CMSAlgorithmProtection attribute is actually included in the given AuthenticatedData. It is assumed that the attribute first is got from the AuthenticatedData:

 AuthenticatedData ad = ...;
 Attribute attribute = authenticatedData.getAuthenticatedAttribute(CMSAlgorithmProtection.oid);
 if (attribute != null) {
   CMSAlgorithmProtection cmsAlgorithmProtection = (CMSAlgorithmProtection)attribute.getAttributeValue();
   cmsAlgorithmProtection.validated(ad);
 } 
 

Parameters:

authenticatedData - the AuthenticatedData to be validated

Throws:

CMSException - if the validation fails for some reason

equals

public boolean equals(java.lang.Object obj)

Compares this CMSAlgorithmProtection to the specified object.

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to compare this CMSAlgorithmProtection against.

Returns:

true, if the given object is equal to this CMSAlgorithmProtection, false otherwise

hashCode

public int hashCode()

Returns a hashcode for this object.

Overrides:

hashCode in class java.lang.Object

Returns:

a hashcode for this object

toString

public java.lang.String toString()

Returns a string representation of this CMAlgorihmProtecion.

Specified by:

toString in class iaik.asn1.structures.AttributeValue

Returns:

this CMAlgorihmProtecion as string