iaik.cms

Class EcOriginatorPublicKey

java.lang.Object

iaik.x509.PublicKeyInfo

iaik.cms.EcOriginatorPublicKey

All Implemented Interfaces:

ASN1Type, java.io.Serializable, java.security.Key, java.security.PublicKey

public class EcOriginatorPublicKey
extends PublicKeyInfo

This class represents an EC originator public key in CMS.

In CMS, when using an ECDH key agreement scheme, the following restrictions are imposed on the EC originator public key:

• The originatorKey algorithm field MUST contain the id-ecPublicKey object identifier with NULL parameters.
• The originatorKey publicKey field MUST contain the DER-encoding of a value of the ASN.1 type ECPoint, which represents the sending agent's ephemeral EC public key.

This class supports and enforces these restrictions; it is intended for use only within CMS.

IMPORTANT: Before an EC originator public key can be used in an cryptographic algorithm through the JCA/JCE it must be convert to standard JCA/JCE EC public key representation using the convertToECPublicKey(PrivateKey) API.

Since:

8.0

See Also:

Serialized Form

Field Summary

Fields inherited from class iaik.x509.PublicKeyInfo

public_key_algorithm

Fields inherited from interface java.security.PublicKey

serialVersionUID

Method Summary

Modifier and Type	Method and Description
java.security.interfaces.ECPublicKey	convertToECPublicKey(java.security.PrivateKey recipientPrivateKey) Converts this public key to standard JCA/JCE representation by decoding the public point contained in the originator EC public key using the EC domain parameters from the recipient private key.
protected void	decode(byte[] subjectPublicKey) Decodes the public key value.
protected byte[]	encode() Encodes the public key value.
java.lang.String	getAlgorithm() Returns the algorithm of this key 'CMS_EC'.

Methods inherited from class iaik.x509.PublicKeyInfo

createPublicKeyInfo, decode, equals, getEncoded, getFingerprint, getFormat, getPublicKey, getPublicKey, toASN1Object, toString, writeTo

Methods inherited from class java.lang.Object

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

Method Detail

decode

protected void decode(byte[] subjectPublicKey)
               throws java.security.InvalidKeyException

Decodes the public key value.

Note: the EC public point is not decoded into ECPoint representation. This cannot be done since the EC domain parameters are not known at decode time.

Specified by:

decode in class PublicKeyInfo

Parameters:

subjectPublicKey - the encoded public key value (the SubjectPublicKeyInfo.subjectPublicKey component)

Throws:

java.security.InvalidKeyException - if an error occurs during decoding

encode

protected byte[] encode()

Encodes the public key value.

Specified by:

encode in class PublicKeyInfo

Returns:

the encoded public key value (the SubjectPublicKeyInfo.subjectPublicKey component)

getAlgorithm

public java.lang.String getAlgorithm()

Returns the algorithm of this key 'CMS_EC'.

Note: This public key is not intended for use in cryptographic operations through the JCA/JCE, so the algorithm is really not important.

Specified by:

getAlgorithm in interface java.security.Key

Specified by:

getAlgorithm in class PublicKeyInfo

Returns:

the key algorithm

convertToECPublicKey

public java.security.interfaces.ECPublicKey convertToECPublicKey(java.security.PrivateKey recipientPrivateKey)
                                                          throws java.security.InvalidKeyException

Converts this public key to standard JCA/JCE representation by decoding the public point contained in the originator EC public key using the EC domain parameters from the recipient private key.

Following this operation, the resulting public key can be used in cryptographic operations through the JCA/JCE (i.e. key agreement).

Parameters:

recipientPrivateKey - the recipient private key that this originator public key is being used with

Returns:

the public key in standard JCA/JCE EC public key representation

Throws:

java.security.InvalidKeyException - if an error occurs during the conversion process