org.apache.xml.security.encryption

Interface AgreementMethod

All Known Implementing Classes:

AgreementMethodImpl

public interface AgreementMethod

A Key Agreement algorithm provides for the derivation of a shared secret key based on a shared secret computed from certain types of compatible public keys from both the sender and the recipient. Information from the originator to determine the secret is indicated by an optional OriginatorKeyInfo parameter child of an AgreementMethod element while that associated with the recipient is indicated by an optional RecipientKeyInfo. A shared key is derived from this shared secret by a method determined by the Key Agreement algorithm.

Note: XML Encryption does not provide an on-line key agreement negotiation protocol. The AgreementMethod element can be used by the originator to identify the keys and computational procedure that were used to obtain a shared encryption key. The method used to obtain or select the keys or algorithm used for the agreement computation is beyond the scope of this specification.

The AgreementMethod element appears as the content of a ds:KeyInfo since, like other ds:KeyInfo children, it yields a key. This ds:KeyInfo is in turn a child of an EncryptedData or EncryptedKey element. The Algorithm attribute and KeySize child of the EncryptionMethod element under this EncryptedData or EncryptedKey element are implicit parameters to the key agreement computation. In cases where this EncryptionMethod algorithm URI is insufficient to determine the key length, a KeySize MUST have been included. In addition, the sender may place a KA-Nonce element under AgreementMethod to assure that different keying material is generated even for repeated agreements using the same sender and recipient public keys.

If the agreed key is being used to wrap a key, then AgreementMethod would appear inside a ds:KeyInfo inside an EncryptedKey element.

The Schema for AgreementMethod is as follows:

Method Summary

Modifier and Type	Method and Description
void	addAgreementMethodInformation(Element info) Adds additional AgreementMethod information.
Iterator<Element>	getAgreementMethodInformation() Returns additional information regarding the AgreementMethod.
String	getAlgorithm() Returns the algorithm URI of this CryptographicMethod.
byte[]	getKANonce() Returns a byte array.
KeyDerivationMethod	getKeyDerivationMethod() Returns KeyDerivationMethod information used in the AgreementMethod.
OriginatorKeyInfo	getOriginatorKeyInfo() Returns information relating to the originator's shared secret.
RecipientKeyInfo	getRecipientKeyInfo() Returns information relating to the recipient's shared secret.
void	removeAgreementMethodInformation(Element info) Removes additional AgreementMethod information.
void	setKANonce(byte[] kanonce) Sets the KANonce.jj
void	setKeyDerivationMethod(KeyDerivationMethod keyDerivationMethod) This method is used to set the KeyDerivationMethod when the AgreementMethod is being used to derive a key.
void	setOriginatorKeyInfo(OriginatorKeyInfo keyInfo) Sets the information relating to the originator's shared secret.
void	setOriginatorPublicKey(PublicKey publicKey) Sets the originator's PublicKey to generate the secret
void	setRecipientKeyInfo(RecipientKeyInfo keyInfo) Sets the information relating to the recipient's shared secret.

Method Detail

getKANonce

byte[] getKANonce()

Returns a byte array.

Returns:

a byte array.

setKANonce

void setKANonce(byte[] kanonce)

Sets the KANonce.jj

Parameters:

kanonce -

getKeyDerivationMethod

KeyDerivationMethod getKeyDerivationMethod()
                                    throws XMLSecurityException

Returns KeyDerivationMethod information used in the AgreementMethod.

Returns:

The KeyDerivationMethod information regarding the AgreementMethod.

Throws:

XMLSecurityException

setKeyDerivationMethod

void setKeyDerivationMethod(KeyDerivationMethod keyDerivationMethod)

This method is used to set the KeyDerivationMethod when the AgreementMethod is being used to derive a key. The KeyDerivationMethod is declared as but is used in ECDH_ES

Parameters:

keyDerivationMethod -

getAgreementMethodInformation

Iterator<Element> getAgreementMethodInformation()

Returns additional information regarding the AgreementMethod.

Returns:

additional information regarding the AgreementMethod.

addAgreementMethodInformation

void addAgreementMethodInformation(Element info)

Adds additional AgreementMethod information.

Parameters:

info - a Element that represents additional information specified by

removeAgreementMethodInformation

void removeAgreementMethodInformation(Element info)

Removes additional AgreementMethod information.

Parameters:

info - a Element that represents additional information specified by

getOriginatorKeyInfo

OriginatorKeyInfo getOriginatorKeyInfo()
                                throws XMLSecurityException

Returns information relating to the originator's shared secret.

Returns:

information relating to the originator's shared secret.

Throws:

XMLSecurityException

setOriginatorKeyInfo

void setOriginatorKeyInfo(OriginatorKeyInfo keyInfo)

Sets the information relating to the originator's shared secret.

Parameters:

keyInfo - information relating to the originator's shared secret.

setOriginatorPublicKey

void setOriginatorPublicKey(PublicKey publicKey)

Sets the originator's PublicKey to generate the secret

Parameters:

publicKey - originator's PublicKey

getRecipientKeyInfo

RecipientKeyInfo getRecipientKeyInfo()
                              throws XMLSecurityException

Returns information relating to the recipient's shared secret.

Returns:

information relating to the recipient's shared secret.

Throws:

XMLSecurityException

setRecipientKeyInfo

void setRecipientKeyInfo(RecipientKeyInfo keyInfo)

Sets the information relating to the recipient's shared secret.

Parameters:

keyInfo - information relating to the recipient's shared secret.

getAlgorithm

String getAlgorithm()

Returns the algorithm URI of this CryptographicMethod.

Returns:

the algorithm URI of this CryptographicMethod