org.apache.xml.security.encryption

Interface AgreementMethod

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.
KeyInfo	getOriginatorKeyInfo() Returns information relating to the originator's shared secret.
KeyInfo	getRecipientKeyInfo() Returns information relating to the recipient's shared secret.
void	revoveAgreementMethodInformation(Element info) Removes additional AgreementMethod information.
void	setKANonce(byte[] kanonce) Sets the KANonce.jj
void	setOriginatorKeyInfo(KeyInfo keyInfo) Sets the information relating to the originator's shared secret.
void	setRecipientKeyInfo(KeyInfo 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 -

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

revoveAgreementMethodInformation

void revoveAgreementMethodInformation(Element info)

Removes additional AgreementMethod information.

Parameters:

info - a Element that represents additional information specified by

getOriginatorKeyInfo

KeyInfo getOriginatorKeyInfo()

Returns information relating to the originator's shared secret.

Returns:

information relating to the originator's shared secret.

setOriginatorKeyInfo

void setOriginatorKeyInfo(KeyInfo keyInfo)

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

Parameters:

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

getRecipientKeyInfo

KeyInfo getRecipientKeyInfo()

Returns information relating to the recipient's shared secret.

Returns:

information relating to the recipient's shared secret.

setRecipientKeyInfo

void setRecipientKeyInfo(KeyInfo 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