Module java.xml.crypto
Package javax.xml.crypto.dsig.keyinfo

## Interface KeyValue

- All Superinterfaces:
    `XMLStructure`

      public interface KeyValue
      extends XMLStructure

  A representation of the XML `KeyValue` element as defined in the W3C Recommendation for XML-Signature Syntax and Processing. A `KeyValue` object contains a single public key that may be useful in validating the signature. The XML schema definition is defined as:

          <element name="KeyValue" type="ds:KeyValueType"/>
          <complexType name="KeyValueType" mixed="true">
            <choice>
              <element ref="ds:DSAKeyValue"/>
              <element ref="ds:RSAKeyValue"/>
              <any namespace="##other" processContents="lax"/>
            </choice>
          </complexType>

          <element name="DSAKeyValue" type="ds:DSAKeyValueType"/>
          <complexType name="DSAKeyValueType">
            <sequence>
              <sequence minOccurs="0">
                <element name="P" type="ds:CryptoBinary"/>
                <element name="Q" type="ds:CryptoBinary"/>
              </sequence>
              <element name="G" type="ds:CryptoBinary" minOccurs="0"/>
              <element name="Y" type="ds:CryptoBinary"/>
              <element name="J" type="ds:CryptoBinary" minOccurs="0"/>
              <sequence minOccurs="0">
                <element name="Seed" type="ds:CryptoBinary"/>
                <element name="PgenCounter" type="ds:CryptoBinary"/>
              </sequence>
            </sequence>
          </complexType>

          <element name="RSAKeyValue" type="ds:RSAKeyValueType"/>
          <complexType name="RSAKeyValueType">
            <sequence>
              <element name="Modulus" type="ds:CryptoBinary"/>
              <element name="Exponent" type="ds:CryptoBinary"/>
            </sequence>
          </complexType>

  A `KeyValue` instance may be created by invoking the `newKeyValue` method of the `KeyInfoFactory` class, and passing it a `PublicKey` representing the value of the public key. Here is an example of creating a `KeyValue` from a `DSAPublicKey` of a `Certificate` stored in a `KeyStore`:

       KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
       PublicKey dsaPublicKey = keyStore.getCertificate("myDSASigningCert").getPublicKey();
       KeyInfoFactory factory = KeyInfoFactory.getInstance("DOM");
       KeyValue keyValue = factory.newKeyValue(dsaPublicKey);

  This class returns the `DSAKeyValue` and `RSAKeyValue` elements as objects of type `DSAPublicKey` and `RSAPublicKey`, respectively. Note that not all of the fields in the schema are accessible as parameters of these types.
  Since:
    1.6
  See Also:
    `KeyInfoFactory.newKeyValue(PublicKey)`

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `static String` | `DSA_TYPE` | URI identifying the DSA KeyValue KeyInfo type: http://www.w3.org/2000/09/xmldsig#DSAKeyValue.
    `static String` | `RSA_TYPE` | URI identifying the RSA KeyValue KeyInfo type: http://www.w3.org/2000/09/xmldsig#RSAKeyValue.

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `PublicKey` | `getPublicKey​()` | Returns the public key of this `KeyValue`.

    - ### Methods inherited from interface javax.xml.crypto.XMLStructure

      `isFeatureSupported`

- - ### Field Detail

    - #### DSA_TYPE

          static final String DSA_TYPE

      URI identifying the DSA KeyValue KeyInfo type: http://www.w3.org/2000/09/xmldsig#DSAKeyValue. This can be specified as the value of the `type` parameter of the `RetrievalMethod` class to describe a remote `DSAKeyValue` structure.
      See Also:
        Constant Field Values

    - #### RSA_TYPE

          static final String RSA_TYPE

      URI identifying the RSA KeyValue KeyInfo type: http://www.w3.org/2000/09/xmldsig#RSAKeyValue. This can be specified as the value of the `type` parameter of the `RetrievalMethod` class to describe a remote `RSAKeyValue` structure.
      See Also:
        Constant Field Values

  - ### Method Detail

    - #### getPublicKey

          PublicKey getPublicKey​()
                          throws KeyException

      Returns the public key of this `KeyValue`.
      Returns:
        the public key of this `KeyValue`
      Throws:
        `KeyException` - if this `KeyValue` cannot be converted to a `PublicKey`