The source code

/**@class java.security.KeyFactory
@extends java.lang.Object

 Key factories are used to convert <I>keys</I> (opaque
 cryptographic keys of type {@code Key}) into <I>key specifications</I>
 (transparent representations of the underlying key material), and vice
 versa.

 <P> Key factories are bi-directional. That is, they allow you to build an
 opaque key object from a given key specification (key material), or to
 retrieve the underlying key material of a key object in a suitable format.

 <P> Multiple compatible key specifications may exist for the same key.
 For example, a DSA public key may be specified using
 {@code DSAPublicKeySpec} or
 {@code X509EncodedKeySpec}. A key factory can be used to translate
 between compatible key specifications.

 <P> The following is an example of how to use a key factory in order to
 instantiate a DSA public key from its encoding.
 Assume Alice has received a digital signature from Bob.
 Bob also sent her his public key (in encoded format) to verify
 his signature. Alice then performs the following actions:

 <pre>
 X509EncodedKeySpec bobPubKeySpec = new X509EncodedKeySpec(bobEncodedPubKey);
 KeyFactory keyFactory = KeyFactory.getInstance("DSA");
 PublicKey bobPubKey = keyFactory.generatePublic(bobPubKeySpec);
 Signature sig = Signature.getInstance("DSA");
 sig.initVerify(bobPubKey);
 sig.update(data);
 sig.verify(signature);
 </pre>

 <p> Android provides the following <code>KeyFactory</code> algorithms:
 <table>
   <thead>
     <tr>
       <th>Algorithm</th>
       <th>Supported API Levels</th>
     </tr>
   </thead>
   <tbody>
     <tr>
       <td>DH</td>
       <td>1+</td>
     </tr>
     <tr>
       <td>DSA</td>
       <td>1+</td>
     </tr>
     <tr>
       <td>EC</td>
       <td>11+</td>
     </tr>
     <tr>
       <td>RSA</td>
       <td>1+</td>
     </tr>
     <tr class="deprecated">
       <td>X.509</td>
       <td>1-8</td>
     </tr>
   </tbody>
 </table>

 These algorithms are described in the <a href=
 "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#KeyFactory">
 KeyFactory section</a> of the
 Java Cryptography Architecture Standard Algorithm Name Documentation.

 @author Jan Luehe

 @see Key
 @see PublicKey
 @see PrivateKey
 @see java.security.spec.KeySpec
 @see java.security.spec.DSAPublicKeySpec
 @see java.security.spec.X509EncodedKeySpec

 @since 1.2
*/
var KeyFactory = {

/**Returns a KeyFactory object that converts
 public/private keys of the specified algorithm.

 <p> This method traverses the list of registered security Providers,
 starting with the most preferred Provider.
 A new KeyFactory object encapsulating the
 KeyFactorySpi implementation from the first
 Provider that supports the specified algorithm is returned.

 <p> Note that the list of registered providers may be retrieved via
 the {@link java.security.Security#getProviders() java.security.Security.getProviders()} method.
@param {String} algorithm the name of the requested key algorithm.
 See the KeyFactory section in the <a href=
 "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#KeyFactory">
 Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 for information about standard algorithm names.
@return {Object {java.security.KeyFactory}} the new KeyFactory object.
@exception NoSuchAlgorithmException if no Provider supports a
          KeyFactorySpi implementation for the
          specified algorithm.
@see Provider
*/
getInstance : function(  ) {},

/**Returns a KeyFactory object that converts
 public/private keys of the specified algorithm.

 <p> A new KeyFactory object encapsulating the
 KeyFactorySpi implementation from the specified provider
 is returned.  The specified provider must be registered
 in the security provider list.

 <p> Note that the list of registered providers may be retrieved via
 the {@link java.security.Security#getProviders() java.security.Security.getProviders()} method.
@param {String} algorithm the name of the requested key algorithm.
 See the KeyFactory section in the <a href=
 "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#KeyFactory">
 Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 for information about standard algorithm names.
@param {String} provider the name of the provider.
@return {Object {java.security.KeyFactory}} the new KeyFactory object.
@exception NoSuchAlgorithmException if a KeyFactorySpi
          implementation for the specified algorithm is not
          available from the specified provider.
@exception NoSuchProviderException if the specified provider is not
          registered in the security provider list.
@exception IllegalArgumentException if the provider name is null
          or empty.
@see Provider
*/
getInstance : function(  ) {},

/**Returns a KeyFactory object that converts
 public/private keys of the specified algorithm.

 <p> A new KeyFactory object encapsulating the
 KeyFactorySpi implementation from the specified Provider
 object is returned.  Note that the specified Provider object
 does not have to be registered in the provider list.
@param {String} algorithm the name of the requested key algorithm.
 See the KeyFactory section in the <a href=
 "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#KeyFactory">
 Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 for information about standard algorithm names.
@param {Object {Provider}} provider the provider.
@return {Object {java.security.KeyFactory}} the new KeyFactory object.
@exception NoSuchAlgorithmException if a KeyFactorySpi
          implementation for the specified algorithm is not available
          from the specified Provider object.
@exception IllegalArgumentException if the specified provider is null.
@see Provider
@since 1.4
*/
getInstance : function(  ) {},

/**Returns the provider of this key factory object.
@return {Object {java.security.Provider}} the provider of this key factory object
*/
getProvider : function(  ) {},

/**Gets the name of the algorithm
 associated with this {@code KeyFactory}.
@return {String} the name of the algorithm associated with this
 {@code KeyFactory}
*/
getAlgorithm : function(  ) {},

/**Generates a public key object from the provided key specification
 (key material).
@param {Object {KeySpec}} keySpec the specification (key material) of the public key.
@return {Object {java.security.PublicKey}} the public key.
@exception InvalidKeySpecException if the given key specification
 is inappropriate for this key factory to produce a public key.
*/
generatePublic : function(  ) {},

/**Generates a private key object from the provided key specification
 (key material).
@param {Object {KeySpec}} keySpec the specification (key material) of the private key.
@return {Object {java.security.PrivateKey}} the private key.
@exception InvalidKeySpecException if the given key specification
 is inappropriate for this key factory to produce a private key.
*/
generatePrivate : function(  ) {},

/**Returns a specification (key material) of the given key object.
 {@code keySpec} identifies the specification class in which
 the key material should be returned. It could, for example, be
 {@code DSAPublicKeySpec.class}, to indicate that the
 key material should be returned in an instance of the
 {@code DSAPublicKeySpec} class.
@param {Object {Key}} key the key.
@param {Object {java.lang.Class}} keySpec the specification class in which
 the key material should be returned.
@param keySpec the specification class in which
 the key material should be returned.
@return {Object {java.security.spec.KeySpec}} the underlying key specification (key material) in an instance
 of the requested specification class.
@exception InvalidKeySpecException if the requested key specification is
 inappropriate for the given key, or the given key cannot be processed
 (e.g., the given key has an unrecognized algorithm or format).
*/
getKeySpec : function(  ) {},

/**Translates a key object, whose provider may be unknown or potentially
 untrusted, into a corresponding key object of this key factory.
@param {Object {Key}} key the key whose provider is unknown or untrusted.
@return {Object {java.security.Key}} the translated key.
@exception InvalidKeyException if the given key cannot be processed
 by this key factory.
*/
translateKey : function(  ) {},


};