<p>
 * The supported configuration properties are:
 * </p>
 * <ul>
 * <li>authentication.provider.url: the full URL to the authentication server.
 * This is the URL that the handler will redirect the browser to in order to
 * authenticate the user. It does not have a default value.</li>
 * <li>public.key.pem: This is the PEM formatted public key of the issuer of the
 * JWT token. It is required for verifying that the issuer is a trusted party.
 * DO NOT include the PEM header and footer portions of the PEM encoded
 * certificate. It does not have a default value.</li>
 * <li>expected.jwt.audiences: This is a list of strings that identify
 * acceptable audiences for the JWT token. The audience is a way for the issuer
 * to indicate what entity/s that the token is intended for. Default value is
 * null which indicates that all audiences will be accepted.</li>
 * <li>jwt.cookie.name: the name of the cookie that contains the JWT token.
 * Default value is "hadoop-jwt".</li>
 * </ul>
<p>
 * The supported configuration properties are:
 * </p>
 * <ul>
 * <li>authentication.provider.url: the full URL to the authentication server.
 * This is the URL that the handler will redirect the browser to in order to
 * authenticate the user. It does not have a default value.</li>
 * <li>public.key.pem: This is the PEM formatted public key of the issuer of the
 * JWT token. It is required for verifying that the issuer is a trusted party.
 * DO NOT include the PEM header and footer portions of the PEM encoded
 * certificate. It does not have a default value.</li>
 * <li>expected.jwt.audiences: This is a list of strings that identify
 * acceptable audiences for the JWT token. The audience is a way for the issuer
 * to indicate what entity/s that the token is intended for. Default value is
 * null which indicates that all audiences will be accepted.</li>
 * <li>jwt.cookie.name: the name of the cookie that contains the JWT token.
 * Default value is "hadoop-jwt".</li>
 * </ul> | JWTRedirectAuthenticationHandler.java