com.clarionmedia.infinitum.web.rest.impl.SharedSecretAuthentication.java Source code

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Here is the source code for com.clarionmedia.infinitum.web.rest.impl.SharedSecretAuthentication.java

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/*
 * Copyright (C) 2012 Clarion Media, LLC
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.clarionmedia.infinitum.web.rest.impl;

import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URLEncoder;

import org.apache.http.impl.client.RequestWrapper;

import com.clarionmedia.infinitum.exception.InfinitumRuntimeException;
import com.clarionmedia.infinitum.web.rest.AuthenticationStrategy;
import com.clarionmedia.infinitum.web.rest.TokenGenerator;

/**
 * <p>
 * Used for token-based/shared-secret authentication. A {@link TokenGenerator}
 * can be supplied to this class in order to implement a token-generation
 * policy.
 * </p>
 * 
 * @author Tyler Treat
 * @version 1.0 03/21/12
 * @since 1.0
 */
public class SharedSecretAuthentication implements AuthenticationStrategy {

    private static final String ENCODING = "UTF-8";

    private String mTokenName;
    private String mToken;
    private TokenGenerator mGenerator;
    private boolean mIsHeader;

    @Override
    public void authenticate(RequestWrapper request) {
        if (isHeader()) {
            request.addHeader(getTokenName(), getToken());
        } else {
            String uri = request.getURI().toString();
            if (uri.contains("?"))
                uri += "&" + getTokenName() + "=" + getToken();
            request.setURI(URI.create(uri));
        }
    }

    /**
     * Indicates whether or not request authentication is included as a header.
     * If not a header, it is included as a query string parameter.
     * 
     * @return {@code true} if it's a header, {@code false} if not
     */
    public boolean isHeader() {
        return mIsHeader;
    }

    /**
     * Sets the value indicating whether or not request authentication is
     * included as a header. If not a header, it is included as a query string
     * parameter.
     * 
     * @param isHeader
     *            value to set
     */
    public void setHeader(boolean isHeader) {
        mIsHeader = isHeader;
    }

    /**
     * Sets the token name. This value represents either the header name or the
     * query string parameter name, depending on what form of authentication is
     * used.
     * 
     * @param tokenName
     *            the token name to use for authentication
     */
    public void setTokenName(String tokenName) {
        try {
            mTokenName = URLEncoder.encode(tokenName, ENCODING);
        } catch (UnsupportedEncodingException e) {
            throw new InfinitumRuntimeException("Invalid encoding '" + ENCODING + "'");
        }
    }

    /**
     * Returns the token name. This value represents either the header name or
     * the query string parameter name, depending on what form of authentication
     * is used.
     */
    public String getTokenName() {
        return mTokenName;
    }

    /**
     * Sets the token value. This value represents the header value or the query
     * string parameter value, depending on what form of authentication is used.
     * 
     * @param token
     *            the shared secret to use for authentication
     */
    public void setToken(String token) {
        try {
            mToken = URLEncoder.encode(token, ENCODING);
        } catch (UnsupportedEncodingException e) {
            throw new InfinitumRuntimeException("Invalid encoding '" + ENCODING + "'");
        }
    }

    /**
     * Returns the token value. This value represents the header value or the
     * query string parameter value, depending on what form of authentication is
     * used. This is either the value provided to
     * {@link SharedSecretAuthentication#setToken(String)} or the value
     * generated from the {@link TokenGenerator} if one has been provided.
     * 
     * @return shared secret
     */
    public String getToken() {
        if (mGenerator != null)
            return mGenerator.generateToken();
        return mToken;
    }

    /**
     * Registers a {@link TokenGenerator} for this
     * {@code SharedSecretAuthentication} strategy. The {@code TokenGenerator}
     * is responsible for creating shared secrets.
     * 
     * @param generator
     *            the {@code TokenGenerator} to register
     */
    public void setTokenGenerator(TokenGenerator generator) {
        mGenerator = generator;
    }

    /**
     * Removes any registered {@link TokenGenerator} from this
     * {@code SharedSecretAuthentication} strategy.
     */
    public void clearTokenGenerator() {
        mGenerator = null;
    }

}