com.google.resting.rest.util.oauth.SignatureUtil.java Source code

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Here is the source code for com.google.resting.rest.util.oauth.SignatureUtil.java

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/*
* Copyright (C) 2010 Google Code.
*
* 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.google.resting.rest.util.oauth;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.List;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;
import org.apache.http.NameValuePair;

import com.google.resting.component.Verb;

/**
 * Utility for signing request as per Oauth 1.0a.
 * 
 * @author sujata.de
 * @since resting 0.1
 *
 */

public class SignatureUtil {
    private static final String SEPARATOR = "://";

    private static String getBaseString(String targetDomain, String requestType, boolean isSecureInvocation,
            String contextPathElement, List<NameValuePair> inputParams, String messageEncoding) {
        String sourceVerb = requestType;
        String sourceUrl = SEPARATOR + targetDomain + contextPathElement;
        if (isSecureInvocation) {
            sourceUrl = RequestConstants.HTTPS + sourceUrl;
        } else {
            sourceUrl = RequestConstants.HTTP + sourceUrl;
        }
        System.out.println("Source url is " + sourceUrl);
        return BaseStringExtractorImpl.extract(sourceVerb, sourceUrl, inputParams, messageEncoding);
    }

    /**
     * Sign request.
     * 
     * @param keyString Consumer key for request signing.
     * @param targetDomain Domain of the REST endpoint (Ex. login.yahoo.com)
     * @param verb Type of REST operation (GET/POST/PUT/DELETE)
     * @param isSecureInvocation HTTP/HTTPS
     * @param contextPathElement Path element in the base REST uri (Ex. /weather/india)
     * @param inputParams Collection of request params for REST request (Ex. city=calcutta )
     * @return
     * @throws NoSuchAlgorithmException The exception is thrown if the encryption algorithm is not supported.
     * @throws InvalidKeyException The exception is thrown if the consumer key is invalid
     * @throws IllegalStateException 
     * @throws UnsupportedEncodingException The exception is thrown if the URL encoding is incorrect.
     */
    public static String getSignature(String keyString, String targetDomain, Verb verb, boolean isSecureInvocation,
            String contextPathElement, List<NameValuePair> inputParams, String messageEncoding)
            throws NoSuchAlgorithmException, InvalidKeyException, IllegalStateException,
            UnsupportedEncodingException {

        String baseString = getBaseString(targetDomain, verb.toString(), isSecureInvocation, contextPathElement,
                inputParams, messageEncoding).replace("+", "%20").replace("*", "%2A").replace("%7E", "~");

        System.out.println("Base string is " + baseString);
        Mac mac = Mac.getInstance("HmacSHA1");
        SecretKeySpec secret = new SecretKeySpec(keyString.getBytes(messageEncoding), mac.getAlgorithm());
        mac.init(secret);
        byte[] digest = mac.doFinal(baseString.getBytes(messageEncoding));
        return new String(Base64.encodeBase64(digest)).replace(RequestConstants.CARRIAGE_RETURN,
                RequestConstants.EMPTY_STRING);
    }
}