com.entertailion.android.shapeways.api.Request.java Source code

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Here is the source code for com.entertailion.android.shapeways.api.Request.java

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/*
 * Copyright (C) 2013 ENTERTAILION 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.entertailion.android.shapeways.api;

import java.net.URL;
import java.net.URLEncoder;
import java.util.TreeSet;

import org.apache.commons.lang3.RandomStringUtils;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.util.encoders.Base64;

import android.util.Log;

/**
 * Handle the OAuth request parameters
 * 
 * @author leon_nicholls
 * 
 */
public class Request {
    private static final String LOG_TAG = "Request";

    private final TreeSet<String> parameters; // sorted
    private final String httpMethod;

    public Request(String httpMethod) {
        this.httpMethod = httpMethod;
        parameters = new TreeSet<String>();
    }

    /**
     * Add an encoded key/value pair to the request
     * 
     * @param key
     * @param value
     * @throws Exception
     */
    public void addParameter(String key, String value) throws Exception {
        Log.d(LOG_TAG, "addParameter: " + key + "=" + value);
        parameters.add(encode(key) + "=" + encode(value));
    }

    /**
     * Sign the request based on OAuth 1.0
     * 
     * @param url
     * @param consumerSecret
     * @param tokenSecret
     * @throws Exception
     */
    public void sign(String url, String consumerSecret, String tokenSecret) throws Exception {
        Log.d(LOG_TAG, "sign: " + url);
        addParameter(ShapewaysClient.OAUTH_SIGNATURE_METHOD, ShapewaysClient.OAUTH_SIGNATURE_METHOD_HMAC_SHA1);
        addParameter(ShapewaysClient.OAUTH_VERSION, ShapewaysClient.OAUTH_VERSION_1_0);
        addParameter(ShapewaysClient.OAUTH_NONCE, RandomStringUtils.randomAlphanumeric(32));
        addParameter(ShapewaysClient.OAUTH_TIMESTAMP, Long.toString(System.currentTimeMillis() / 1000));

        StringBuffer stringBuffer = new StringBuffer();
        for (String parameter : parameters) {
            if (stringBuffer.length() != 0) {
                stringBuffer.append(ShapewaysClient.AMPERSAND);
            }
            stringBuffer.append(parameter);
        }

        String baseString = String.format("%s&%s&%s", encode(httpMethod), encode(normalize(url)),
                encode(stringBuffer.toString()));
        Log.d(LOG_TAG, "base=" + baseString);

        addParameter(ShapewaysClient.OAUTH_SIGNATURE,
                generateHmac(encode(consumerSecret) + ShapewaysClient.AMPERSAND + encode(tokenSecret), baseString));
    }

    /**
     * Normalize the URL parameters
     * 
     * @param urlValue
     * @return
     * @throws Exception
     */
    private final String normalize(String urlValue) throws Exception {
        Log.d(LOG_TAG, "normalize: " + urlValue);
        URL url = new URL(urlValue);
        if (url.getQuery() != null) {
            String[] parameters = url.getQuery().split(ShapewaysClient.AMPERSAND);

            for (String parameter : parameters) {
                if (parameter != null) {
                    String[] keyValue = parameter.split(ShapewaysClient.EQUALS);
                    if (keyValue != null) {
                        addParameter(keyValue[0], keyValue[1]);
                    }
                }
            }
        }

        return urlValue;
    }

    public String toString() {
        StringBuffer stringBuffer = new StringBuffer();
        for (String parameter : parameters) {
            if (stringBuffer.length() != 0) {
                stringBuffer.append(ShapewaysClient.AMPERSAND);
            }
            stringBuffer.append(parameter);
        }
        return stringBuffer.toString();
    }

    private final static String encode(String value) throws Exception {
        Log.d(LOG_TAG, "encode: " + value);
        if (value == null) {
            return "";
        }
        return URLEncoder.encode(value, ShapewaysClient.ENCODING).replace("+", "%20").replace("*", "%2A")
                .replace("%7E", "~");
    }

    /**
     * Generate HMAC-SHA1 for message
     * 
     * @param key
     * @param message
     * @return
     * @throws Exception
     */
    private static String generateHmac(String key, String message) throws Exception {
        Log.d(LOG_TAG, "generateHmac: " + key + "=" + message);
        byte[] keyBytes = key.getBytes(ShapewaysClient.ENCODING);
        byte[] data = message.getBytes(ShapewaysClient.ENCODING);

        HMac macProvider = new HMac(new SHA1Digest());
        macProvider.init(new KeyParameter(keyBytes));
        macProvider.reset();

        macProvider.update(data, 0, data.length);
        byte[] output = new byte[macProvider.getMacSize()];
        macProvider.doFinal(output, 0);

        byte[] hmac = Base64.encode(output);
        return new String(hmac).replaceAll("\r\n", "");
    }

}