org.apereo.openlrs.utils.OAuthUtils.java Source code

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Here is the source code for org.apereo.openlrs.utils.OAuthUtils.java

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/*******************************************************************************
 * Copyright (c) 2015 Unicon (R) Licensed under the
 * Educational Community 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.osedu.org/licenses/ECL-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 org.apereo.openlrs.utils;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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

import org.apache.commons.codec.binary.Base64;
import org.apache.log4j.Logger;

/**
 * @author ggilbert
 *
 */
public class OAuthUtils {
    private static Logger log = Logger.getLogger(OAuthUtils.class);

    private static final Pattern AUTHORIZATION_PATTERN = Pattern.compile("\\s*(\\w*)\\s+(.*)");
    private static final Pattern KEYVALUEPAIR_PATTERN = Pattern.compile("(\\S*)\\s*\\=\\s*\"([^\"]*)\"");

    private static final Map<String, String> algorithms;

    static {
        algorithms = new HashMap<String, String>();
        algorithms.put("HMAC-SHA1", "HmacSHA1");
    }

    public static Map<String, String> decodeAuthorization(String authorization) {
        Map<String, String> oauthParameters = new HashMap<String, String>();
        if (authorization != null) {
            Matcher m = AUTHORIZATION_PATTERN.matcher(authorization);
            if (m.matches()) {
                if ("oauth".equalsIgnoreCase(m.group(1))) {
                    for (String keyValuePair : m.group(2).split("\\s*,\\s*")) {
                        m = KEYVALUEPAIR_PATTERN.matcher(keyValuePair);
                        if (m.matches()) {
                            String key = OAuthUtils.decodePercent(m.group(1));
                            String value = OAuthUtils.decodePercent(m.group(2));
                            oauthParameters.put(key, value);
                        }
                    }
                }
            }
        }

        return oauthParameters;
    }

    public static String sign(String secret, Map<String, String> oauthParameters, String algorithm, String method,
            String url) {

        StringBuilder signatureBase = new StringBuilder(OAuthUtils.percentEncode(method));
        signatureBase.append("&");
        signatureBase.append(OAuthUtils.percentEncode(url));
        signatureBase.append("&");

        Map<String, String> treeMap = new TreeMap<String, String>(oauthParameters);
        treeMap.remove("oauth_signature");
        treeMap.remove("realm");

        boolean first = true;
        for (Map.Entry<String, String> entry : treeMap.entrySet()) {
            if (!first)
                signatureBase.append(OAuthUtils.percentEncode("&"));
            else
                first = false;

            signatureBase.append(OAuthUtils.percentEncode(entry.getKey() + "=" + entry.getValue()));
        }

        Mac mac = null;
        try {
            SecretKeySpec secretKeySpec = new SecretKeySpec((OAuthUtils.percentEncode(secret) + "&").getBytes(),
                    algorithm);

            mac = Mac.getInstance(secretKeySpec.getAlgorithm());
            mac.init(secretKeySpec);

        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        if (log.isDebugEnabled()) {
            log.debug("signatureBaseString: " + signatureBase.toString());
        }

        byte[] bytes = mac.doFinal(signatureBase.toString().getBytes());
        byte[] encodedMacBytes = Base64.encodeBase64(bytes);

        return new String(encodedMacBytes);
    }

    public static final String mapToJava(String name) {
        String algorithm = algorithms.get(name);
        if (algorithm == null) {
            throw new UnsupportedOperationException("Signature algorithm of " + name + " is unsupported.");
        }
        return algorithm;
    }

    private static String percentEncode(String s) {
        if (s == null) {
            return "";
        }
        try {
            return URLEncoder.encode(s, "UTF-8").replace("+", "%20").replace("*", "%2A").replace("%7E", "~");
        } catch (UnsupportedEncodingException uee) {
            throw new RuntimeException(uee.getMessage(), uee);
        }
    }

    private static String decodePercent(String s) {
        try {
            return URLDecoder.decode(s, "UTF-8");
        } catch (java.io.UnsupportedEncodingException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

}