com.monarchapis.client.authentication.HawkV1RequestProcessor.java Source code

Introduction

Here is the source code for com.monarchapis.client.authentication.HawkV1RequestProcessor.java

Source

/*
 * Copyright (C) 2015 CapTech Ventures, Inc.
 * (http://www.captechconsulting.com) All Rights Reserved.
 *
 * 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.monarchapis.client.authentication;

import java.net.URI;
import java.security.MessageDigest;

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

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.RandomStringUtils;
import org.apache.commons.lang3.StringUtils;

import com.monarchapis.client.rest.BaseClient;
import com.monarchapis.client.rest.RequestProcessor;
import com.monarchapis.common.util.HmacUtils;

public class HawkV1RequestProcessor implements RequestProcessor {
    private String apiKey;
    private String sharedSecret;
    private String algorithm;
    private boolean requestPayloadVerification = true;
    private AccessTokenSource accessTokenSource;

    public HawkV1RequestProcessor(String apiKey, String sharedSecret, String algorithm) {
        this(apiKey, sharedSecret, algorithm, null);
    }

    public HawkV1RequestProcessor(String apiKey, String sharedSecret, String algorithm,
            AccessTokenSource accessTokenSource) {
        if (StringUtils.isBlank(apiKey)) {
            throw new IllegalArgumentException("apiKey must not be blank or null");
        }

        if (StringUtils.isBlank(sharedSecret)) {
            throw new IllegalArgumentException("sharedSecret must not be blank or null");
        }

        if (StringUtils.isBlank(algorithm)) {
            throw new IllegalArgumentException("algorithm must not be blank or null");
        }

        this.apiKey = apiKey;
        this.sharedSecret = sharedSecret;
        this.algorithm = algorithm;
        this.accessTokenSource = accessTokenSource;
    }

    @Override
    public void processRequest(BaseClient<?> client) {
        String accessToken = null;

        if (accessTokenSource != null) {
            accessToken = accessTokenSource.getAccessToken();
        }

        String payloadHash = requestPayloadVerification ? getHawkHash(client) : null;
        String header = getHawkHeader(client, accessToken, payloadHash, null);
        client.authorization(header);
    }

    private static String getHawkHash(BaseClient<?> client) {
        try {
            StringBuilder sb = new StringBuilder();
            String httpContent = client.getBody();
            String mimeType = "";
            String content = "";

            if (httpContent != null) {
                mimeType = StringUtils.trimToEmpty(StringUtils.substringBefore(client.getContentType(), ";"));
                content = httpContent;
            }

            sb.append("hawk.1.payload\n");
            sb.append(mimeType);
            sb.append("\n");
            sb.append(content);
            sb.append("\n");

            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            byte[] hash = digest.digest(sb.toString().getBytes("UTF-8"));
            return Base64.encodeBase64String(hash);
        } catch (Exception e) {
            throw new RuntimeException("Could not create hawk hash", e);
        }
    }

    private String getHawkHeader(BaseClient<?> client, String accessToken, String payloadHash, String extData) {
        try {
            StringBuilder sb = new StringBuilder();

            long ts = System.currentTimeMillis() / 1000;
            String nonce = RandomStringUtils.randomAlphanumeric(6);

            URI uri = URI.create(client.getUrl());

            sb.append("hawk.1.header\n");
            sb.append(ts);
            sb.append("\n");
            sb.append(nonce);
            sb.append("\n");
            sb.append(client.getMethod());
            sb.append("\n");
            sb.append(uri.getRawPath());
            sb.append("\n");
            sb.append(uri.getHost());
            sb.append("\n");
            sb.append(uri.getPort());
            sb.append("\n");

            if (payloadHash != null) {
                sb.append(payloadHash);
            }

            sb.append("\n");

            if (extData != null) {
                sb.append(extData);
            }

            sb.append("\n");

            if (accessToken != null) {
                sb.append(apiKey);
                sb.append("\n");
            }

            String stringData = sb.toString();

            String algo = HmacUtils.getHMacAlgorithm(algorithm);
            byte[] key = sharedSecret.getBytes();
            SecretKeySpec signingKey = new SecretKeySpec(key, algo);

            Mac mac256 = Mac.getInstance(algo);
            mac256.init(signingKey);

            // compute the hmac on input data bytes
            byte[] hash = mac256.doFinal(stringData.getBytes("UTF-8"));
            String mac = Base64.encodeBase64String(hash);

            return "Hawk id=\"" + (accessToken != null ? accessToken : apiKey) + "\", ts=\"" + ts + "\", nonce=\""
                    + nonce + "\"" + (payloadHash != null ? ", hash=\"" + payloadHash + "\"" : "")
                    + (extData != null ? ", ext=\"" + extData + "\"," : "") + ", mac=\"" + mac + "\""
                    + (accessToken != null ? ", app=\"" + apiKey + "\"" : "");
        } catch (Exception e) {
            throw new RuntimeException("Could not create hawk header", e);
        }
    }
}