個人的に認証周りの実装は好きだが、Google OAuthの実装はやってなかったので、この機会に実装してみた。

OAuthの機能は、FaceBookやYahoo、Twitterなど色んなベンダーが提供しているが、Googleに関しては都度JavaScriptで動的にパラメータを生成しているので、認証部分はchromedriver/Selenium(スクレイピングライブラリ)を使いブラウザベースの自動認証を実装することにした。

また、厄介なのが自動ログインの場合、Googleはユーザ名・パスワードに加え、二段階認証を要求してくるので、自動化しがいがかなりある。。
自動ログインを試みた際は、Googleからメールで二段階認証用の認証コードが再設定用メールアドレスに送られてくるが、今回はこのメールをAWS SESを用いた受信専用メールサーバへ飛ばし、そのメールをS3へ格納した後に、メール本文に記載してある認証コードを自動で読み取り、その値を自動入力するようにした。

SESの設定は、今更感があるが念の為以下に参考URLを載せておく。
https://docs.aws.amazon.com/ja_jp/ses/latest/DeveloperGuide/receiving-email-setting-up.html

シーケンスとしては以下のようになるが、以下の流れ(ブラウザ起動 > 認証リクエスト > 認証 > アクセストークン発行)を全て自動化してみた。

環境:
　Java: 1.8
　Selenium: 3.12.0
　ChromeDriver: 77.0.3865.40
　Chrome: 77.0.3865.90

今回ビルドツールには、Mavenを使用したので、以下pom.xmlの内容。

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>googleOAuth</groupId>
  <artifactId>googleOAuth</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>googleOAuth</name>
  <dependencies>
  <dependency>
    <groupId>org.seleniumhq.selenium</groupId>
    <artifactId>selenium-java</artifactId>
    <version>3.12.0</version>
</dependency>
<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-s3</artifactId>
    <version>1.11.651</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.9.7</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.7</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.9.7</version>
</dependency>
<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-sts</artifactId>
    <version>1.9.6</version>
</dependency>
</dependencies>
  <build>
  	<plugins>
  		<plugin>
  			<groupId>org.apache.maven.plugins</groupId>
  			<artifactId>maven-shade-plugin</artifactId>
  			<version>3.2.1</version>
  		</plugin>
  		      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>single</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
            <archive>
              <manifest>
                <mainClass>googleOAuth.GoogleOAuth2</mainClass>
              </manifest>
            </archive>
          <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
          </descriptorRefs>
        </configuration>
      </plugin>
  	</plugins>
  </build>
</project>

GoogleOAuth.java

package google;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.DeleteObjectRequest;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.ListObjectsRequest;
import com.amazonaws.services.s3.model.ObjectListing;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectSummary;
import com.amazonaws.util.IOUtils;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

public class GoogleOAuth {

	private final String clientId;
	private final String clientSecret;
	private final String redirectUri;
	private final String scope;
	private final String responseType;
	private final String tokenUrl;
	private final String driverpath;
	private String emailAddress;
	private String password;
	private String recEmailAddress;
	private String lastName;
	private String firstName;
	private String BucketName;
	private String LocalPath;

	public GoogleOAuth() {
		clientId = "*****"; //クライアントID
		clientSecret = "*****"; //クライアントシークレット
		redirectUri = "*****"; //リダイレクトURI
		scope = "https://www.googleapis.com/auth/userinfo.profile";
		responseType = "code";
		tokenUrl = "https://accounts.google.com/o/oauth2/token";
		BucketName = "*****"; //S3バケット名
		LocalPath = "*****"; //メール保存パス
		driverpath = "*****"; //chromedriverパス
		emailAddress = "*****"; //ログインメールアドレス
		password = "*****"; //パスワード
		recEmailAddress = "*****"; //SES受信メールサーバアドレス
		lastName = "*****"; //LastName
		firstName = "*****"; //FirstName
	}

	public static void main(String[] args) throws IOException {
		GoogleOAuth google = new GoogleOAuth();
		String aZcode = google.getAzCode();
		JsonNode access_token = google.getAccessToken(aZcode);
		System.out.println(access_token);

	}

	public String getAzCode() throws IOException {
		final String PATH = this.driverpath;
		System.setProperty("webdriver.chrome.driver", PATH);
        WebDriver driver = new ChromeDriver();
        final String URL = "https://accounts.google.com/o/oauth2/auth?client_id=" + this.clientId + "&redirect_uri=" +
        		this.redirectUri + "&scope=" + this.scope + "&response_type=" + this.responseType;

        driver.get(URL);


        try {
        	driver.findElement(By.xpath("//*[@id=\"identifierId\"]")).sendKeys(this.emailAddress);;
	        driver.findElement(By.xpath("//*[@id=\"yDmH0d\"]")).click();
	        Thread.sleep(5000);

	        driver.findElement(By.xpath("//*[@id=\"recoveryIdentifierId\"]")).sendKeys(this.recEmailAddress);;
	        driver.findElement(By.xpath("//*[@id=\"queryPhoneNext\"]/span/span")).click();
	        Thread.sleep(5000);

	        driver.findElement(By.xpath("//*[@id=\"lastName\"]")).sendKeys(this.lastName);;
	        driver.findElement(By.xpath("//*[@id=\"firstName\"]")).sendKeys(this.firstName);;
	        driver.findElement(By.xpath("//*[@id=\"collectNameNext\"]/span/span")).click();
	        Thread.sleep(5000);

        	driver.findElement(By.xpath("//*[@id=\"idvpreregisteredemailNext\"]/span/span")).click();
        	Thread.sleep(5000);

        	this.downloadFile();
        	Thread.sleep(3000);
        	String token = this.getToken();

	        driver.findElement(By.xpath("//*[@id=\"idvPinId\"]")).sendKeys(token);;
	        driver.findElement(By.xpath("//*[@id=\"idvpreregisteredemailNext\"]/span")).click();
	        Thread.sleep(3000);

	        driver.findElement(By.xpath("//*[@id=\"view_container\"]/div/div/div[2]/div/div/div/form/span/section/div/div/div/div/ul/li[3]/div/div/div[2]")).click();
	        Thread.sleep(3000);

	        driver.findElement(By.xpath("//*[@id=\"identifierId\"]")).sendKeys(this.emailAddress);;
	        driver.findElement(By.xpath("//*[@id=\"identifierNext\"]/span/span")).click();
	        Thread.sleep(3000);

	        driver.findElement(By.xpath("//*[@id=\"password\"]/div[1]/div/div[1]/input")).sendKeys(this.password);;
	        driver.findElement(By.xpath("//*[@id=\"passwordNext\"]/span/span")).click();
	        Thread.sleep(3000);
	        } catch (InterruptedException e) {
	        	System.out.println("Caught InterruptedException: " + e);
	        }

        	String currentUrl = driver.getCurrentUrl();
        	//System.out.println(currentUrl);
    		int biginIdx = currentUrl.indexOf("code=");
    		int endIdx = currentUrl.indexOf("&scope");
    		String aZcode = currentUrl.substring(biginIdx+5, endIdx);

    		driver.quit();

    		return aZcode;
		}


	public JsonNode getAccessToken(String code) throws IOException {
		URL url = new URL(this.tokenUrl);
		StringBuffer result = new StringBuffer();
		HttpURLConnection  conn = null;
		conn = (HttpURLConnection) url.openConnection();
		conn.setDoOutput(true);
		conn.setRequestMethod("POST");
		conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
		conn.setUseCaches(false);
		String params = new String("code=" + code + "&client_id=" + this.clientId + "&client_secret=" + this.clientSecret +
				"&redirect_uri=" + this.redirectUri + "&grant_type=authorization_code");
        OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
        out.write(params);
        out.close();
        conn.connect();

        final int status = conn.getResponseCode();
        if (status == 200) {
            final InputStream input = conn.getInputStream();
            String encoding = conn.getContentEncoding();
            if(null == encoding){
                encoding = "UTF-8";
            }
            final InputStreamReader inReader = new InputStreamReader(input, encoding);
            final BufferedReader bufReader = new BufferedReader(inReader);
            String line = null;
            while((line = bufReader.readLine()) != null) {
                result.append(line);
            }
            bufReader.close();
            inReader.close();
            input.close();
        } else {
            System.out.println(status);
        }

        conn.disconnect();

        ObjectMapper mapper = new ObjectMapper();
        JsonNode root = mapper.readTree(result.toString());

        return root;
	}

	public void downloadFile() throws IOException {
		AmazonS3 s3 = AmazonS3ClientBuilder.standard()
                .withRegion("us-east-1")
                .build();

		ObjectListing objectListing = s3.listObjects(new ListObjectsRequest()
		        .withBucketName(this.BucketName));

		for (S3ObjectSummary objectSummary : objectListing.getObjectSummaries()) {
		    System.out.println(objectSummary.getKey());
		    String objectKey = objectSummary.getKey();
		    S3Object object = s3.getObject(new GetObjectRequest(this.BucketName, objectKey));
		    try {
				FileOutputStream fos = new FileOutputStream(new File(this.LocalPath));
				IOUtils.copy(object.getObjectContent(), fos);
				fos.close();
				s3.deleteObject(new DeleteObjectRequest(this.BucketName, objectKey));
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			}
		}
	}

	public String getToken() throws IOException {
		File file = new File(this.LocalPath);
		FileReader fr = new FileReader(file);
		BufferedReader br = new BufferedReader(fr);
		String json_str;
		String data = "";
		int cnt = 0;

		while ((json_str = br.readLine()) != null) {
			cnt += 1;
			if ((cnt>= 73)&&(128 >= cnt)){
			data += json_str;
			}
		}

        Charset charset = StandardCharsets.UTF_8;
        byte[] bytes = Base64.getDecoder().decode(data.getBytes());
        String decode_str = new String(bytes, charset);
		int biginIdx = decode_str.indexOf("<strong style=\"text-align: center; font-size: 24px; font-weight: bold;\">");
		int endIdx = decode_str.indexOf("</strong>");
		String token = decode_str.substring(biginIdx+72, endIdx);

		br.close();
		return token;
	}
}

上記コードを実行し、認証/認可が完了すると、最終的に以下の通りアクセストークンが取得できる。

{"access_token":"ya29.ImCiBwhJcCZ-JIW9ZlGDe2ysCBkNzRpG9mgr_-ocM_A32Dh1bzJbHAHOT_iKi6GNAVovWDLgyKclHJaP1uqTODQ61LJomWAUzhWSnMsd4ddGKTeIUfOeSQocVbUzikxcWjU","expires_in":3596,"scope":"https://www.googleapis.com/auth/userinfo.profile","token_type":"Bearer","id_token":"eyJhbGciOiJSUzI1NiIsImtpZCI6IjNkYjNlZDZiOTU3NGVlM2ZjZDlmMTQ5ZTU5ZmYwZWVmNGY5MzIxNTMiLCJ0eXAiOiJKV1QifQ.eyJpc3MiOiJhY2NvdW50cy5nb29nbGUuY29tIiwiYXpwIjoiNjUwMDQxMDk4ODAzLTBtMG81Y2IxZ2ZraW43cDJwN2ZuaWNhYnUxaWdvdnVnLmFwcHMuZ29vZ2xldXNlcmNvbnRlbnQuY29tIiwiYXVkIjoiNjUwMDQxMDk4ODAzLTBtMG81Y2IxZ2ZraW43cDJwN2ZuaWNhYnUxaWdvdnVnLmFwcHMuZ29vZ2xldXNlcmNvbnRlbnQuY29tIiwic3ViIjoiMTE1OTcwNTg3NjcwMjI4MTk2Njc4IiwiYXRfaGFzaCI6IjhGZmJSa3BYQ1VoWUduX0VTN2tENnciLCJpYXQiOjE1NzEzMzE4ODYsImV4cCI6MTU3MTMzNTQ4Nn0.oXK4EhivivgJqhO6cjJ7ZyeTBPW9IrTOvM_GGeDcNJ6XXTOVtRd8nv3pRT1SHDSTTgkco6tAI8ZN-dWDD-LVhqkhGTjM-USzR2UbXhMsd4z6WRYGMPfzuLCkGRGZwp0Gqd7ctITlIWJr0N8xLPEGNSHx_IPZtabOaP4ME9YN0-XQg-x2tE32LdRI4ttvW7D1lSeYPKdzWf_12i9zoLnblc2MiGTupww91PlQSaLGoprFPVutI_57c1IraBsCmMGuW0Nke4vps7YoFhaaxDhB4XuJCpyIvpADHuOydq3RPY5WCV8YIzFXsFCa1f-Z7QyJNuZgcFf7WLWcjXQZkD4i8g"}