Answers SSO java example

CryptographyUtil.java

package test;

import com.google.common.io.BaseEncoding;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;



public class CryptographyUtil {

    public static String encrypt(String secret, String data) {
        try {
            SecretKeySpec secretKey = getKey(secret, "SHA");
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            return BaseEncoding.base64Url().omitPadding().encode(cipher.doFinal(data.getBytes("UTF-8")));
        } catch (Exception ignored) {
        }
        return null;
    }


    private static SecretKeySpec getKey(String secret, String algorithm) {
        try {
            byte[] key = secret.getBytes("UTF-8");
            key = Arrays.copyOf(MessageDigest.getInstance(algorithm).digest(key), 16);
            return new SecretKeySpec(key, "AES");
        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }

}

Main.java

package test;

import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;

/**
 * @author asafb
 * @since 08/06/2016
 * 
 * The SSO login flow is as follows:
 * 
 * 1. The tenant generates an api key and secret in his Wix Answers account settings - the secret will be used to encrypt the sso token by the 
 *    the tenants' user system. The tenant then configures in his Wix Answers account settings his sso form url and sso logout url.     
 *    
 * 2. When a user clicks on the login button in Wix Answers, he is redirected to the tenants' login page (sso form url).
 *    Before performing the redirect to the the tenants' login form, Wix Answers appends a redirectUrl parameter to the request - this is the 
 *    Wix Answers callback url the tenant's user system should redirect back after the user is authenticated.
 *    
 * 3. After the user is authenticated by the tenants' user system, the tenants' user system should create an encrypted sso token for 
 *    that user using his api secret (see example code below), append the encrypted token parameter to the Wix Answers call back url and 
 *    the key id attached to the secret used for the token encryption and redirect back to Wix Answers.
 * 
 * 4. The SSO token is an encrypted json string (see SSOParams.java) containing the authenticated user data. 
 *    
 *    The required fields in the json are:
 * 
 *    id - the user id in the tenants' user system
 * 
 *    email - the user email
 * 
 *    timestamp - current timestamp (UTC) in milliseconds (Unix/Epoch time) 
 * 
 *    Optional fields in the json are:
 *   
 *    firstName
 *    lastName
 *    displayName
 *    profileImage - full url to the users' profile image
 *     
 *
 * e.g.:
 * 
 * The tenants' user system login page configured in Wix Answers is:  https://labworm.com/login
 * 
 * Answers will redirect the user to https://labworm.com/login?redirectUrl=<answers-sso-callback-url>
 *     
 * After user is authenticated by tenants' user system, the tenants' user system builds the encrypted sso token for the authenticated user
 * and redirects the user back to Wix Answers with the token and key id appended to the callback url (answers-sso-callback-url):
 * 
 * <answers-sso-callback-url>?token=<encrypted sso token>&key=<api key id>
 * 
 */

public class Main {

    private static String KEY_ID = "<your api key id>";
    private static String SECRET = "<your api key secret>";

    public static void main(String[] args) {
        SSOParams params = new SSOParams();
        params.setDisplayName("<the user name>");
        // set the users' external user id from tenants external user system
        params.setId("<the user id in tenants' user system>");
        params.setEmail("<the user email>");
        params.setTimestamp(new DateTime().withZone(DateTimeZone.UTC).getMillis());

        // this token should be sent as a request parameter back to Wix Answers after user is authenticated along with the 
        // api key id:  token=<encrypted sso token>&key=KEY_ID
        String ssoToken = getSSOToken(params); 

        
    }


    private static String getSSOToken(SSOParams params) {
        // create json string from params object
        String serializedParams = toJson(params);
        return CryptographyUtil.encrypt(SECRET, serializedParams);
    }

    private static String toJson(SSOParams params) {
        String json = null;

        // json = .... serialize params to json string
        return json;
    }


}

SSOParams.java

package test;

import javax.validation.constraints.NotNull;

/**
 * @author asafb
 * @since 6/22/15
 *
 * This class represents the generic json for sso sign in.
 */
public class SSOParams {

    @NotNull
    private String id;

    @NotNull
    private String email;

    @NotNull
    private Long timestamp;

    private String firstName;
    private String lastName;
    private String displayName;
    private String profileImage;
    

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Long timestamp) {
        this.timestamp = timestamp;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getDisplayName() {
        return displayName;
    }

    public void setDisplayName(String displayName) {
        this.displayName = displayName;
    }

    public String getProfileImage() {
        return profileImage;
    }

    public void setProfileImage(String profileImage) {
        this.profileImage = profileImage;
    }

}