Implementing API to allow Admins to modify config of devices of any user

As any user can add or remove devices from their account, there needed to be a way by which Admins can manage the user devices. The Admins and higher user roles should have the access to modify the config of devices of any user. This blog post explains how an API has been implemented to facilitate Admins and higher user roles to change config of devices of any user.

Implementing a servlet to allow changing review status of a Skill

The basic task of the servlet is to allow Admin and higher user roles to modify the config of devices of any user. The Admin should be allowed to edit the name of the device and also the room of the device, similar to how a user can edit his own devices.

Here is the implementation of the API:

  1. The API should be usable to only the users who have a user role Admin or higher. Only those with minimum Admin rights should be allowed to control what Skills are displayed on the CMS site. This is implemented as follows:

   @Override
    public UserRole getMinimalUserRole() {
        return UserRole.ADMIN;
    }

 

  1. The endpoint for the API is ‘/cms/modifyUserDevices.json’. This is implemented as follows:

   @Override
    public String getAPIPath() {
        return "/cms/modifyUserDevices.json";
    }

 

  1. The main method of the servlet is the serviceImpl() method. This is where the actual code goes which will be executed each time the API is called. This is implemented as follows:

    JSONObject result = new JSONObject(true);
    Collection<ClientIdentity> authorized = DAO.getAuthorizedClients();
    List<String> keysList = new ArrayList<String>();
    authorized.forEach(client -> keysList.add(client.toString()));
    String[] keysArray = keysList.toArray(new 
    String[keysList.size()]);

    List<JSONObject> userList = new ArrayList<JSONObject>();
    for (Client client : authorized) {
        JSONObject json = client.toJSON();

        if(json.get("name").equals(email)) {
            ClientIdentity identity = new ClientIdentity(ClientIdentity.Type.email, client.getName());
            Authorization authorization = DAO.getAuthorization(identity);

            ClientCredential clientCredential = new ClientCredential(ClientCredential.Type.passwd_login, identity.getName());
            Authentication authentication = DAO.getAuthentication(clientCredential);

            Accounting accounting = DAO.getAccounting(authorization.getIdentity());

            if(accounting.getJSON().has("devices")) {

                JSONObject userDevice = accounting.getJSON().getJSONObject("devices");
                if(userDevice.has(macid)) {
                    JSONObject deviceInfo = userDevice.getJSONObject(macid);
                    deviceInfo.put("name", name);
                    deviceInfo.put("room", room);
                }
                else {
                    throw new APIException(400, "Specified device does not exist.");
                }

            } else {
                json.put("devices", "");
            }
            accounting.commit();
        }
    }

 

Firstly, the list of authorized clients is fetched using DAO.getAuthorizedClients() and is put in an ArrayList. Then we traverse through each element of this ArrayList and check if the device exists by checking if there’s a key-value pair corresponding to the macid passed in the query parameter. If the device doesn’t exist, then an exception is thrown. However, if the macid exists in the traversed element of the ArrayList, then we put the name and the room of the device as passed as query parameters in that particular element of the ArrayList, so as to overwrite the existing name and room of the device of the user.

This is how an API has been implemented which allows Admins and higher user roles to modify the config of devices of any user.

Resources

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Implementing API to Fetch all Ratings by a User on Different Skills on SUSI.AI Web Client

SUSI Skill CMS allows the users to rate any Skill on a scale of 1 to 5. The user can also provide a feedback to any Skill. This paves the path to implementing a Dashboard, which has all the analytic data of the user. Hence, an API needed to be implemented which could return the ratings done by a particular user on all different Skills.

How are servlets implemented in SUSI.AI?

All servlets in SUSI extend AbstractAPIHandler class and implement APIHandler. All servlets have 4 methods, which we overwrite depending on what we want the servlet to do. They are as follows :

    @Override
    public String getAPIPath() {
        return null;
    }

    @Override
    public BaseUserRole getMinimalBaseUserRole() {
        return null;
    }

    @Override
    public JSONObject getDefaultPermissions(BaseUserRole baseUserRole) {
        return null;
    }

    @Override
    public ServiceResponse serviceImpl(Query post, HttpServletResponse response, Authorization rights, JsonObjectWithDefault permissions) throws APIException {
        return null;
    }

 

How these 4 methods work together?

  • First method is getAPIPath(). It returns the endpoint of the servlet.
  • The second method is getMinimalBaseUserRole(). It returns the minimum privilege level required to access the endpoint.
  • The third method is getDefaultPermissions(). It gets the Default Permissions of a UserRole in SUSI Server. Different UserRoles have different permissions defined in SUSI Server.
  • Whenever the endpoint defined in the getAPIPath() method is called properly, it responds with whatever is defined in the fourth method, which is serviceImpl().

Implementing a servlet to fetch all ratings by a user on different Skills

The task of this servlet is to fetch all the ratings done by a user on all the different Skills, so that this fetched data could be used later on for implementation of various user specific features like Dashboard page. This is the implementation of the 4 methods of this servlet:

    @Override
    public UserRole getMinimalUserRole() {
        return UserRole.USER;
    }

    @Override
    public JSONObject getDefaultPermissions(UserRole baseUserRole) {
        return null;
    }

    @Override
    public String getAPIPath() {
        return "/cms/getProfileDetails.json";
    }

    @Override
    public ServiceResp onse serviceImpl(Query query, HttpServletResponse response, Authorization authorization, final JsonObjectWithDefault permissions) throws APIException {

    JsonTray fiveStarSkillRating = DAO.fiveStarSkillRating;
    // JSONObject and JsonArray Declarations

    // Checking if access_token has been given and is valid
    if (authorization.getIdentity() == null) {
        throw new APIException(400, "Specified user data not found, ensure you are logged in");
    } 


    // Fetching email of the user from access token and storing it in a string
    String email = authorization.getIdentity().getName();


    // Iterating over the fiveStarSkillRating JsonTray by extracting keys at every level and accessing their child objects through the extracted keys
    for(String model_name : fiveStarSkillRating.keys())
    {
        // Storing the list of group names and iterating over them
        for(String group_name : groupnameKeysList)
        {
            // Storing the list of language names and iterating over them
            for(String language_name : languagenameKeysList)
            {
                // Storing the list of skill names and iterating over them
                for(String skill_name : skillnamesKeysList)
                {
                    skillnameArray = languageObject.getJSONArray(skill_name);
                    // Iterating over the different Skill JSONObjects
                    for(int i=0; i<skillnameArray.length(); i++) {
                        String jsonEmail = skillnameArray.getJSONObject(i).get("email").toString();
                        if(jsonEmail.equals(email)) {
                        // If the Skill has been rated by the required author, then put the Skill JSONObject into the result array
                        }
                    }
                }
            }
        }
    }

    if(result.length()==0) {
        // Handling case when user hasn’t rated any Skill yet
        result.put("accepted", false);
        result.put("message", "User has not rated any Skills yet.");
        return new ServiceResponse(result);
    }
    result.put("accepted", true);
    result.put("message", "User ratings fetched.");
    return new ServiceResponse(result);
    }

 

As it can be seen from the above code, the endpoint for this servlet is /cms/getProfileDetails.json and it requires 1 parameter – the access token of the user.

As the main task of this servlet is user specific, and should only be accessible to the particular user, hence we returned UserRole as USER in the getMinimalUserRole() method.

In the serviceImpl() method, we iterate over the fiveStarSkillRating.json JsonTray and keep on extracting keys and accessing the corresponding JSONObjects until we reach the lowermost layer, where all the Skill names are listed. Iterating over the JSONObjects corresponding to each Skill, we check the email in the Skill JSONObject to identify the user. If the email present in the Skill JSONObject matches with the email corresponding to the access token provided as a query parameter, we extract rating and the timestamp for the Skill and put it in a JSONArray. Then, finally we put the JSONArray into our resulting JSONObject.

This is how we can fetch all the ratings by a user on all the different Skills.

Resources

 

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Implementing API to facilitate changing review status of a Skill

As any registered user can make Skills in SUSI Skill CMS, sometimes the Skill made is not up to the mark to be displayed on the CMS site. There needs to be a feature implemented where the Admin and higher user roles can review a Skill and approve it accordingly. Then only the approved Skills should be displayed on the Skill CMS. This feature required implementation of an API to allow Admin and higher user roles to change the review status of a Skill. This blog post explains how such an API has been implemented.

Implementing a servlet to allow changing review status of a Skill

The basic task of the servlet is to allow Admin and higher user roles to allow changing the review status of a Skill. The review status of a Skill can either be ‘true’, indicating that the Skill has been approved by the Admin, or ‘false’, which would indicate that the Skill still needs some improvements before it is actually displayed on the SUSI Skill CMS.

Here is the implementation of the API:

  1. The API should be usable to only the users who have a user role Admin or higher. Only those with minimum Admin rights should be allowed to control what Skills are displayed on the CMS site. This is implemented as follows:
   @Override
    public UserRole getMinimalUserRole() {
        return UserRole.ADMIN;
    }

 

  1. The endpoint for the API is ‘/cms/changeSkillStatus.json’. This is implemented as follows:
   @Override
    public String getAPIPath() {
        return "/cms/changeSkillStatus.json";
    }

 

  1. The main method of the servlet is the serviceImpl() method. This is where the actual code goes which will be executed each time the API is called. This is implemented as follows:

    @Override
    public ServiceResponse serviceImpl(Query call, HttpServletResponse response, Authorization authorization, JsonObjectWithDefault permissions) throws APIException {

       // Store the query parameters in variables

        if(skill_name == null || !(reviewed.equals("true") || reviewed.equals("false"))) {
            throw new APIException(400, "Bad service call, missing arguments.");
        }

        JSONObject result = new JSONObject();
        JsonTray skillStatus = DAO.skillStatus;
        JSONObject modelName = new JSONObject();
        JSONObject groupName = new JSONObject();
        JSONObject languageName = new JSONObject();
        JSONObject skillName = new JSONObject();

        if(reviewed.equals("true")) {
            JSONObject reviewStatus = new JSONObject();
            reviewStatus.put("reviewed", true);
                // traverse through the skillStatus.json file down to the Skill name and put review status ‘true’ in it
                skillName.put("reviewed", true);
                result.put("accepted", true);
                result.put("message", "Skill review status changed successfully.");
                return new ServiceResponse(result);
            }


            // deleting skill name from skillStatus.json file if it’s review status is being changed to ‘false’
            else {
                if (skillStatus.has(model_name)) {
                    modelName = skillStatus.getJSONObject(model_name);
                    if (modelName.has(group_name)) {
                        groupName = modelName.getJSONObject(group_name);
                        if (groupName.has(language_name)) {
                          languageName = groupName.getJSONObject(language_name);
                            if (languageName.has(skill_name)) {
                                languageName.remove(skill_name);
                                    skillStatus.remove(model_name);
                                }
                                skillStatus.commit();
                            }
                        }
                    }
                }
                result.put("accepted", true);
                result.put("message", "Skill review status changed successfully.");
                return new ServiceResponse(result);
            }
        }

 

The list of reviewed Skills is being stored in the ‘skillStatus.json’ file. So we need to traverse through that file and store the review status of the Skill as required while making the API call.

The API takes 5 parameters:

  • Model of the Skill
  • Group of the Skill
  • Language of the Skill
  • Skill name
  • Review status to be set for the Skill – true or false

On making the API call, if the value of the query parameter ‘reviewed’ is ‘true’, then the Skill name along with its review status is being appended in the ‘skillStatus.json’ file. This is done by traversing through the file using the specified model, group and language info of the Skill.

However, if the value of the query parameter ‘reviewed’ is ‘false’, then we need to check if the Skill is already there in the ‘skillStatus.json’ file. If it is already there, then we remove its entry from the file. If it isn’t in the file already, then it’s review status is already ‘false’. We also need to commit this change to the JsonTray for it to get reflected in the Server.

This is how an API has been implemented which would allow Admin and higher user roles to change the review status of any Skill, which would then facilitate showing only the approved Skills on the CMS site.

  1. Resources

     

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Store User’s Personal Information with SUSI

In this blog, I discuss how SUSI.AI stores personal information of it’s users. This personal information is mostly about usernames/links to different websites like LinkedIn, GitHub, Facebook, Google/Gmail etc. To store such details, we have a dedicated API. Endpoint is :

https://api.susi.ai/aaa/storePersonalInfo.json

In this API/Servlet, storing the details and getting the details, both the aspects are covered. At the time of making the API call, user has an option either to ask the server for a list of available store names along with their values or request the server to store the value for a particular store name. If a store name already exists and a client makes a call with new/updated value, The servlet will update the value for that particular store name.

The reason you are looking at minimal user role as USER is quite obvious, i.e. these details correspond to a particular user. Hence neither we want someone writing such information anonymously nor we want this information to be visible to anonymous user until allowed by the user.

In the next steps, we start evaluating the API call made by the client. We look at the combination of the parameters present in the request. If the request is to fetch list of available stores, server first checks if Accounting object even has a JSONObject for “stores” or not. If not found, it sends an error message “No personal information is added yet.” and error code 420. Prior to all these steps, server first generates an accounting object for the user. If found, details are encoded as JSONObject’s parameter. Look at the code below to understand things fairly.

Accounting accounting = DAO.getAccounting(authorization.getIdentity());
        if(post.get("fetchDetails", false)) {
            if(accounting.getJSON().has("stores")){
                JSONObject jsonObject = accounting.getJSON().getJSONObject("stores");
                json.put("stores", jsonObject);
                json.put("accepted", true);
                json.put("message", "details fetched successfully.");
                return new ServiceResponse(json);
            } else {
                throw new APIException(420, "No personal information is added yet.");
            }
        }

If the request was not to fetch the list of available stores, It means client wants server to save a new field or update a previous value for that of a store name. A combination of If-else evaluates whether the call even contains required parameters.

if (post.get(“storeName”, null) == null) {
throw new APIException(422, “Bad store name encountered!”);
}

String storeName = post.get(“storeName”, null);
if (post.get(“value”, null) == null) {
throw new APIException(422, “Bad store name value encountered!”);
}

If request contains all the required data, then store name & value are extracted as key-value pair from the request.

In the next steps, since the server is expected to store list of the store names for a particular user, First the identity is gathered from the already present authorization object in “serviceImpl” method. If the server finds a “null” identity, It throws an error with error code 400 and error message “Specified User Setting not found, ensure you are logged in”.

Else, server first checks if a JSONObject with key “stores” exists or not. If not, It will create an object and will put the key value pair in the new JSONObject. Otherwise it would anyways do so.

Since these details are for a particular account (i.e. for a particular user), these are placed in the Accounting.json file. For better knowledge, Look at the code snippet below.

if (accounting.getJSON().has("stores")) {
                accounting.getJSON().getJSONObject("stores").put(storeName, value);
            } else {
                JSONObject jsonObject = new JSONObject(true);
                jsonObject.put(storeName, value);
                accounting.getJSON().put("stores", jsonObject);
            }

            json.put("accepted", true);
            json.put("message", "You successfully updated your account information!");
            return new ServiceResponse(json);

Additional Resources :

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List all the Users Registered on SUSI.AI

In this blog, I’ll be telling on how SUSI admins can access list of all the registered users from SUSI-server. Following this, they may modify/edit user role of any registered user.

What is User Role?

A UserRole defines the servlet access right. Not all users are allowed to access all the data and services. For  example, To list all the users, minimal user role expected is ADMIN. This classification of users are inspired by the wikipedia User Access Levels, see https://en.wikipedia.org/wiki/Wikipedia:User_access_levels.While querying SUSI, Users are classified into 7 different categories, namely :

  • BOT
  • ANONYMOUS
  • USER  
  • REVIEWER
  • ACCOUNTCREATOR
  • ADMIN
  • BUREAUCRAT

* Please see that these are as of the date of publish of this blog. These are subject to change, which is very unlikely.

All the users who are not logged in but interacting with SUSI are anonymous users. These are only subject to chat with SUSI, login, signup or may use forgot password service. Once a user login to the server, a token is generated and sent back to client to maintain the identity, hence acknowledging them. Privileged users are those who have special rights with them. These are more like moderators with much special rights than any other user. At the top level of the hierarchy are the admins. These users have more rights than anyone. They can change role of any other user, override decision of any privileged user as well.

Let us now look at the control flow of this.

First things first, make a component of User List in the project. Let us name it ListUsers and since it has to be accessible by those users who possess ADMIN rights, you will find it enclosed in Admin package in components folder. Open up

index.js file, import Listusers component  and add route to it in the following way :

...//other import statements
import ListUser from "./components/Admin/ListUser/ListUser";
...//class definition and other methods
<Route path="/listUser" component={ListUser}/>
//other routes defined

Find a suitable image for “List Users” option and add the option for List Users in static appbar component along with the image. We have used Material UI’s List image in our project.

...// other imports

import List from 'material-ui/svg-icons/action/list';

Class and method definition

<MenuItem primaryText="List Users"
          onTouchTap={this.handleClose}
          containerElement={<Link to="/listUser" />}
                rightIcon={<List/>}
      />

...//other options in top right corner menu

Above code snippet will add an option to redirect admins to ‘/listUsers’ route. Let us now have a closer look at functionality of both client and server. By now you must have known what ComponentDidMount does. {If not, I’ll tell you. This is a method which is given first execution after the page is rendered. For more information, visit this link}. As mentioned earlier as well that this list will be available only for admins and may be even extended for privileged users but not for anonymous or any other user, an AJAX call is made to server in ComponentDidMount of ‘listuser’ route which returns the base user role of current user. If user is an Admin, another method, fetchUsers() is called.

let url;
        url = "http://api.susi.ai/aaa/account-permissions.json";
        $.ajax({
            url: url,
            dataType: 'jsonp',
            jsonpCallback: 'py',
            jsonp: 'callback',
            crossDomain: true,
            success: function (response) {
                console.log(response.userRole)
                if (response.userRole !== "admin") {
                    console.log("Not an admin")
                } else {
                    this.fetchUsers();
                    console.log("Admin")
                }
            }.bind(this),
});

In fetchUsers method, an AJAX call is made to server which returns username in JSONArray. The response looks something likes this :

{
	"users" : {
		"email:""[email protected]",
...
},
"Username":["[email protected]", "[email protected]"...]
}

Now, only rendering this data in a systematic form is left. To give it a proper look, we have used material-ui’s table. Import Table, TableBody, TableHeader,

   TableHeaderColumn, TableRow, TableRowColumn from material-ui/table.

In fetchUsers method, response is catched in data Oblect. Now the keys are extracted from the JSON response and mapped with an array. Iterating through array received as username array, we get list of all the registered users. Now, popuulate the data in the table you generated.

return (
                        <TableRow key={i}>
                            <TableRowColumn>{++i}>
                            <TableRowColumn>{name}</TableRowColumn>
                            <TableRowColumn> </TableRowColumn>
                            <TableRowColumn> </TableRowColumn>
                            <TableRowColumn> </TableRowColumn>
                            <TableRowColumn> </TableRowColumn>
                        </TableRow>
                    )

Above piece of code may help you while populating the table. These details are returned from susi server which gets a list of all the registered in the following manner. First, it checks if base url of this user is something apart from admin. If not, it returns error which may look like this :

Failed to load resource: the server responded with a status of 401 (Base user role not sufficient. Your base user role is 'ANONYMOUS', your user role is 'anonymous')

Otherwise, it will generate a client identity, use to to get an authorization object which will loop through authorization.json file and return all the users encoded as JSONArray.

Additional Resources

  1. Official Material UI Documentation on Tables from marterial-ui
  2. Answer by Marco Bonelli on Stackoverflow on How to map JSON response in JavaScript?
  3. Answer by janpieter_z on Stackoverflow – on Render JSON data in ReactJS table
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SUSI.AI User Roles and How to Modify Them

In this blog, I discuss what is ‘user-role’ in SUSI.AI, what are the various roles and how SUSI admins can modify/update a user’s roles.

What is User Role?

A UserRole defines the servlet access right. Not all users are allowed to access all the data and services. For  example, To list all the users, minimal user role expected is ADMIN. This classification of users are inspired by the wikipedia User Access Levels, see https://en.wikipedia.org/wiki/Wikipedia:User_access_levels.While querying SUSI, Users are classified into 7 different categories, namely :

  • BOT
  • ANONYMOUS
  • USER  
  • REVIEWER
  • ACCOUNTCREATOR
  • ADMIN
  • BUREAUCRAT

* Please see that these are as of the date of publish of this blog. These are subject to change, which is very unlikely.

If SUSI is active as a bot on some bot integrated platform (like line or kik), the user role assigned to it will be that of BOT. This user role just has technical access to the server.

All the users who are not logged in but interacting with SUSI are ANONYMOUS users. These are only subject to chat, login and signup. They may use forgot password service and reset password services as well.

Once a user login to the server, a token is generated and sent back to client to maintain the identity, hence acknowledging them as USER(s).

Users with role assigned as “REVIEWERS” are expected to manage the Skill CMS. There might be some dispute or conflict in a skill. REVIEWERS then take the access of skill data and finalise the conflict there itself for smooth functionality.

ADMIN users are those who have special rights with them. These are more like moderators with much special rights than any other user.

At the top level of the hierarchy are the BUREAUCRATS. These users have more rights than anyone. They can change role of any other user, override decision of any ADMIN user as well. Both admins and bureaucrats have the access to all the settings file on the server. They not only can look at the list, but also download and upload them. Now these users also have right to upgrade or downgrade any other user as well.

All these user roles are defined in UserRole.java file.

In each request received by the server, the user role of user making the request is compared with the minimal user role in getMinimalUserRole() method. This method is defined in AbstractAPIHandler which validates if a user is allowed to access a particular servlet or not.

private void process(HttpServletRequest request, HttpServletResponse response, Query query) throws ServletException, IOException {
	// object initialisation and comparsions
// user authorization: we use the identification of the user to get the assigned authorization
        Authorization authorization = DAO.getAuthorization(identity);

        if (authorization.getUserRole().ordinal() < minimalUserRole.ordinal()) {
        	response.sendError(401, "Base user role not sufficient. Your base user role is '" + authorization.getUserRole().name() + "', your user role is '" + authorization.getUserRole().getName() + "'");
			return;
        }
// evaluations based on other request parameters.
}

Now that we know about what User Roles actually are, let us look at how the servlet which allows the users {with at least ADMIN login} to change user role of some other user works.

In the request, 2 parameters are expected. These are :

  • user : email id of the user whose role has to be changed.
  • role : new role which will be assigned to this user.

Using a switch case, we identify the user role which is requested. If role is found to be null or any other value apart from “bot”, “anonymous”, “user”, “reviewer”, “accountcreator”, “admin” or “bureaucrat”, an error with error code 400 and error message “Bad User role” is thrown.

In the next steps, server generates client identity in order to get the corresponding Authorization object. If the user is not found in the database, again an error is thrown with error code 400 and error message “role not found

ClientCredential credential = new ClientCredential(ClientCredential.Type.passwd_login, userTobeUpgraded);
            ClientIdentity identity = new ClientIdentity(ClientIdentity.Type.email, credential.getName());
            if (!DAO.hasAuthorization(identity)) {
                throw new APIException(400, "Username not found");
            }

By now, server is clear with the user identity and new role to be assigned. Since the user role is defined in authorization.json file, we overwrite the existing user role and finally server sends back the new user role of the use

Authorization auth = DAO.getAuthorization(identity);
            try {
                auth.setUserRole(userRole);
            } catch (IllegalArgumentException e) {
                throw new APIException(400, "role not found");
            }

            // Print Response
            result.put("newDetails", auth.getJSON());
            result.put("accepted", true);
            result.put("message", "User role changed successfully!!");
            return new ServiceResponse(result);

 

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Implementing Change Password Feature in SUSI Android App using Custom Dialogs

Recently a new servlet was implemented on the SUSI Server about changing the password of the logged in user. This feature comes in handy to avoid unauthorized usage of the SUSI Account. Almost all the online platforms have this feature to change the password to avoid notorious user to unethical use someone else’s account. In SUSI Android app this new API was used with a nice UI to change the password of the user. The process is very simple and easy to grasp. This blog will try to cover the API information and implementation of the Change Password feature in the android client.

API Information

For changing the password of SUSI Account of the user, we have to call on  /aaa/changepassword.json

We have to provide three parameters along with this api call:

  1. changepassword:  Email of user (type string) using which user is logged in.
  2. password:  Old password (type string with min length of 6) of the user.
  3. newpassword: New password (type string with min length of 6) of the user.
  4. access_token: An encrypted access_token indicating user is logged in.

Sample Response (Success)

{
  "session": {"identity": {
    "type": "email",
    "name": "YOUR_EMAIL_ADDRESS",
    "anonymous": false
  }},
  "accepted": true,
  "message": "Your password has been changed!"
}

Error Response (Failure). This happens when user is not logged in:

HTTP ERROR 401
Problem accessing /aaa/changepassword.json. Reason:
   Base user role not sufficient. Your base user role is 'ANONYMOUS', your user role is 'anonymous'

Implementation in SUSI Android App

The change password option is located in Settings Activity and displayed only when user is logged in. So, if a logged in user wants to change the password of his/her SUSI AI account, he/she can simply go to the Settings and click on the option. Clicking on the options open up a dialog box with 3 input layouts for:

  1. Current Password
  2. New Password
  3. Confirm New Password

So, user can simply add these three inputs and click “Ok”. This will change the password of their account. Let’s see some code explanation.

  1. When user clicks on the “reset password” option from the settings, the showResetPasswordAlert() method is called which displays the dialog. And when user clicks on the “OK” button the resetPassword method() in the presenter is called passing input from the three input layout as parameters.

settingsPresenter.resetPassword(password.editText?.text.toString(), newPassword.editText?.text.toString(), conPassword.editText?.text.toString())

fun showResetPasswordAlert() {
   val builder = AlertDialog.Builder(activity)
   val resetPasswordView = activity.layoutInflater.inflate(R.layout.alert_reset_password, null)
   password = resetPasswordView.findViewById(R.id.password) as TextInputLayout
   newPassword = resetPasswordView.findViewById(R.id.newpassword) as TextInputLayout
   conPassword = resetPasswordView.findViewById(R.id.confirmpassword) as TextInputLayout
   builder.setView(resetPasswordView)
   builder.setTitle(Constant.CHANGE_PASSWORD)
           .setCancelable(false)
           .setNegativeButton(Constant.CANCEL, null)
           .setPositiveButton(getString(R.string.ok), null)
   resetPasswordAlert = builder.create()
   resetPasswordAlert.show()
   setupPasswordWatcher()
   resetPasswordAlert.getButton(AlertDialog.BUTTON_POSITIVE)?.setOnClickListener {
       settingsPresenter.resetPassword(password.editText?.text.toString(), newPassword.editText?.text.toString(), conPassword.editText?.text.toString())
   }
}
  1. In the resetPassword method, all details about the passwords are checked like:
  1. If passwords are not empty.
  2. If passwords’ lengths are greater than 6.
  3. If new password and confirmation new password matches

   

When all the conditions are satisfied and all the inputs are valid, resetPassword() in model is called which makes network call to change password of the user.

settingModel.resetPassword(password,newPassword,this)

override fun resetPassword(password: String, newPassword: String, conPassword: String) {
   if (password.isEmpty()) {
       settingView?.invalidCredentials(true, Constant.PASSWORD)
       return
   }
   if (newPassword.isEmpty()) {
       settingView?.invalidCredentials(true, Constant.NEW_PASSWORD)
       return
   }
   if (conPassword.isEmpty()) {
       settingView?.invalidCredentials(true, Constant.CONFIRM_PASSWORD)
       return
   }

   if (!CredentialHelper.isPasswordValid(newPassword)) {
       settingView?.passwordInvalid(Constant.NEW_PASSWORD)
       return
   }

   if (newPassword != conPassword) {
       settingView?.invalidCredentials(false, Constant.NEW_PASSWORD)
       return
   }
   settingModel.resetPassword(password,newPassword,this)
}

Summary

So, this blog talked about how the Change Password feature is implemented in SUSI Android App. This included how a network call is made, logic for making network, information about API, making dialogs with custom UI, etc. So, If you are looking forward to contribute to SUSI Android App, this can help you a little. But if not so, this may also help you in understanding and how you can implement a dialog box with custom UI.

References

  1. To know about servlets https://en.wikipedia.org/wiki/Java_servlet
  2. To see how to implement one https://www.javatpoint.com/servlet-tutorial
  3. To see how to make network calls in android using Retrofit https://guides.codepath.com/android/Consuming-APIs-with-Retrofit
  4. Official docs for displaying dialog https://developer.android.com/guide/topics/ui/dialogs.html
  5. Implementing dialog boxes with custom UI https://stackoverflow.com/questions/13341560/how-to-create-a-custom-dialog-box-in-android
  6. Pull Request for API reference: https://github.com/fossasia/susi_server/pull/352
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API to List All Users on SUSI.AI

In this blog, I discuss how the SUSI server helps in listing out all the users registered on it. The only role Susi server plays is, Whenever it receives a request at

http://api.susi.ai/aaa/getUsers.json

The server evaluate the parameters in the request, validates them and notify the user accordingly. API needs 2 parameters, out of which access-token is a necessary. 2nd parameter has to be one from the given list :

Parameter Data type

  • getPageCount boolean
  • GetUserCount boolean
  • Page integer

On the basis of this 2nd parameter, server gets to know what does the client with given access-token is requesting. Server evaluates the access-token and validates that if the access token belongs to a user with user role atleast ADMIN, then the request is valid and proceed further with fetching the data in next step. Otherwise, server responds with error code “401” and error message “Base user role not sufficient”. It is advisable for clients that before redirecting users to admin panel or any other service, Please hit

http://api.susi.ai/aaa/showAdminService.json

And check that whether the user logged in is allowed to access the admin panel or not. The servlet /showAdminService.json is quite easy to understand for even those new to programming.

Coming back to our topic, by now, server knows that this client is authorized to access the user list. But what all information does server needs to provide? In response to this request, server encodes following attributes in the JSON Array {which is part of JSON object} and sends it to user :

Attribute Description

  • Name Email-Id of the user
  • Anonymous Is this user anonymous or not
  • User Role User Role of the user
  • Confirmed User has verified account or not
  • Last Login IP Last IP from which login was requested
  • Last Login Time Time when last login request was made
  • Signup Time When did the user signed up

First things first, check if enough parameters are provided or not. If not, respond with error stating “Bad Request. No parameter present”. Otherwise, server does a general iteration which has to be done irrespective of the 2nd parameter.

First of all, get a list of all the authorized users using getAuthorizedClients method of Data Access Object class. This method picks up all the keys from authorized file {which are nothing but identification of clients from which requests are received}. Though it, skips those key which are host addresses (which can not be used to identify a user), it does includes all the email ids {which are obvious identification of users}.

public static Collection<ClientIdentity> getAuthorizedClients() {
		ArrayList<ClientIdentity> i = new ArrayList<>();
		for (String id: authorization.keys()) {
		    if(id.contains("host"))
		        continue;
			i.add(new ClientIdentity(id));
		}
		return i;
	}

In next steps, the collection is converted to suitable data types over which iterations are easy and can be converted to JSON objects and Arrays easily. After this, server evaluates which parameter is requested in the request. Let us pick each case one by one for simplicity.

  1. Client has requested number of pages in the request.

Server finds the size of keysArray {one of the object containing list of all the users}. Basic Mathematics to find out how many pages would be formed if size of each page is 50 elements and total elements are given.

if (call.get("getPageCount", false) == true) {
            int pageCount = keysArray.length % 50 == 0 ? (keysArray.length / 50) : (keysArray.length / 50) + 1;
            result.put("pageCount", pageCount);
            result.put("accepted", true);
            result.put("message", "Success: Fetched count of pages");
            return new ServiceResponse(result);
        }
  1. User count is requested

Simply return sizeof list which has list of all the users. List to be used can be anyone from authorized, keysArray or any other derivative of authorized collection. Code is quite easy.

  1.      List of users on any page is requested.

Get the page number and after applying unitary maths, you will figure out the elementary of this.

for (Client client : authorized) {
                JSONObject json = client.toJSON();
                ClientIdentity identity = new ClientIdentity(ClientIdentity.Type.email, client.getName());
                Authorization authorization = DAO.getAuthorization(identity);
                UserRole userRole = authorization.getUserRole();
                json.put("userRole", userRole.toString().toLowerCase());
                userList.add(json);
            }

If any other attribute that is required, it’s encoding will be done here.  For example, to get user role of a user, generate a client identity followed by retrieval of user role from it. Encode it and send back to user.

Other details like last login IP, last login time and signup time are also fetched from respective files.

Resources

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Change Password for SUSI Accounts Using Access Token and Email-ID

In this blog, I discuss how the SUSI server synchronizes with SUSI Accounts and SUSI webchat for users to Change Password. When a user logs in, the clients store the email id of the user along with the access token in cookies. These are stored once the client gets a positive login response from the server. Both of these are required at the time of making the final call. Web clients store the email id and access token in the following way.

cookies.set('loggedIn', loggedIn, { path: '/', maxAge: time });
cookies.set('emailId', email, { path: '/', maxAge: time });

First, the client has to ask the user to enter their current password. A javascript test is used to validate that at least 6 characters must be entered by the user. A similar test is run on the new password. But while confirming the password, client checks whether the user has entered the same password as new password or not. These are just the basics. In next stage (which is achieved only when all the above conditions are met), client encodes the email id (which it gets from cookies), current password, new password and the access token (which it again extracts from cookies).

Now, Client just has to make an ajax request to the server. The response is processed and sent back to the client. Let us now look at PasswordChange Servlet.

The base user role is defined as USER. Initial steps of the servlet are to extract the values form the request it receives. The values extracted from the request are in turn used to make a client’s identity. Before that, server checks if current and new password have same values or not. If not, then server returns a JSON response to user stating, “Your current password and new password matches”. Otherwise, it will continue its control flow as it is. Look at the code snippet below:

if(password.equals(newpassword)){
            result.put("message", "Your current password and new password matches");
            result.put("accepted", false);
            return new ServiceResponse(result);
        }

The reader here may think that they have discovered a hack. But they have not. Why? Because this is just the first step. In later stages, the hash of passwords are used to match to see whether the passwords match or not. To obtain a proper client identity, first a Client credentials object is made with support from the email id which is received in ‘changepassword’ attribute. Using the ClientCredentials object made above, an object of Authentication class is made. This object uses a method defined in its class to return a valid client identity. Using the client identity, value of password hash is extracted from the database along with the salt used to hash the password. If any error is encountered while extracting the client’s password hash value and/or salt value, an error is thrown towards the client, with a message stating “invalid credentials”.

ClientCredential pwcredential = new ClientCredential(ClientCredential.Type.passwd_login, useremail);
            Authentication authentication = DAO.getAuthentication(pwcredential);
            ClientCredential emailcred = new ClientCredential(ClientCredential.Type.passwd_login,
                authentication.getIdentity().getName());
            ClientIdentity identity = authentication.getIdentity();
            String passwordHash;
            String salt;

            try {
                passwordHash = authentication.getString("passwordHash");
                salt = authentication.getString("salt");
            } catch (Throwable e) {
                Log.getLog().info("Invalid password try for user: " + identity.getName() + " from host: " + post.getClientHost() + " : password or salt missing in database");
                result.put("message", "invalid credentials");
                throw new APIException(422, "Invalid credentials");
            }

Using the same salt value that was used earlier, a hash for password entered by the user will be generated which now matches  the previous value. This is the point where the hack you were thinking you found, failed. Again the server throws an error message if user’s credential did not match. Passwords are hard to handle and easy to guess. So here we have used quite many tests before changing them. Users are not allowed to use their email id as a password as well.

If the server is clear on all the above facts and tests, It finally generates a new hashed value of the password received in the parameter ‘newpassword’ and replaces the old hash value with the new one. To notify the clients that password change exited with a success response, it sends a JSON object with message “Your password has been changed!” and accepted flag set to true.

if (DAO.hasAuthentication(emailcred)) {
                    Authentication emailauth = DAO.getAuthentication(emailcred);
                    String newsalt = createRandomString(20);
                    emailauth.remove("passwordHash");
                    emailauth.put("passwordHash", getHash(newpassword, salt));
                    Log.getLog().info("password change for user: " + identity.getName() + " via newpassword from host: " + post.getClientHost());
                    result.put("message", "Your password has been changed!");
                    result.put("accepted", true);
                }

 

Additional Resources:

Wikipedia article: What is DAO?

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