RESTful API: How to model 'request new password'? - api

I am designing a RESTful API for a booking application and was quite happy to see I could map all details of the application to the 4 HTTP methods.
/users - GET, POST
/users/({id}|myself) - GET, POST, PUT, DELETE
/users/({id}|myself)/bookings - GET, POST
/users/({id}|myself)/bookings/{id} - GET, POST, PUT, DELETE
Example: Updating my own user uses a PUT to /users/myself.
But now I found out that one thing is missing: The possibility to request a new password if I forgot my old one. Any idea how I could add this?

Since the action is essentially an update -- a new password will generated -- I would use the POST verb. You'll have to figure out an alternative way of delivering the password unless you have already arranged some challenge/response protocol based on shared secrets that can be used to validate the requester in the absence of the password. The easiest way is probably to email the user at the account of record with a link that can be used to effect the change and display their new password.

Assuming by requesting a new password, you are referring to the typical action of the system assigning a new temporary password and then allowing the user to reset it, I would do somethign along the lines of:
POST : /users/myself/resetPassword
and then return the temporary password, send an email to the user or some other method of passing the new temp password back to the user.

/users/({id}|myself)/forgottenpassword/, GET or PUT
or just implement some way of telling the user to go to the website.

Related

Making simple signup and login with mockoon

one question, maybe it's a bit longer, but i really hope someone can help me 🙏
I've been reading the docs but simply can't figure it out.
Is there a way i can create a signup feature where user creates an account (only simple one, email and pw) , and that account data is saved somewhere in a json file
And then the user can login via post method by typing his credntials.
And if credentials are correct (out of any other credentials there are in that particular json file) he gets a random jwt.
I mean i know i need to set up the rules if email and pw match any user and pw from the json file
Thanks!
Mockoon offers mostly stateless and independant endpoints mocking. Which means, there is currently no easy way to "code" it for such advanced use cases.
You can simulate a POST /signup and POST /login call, make sure the request looks OK by using Mockoon's rules, but they will not be linked and the credentials will not be persisted.
A system of CRUD endpoints is currently under development but it will allow for JSON manipulation only, not the kind of behavior you describe which is also very close to a production application.

CreateOrUpdate endpoint on DDD

I have a rest API for an application that I am developing. One of the endpoints receives the name, email and phone fields to create a new user (without password). Obviously the endpoint would be /users [POST]
Would it be correct to take advantage of this endpoint to, if the user already exists, update it with the new data? Or is it better to create a different endpoint (PUT) to update the user? If so I would have to put the business logic outside of this API, and I don't like that idea.
This question is not related to DDD, as DDD does not provide guidance on API design.
But to answer your question, whether or not you should use PUT or POST will depend on whether or not the action should be idempotent.
POST is typically used to create a new resource
POST is not idempotent, if the same request is sent multiple times there will be different results (new resource gets created each time). The same request sent to POST /users will create a new resource each time.
PUT is used to either create or replace an existing resource (not necessarily update).
The PUT method is idempotent, so if the same request is sent multiple times it will be the same as if it is sent once. The same request sent to PUT /users/1 will have the same result.
If you want to update part of the resource (update rather than replace), you can use PATCH.

Change email workflow in ASP.NET Core

If a user wants to change to a new email address, I use:
var token = await _userManager.GenerateChangeEmailTokenAsync(user, newEmail);
...and send a confirmation mail which includes this change token. The user clicks the link in the email, arrives back at the site, and now I need to change the email.
BUT, I don't know the new email address.
I've gone through the hassle of an confirmation mail loop, so I want to use it. Asking for the email again risks mistypings that could lock out the user from his account, and is also another hurdle for the user, and more code to maintain for me.
Obvious solutions:
ask for it again (and risk mistypings, and make the mail loop pointless)
store the new email address in User.NewEmailTemp (yuck, want to keep this stateless)
include it in the link in the email (bad security!)
There may be a better way. The change token includes a bunch of data, including a "purpose" which contains the new email address. Can I somehow extract/decode the purpose, or is it mangled as part of a hashing process?
The answer is simply to persist it. Stateless isn't really an option. However, that doesn't mean you need to necessarily pollute the user subdomain with it. You can, for example, create a separate entity like EmailChangeRequest, with props for the new email, the token, and probably a timestamp (mostly for pruning/expiration). The token, here, wouldn't be for validation, but rather for lookup, so it could be considered a key on the table.
Long and short, when the user clicks the link, you look up the request via the token, get the new email from that, and then call ChangeEmailAsync with that new email and the token.
If you're really opposed to persistence of any sort, I've toyed around personally with a JWT-esque approach previously. I say "-esque" because passing around a full encrypted and signed JWT as a query or route param is going to make for extremely long URLs for your confirmation links, perhaps even approach request limits. What I did instead, was chop off the header of the JWT, since the header is mostly meant for cross-client communication. In this scenario, I can safely assume an encryption method and issuer and such is unnecessary.
Another change I made was to use TOTP-style tokens instead of the encrypted hashes used by default. This serves to further reduce the JWT token size, and since I'm encrypting the JWT itself, it's not that important if the token inside is encrypted itself. The token provider for things like email confirmation can be easily customized in ConfigureServices, and there's built-in TOTP token providers that can be used, so this is also relatively low-friction.
I still don't think it's necessarily a bad thing to persist it, especially if you use a separate entity outside of your user subdomain. However, the pseudo JWT approach might fit your needs better if you don't want to go that route.

Add instruction 'how' to perform a REST API request by adding header or body param?

Imagine a simple REST API that allows to create a user account, by sending a JSON resource to POST /users as in the following. By default it sends out a confirmation email to the user.
{
"username": "john#appleseed.com",
"password": "secret"
}
However sometimes there are good reasons for not sending out a confirmation based on the use case, e.g. another API client, or admins signing up users on their behalf.
Since it doesn't have any implications on the created resource but is more of an instruction how to create the user, should it be separate from the request body? What's the best way to do this?
Specify a custom header Confirmation: no-confirmation
Add a query param ?confirmation=false
Add a send_confirmation field to the request body
Let's take the options in order:
Adding a header value to indicate some semantic difference should be generally avoided. The API should be "browseable", meaning it should be discoverable following links only.
Adding a query parameter is, from REST perspective completely equal to creating another URI. It does not really matter how you expose it, the point is that the client needs to follow some links from the previous "state" it was in. This is actually ok, as long as the links to these resources indicate the different semantics you described: like creating users by admin, users creating themselves, etc.
Also note, that the API should not necessarily expose whether a confirmation is sent. The API should expose the "purpose", the server then can decide whether the use-case warrants a confirmation email.
Putting a send_confirmation in the JSON representation itself. This is ok, if this is a functionality available for the user. For example I can ask for a confirmation email. If I can't, and it is only used for differentiating different use-cases, then I would rather prefer option 2.
Summary: For the case you are describing I would pick option 2: different resources for admins and normal users.

User registration/authentication flow on a REST API

I know this is not the first time the topic is treated in StackOverflow, however, I have some questions I couldn't find an answer to or other questions have opposed answers.
I am doing a rather simple REST API (Silex-PHP) to be consumed initially by just one SPA (backbone app). I don't want to comment all the several authentication methods in this question as that topic is already fully covered on SO. I'll basically create a token for each user, and this token will be attached in every request that requires authentication by the SPA. All the SPA-Server transactions will run under HTTPS. For now, my decision is that the token doesn't expire. Tokens that expire/tokens per session are not complying with the statelessness of REST, right? I understand there's a lot of room for security improvement but that's my scope for now.
I have a model for Tokens, and thus a table in the database for tokens with a FK to user_id. By this I mean the token is not part of my user model.
REGISTER
I have a POST /users (requires no authentication) that creates a user in the database and returns the new user. This complies with the one request one resource rule. However, this brings me certain doubts:
My idea is that at the time to create a new user, create a new token for the user, to immediately return it with the Response, and thus, improving the UX. The user will immediately be able to start using the web app. However, returning the token for such response would break the rule of returning just the resource. Should I instead make two requests together? One to create the user and one to retrieve the token without the user needing to reenter credentials?
If I decided to return the token together with the user, then I believe POST /users would be confusing for the API consumer, and then something like POST /auth/register appears. Once more, I dislike this idea because involves a verb. I really like the simplicity offered in this answer. But then again, I'd need to do two requests together, a POST /users and a POST /tokens. How wrong is it to do two requests together and also, how would I exactly send the relevant information for the token to be attached to a certain user if both requests are sent together?
For now my flow works like follows:
1. Register form makes a POST /users request
2. Server creates a new user and a new token, returns both in the response (break REST rule)
3. Client now attaches token to every Request that needs Authorization
The token never expires, preserving REST statelessness.
EMAIL VALIDATION
Most of the current webapps require email validation without breaking the UX for the users, i.e the users can immediately use the webapp after registering. On the other side, if I return the token with the register request as suggested above, users will immediately have access to every resource without validating emails.
Normally I'd go for the following workflow:
1. Register form sends POST /users request.
2. Server creates a new user with validated_email set to false and stores an email_validation_token. Additionally, the server sends an email generating an URL that contains the email_validation_token.
3. The user clicks on the URL that makes a request: For example POST /users/email_validation/{email_validation_token}
4. Server validates email, sets validated_email to true, generates a token and returns it in the response, redirecting the user to his home page at the same time.
This looks overcomplicated and totally ruins the UX. How'd you go about it?
LOGIN
This is quite simple, for now I am doing it this way so please correct me if wrong:
1. User fills a log in form which makes a request to POST /login sending Basic Auth credentials.
2. Server checks Basic Auth credentials and returns token for the given user.
3. Web app attached the given token to every future request.
login is a verb and thus breaks a REST rule, everyone seems to agree on doing it this way though.
LOGOUT
Why does everyone seem to need a /auth/logout endpoint? From my point of view clicking on "logout" in the web app should basically remove the token from the application and not send it in further requests. The server plays no role in this.
As it is possible that the token is kept in localStorage to prevent losing the token on a possible page refresh, logout would also imply removing the token from the localStorage. But still, this doesn't affect the server. I understand people who need to have a POST /logout are basically working with session tokens, which again break the statelessness of REST.
REMEMBER ME
I understand the remember me basically refers to saving the returned token to the localStorage or not in my case. Is this right?
If you'd recommend any further reading on this topic I'd very much appreciate it. Thanks!
REGISTER
Tokens that expire/tokens per session are not complying with the statelessness of REST, right?
No, there's nothing wrong with that. Many HTTP authentication schemes do have expiring tokens. OAuth2 is super popular for REST services, and many OAuth2 implementations force the client to refresh the access token from time to time.
My idea is that at the time to create a new user, create a new token for the user, to immediately return it with the Response, and thus, improving the UX. The user will immediately be able to start using the web app. However, returning the token for such response would break the rule of returning just the resource. Should I instead make two requests together? One to create the user and one to retrieve the token without the user needing to reenter credentials?
Typically, if you create a new resource following REST best practices, you don't return something in response to a POST like this. Doing this would make the call more RPC-like, so I would agree with you here... it's not perfectly RESTful. I'll offer two solutions to this:
Ignore this, break the best practices. Maybe it's for the best in this case, and making exceptions if they make a lot more sense is sometimes the best thing to do (after careful consideration).
If you want be more RESTful, I'll offer an alternative.
Lets assume you want to use OAuth2 (not a bad idea!). The OAuth2 API is not really RESTful for a number of reasons. I'm my mind it is still better to use a well-defined authentication API, over rolling your own for the sake of being RESTful.
That still leaves you with the problem of creating a user on your API, and in response to this (POST) call, returning a secret which can be used as an access/refresh token.
My alternative is as follows:
You don't need to have a user in order to start a session.
What you can do instead is start the session before you create the user. This guarantees that for any future call, you know you are talking to the same client.
If you start your OAuth2 process and receive your access/refresh token, you can simply do an authenticated POST request on /users. What this means is that your system needs to be aware of 2 types of authenticated users:
Users that logged in with a username/password (`grant_type = passsword1).
Users that logged in 'anonymously' and intend to create a user after the fact. (grant_type = client_credentials).
Once the user is created, you can assign your previously anonymous session with the newly created user entity, thus you don't need to do any access/refresh token exchanges after creation.
EMAIL VALIDATION
Both your suggestions to either:
Prevent the user from using the application until email validation is completed.
Allow the user to use the application immediately
Are done by applications. Which one is more appropriate really depends on your application and what's best for you. Is there any risk associated with a user starting to use an account with an email they don't own? If no, then maybe it's fine to allow the user in right away.
Here's an example where you don't want to do this: Say if the email address is used by other members of your system to add a user as a friend, the email address is a type of identity. If you don't force users to validate their emails, it means I can act on behalf of someone with a different email address. This is similar to being able to receive invitations, etc. Is this an attack vector? Then you might want to consider blocking the user from using the application until the email is validated.
You might also consider only blocking certain features in your application for which the email address might be sensitive. In the previous example, you could prevent people from seeing invitations from other users until the email is validated.
There's no right answer here, it just depends on how you intend to use the email address.
LOGIN
Please just use OAuth2. The flow you describe is already fairly close to how OAuth2 works. Take it one step further an actually use OAuth2. It's pretty great and once you get over the initial hurdle of understanding the protocol, you'll find that it's easier than you thought and fairly straightforward to just implement the bits you specifically need for your API.
Most of the PHP OAuth2 server implementations are not great. They do too much and are somewhat hard to integrate with. Rolling your own is not that hard and you're already fairly close to building something similar.
LOGOUT
The two reasons you might want a logout endpoint are:
If you use cookie/session based authentication and want to tell the server to forget the session. It sounds like this is not an issue for you.
If you want to tell the server to expire the access/refresh token earlier. Yes, you can just remove them from localstorage, and that might be good enough. Forcing to expire them server-side might give you that little extra confidence. What if someone was able to MITM your browser and now has access to your tokens? I might want to quickly logout and expire all existing tokens. It's an edge case, and I personally have never done this, but that could be a reason why you would want it.
REMEMBER ME
Yea, implementing "remember me" with local storage sounds like a good idea.
I originally took the /LOGON and /LOGOUT approach. I'm starting to explore /PRESENCE. It seems it would help me combine both knowing someone's status and authentication.
0 = Offline
1 = Available
2 = Busy
Going from Offline to anything else should include initial validation (aka require username/password). You could use PATCH or PUT for this (depending how you see it).
You are right, SESSION is not allowed in REST, hence there is no need to login or logout in REST service and /login, /logout are not nouns.
For authentication you could use
Basic authentication over SSL
Digest authentication
OAuth 2
HMAC, etc.
I prefer to use PUBLIC KEY and PRIVATE KEY [HMAC]
Private key will never be transmitted over web and I don't care about public key. The public key will be used to make the user specific actions [Who is holding the api key]
Private key will be know by client app and the server. The private key will be used to create signature. You generate a signature token using private key and add the key into the header. The server will also generate the signature and validate the request for handshake.
Authorization: Token 9944b09199c62bcf9418ad846dd0e4bbdfc6ee4b
Now how you will get private key? you have to do it manually like you put facebook, twitter or google api key on you app.
However, in some case you can also return [not recommended] the key only for once like Amazon S3 does. They provide "AWS secret access key" at the registration response.