I am getting the apikey that generates the /api/login, but that apikey I don't see how to use it in the other endpoints since in the Docs it talks about making request with the OAuth2.
https://files.slack.com/files-pri/T11NA9FSN-F03CMAN5H6X/captura_desde_2022-04-22_15-38-11.png
In case you need to use
generated via "api/login" method API key in the scope of Sandbox you should:
generate API key via "api/login" method by passing login and password of customer user
sign in with the same user or just refresh Sandbox page, in case you already signed in
after authentication method will be changed to WSSE (in case if it is still session switch it manually)
after WSSE will be used for every call
In case you need to use WSSE authentication from code please see the next article (especially "Header Generation" part): https://doc.oroinc.com/api/authentication/wsse/
I've been asked by my employer to implement a log-in system for our web application using users' GitHub accounts. I've looked around online but I haven't been able to find a clear explanation of how to go about doing this with GitHub accounts (as opposed to with Facebook or Google accounts).
I just spent about a week's worth of effort figuring out how to do this, so I thought I'd write up an explanation to save future developers time.
The short(er) answer
You'll want to follow this guide in GitHub's docs ("Authorizing OAuth Apps"), with some additions (explained below) to allow it to work as a method of user authentication.
I implemented the "web application flow" for when our application will be deployed on our company's servers (where we can keep our company's GitHub app's "client secret" a secret), and the "device flow" for when our application will be deployed on our client's computers (because in that situation we won't be able to keep our "client secret" a secret).
GitHub's guide doesn't mention the steps below (because that guide is not intended specifically for implementing social login), but to get social login working I also did the following:
I created a users database table, with the idea being that each GitHub account used to log in would have its own corresponding row in this table.
Example users table schema:
id - INTEGER
email - VARCHAR
name - VARCHAR
github_id - VARCHAR
I created an oauth_tokens database table to store a copy of all of the GitHub access tokens that our back-end receives from GitHub.
This is needed to prevent other malicious websites from impersonating our users with valid GitHub access tokens generated by the user authorizing an access token for the malicious website.
Example oauth_tokens table schema:
id - INTEGER
user_id - INTEGER
access_token - VARCHAR
expires_at - DATETIME
refresh_token - VARCHAR
refresh_token_expires_at - DATETIME
device_code - VARCHAR <-- Used for the "device flow". I have the back-end send the
front-end the device code immediately upon starting the device flow, and I then
have the front-end poll the back-end with it until the back-end has received
the access token from GitHub, at which point the front-end discards the device
code and uses the access token as its authentication token.
I had the back-end send the front-end (the user) the GitHub access token for it to present with future requests as its authentication mechanism.
The front-end should store the token in localStorage if you want the user to remain logged in even after they close the browser tab they logged in with.
I added middleware on the back-end that--for each incoming request--looks up the provided access token in our database to see if it's expired, and if so, attempts to refresh it. If it succeeds in refreshing the token, it proceeds with the request as normal and includes the new access token in the response to the front-end in a custom response header the front-end is keeping an eye out for (I named it x-updated-access-token). If it fails to refresh the token, it aborts the request and sends a 401 response that the front-end takes as a signal to redirect the user to the login page.
Setting up your app to only allow unexpired access tokens to serve as a method of authentication is necessary to make it possible for the user to sign out of the application remotely from their settings page at GitHub.com.
I added front-end code to handle the saving / updating / removing of the GitHub access token, both to/from localStorage as well as to all requests to the back-end, as well as redirecting to a /login route if the front-end doesn't find an "access_token" localStorage variable set.
The code is further below if you want an in-depth explanation, but basically I used this article as a rough guide for how the front-end code should work for the "web application flow": OpenID Connect Client by Example - Codeburst.io
More information
To clarify some vocabulary: The goal here is to do user authentication via social login. Social login is a type of single-sign on.
The first thing you should understand is that--as of the time I'm writing this--GitHub has not set itself up to be a provider of social login in the way Facebook and Google have.
Facebook and Google both have developed special JavaScript libraries that you can use to implement social login without needing to write any(?) login-specific back-end code. GitHub has no such library, and from what I can tell it's not even possible for a third party to develop such a library because GitHub's API doesn't offer the functionality required to make such a library possible (specifically, they seem to support neither the "implicit flow" nor OpenID Connect).
The next thing you should understand is that--as of the time I'm writing this--GitHub's API does not seem to support the use of OpenID Connect to implement social login using GitHub accounts.
When I started doing research into how to implement social login I was confused by the fact that the most-recent online guides were saying that OpenID Connect was the current best-practice way to do it. And this is true, if the Identity Provider (e.g. GitHub) you're using supports it (i.e. their API can return OpenID Connect ID tokens). As far as I can tell, GitHub's API doesn't currently have the ability to return OpenID Connect ID tokens from the endpoints we'd need to request them from, although it does seem they support the use of OpenID Connect tokens elsewhere in their API.
Thus, the way web apps will generally want to implement social login with GitHub accounts is to use the OAuth 2.0 flow that most websites used before OpenID Connect, which most online resources call the "authorization code flow", but which GitHub's docs refer to as the "web application flow". It's just as secure but requires some more work/code than the other methods to implement properly. The takeaway is that implementing social login with GitHub is going to take more time than using an Identity Provider like Facebook or Google that have streamlined the process for developers.
If you (or your boss) still want to use GitHub for social login even after understanding it's going to take more time, it's worth spending some time to watch some explanations of how the OAuth 2.0 flow works, why OpenID Connect was developed (even though GitHub doesn't seem to support it), and become familiar with some key technical terms, as it'll make it easier to understand the GitHub guide.
OAuth 2.0
The best explanation of OAuth 2.0 that I found was this one by Okta: An Illustrated Guide to OAuth and OpenID Connect
The most important technical terms:
Identity Provider - This is GitHub, Facebook, Google, etc.
Client - This is your app; specifically, the back-end part of your app.
Authorization Code - "A short-lived temporary code the Client gives the [Identity Provider] in exchange for an Access Token."
Access Token: This is what lets your app ask GitHub for information about the user.
You may also find this graph helpful:
The slide title is "OIDC Authorization Code Flow" but the same flow is used for a non-OIDC OAuth 2.0 authorization code flow, with the only difference being that step 10 doesn't return an ID token, just the access token and refresh token.
The fact that step 11 is highlighted in green isn't significant; it's just the step the presenter wanted to highlight for this particular slide.
The graph shows the "Identity Provider" and "Resource Server" as separate entities, which might be confusing. In our case they're both GitHub's API; the "Identity Provider" is the part of GitHub's API that gets us an access token, and the "Resource Server" is the part of GitHub's API that we can send the access token to to take actions on behalf of the user (e.g. asking about their profile).
Source: Introduction to OAuth 2.0 and OpenID Connect (PowerPoint slides) - PragmaticWebSecurity.com
OpenID Connect (OIDC)
Again, GitHub doesn't seem to support this, but it's mentioned a lot online, so you may be curious to know what's going on here / what problem it solves / why GitHub doesn't support it.
The best explanation I've seen for why OpenID Connect was introduced and why it would be preferred over plain OAuth 2.0 for authentication is my own summary of a 2012 ThreadSafe blog post: Why use OpenID Connect instead of plain OAuth2?.
The short answer is that before OIDC existed, pure-frontend social login JavaScript libraries (like Facebook's) were using plain OAuth 2.0, but this method was open to an exploit where a malicious web app could have a user sign into their site (for example, using Facebook login) and then use the generated (Facebook) access token to impersonate that user on any other site that accepted that (Facebook) access token as a method of authentication. OIDC prevents that exploit.
This particular exploit is what people are referring to when they say "OAuth 2.0 is an authorization protocol, not an authentication protocol...OAuth says absolutely nothing about the user, nor does it say how the user proved their presence or even if they're still there.", which I saw mentioned over and over again while doing research on how to use OAuth 2.0 to implement social login, and which had me initially thinking that I needed to use OpenID Connect.
But GitHub doesn't have a pure-frontend social login JavaScript library, so it doesn't need to support OpenID Connect to address that exploit. You just need to make sure your app's back-end is keeping track of which GitHub access tokens it has generated rather than just trusting any valid GitHub access token it receives.
While doing research I came across HelloJS and wondered if I could use it to implement social login. From what I can tell, the answer is "not securely".
The first thing to understand is that when you use HelloJS, it is using the same authentication code flow I describe above, except HelloJS has its own back-end ("proxy") server set up to allow you to skip writing the back-end code normally needed to implement this flow, and the HelloJS front-end library allows you to skip writing all the front-end code normally needed.
The problem with using HelloJS for social login is the back-end server/proxy part: there seems to be no way to prevent the kind of attack that OpenID Connect was created to prevent: the end result of using HelloJS seems to be a GitHub access token, and there seems to be no way for your app's back-end to tell whether that access token was created by the user trying to log into your app or if it was created when the user was logging into some other malicious app (which is then using that access token to send requests to your app, impersonating the user).
If your app doesn't use a back-end then you could be fine, but most apps do rely on a back-end to store user-specific data that should only be accessible to that user.
You could get around this problem if you were able to query the proxy server to double-check which access tokens it had generated, but HelloJS doesn't seem to have a way to do this out-of-the-box, and if you decide to create your own proxy server so that you can do this, you seem to be ending up in a more-complicated situation than if you'd just avoided HelloJS from the beginning.
HelloJS instead seems to be intended for situations where your front-end just wants to query the GitHub API on behalf of the user to get information about their account, like their user details or their list of repositories, with no expectation that your back-end will be using the user's GitHub access token as a method for that user to access their private information on your back-end.
To implement the "web application flow" I used the following article as a reference, although it didn't perfectly map to what I needed to do with GitHub: OpenID Connect Client by Example - Codeburst.io
Keep in mind that this guide is for implementing the OpenID Connect authentication flow, which is similar-to-but-not-the-same-as the flow we need to use for GitHub.
The code here was especially helpful for getting my front-end code working properly.
GitHub does not allow for the use of a "nonce" as described in this guide, because that is a feature specific to (some implementations of?) OpenID Connect, and GitHub's API does not support the use of a nonce in the same way that Google's API does.
To implement the "device flow" I used the following article as inspiration: Using the OAuth 2.0 device flow to authenticate users in desktop apps
The key quote is this: "Basically, when you need to authenticate, the device will display a URL and a code (it could also display a QR code to avoid having to copy the URL), and start polling the identity provider to ask if authentication is complete. You navigate to the URL in the browser on your phone or computer, log in when prompted to, and enter the code. When you’re done, the next time the device polls the IdP, it will receive a token: the flow is complete."
Example code
The app I'm working on uses Vue + Quasar + TypeScript on the front-end, and Python + aiohttp on the back-end. Obviously you may not be able to use the code directly, but hopefully using it as a reference will give you enough of an idea of what the finished product should look like that you can more-quickly get your own code working.
Because of Stack Overflow's post length limits, I can't include the code in the body of this answer, so instead I'm linking the code in individual GitHub Gists.
App.vue
This is the 'parent component' which the entire front-end application is contained within. It has code that handles the situation during the "web application flow" where the user has been redirected by GitHub back to our application after authorizing our application. It takes the authorization code from the URL query parameters and sends it to our application's back-end, which in turn sends the authorization code to GitHub in exchange for the access token and refresh token.
axios.ts
This is most of the code from axios.ts. This is where I put the code that adds the GitHub access token to all requests to our app's back-end (if the front-end finds such a token in localStorage), as well as the code that looks at any responses from our app's back-end to see if the access token has been refreshed.
auth.py
This is the back-end file that contains all the routes used during the login process for both the "web application flow" and the "device flow". If the route URL contains "oauth" it's for the "web application flow", and if the route URL contains "device" it's for the "device flow"; I was just following GitHub's example there.
middleware.py
This is the back-end file that contains the middleware function that evaluates all incoming requests to see if the presented GitHub access token is one in our app's database, and hasn't yet expired. The code for refreshing the access token is in this file.
Login.vue
This is the front-end component that displays the "Login page". It has code for both the "web application flow" as well as the "device flow".
Summary of the two login flows as implemented in my application:
The web application flow
The user goes to http://mywebsite.com/
The front-end code checks whether there's an access_token localStorage variable (which would indicate the user has already logged in), and doesn't find one, so it redirects the user to the /login route.
See App.vue:mounted() and App.vue:watch:authenticated()
At the Login page/view, the user clicks the "Sign in with GitHub" button.
The front-end sets a random state localStorage variable, then redirects the user to GitHub's OAuth app authorization page with our app's client ID and the random state variable as URL query parameters.
See Login.vue:redirectUserToGitHubWebAppFlowLoginLink()
The user signs into GitHub (if they're not already signed in), authorizes our application, and is redirected back to http://mywebsite.com/ with an authentication code and the state variable as URL query parameters.
The app is looking for those URL query parameters every time it loads, and when it sees them, it makes sure the state variable matches what it stored in localStorage, and if so, it POSTs the authorization code to our back-end.
See App.vue:mounted() and App.vue:sendTheBackendTheAuthorizationCodeFromGitHub()
Our app's back-end receives the POSTed authorization code and then very quickly:
Note: the steps below are in auth.py:get_web_app_flow_access_token_and_refresh_token()
It sends the authorization code to GitHub in exchange for the access token and refresh token (as well as their expiration times).
It uses the access token to query GitHub's "/user" endpoint to get the user's GitHub id, email address, and name.
It looks in our database to see if we have a user with the retrieved GitHub id, and if not, creates one.
It creates a new "oauth_tokens" database record for the newly-retrieved access tokens and associates it with the user record.
Finally, it sends the access token to the front-end in the response to the front-end's request.
The front-end receives the response, sets an access_token variable in localStorage, and sets an authenticated Vue variable to true, which the app is constantly watching out for, and which triggers the front-end to redirect the user from the "login" view to the "app" view (i.e. the part of the app that requires the user to be authenticated).
See App.vue:sendTheBackendTheAuthorizationCodeFromGitHub() and App.vue:watch:authenticated()
The device flow
The user goes to http://mywebsite.com/
The front-end code checks whether there's an access_token localStorage variable (which would indicate the user has already logged in), and doesn't find one, so it redirects the user to the /login route.
See App.vue:mounted() and App.vue:watch:authenticated()
At the Login page/view, the user clicks the "Sign in with GitHub" button.
The front-end sends a request to our app's back-end asking for the user code that the user will enter while signed into their GitHub account.
See Login.vue:startTheDeviceLoginFlow()
The back-end receives this request and:
See auth.py:get_device_flow_user_code()
Sends a request to GitHub asking for a new user_code.
Creates an asynchronous task polling GitHub to see if the user has entered the user_code yet.
Sends the user a response with the user_code and device_code that it got from GitHub.
The front-end receives the response from our app's back-end and:
It stores the user_code and device_code in Vue variables.
See Login.vue:startTheDeviceLoginFlow()
The device_code is also saved to localStorage so that if the user closes the browser window that has the "log in" page open and then opens up a new one, they won't need to restart the login process.
It displays the user_code to the user.
See Login.vue in the template code block starting <div v-if="deviceFlowUserCode">
It shows a button that will open the GitHub URL where the user can enter the user_code (it will open the page in a new tab).
It shows a QR code that links to the same GitHub link, so that if the user is using the application on a computer and wants to enter the code on their phone, they can do that.
The app uses the received device_code to set a deviceFlowDeviceCode variable. A separate part of the code in the app is constantly checking to see if that variable has been set, and when it sees that it has, it begins polling the back-end to see if the back-end has received the access_token yet from GitHub.
See Login.vue:watch:deviceFlowDeviceCode() and Login.vue:repeatedlyPollTheBackEndForTheAccessTokenGivenTheDeviceCode()
The user either clicks the aforementioned button or scans the QR code with their phone, and enters the user code at https://github.com/login/device while logged into their GitHub account, either on the same device this application is running on or some other device (like their phone).
The back-end, while polling GitHub every few seconds as previously mentioned, receives the access_token and refresh_token, and as mentioned while describing the "web app flow", sends a request to GitHub's "/user" endpoint to get user data, then gets or creates a user db record, and then creates a new oauth_tokens db record.
See auth.py:_repeatedly_poll_github_to_check_if_the_user_has_entered_their_code()
The front-end, while polling our application's back-end every few seconds, finally receives a response from the back-end with the access_token, sets an access_token variable in localStorage, redirects the user to the "app" view (i.e. the part of the app that requires the user to be authenticated).
See Login.vue:repeatedlyPollTheBackEndForTheAccessTokenGivenTheDeviceCode()
Currently Google Assitant includes an easy way to request non-identifiable information about the user and a detailed flow to authenticate the user on a third party service through OAuth2. What about if all I need is have the user authenticate on Google itself? I tried filling in the account linking flow using Google OAuth2 information, but that seems not to work. If that last thing is supposed to work fluently than that would be enough of an answer.
Context: Users already authenticate only with Google on a related webpage. All I need is to link this already authenticated account with the less-authenticated account on Google Assistant.
Update, 25 Oct 2018:
As of 13 September 2018, there is now a much simpler way to access the user's account if your project uses Google Sign-In. Google Sign-In for Assistant will give you an ID Token with information about the user, including their Google ID, with their permission. This permission can be granted just using voice and is fairly streamlined.
You can combine this with a web- or app-based Google Sign-In to get their permission to access OAuth scopes if you need to access Google's APIs.
Update, 25 Oct 2017:
As of around 4 Oct or 7 Oct, Google has updated their policy (again) to restore language restricting OAuth endpoints that are valid. The terms now include
When implementing account linking using OAuth, you must own your OAuth endpoint
and it appears (from the comments below) that they now check for the Google endpoints to prevent this method from working.
At this point, the only thing you can do is setup your own OAuth2 server.
Original Post:
Broadly speaking, the auth tasks you need to do are in four parts:
Configure your project (in the cloud console) so that the Calendar API is enabled and that the OAuth2 client is correctly configured.
Configure the Action for account linking in the action console.
Configure the Actions on Google Integration for your API.AI Agent to indicate that sign-in is required.
When API.AI calls your webhook to fulfill an Intent, it will include an auth token as part of the JSON. You can use this token to make calls to the Google APIs you need.
Configure Cloud Project
You need to configure your cloud project so that it has access to the Google APIs you need and setup the OAuth2 Client ID, Secret, and Redirect URI.
Go to https://console.cloud.google.com/apis/dashboard and make sure you have the project you're working with selected. Then make sure you have the APIs you need enabled.
Select the "Credentials" menu on the left. You should see something like this:
Select "Create credentials" and then "OAuth client ID"
Select that this is for a "Web application" (it is... kinda...)
Enter a name. In the screen shot below, I used "Action client" so I remember that this is actually for Actions on Google.
In the "Authorized Redirect URIs" section, you need to include a URI of the form https://oauth-redirect.googleusercontent.com/r/your-project-id replacing the "your-project-id" part with... your project ID in the Cloud Console. At this point, the screen should look something like this:
Click the "Create" button and you'll get a screen with your Client ID and Secret. You can get a copy of these now, but you can also get them later.
Click on "Ok" and you'll be taken back to the "Credentials" screen with the new Client ID added. You can click the pencil icon if you ever need to get the ID and Secret again (or reset the secret if it has been compromised).
Configure the Action Console
Once we have OAuth setup for the project, we need to tell Actions that this is what we'll be using to authenticate and authorize the user.
Go to https://console.actions.google.com/ and select the project you'll be working with.
In the Overview, make your way through any configuration necessary until you can get to Step 4, "Account Linking". This may require you to set names and icons - you can go back later if needed to correct these.
Select the Grant Type of "Authorization Code" and click Next.
In the Client Information section, enter the Client ID and Client Secret from when you created the credentials in the Cloud Console. (If you forget, go to the Cloud Console API Credentials section and click on the pencil.)
For the Authorization URL, enter https://accounts.google.com/o/oauth2/v2/auth
For the Token URL, enter https://www.googleapis.com/oauth2/v4/token
Click Next
You now configure your client for the scopes that you're requesting. Unlike most other places you enter scopes - you need to have one per line. Then click Next.
You need to enter testing instructions. Before you submit your Action, these instructions should contain a test account and password that the review team can use to evaluate it. But you can just put something there while you're testing and then hit the Save button.
Configure API.AI
Over in API.AI, you need to indicate that the user needs to sign-in to use the Action.
Go to https://console.api.ai/ and select the project you're working with.
Select "Integrations" and then "Actions on Google". Turn it on if you haven't already.
Click the "Sign in required for welcome intent" checkbox.
Handle things in your webhook
After all that setup, handling things in your webhook is fairly straightforward! You can get an OAuth Access Token in one of two ways:
If you're using the JavaScript library, calling app.getUser().authToken
If you're looking at the JSON body, it is in originalRequest.data.user.accessToken
You'll use this Access Token to make calls against Google's API endpoints using methods defined elsewhere.
You don't need a Refresh Token - the Assistant should hand you a valid Access Token unless the user has revoked access.
After contacting Google the current situation seems to be that you should set up your own OAuth2 server, and then on the login screen of your OAuth2 server you should start the Google OAuth2 flow.
you have to have your own endpoint with Google Oauth2 - it is correct that you can't use Google Oauth itself as a provider. To use the Google OAuth service, you can use a "sign in with Google" button in your own endpoint instead.
Source: Contacting Google Actions on Google Support
Kind of speechless right now... as this seems to be a huge oversight on Google's part.
I am able to make it work after a long time.
We have to enable the webhook first and we can see how to enable the webhook in the dialog flow fulfillment docs
If we are going to use Google Assistant, then we have to enable the Google Assistant Integration in the integrations first.
Then follow the steps mentioned below for the Account Linking in actions on google:-
Go to google cloud console -> APIsand Services -> Credentials -> OAuth 2.0 client IDs -> Web client -> Note the client ID, client secret from there
-> Download JSON - from json note down the project id, auth_uri, token_uri
-> Authorised Redirect URIs -> White list our app's URL -> in this URL fixed part is https://oauth-redirect.googleusercontent.com/r/ and append the project id in the URL
-> Save the changes
Actions on Google -> Account linking setup
1. Grant type = Authorisation code
2. Client info
1. Fill up client id,client secrtet, auth_uri, token_uri
2. Enter the auth uri as https://www.googleapis.com/auth and token_uri as https://www.googleapis.com/token
3. Save and run
4. It will show an error while running on the google assistant, but dont worry
5. Come back to the account linking section in the assistant settings and enter auth_uri as https://accounts.google.com/o/oauth2/auth
and token_uri as https://accounts.google.com/o/oauth2/token
6. Put the scopes as https://www.googleapis.com/auth/userinfo.profile and https://www.googleapis.com/auth/userinfo.email
and weare good to go.
7. Save the changes.
In the hosting server logs, we can see the access token value and through access token, we can get the details regarding the email address.
Append the access token to this link "https://www.googleapis.com/oauth2/v1/userinfo?access_token=" and we can get the required details in the resulting json page.
accessToken = req.get("originalRequest").get("data").get("user").get("accessToken")
r = requests.get(link)
print("Email Id= " + r.json()["email"])
print("Name= " + r.json()["name"])
You need to implement the Oauth protocol with whatever Google Assistant app you are developing. Let me be a bit more clear:
The user is on the assistant, you need to link him to any data
you have on your App side
The access to the data you have about
your user is protected by an access token
Google then needs to
ask you for this token to have access to this resource
When
google has the token it can send it to the app so it validates every
requests to get the resource.
This is why you need to implement your own oauth server (Honestly it is just two more endpoints in your application): the identity is checked on google's side, but the link between the user and the resource to access can only be known by you.
The process above is valid, you just need to specify your own token endpoint and your own auth endpoint.
Note that if you only want to check that the user is logged in into google and get his email, you just need to implement the streamlined identity flow that does not require the /auth endpoint (Automatically Sign Up Users with Streamlined Identity Flows)
That beeing said I implemented the flow but get the same error :
expected_inputs[0].possible_intents[0]: Transactions/Identity API must be enabled before using.
I am using eventbrite omniauth to authenticate the user. With reference to https://github.com/k504866430/omniauth-eventbrite I included the gem and created a file omniauth.rb file as:
Rails.application.config.middleware.use OmniAuth::Builder do
provider :eventbrite, ENV['EVENTBRITE_CLIENT_ID'], ENV['EVENTBRITE_CLIENT_SECRET']
end
On the show page of each event there is link to Authenticate with eventbrite.
events/24
= link_to "Authenticate with Eventbrite", "/auth/eventbrite"
When the user allows to access I want the callback url to redirect to same event page.
Thus I need to know how to pass the event_id in params so that the application can return to the same event page and how should the callback url be defined in routes.rb file
Eventbrite's OAuth2.0 implementation does not allow you to define the OAuth callback URL as a querystring parameter. This callback_url can only be defined by configuring your Eventbrite application key's 'redirect_uri' setting.
Pass-through of custom querystring parameters (such as an event_id) is also not supported.
Besides, you'll need to do a bit of follow-up work AFTER the user arrives back on your site.
If you need to redirect a user after they return to your website, I would consider stashing the 'redirect_url' (and possibly the event_id as well) in the user's browser session or another data store.
Setting up a single landing page (to match your redirect_uri) should allow you to complete the OAuth2.0 handshake before sending the user on to a url of your choice.
I'm trying to write a new application using the Flattr REST-API version 1 (not the beta v2). The application acquires a request token at first, which seems to work properly. But I run into a problem authenticating the user. The link created for authentication looks like this:
https://api.flattr.com/oauth/authenticate?access_scope=read,click&oauth_token=MY_REQUEST_TOKEN
Clicking the link everything seems alright. Information about the application and the scope requested is shown, but clicking "Authenticate", there's no pin code, but the following error from https://flattr.com/apps/pincode/MY_REQUEST_TOKEN:
Something went wrong. Please try again
BUT now the Application IS in the authorized application list of the user though that doesn't really help if the user can't get the pin code...
The Application type is set to client. It's the first time I try to work with the API so I'm not sure if I miss anything important? Would be grateful for some help.
Just as an update: We finally changed to API v2. Getting Authorization for our application feels a bit clumsy, as we set the redirecturi to some webpage, where we display the returned code and let the user copy&paste it into our client application... we kind of made our own pincode-flow :/
If possible, please use the v2 api, which uses oauth2 + bearer token.
However, the new API doesn't support authentication using the pincode flow.
As stated by Maike this is probably a bug that has surfaced yet again :(
I'll create an internal bug ticket and try to get it fixed.
The pincode isn't a feature planned. You can use the oauth2 "implicit grant" to authenticate the resources owner. This isn't documented at the moment but is possible.
When you do the request to https://flattr.com/oauth/authorize you pass the response_type token instead of code. This will append a access_token fragment in your callback URL. In your http client it might be possible to catch the 302 from our server and parse the access_token from the fragment.
All this requires a http client in your application whom you can control the flow inside your app.