DocuSign OAuth Flow - oauth

I am implementing DocuSign's OAuth flow by following OAuth2 Authentication Support in DocuSign REST API
According to the documentation, in order to carry out the OAuth Token Request the client application should show a UI to prompt the user for email/password and is responsible to keep the information confidential and not store it locally.
I would like to know if DocuSign supports OAuth in the manner where the client application does not take hold of the user's email and password and is just concerned with the authentication token of the user.

The DocuSign Developer Center has some info on the OAuth process on their SOBO (Send-On-Behalf-Of) feature page. Check out Explore -> Features -> SOBO.
It's pretty easy to request an access token, just make the following call:
URL
https://{server}/restapi/{apiVersion}/oauth2/token
METHOD
POST
BODY
grant_type=password&client_id={IntegratorKey}&username={email}&password={password}&scope=api
For the body make sure you replace IntegratorKey, email, and password with your credentials.
A successful call will generate the following response:
{
"access_token": "<access token for user>",
"scope": "api",
"token_type": "bearer"
}
And finally, you can then use that access token in subsequent api calls using the Authorization: bearer header like so:
Authorization: bearer <access_token>
One important thing to remember is that you are only allowed 10 OAuth tokens in your account (which can be seen on the Preferences -> Connected Apps screen in the DocuSign Console). If you have 10 and request a new token the call will fail, you'll need to revoke an existing one in that case if you want to create a new one.

According to the DocuSign documentation, it supports two grants: (1) the Resource Owner Password Credentials Grant and (1) the SAML2 Grant, which is an extension to the base OAuth2 spec. Neither of these grants issue an authentication token. In the first grant, the resource owner must share his credentials with the client application. In the second grant, the resource owner approves access by the client application in advance. The client app generates a SAML assertion which is validated by the authorization server and (if the assertion is valid) is issued an access token.
The authentication token is used only by the Authentication Code Grant which, according to the DocuSign documentation, is not supported.

Related

OAuth2 authentication code for already logged in user

With an OAuth2 implementation (either developed in-house, or a 3rd party like Google, Facebook, Login With Amazon, etc.), is it possible to generate an authentication code on behalf of a user logged into a mobile app or web app without requiring any action from the user?
The typical flow to obtain the authentication code requires the user to authenticate and authorize the requested scope. But in this case, the user is already authenticated into the app, so I want to avoid requiring the user to log in again.
The authentication code is required for invoking an external third-party API that will eventually exchange the authentication code for refresh/access tokens. The backend system (associated with the API) needs to get its own refresh/access token based on the authentication code shared with it. This is not for a one-time use of the token; the system needs to have its own tokens for that logged in user, independent of the mobile client.
It is possible to get user token for another client. You do not need new authentication code, you just call token endpoind with some params. For example, in Keycloak this flow is called Token Exchange. You need to configure clients in the Keycloak and then you can call token endpoint with access token you have.
{
client_id: your client id,
client_secret: your client secret,
subject_token: token you have
audience: target client id,
grant_type: urn:ietf:params:oauth:grant-type:token-exchange,
requested token type: urn:ietf:params:oauth:token-type:refresh_token
}
You can read about this flow here:
https://tools.ietf.org/id/draft-ietf-oauth-token-exchange-12.html
It is also called On-Behalf-Of flow like in Azure:
https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-on-behalf-of-flow

Using access_tokens and id_tokens together Auth0

While starting to integrate auth0, I came across this article
So its clear that to secure apis, all we need is the access_token and that is sent with each http request in the request Authorization header(Bearer scheme).
But then auth0(and possibly other providers) also send an Id_token that contains information about the user. My confusion is that how do I use this id_token to pass user information to my api. ( I have a spa running front end that authenticates to auth0 and gets these 2 tokens).
I can ofc call the userInfo end point in my api to get user info. But then wouldn't this defeat the purpose of the Id tokens?
The ID Token is consumed by the application and the claims included,
are typically used for UI display. It was added to the OIDC
specification as an optimization so the application can know the
identity of the user, without having to make an additional network
requests.
So my question is how do I access user profile in my api using id tokens?
"My confusion is that how do I use this id_token to pass user information to my api"
for that confusion, you just pass your JWT token. while generating JWT token, you need to add user information in payload part in JWT token. When your api get the JWT token, just check your JWT token is correct or not by the use of secret key and if correct, you can get data. How to get is just go from that JWT Authentication for Asp.Net Web Api
ID token is sent from the authorization server as a part of OIDC protocol. The purpose of this is to authenticate the user to your client application (SPA in this case). i.e. to let your API or the application know which particular user authorized the client to access a certain resource on its behalf.
Best way to use the ID token is by decoding and verifying it using a library. This will allow you to verify the signature of the token and any other claim that is included in the token (you can add custom claims to the tokens). Validation of those claims can be used to determine identity of the user and match with the user profile in your API. You will have to check the documentation related to your IdP(auth0) to figure out how to add new claims that are used by the user profile in your API.

Example IdentityServer 4 refresh token flow for Hybrid with Postman

I have configured my client to use Hybrid flow with a grant type of password and offline. The user is able to generate an access token and the response does include a refresh token.
My question is I do not see documentation on how to use the refresh token for non .Net environments. Specifically I am curious if any body has a sample refresh flow in another language or Postman that shows which endpoints to hit and what the request needs to look like when the user requests a new token via the refresh token.
Thanks in advance,
G
This is documented at http://docs.identityserver.io/en/latest/endpoints/token.html
The token endpoint can be used to programmatically request tokens. It supports the password, authorization_code, client_credentials and refresh_token grant types). Furthermore the token endpoint can be extended to support extension grant types.
Example
POST /connect/token client_id=client1&client_secret=secret& grant_type=refresh_token&refresh_token=hdh922&redirect_uri=https://myapp.com/callback

Can I authenticate with OAuth Authorization server by passing username and password in Authorization header?

In case of OAuth 2.0 authorization code and implicit flow cases, on hitting the Authorization Url user is redirected to OAuth providers login page.
To avoid showing up the OAuth providers page in my application, can i make user to enter username and password in text fields and pass them as Authorization header of authorization Url and get back access_token from OAuth provider and use it for further requests ?
Is it legal, valid and feasible ?
Is it legal, valid and feasible ?
No. Not with the flow you are using right now. Implicit flow is not built for this purpose, so you cannot do it.
But, OAuth 2.0 provide you a dedicated flow for your requirement.
4.3. Resource Owner Password Credentials Grant
The resource owner password credentials grant type is suitable in
cases where the resource owner has a trust relationship with the
client, such as the device operating system or a highly privileged application.
As described in protocol, in this flow, your end user(resource owner) provide their credentials to client application. Client application call token endpoint with resource owner credentials to obtain access tokens.
Flow overview (From RFC6749)
Token request request (From RFC6749)
As specification mention, this flow is there to support old systems which are unable to fully utilise OAuth 2.0. For example clients which use basic authentication.

Clarification on id_token vs access_token

I'm building a system with OIDC and OAuth 2.0 (using Auth0), and I'm unsure how to properly use the id_token and access_token. Or rather, I'm confused about which roles to assign to the various services in my setup.
I have a fully static frontend-application (single-page app, HTML + JS, no backend) that ensures that the user is authenticated using the implicit flow against Auth0. The frontend-application then fetches data from an API that I am also building.
Now, which is right?
The frontend SPA is the OAuth client application
My API service is an OAuth resource server
...or:
The frontend and my API service are both the client application
If both my frontend and backend API can be considered to be the client, I see no real harm in using the id_token as the bearer token on requests from my frontend to my backend - this is appealing because then I can simply verify the signed token on the backend, and I have all the information about the user that I need. However, if my API is considered a resource server, I should probably use the access_token, but then I have to connect to Auth0's servers on every API request to both verify the token, and get basic user info, won't I?
I've read this which seems to suggest that the access_token is the only valid token for use with my API. But like I said, I'm not sure about the roles of the individual services. And using the id_token is tempting, because it requires no network connections on the backend, and contains information I need to extract the right data.
What is the right way to go about this?
I like this Medium post about the difference, all cred to this author.
https://medium.com/#nilasini/id-token-vs-access-token-17e7dd622084
If you are using Azure AD B2C like I am you can read more here:
https://learn.microsoft.com/en-us/azure/active-directory-b2c/openid-connect
ID Token
You will get id token if you are using scope as openid. Id token is specific to openid scope. With openid scope you can get both id token and access token.
The primary extension that OpenID Connect makes to OAuth 2.0 to enable End-Users to be Authenticated is the ID Token data structure. The ID Token is a security token that contains Claims(claims are name/value pairs that contain information about a user) about the Authentication of an End-User by an Authorization Server when using a Client, and potentially other requested Claims. The ID Token is represented as a JSON Web Token (JWT)
{
"iss": "https://server.example.com",
"sub": "24400320",
"aud": "s6BhdRkqt3",
"nonce": "n-0S6_WzA2Mj",
"exp": 1311281970,
"iat": 1311280970,
"auth_time": 1311280969,
"acr": "urn:mace:incommon:iap:silver"
}
The above is default JWT claims, in addition to that, if you requested claims from service provider then you will get those as well.
An id_token is a JWT, per the OIDC Specification. This means that:
identity information about the user is encoded right into the token
and
the token can be definitively verified to prove that it hasn't been
tampered with.
There's a set of rules in the specification for validating an id_token. Among the claims encoded in the id_token is an expiration (exp), which must be honored as part of the validation process. Additionally, the signature section of JWT is used in concert with a key to validate that the entire JWT has not been tampered with in any way.
Access Tokens
Access tokens are used as bearer tokens. A bearer token means that the bearer (who hold the access token) can access authorized resources without further identification. Because of this, it's important that bearer tokens are protected. If I can somehow get ahold of and "bear" your access token, I can pretend as you.
These tokens usually have a short lifespan (dictated by its expiration) for improved security. That is, when the access token expires, the user must authenticate again to get a new access token limiting the exposure of the fact that it's a bearer token.
Although not mandated by the OIDC spec, Okta uses JWTs for access tokens as (among other things) the expiration is built right into the token.
OIDC specifies a /userinfo endpoint that returns identity information and must be protected. Presenting the access token makes the endpoint accessible.
http://openid.net/specs/openid-connect-core-1_0.html
https://connect2id.com/learn/openid-connect#cool-id-token-uses
https://developer.okta.com/blog/2017/07/25/oidc-primer-part-1
Your frontent is your OAuth client application, once it stores the token it can take actions on the OAuth flow. And your API service is resource server, because it accepts the access_token issued by your identity server.
Also I would say that your id_token stands for the identification of the logged user and may contain sensitive data for your app. The access_token is standing as your credential to access a resource.
At the end you will use an access_token to request a resource, and then if you need specific data from the logged in user (resource owner), you may request the ID token from the token endpoint.
In my opinion, the first approach is correct. Your SPA is the client application and your APIs are resource servers.
I would suggest you limit the use of id_token till your SPA only. You can use the basic information present in the id token (like username and email) to display user information within your UI. If you can generate access tokens as JWTs too then your API can validate the access tokens without going to the Identity provider. You can include roles (or similar) in your access token to get authorization information in your access token.
I was also wondering if I need to talk to the IdP on every request if I'm using the tokens received from the IdP. I ended up with the following setup:
Only the backend talks to the IdP, the frontend does not.
Upon the IdP callback the backend issues a JWT for the frontend.
User session and frontend-backend communication is managed entirely by my app using the JWT token.
Check this article: OAuth2 in NestJS for Social Login (Google, Facebook, Twitter, etc)
and this repo: https://github.com/thisismydesign/nestjs-starter
and this question: OAuth2 flow in full-stack NestJS application
The id_token is an cryptographically encoded token for authentication. The OP (the auth provider) is the one that generates it and the RP (relying party or the resource) will eventually re-present the token to the OP to counter validate when handed over by the client. In short the id_token is tied to authn workflow.
The access_token enables resource access. It does subsume the userinfo i.e., the id_token or any other principal on whose behalf the access is being requested. So this token includes both user claims plus claims to groups that are authorized. In short the access_token is tied to your authz workflow.

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