Facilitator

Gojek and GoBiz both use OAuth2 method to authenticate the client.

The Facilitator is authenticated using Authorization Code. Authorization Code is applicable for integrations involving a highly secure back-channel (backend service) and an insecure front channel (web browser).

In facilitator integration,

• Client is any Facilitator (value-adding service) in the GoBiz application.
• User is the merchant (end-user) of the GoBiz application.

Gojek authorizes both client and user.

info

• The section below uses terminologies defined in,
  • RFC 6749: Section 1.1 - Roles
  • RFC 6749: Section 1.4, 3.1, 3.2
  • RFC 2616: Section 1.3 - Terminology
  • OpenID Connect Core 1.0 incorporating errata set 1
• Gojek requires Integrator to provide callback or redirect URIs. Refer RFC 6749: Section 3.1.2 to redirect the user to the client after authorization. :::

The requirements for authorization using the Authorization Code are described in the table given below.

Parameter	Description
Resource Owner	It is the entity that grants access to a protected resource. Value: GoBiz
Resource Server	It is the server that hosts the protected resources. It accepts and responds to the requests from the client using access tokens. GoBiz API is the resource server.
Client	It is the web application that accesses the information of the end-user from GoBiz.
Authorization Server	It is the server that issues access tokens to the client after authenticating the resource owner and obtaining authorization. Value: Gojek
Integrator	It is the organization that integrates the client with GoBiz.
User Agent	It is the interface (browser) used to redirect the end-user to Gojek (for authorization) and back to the client.
Authorization Endpoint	It is used to interact with the resource owner and obtain an authorization grant. The authorization server must first verify the identity of the resource owner. Value: OAUTH_URL/oauth2/auth
Token Endpoint	It is used by the client to refresh token or obtain an access token by presenting its authorization grant. Value: OAUTH_URL/oauth2/token
Access Token	It is the token required to access GoBiz APIs.
ID Token	It is a JSON Web Token (JWT) that contains information about the end-user.

• OAuth 2.0 and OpenID Connect are complex specifications with many security considerations and implications. We recommend you to use a pre-written battle-tested client library that is suitable for the selected language/framework, for developing the client application. You can find a list of libraries at https://oauth.net/code/ (Not maintained by Gojek).

• We strongly encourage you to refer RFC 6819: OAuth 2.0 Threat Model and Security Considerations to ensure secure integration. :::

The image below represents the Gojek Authorization Code workflow.

The subsequent sections describe the steps in the workflow and their significance.

Creating Anti-forgery 'state' Token

A state parameter is required for preventing cross-site request forgery (CSRF) attacks (Refer RFC 6749: Section 10.12). The state parameter is a unique session token created by the client and holds the state between the client and the user agent (browser). When the user is redirected back to the client after successful authentication and consent, the client should cross-verify the state token for legitimacy. Thus, the client ensures that the request is coming from legitimate user agent and not a malicious attacker.

• state must be at least 8 characters long
• state must be URL-safe encoded

Sample Code - Python

Sample code for creating 'state' token

import os
import hashlib
state = hashlib.sha256(os.urandom(10)).hexdigest()[:16]

Building Query String

The different parameters in the authorization request are described in the table given below.

Parameter	Description	Type	Required
client_id	It is a unique identifier given to the client by Gojek during generation of the client credentials.	String	Required
response_type	It should be set to 'code' for authorization code integration.	String	Required
scope	It is used in authorization code requests to request additional levels of access. The value should be at least openid.	String	Required
state	It is a unique session token created for preventing CSRF attacks.	String	Required
redirect_uri	It is the endpoint of the client (backend server). The user is redirected to this URL after authorization. The value should match one of the redirect URIs registered during generation of client credentials.	String	Required
user_type	It is used to specify the user type of the application. Available values : merchant	String	Required
nonce	It is a case-sensitive string value that is used to associate a client session with an ID Token and to mitigate replay attacks.	String	Optional
max_age	It is the maximum age of the authentication session. It forces login if session is older than this value.	Integer	Optional
ui_locales	It is used to specify the end-user's preferred language and script for the user interface. For example: id or en	String	Optional

Sample URL Param - Query String

Sample authorization URL for redirecting the user to Gojek

https://integration-goauth.gojekapi.com/oauth2/auth?
    client_id=my_client_id&
    response_type=code&
    scope=openid&
    redirect_uri=https://client-backend.com/gojek/callback&
    state=0ee05c09e1cda629&
    user_type=merchant

The available scopes or access levels are described in the table given below.

Scope	Scope Description
openid	To read basic token info.
offline	To regenerate access token.
partner:outlet:read	To read outlet data.
partner:outlet:write	To edit or update outlet data.
gofood:catalog:read	To read GoFood menu.
gofood:catalog:write	To modify GoFood menu.
gofood:order:read	To read GoFood order data.
gofood:order:write	To mark an order is ready.
promo:food_promo:read	To retrieve GoFood promotions.
promo:food_promo:write	To modify GoFood promotions.
payment:transaction:read	To read payment transaction.
payment:transaction:write	To modify payment transaction.
payment:pop:read	To read payment PoP data.
mokapos:library:read	To read mokapos libray data.
mokapos:transaction:read	To read mokapos transaction data.
mokapos:reporting:read	To read mokapos reporting data.
mokapos:customer:read	To read mokapos libray data.
mokapos:checkout:write	To update mokapos checkout data.
mokapos:salestype:read	To read mokapos sales type data.

Redirecting User to Gojek Server

The client sends the user to Gojek authorization endpoint (/oauth2/auth) by redirecting the user agent to the Gojek sign-in page (refer to RFC 6749: Section 1.7). This allows the user to login with Gojek credentials and to authorize the client to access their information on Gojek.

Processing Authorization Callback

When the Gojek server authenticates the user and authorizes the client to access information, Gojek generates an authorization code. Gojek then redirects the user to redirect_uri with the code and the state originally sent by the client.

On receiving this callback, the client verifies the state parameter and ensures that the value is same as the one sent earlier.

Sample URL Param - Authorization Callback

Sample URL to which user is redirected after authorization

https://client-backend.com/gojek/callback?
    code=e3q4dqlkjasjdl&
    state=0ee05c09e1cda629

Exchanging Code for Access Token & ID Token

The code returned in the previous step is single-use authorization code and is short-lived (expires in two minutes after receiving the redirection). The client exchanges this code with Gojek to request an access token and an ID token containing information about the user.

A POST request is sent to the /oauth2/token endpoint with following parameters in the request body:

Endpoint = OAUTH_URL/oauth2/token

Request Parameters

JSON Attribute	Description	Type	Required
grant_type	It is the authorization_code as defined in OAuth2 Authorization Code Grant.	String	Required
code	It is the value received as part of redirection to redirect_uri.	String	Required
client_id	It is the client identifier issued by GoJek. It should be the same as the one sent during /oauth2/auth.	String	Required
client_secret	It is the Client Secret issued by GoJek for the client_id.	String	Required
redirect_uri	It is the redirection URI used during the /oauth2/auth call.	String	Required

Sample Request

Sample Request

curl -X POST https://integration-goauth.gojekapi.com/oauth2/token \
  -u "my_client_id:my_client_secret" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=authorization_code" \
  -d "code=e3q4dqlkjasjdl" \
  -d "redirect_uri=https://client-backend.com/gojek/callback"

When the client credentials are successfully verified, the code results in a JSON response with the information given in the table below.

Response Parameters

JSON Attribute	Description	Type
access_token	It is a token used to access GoBiz API.	String
id_token	It is an identifier for the token.	String
expires_in	It is the approximate lifetime (in seconds) of the token that is remaining since receiving the response.	Integer
token_type	It is the type of token returned. It is always Bearer.	String
refresh_token	It is a refresh token for renewing access tokens offline (without user). This is present only if the scope contains offline_access.	String

Sample Response

Sample Response

{
  "access_token": "this_is_the_access_token",
  "expires_in": 3600,
  "token_type": "Bearer",
  "id_token": "this_is_the_token_identifier"
}

Handling Errors

In case of an error, we recommend that you display a user-friendly screen that describes the error, and redirect the user to the login screen so that the user can try to login again.

Error responses and error codes are similar to those defined in RFC 6749: OAuth2.0, except when specified otherwise.

In case of an error during /oauth2/auth redirection, the error is sent to the client backend as one of the query parameters of the redirect_uri, as specified in the OAuth 2.0 RFC.