Crowd provides APIs that allow external services to access resources on a user's behalf using the OAuth 2.0 protocol.

On this page:

• Supported OAuth 2.0 flows
• Security recommendations
• Authorization code with Proof Key for Code Exchange (PKCE)
• Authorization code
• Access Crowd API with access token

Supported OAuth 2.0 flows

We support the following OAuth 2.0 flows:

• Authorization code with Proof Key for Code Exchange (PKCE)

• Authorization code

We don’t support Implicit Grant and Resource Owner Password Credentials flows, as they'll be deprecated in the next OAuth 2.0 specification version. For more information on how these flows work, see the OAuth 2.0 RFC. This should help you understand the flows and choose the right one for you.

Security recommendations

Here are some recommendations to improve security:

• Prevent CSRF attacks: to protect redirect-based flows, the OAuth 2.0 specification recommends using “One-time use CSRF tokens carried in the state parameter, which are securely bound to the user agent” using the state query parameter with each request to the /rest/oauth2/latest/authorize endpoint. This can prevent CSRF attacks.

• Use HTTPS in production: For production environments, use HTTPS for the redirect uri. This is important because OAuth 2.0 bases its security on the transport layer. For more information, see the OAuth 2.0 RFC and the OAuth 2.0 Threat Model RFC. For the same reason, we also enforce HTTPS for the base URL of production environments. You can use insecure URIs and base URLs for staging or development environments by enabling the relevant system properties.

Authorization code with Proof Key for Code Exchange (PKCE)

This flow lets you securely perform the OAuth exchange of client credentials for access tokens on public clients. The following steps and parameters describe our implementation of this flow.

Before you begin

• Register your application in Crowd by creating an incoming link in application links. During registration, you can enable proper scopes to limit the range of resources that the application can access. After creating the link, you should receive the OAuth 2.0 credentials: Client ID and Client secret - keep them secure. For more information, see Configure an incoming link.

• Before starting the flow, generate the state (optional), code_verifier, code_challenge, and code_challenge_method.

Parameters

Here are the parameters you’ll use in this flow.

Making requests to the API with the access token

1. Request an authorization code by redirecting the user to the /rest/oauth2/latest/authorize page with the following query parameters:

   curl https://atlassian.example.com/rest/oauth2/latest/authorize?client_id=CLIENT_ID&redirect_uri=REDIRECT_URI&response_type=code&state=STATE&scope=SCOPE&code_challenge=CODE_CHALLENGE&code_challenge_method=S256

   This is the consent screen that asks the user to approve the application’s request to access their account with the scopes specified in scope. The user is then redirected to the URL specified in redirect_uri. The redirect includes the authorization code, like in the following example:
   

   https://atlassian.example.com/plugins/servlet/oauth2/consent?client_id=CLIENT_ID&redirect_uri=REDIRECT_URI&response_type=code&scope=SCOPE&state=STATE&code_challenge_method=CODE_CHALLENGE_METHOD&code_challenge=CODE_CHALLENGE

2. With the authorization code returned from the previous request, you can request an access_token, with any HTTP client. The following example uses curl:
   

   curl -X POST https://atlassian.example.com/rest/oauth2/latest/token?client_id=CLIENT_ID&code=CODE&grant_type=authorization_code&redirect_uri=REDIRECT_URI&code_verifier=CODE_VERIFIER

   Example response is:

   {
   
    "access_token": "eyJhbGciOiJIUzI1NiJ9.eyJpZCI6IjNmMTQ3NTUzYjg3OTQ2Y2FhMWJhYWJkZWQ0MzgwYTM4In0.EDnpBl0hd1BQzIRP--xEvyW1F6gDuiFranQCvi98b2c",
   
    "token_type": "bearer",
   
    "expires_in": 7200,
   
    "refresh_token": "eyJhbGciOiJIUzI1NiJ9.eyJpZCI6ImMwZTMxYmZjYTI2NWI0YTkwMzBiOGM2OTJjNWIyMTYwIn0.grHOsso3B3kaSxNd0QJfj1H3ayjRUuA75SiEt0usmiM",
   
    "created_at": 1607635748
   
   }

   
   

3. To retrieve a new access_token, use the refresh_token parameter. Refresh tokens may be used even after the access_token itself expires. The following request:

   • Invalidates the existing access_token and refresh_token.

   • Sends new tokens in the response

curl -X POST https://atlassian.example.com/rest/oauth2/latest/token?client_id=CLIENT_ID&client_secret=CLIENT_SECRET&refresh_token=REFRESH_TOKEN&grant_type=refresh_token&redirect_uri=REDIRECT_URI

Example response is:

{

  "access_token": "eyJhbGciOiJIUzI1NiJ9.eyJpZCI6ImJmZjg4MzU5YTVkNGUyZmQ3ZmYwOTEwOGIxNjg4MDA0In0.BocpI91mpUzWskyjxHp57hnyl8ZcHehGJwmaBsGJEMg",

  "token_type": "bearer",

  "expires_in": 7200,

  "refresh_token": "eyJhbGciOiJIUzI1NiJ9.eyJpZCI6Ijg1NjQ1YjA1NGJiYmZkNjVmMDNkMzliYzM0YzQ4MzZjIn0.4MSMIG46zjB9QCV-qCCglgojM5dL7_E2kcqmiV46YQ4",

  "created_at": 1628711391

}

You can now make requests to the API with the access token. For more info, see Access Crowd API with access token below.

Authorization code

This flow lets you securely perform the OAuth 2.0 exchange of client credentials for access tokens on public clients.

Parameters

Here are the parameters you’ll use in this flow:

Access Crowd API with access token

The access token allows you to make requests to the API on behalf of a user. You can put the token in the Authorization header:

curl --header "Authorization: Bearer OAUTH2-TOKEN" "https://atlassian.example.com//rest/admin/1.0/server-info"