After an access token is generated, sometimes you might have to refresh or renew the old token due to expiration or security concerns. You use the refresh token grant when a new access token is needed. With this grant type, the refresh token acts as credentials that are issued to the client by the authorization server. Issuing a refresh token is optional. If the authorization server issues a refresh token, it is included when issuing an access token. Refresh tokens are issued for all other grant types other than the implicit grant as recommended by the OAuth 2.0 specification.
Tip: Be sure to keep the refresh token private, similar to the access token as this token issues access tokens without user interactions.
To use this grant type, you need a refresh token, using which you can get a new access token and a refresh token. This can be done by issuing a REST call to the Token API through a REST client like cURL, with the following parameters:
- The Token API URL is
https://gateway.api.cloud.wso2.com/token
. - payload -
"grant_type=refresh_token&refresh_token=<retoken>"
. Replace the<retoken>
value with the refresh token that you have. - headers -
Authorization :Basic <base64 encoded string of consumer-key:consumer-secret>, Content-Type: application/x-www-form-urlencoded
. Replace<base64-encoded string-of-consumer-key:consumer-secret>
as appropriate.
For example, the following cURL command can be used to access the Token API and grant a refresh token.
curl -k -d "grant_type=refresh_token&refresh_token=<retoken>" -H "Authorization: Basic SVpzSWk2SERiQjVlOFZLZFpBblVpX2ZaM2Y4YTpHbTBiSjZvV1Y4ZkM1T1FMTGxDNmpzbEFDVzhh, Content-Type: application/x-www-form-urlencoded" https://gateway.api.cloud.wso2.com/token
When you use the refresh grant to get a new access token, the refresh token is renewed by default. The new refresh token has a new expiry time and the previous refresh token becomes inactive.
Revoking access tokens
After issuing an access token, a user or an admin can revoke it in case of theft or a security violation. You can do this by calling the Revoke API using a REST Client. The Revoke API's endpoint URL is https://gateway.api.cloud.wso2.com/revoke
. The parameters required to invoke this API are as follows:
- The token to be revoked
- Consumer key and consumer secret key. Must be encoded using Base64 algorithm
For example:
curl -k -d "token=<access-token-to-be-revoked>" -H "Authorization: Basic Base64Encoded(Consumer-key:consumer-secret)" https://gateway.api.cloud.wso2.com/revoke