doc-exports/docs/ims/api-ref/en-us_topic_0121671869.html

Authentication

Requests for calling an API can be authenticated using either of the following methods:

• Token authentication: Requests are authenticated using tokens.
• AK/SK authentication: Requests are encrypted using AK/SK pairs. AK/SK authentication is recommended because it is more secure than token authentication.

Token Authentication

The validity period of a token is 24 hours. When using a token for authentication, cache it to prevent frequently calling the IAM API used to obtain a user token.

A token specifies temporary permissions in a computer system. During API authentication using a token, the token is added to requests to get permissions for calling the API. You can obtain a token by calling the Obtaining User Token API.

A cloud service can be deployed as either a project-level service or global service.

• For a project-level service, you need to obtain a project-level token. When you call the API, set auth.scope in the request body to project.
• For a global service, you need to obtain a global token. When you call the API, set auth.scope in the request body to domain.

IMS is a project-level service. When you call the API, set auth.scope in the request body to project.

{
    "auth": {
        "identity": {
            "methods": [
                "password"
            ],
            "password": {
                "user": {
                    "name": "username",
                    "password": "********",
                    "domain": {
                        "name": "domainname"
                    }
                }
            }
        },
        "scope": {
            "project": {
                "name": "xxxxxxxx"
            }
        }
    }
}

After a token is obtained, the X-Auth-Token header field must be added to requests to specify the token when calling other APIs. For example, if the token is ABCDEFJ...., X-Auth-Token: ABCDEFJ.... can be added to a request as follows:

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POST https://{{endpoint}}/v3/auth/projects Content-Type: application/json X-Auth-Token: ABCDEFJ....

AK/SK Authentication

AK/SK authentication supports API requests with a body not larger than 12 MB. For API requests with a larger body, token authentication is recommended.

In AK/SK authentication, AK/SK is used to sign requests and the signature is then added to the requests for authentication.

• AK: access key ID, which is a unique identifier used in conjunction with a secret access key to sign requests cryptographically.
• SK: secret access key, which is used in conjunction with an AK to sign requests cryptographically. It identifies a request sender and prevents the request from being modified.

In AK/SK authentication, you can use an AK/SK to sign requests based on the signature algorithm or using the signing SDK.

The signing SDK is only used for signing requests and is different from the SDKs provided by services.

Parent topic: Calling APIs