To update the state of an HMAC key for the specified service account, make a `POST` request
that is scoped to a project. The authenticated user must have
`storage.hmacKeys.update` permission for the project in which the key will be updated.

For general information about HMAC keys in Cloud Storage, see
[HMAC Keys](https://docs.cloud.google.com/storage/docs/authentication/hmackeys.md.txt).

## HTTP Request

```
POST https://storage.googleapis.com/?Action=UpdateAccessKey&AccessKeyId=AccessKeyId&Status=Status
```

### Query string parameters

| Parameter | Description | Required |
|---|---|---|
| `Action` | The HMAC key operation to be performed. | Yes |
| `AccessKeyId` | Access Key ID for the HMAC key. | Yes |
| `Status` | Update the status of this HMAC key. Valid values are: - `Active`: This key can be used to sign requests. - `Inactive`: Requests signed with this key will be denied. | Yes |
| `UserName` | The email address of a service account in the project. This is only used to validate that the specified service account owns the key before updating. The service account owner of a key cannot be updated. | No |

## Request headers

Use the [common request headers](https://docs.cloud.google.com/storage/docs/xml-api/post-hmac-key.md.txt#request-headers).

## Response

If successful, this method returns a response body with the following structure:

```
<UpdateAccessKeyResponse>
 <ResponseMetadata>
    <RequestId>EXAMPLE-REQUEST-ID</RequestId>
 </ResponseMetadata>
</UpdateAccessKeyResponse>
```

| Parameter name | Value | Description |
|---|---|---|
| `RequestId` | `string` | Unique ID for the request. |