<p>Uploads an X.509 signing certificate and associates it with the specified IAM user. Some Amazon Web Services services require you to use certificates to validate requests that are signed with a corresponding private key. When you upload the certificate, its default status is <code>Active</code>.</p> <p>For information about when you would use an X.509 signing certificate, see <a href="https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_server-certs.html">Managing server certificates in IAM</a> in the <i>IAM User Guide</i>.</p> <p>If the <code>UserName</code> is not specified, the IAM user name is determined implicitly based on the Amazon Web Services access key ID used to sign the request. This operation works for access keys under the Amazon Web Services account. Consequently, you can use this operation to manage Amazon Web Services account root user credentials even if the Amazon Web Services account has no associated users.</p> <note> <p>Because the body of an X.509 certificate can be large, you should use POST rather than GET when calling <code>UploadSigningCertificate</code>. For information about setting up signatures and authorization through the API, see <a href="https://docs.aws.amazon.com/general/latest/gr/signing_aws_api_requests.html">Signing Amazon Web Services API requests</a> in the <i>Amazon Web Services General Reference</i>. For general information about using the Query API with IAM, see <a href="https://docs.aws.amazon.com/IAM/latest/UserGuide/IAM_UsingQueryAPI.html">Making query requests</a> in the <i>IAM User Guide</i>.</p> </note>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}