This solutions assumes that the SSL Certificate has been installed through IIS manager and must be assigned to Citrix Secure Gateway.
To assign SSL certificate to Citrix Secure Gateway, perform the following steps:
1. Run the Secure Gateway Configuration Wizard:
2. Select Start > All Programs > Administration Tools > Secure Gateway Configuration Wizard.
3. Click OK to accept the product selection.
4. Click Next to accept the configuration type.
5. Select the Server Certificate installed through IIS.
6. Click View to ensure you have selected the one with the new expiry date.
7. Click Next to accept the certificate.
8. Click Next to accept inbound client connections on the configured TCP port.
9. Click Next to accept outbound connections.
10. Click Next to accept the existing STA configuration.
11. Click Next to accept the Web Interface options.
12. Click OK to accept the logging level.
13. Click Finish to restart the Secure Gateway service.
For more information, please refer to Citrix Support