ICA file signing
StoreFront provides the option to digitally sign ICA files so that versions of Citrix Workspace app that support this feature can verify that the file originates from a trusted source. When file signing is enabled in StoreFront, the ICA file generated when a user starts an application is signed using a certificate from the personal certificate store of the StoreFront server. ICA files can be signed using any hash algorithm supported by the operating system running on the StoreFront server. The digital signature is ignored by clients that do not support the feature or are not configured for ICA file signing. If the signing process fails, the ICA file is generated without a digital signature and sent to Citrix Workspace app, the configuration of which determines whether the unsigned file is accepted.
To be used for ICA file signing with StoreFront, certificates must include the private key and be within the allowed validity period. If the certificate contains a key usage extension, this must allow the key to be used for digital signatures. Where an extended key usage extension is included, it must be set to code signing or server authentication.
For ICA file signing, Citrix recommends using a code signing or SSL signing certificate obtained from a public certification authority or from your organization’s private certification authority. If you are unable to obtain a suitable certificate from a certification authority, you can either use an existing SSL certificate, such as a server certificate, or create a new root certification authority certificate and distribute it to users’ devices.
ICA file signing is disabled by default in stores. To enable ICA file signing, you edit the store configuration file and execute Windows PowerShell commands. For more information about enabling ICA file signing in Citrix Workspace app for Windows, see ICA File Signing.
The StoreFront and PowerShell consoles cannot be open at the same time. Always close the StoreFront management console before using the PowerShell console to administer your StoreFront configuration. Likewise, close all instances of PowerShell before opening the StoreFront console.
Ensure that the certificate you want to use to sign ICA files is available in the Citrix Delivery Services certificate store on the StoreFront server and not the current user’s certificate store.
Enable signing using the
$storeService = Get-STFStoreService Set-STFStoreService $storeService -IcaFileSigning $true -IcaFileSigningCertificateThumbprint [certificatethumbprint] <!--NeedCopy-->
Where [certificatethumbprint] is the digest (or thumbprint) of the certificate data produced by the hash algorithm.
If you want to use a hash algorithm other than SHA-1, add a parameter -IcaFileSigningHashAlgorithm set to sha256, sha384, or sha512, as required.