Ports used by GnuPG [VS-]Desktop

In principle, GnuPG [VS-]Desktop can be used without a network connection and is therefore also suitable for air-gapped systems. Depending on the configuration, the following ports may be required:

LDAP queries for OpenPGP certificates, if explicitly configured (TCP):

• LDAP (Port 389) for unsecured connections or connections secured with STARTTLS.
• LDAPS (Port 636) for connections secured with TLS.

Web Key Directory queries for OpenPGP certificates, active by default:

• HTTPS (port 443)

When using and checking S/MIME certificates using CRLs or the Online Certificates Status Protocol (OCSP):

• HTTP (port 80)
• HTTPS (port 443)

Public keyserver queries for OpenPGP certificates (not used by GnuPG [VS-]Desktop by default), via Horowitz Key-Server Protocol (HKP)

• HKP (port 11371)