ssscache

ssscache is a caching component associated with the System Security Services Daemon (SSSD) used on Linux and other Unix-like systems. It maintains a local cache of identity and authentication data retrieved from remote identity providers such as LDAP directories, Active Directory, or Kerberos.

The cache aims to improve authentication performance and provide offline access when the remote directory is temporarily unavailable. Cached entries typically include user and group information, as well as domain and host data used by NSS and PAM operations.

Management is handled by a dedicated command-line utility, sss_cache (sometimes referred to as ssscache), which can populate, refresh, or clear the cache. Admins can preload entries, force a refresh after changes in the directory, or flush the cache to address inconsistencies.

Storage location and format: on-disk cache data is stored under the system's SSSD data directory (commonly /var/lib/sss/ or /var/cache/sss/), with permissions restricting access to privileged users. The exact layout is implementation-specific and may vary by distribution.

Relation and history: ssscache is part of the SSSD project, which provides centralized identity, authentication, and authorization services. It is used in environments that require consistent identity data across heterogeneous directory services.

See also: System Security Services Daemon (SSSD), LDAP, Active Directory, Kerberos, NSS.