Software
skarnet.org

nsss

What is it ?

nsss is an implementation of a subset of the pwd.h, group.h and shadow.h family of functions, performing user database access on Unix systems.

Usually, user database access via getpwnam() and similar function is provided by the system's libc. However, not all libcs implement a configurable backend for the user/group database. For instance the musl libc, on Linux, only supports the standard /etc/passwd mechanism; it also supports the nscd protocol but this is not quite enough to implement the full set of database access functions with certain backends (such as a LDAP server).

nsss is a secure implementation of configurable user/group/shadow database access, providing getpwnam() et al. functionality by communicating over a Unix domain socket with a daemon; the daemon can perform lookups in any database it chooses.

Unlike NSS, nsss does not perform dynamic module loading, only adds a small footprint to the application's binary, and does not add any complex decision engine into the client's address space. Applications can be statically linked against the nsss library, and still benefit from configurable user database access functions.

• An overview of nsss

Installation

Requirements

• A POSIX-compliant system with a standard C development environment
• GNU make, version 3.81 or later
• skalibs version 2.6.5.0 or later. It's a build-time requirement. It's also a run-time requirement if you link against the shared version of the skalibs library.

Licensing

nsss is free software. It is available under the ISC license.

Download

• The current released version of nsss is 0.0.1.0.
• Alternatively, you can checkout a copy of the nsss git repository:

   git clone git://git.skarnet.org/nsss 

• There's also a GitHub mirror of the nsss git repository.

Compilation

• See the enclosed INSTALL file for installation details.

Upgrade notes

• This page lists the differences to be aware of between the previous versions of nsss and the current one.

Reference

Commands

Libraries

• The nsss library interface
• The following primitives are also implemented:
  • endpwent()
  • setpwent()
  • getpwent()
  • getpwent_r()
  • getpwuid()
  • getpwuid_r()
  • getpwnam()
  • getpwnam_r()
  • endgrent()
  • setgrent()
  • getgrent()
  • getgrent_r()
  • getgrgid()
  • getgrgid_r()
  • getgrnam()
  • getgrnam_r()
  • endspent()
  • setspent()
  • getspent()
  • getspent_r()
  • getspnam()
  • getspnam_r()

nsss discussion

• nsss is discussed on the skaware mailing-list.