Install gsasl with Homebrew

Project links

• Homepage

Commands and aliases

• gsasl

Project history

The project began in 2002 as libgsasl and became an official GNU package in December 2002. The GNU project page records the initial 0.0.0 release on 2002-10-07, the rename from libgsasl to GNU SASL in 0.0.4, and the opening of GNU web pages with development moved to Savannah.

Early development focused on establishing a clean-room SASL implementation with clear copyright and licensing, then broadening mechanism support. The GNU page lists goals such as thread safety, internationalization through SASLprep, portability, and callbacks that let the embedding application control authorization infrastructure.

The licensing story is part of the project's identity. The GNU SASL page says the library was changed to LGPLv2.1+ because other free SASL implementations existed and the maintainer expected that LGPL terms would invite more help, while the command-line application and tests later moved to GPLv3-or-later.

The project evolved through major protocol additions: GSSAPI support in 2003, SCRAM-SHA-1 experiments in 2009, GS2-KRB5 and SCRAM-SHA-1(-PLUS) in the 2010 stable series, SAML20 and OPENID20 in 2012, SCRAM-SHA-256 in 2021, and a 2.0.0 line in 2022 that dropped obsolete APIs.

Adoption history

GNU SASL's adoption is best visible in other network software. The project page lists free software users including Exim, Mutt, GNU Mailutils, msmtp and mpop, VMime, curl, Jabberd2, and GNU Anubis.

Its adoption pattern is typical of infrastructure libraries: few end users invoke it directly, but maintainers of mail, XMPP, and transfer software package it so that authentication mechanisms are available through a shared implementation rather than duplicated in every client.

The project also tracks portability explicitly. The GNU page mentions Windows resources, a native Visual Studio build in 2008, and release engineering around reproducible tarballs and CI across several GNU/Linux-derived systems in the 2.2 series.

How it is used

Library users embed libgsasl and provide callbacks for authentication and authorization data. The command-line gsasl tool is useful for testing SASL exchanges and for exercising mechanisms outside a full mail or chat client.

The supported mechanism list is broad for a small C library: ANONYMOUS, CRAM-MD5, DIGEST-MD5, EXTERNAL, GS2-KRB5, GSSAPI, LOGIN, NTLM, OPENID20, PLAIN, SCRAM-SHA-1, SCRAM-SHA-1-PLUS, SCRAM-SHA-256, SCRAM-SHA-256-PLUS, SAML20, and SECURID are documented by the project README and GNU page.

Why package nerds care

GNU SASL is package-nerd material because it is a low-level authentication dependency with a CLI attached. It is easy to overlook until a mail client, MTA, or XMPP server needs a specific SASL mechanism or a distro wants one shared, auditable implementation.

Its release history also exposes packaging concerns that library maintainers care about: ABI/API transitions, optional Kerberos/GSS choices, Windows portability, reproducible tarballs, and integration tests against Dovecot and GNU Mailutils.

Timeline

• 2002: Initial 0.0.0 release.
• 2002: Became an official GNU project and moved development to Savannah.
• 2004: 0.2.0 marked a new major release and the library license moved toward LGPL terms.
• 2007: Development moved from CVS to git, and the command-line tool and tests moved to GPLv3-or-later.
• 2010: Stable 1.6.0 added SCRAM-SHA-1(-PLUS) and GS2-KRB5 support.
• 2012: Stable 1.8.0 added SAML20 and OPENID20 support.
• 2021: Stable 1.10.0 added SCRAM-SHA-256 support.
• 2022: Stable 2.0.0 dropped obsolete APIs.

Related projects

• GNU Mailutils is both a related GNU mail package and an integration-test target mentioned in GNU SASL release notes.
• Dovecot appears in later GNU SASL integration tests for GSSAPI behavior.
• GnuTLS and GSS-API implementations such as GNU GSS, MIT Kerberos, Heimdal, and libgssglue are optional or related pieces around secure authentication.

Sources

• https://gitlab.com/gsasl/gsasl/-/raw/master/NEWS
• https://gitlab.com/gsasl/gsasl/-/raw/master/README.md
• https://www.gnu.org/software/gsasl/
• https://www.gnu.org/software/gsasl/manual/html_node/Introduction.html