DACS is a light-weight single sign-on and rule-based access control system for web servers and server-based software. DACS makes secure resource sharing and remote access via the web easier, safer, and more efficient. DACS is particularly well suited to providing single sign-on across organizational or departmental web servers, and to limiting access to their web-based resources.
DACS is also an authentication and cryptographic toolkit, providing standard and state-of-the-art functionality.
Released under an open source license, DACS gives you:
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DACS works with virtually any authentication method and unifies an assortment of accounts into a single identity. You can leverage the user accounts and authentication methods that you already use, or introduce new ones easily. Out of the box, DACS lets users authenticate using: DACS username/password, X.509 client certificate, self-issued or managed Information Card, one-time password, Unix account, Apache password files, Windows NTLM, ADS/LDAP, CAS, HTTP, PAM, Basic or Digest Auth, special URLs, two-factor authentication, expressions, and more.
Our highest priority is for DACS to remain a secure, stable, and well-documented system.
Once a user has signed on through DACS, he will be recognized throughout a federation of web servers.
While it shares many of the advantages of other single sign-on systems, DACS offers some unique features and is more efficient, and simpler to understand, customize, and administer compared to the heavy-weight, enterprise-level alternatives. If your single sign-on needs are modest, or if you are not even certain what they are, you should look at DACS. DACS does the hardest parts for you - all that you need to do is configuration and "look & feel" customizations.
DSS is pleased to announce the release of DACS 1.4.42. General download information, links to the latest tarfiles, and details about the latest release are available. It is important to review the Post-Release Notes before building DACS. All sites are encouraged to upgrade.
Apache 2.4.39 (with APR 1.6.5 and APR-util 1.6.1) has been released, which fixes a significant bug. It is currently being tested with DACS.
The Apache HTTP Server Project has discontinued all development and patch review of the 2.2.x series of releases. The final release, 2.2.34, was published in July 2017. No further evaluation of security risks will be published for 2.2.x releases. Because of this, DACS 1.4.40 is the final release to officially support and be tested with the Apache 2.2 series.
The latest release of DACS was tested with OpenSSL 1.1.1a.
OpenSSL 1.1.1b, which includes the latest security and bug fixes, was recently released and appears to work with DACS.
DACS has transitioned from OpenSSL 1.0.2 to the OpenSSL 1.1.1 series, which is the latest stable version of OpenSSL (and supported until 11-Sep-2023). Users of OpenSSL 1.0.2 and 1.1.0 have been encouraged to upgrade to 1.1.1 as soon as possible. Support for OpenSSL 0.9.8, 1.0.0, and 1.0.1 has been officially discontinued and those versions should not be used.
System admins should be aware of CVE-2017-3737, CVE-2017-3736, CVE-2017-9798, and CVE-2017-1000364 (and related security vulnerabilities) that are not directly related to DACS but may affect its platforms. CVE-2017-7494, a Samba security vulnerability, should not affect DACS. DACS can use Samba for optional authentication functionality but never in a server capacity. On 7-Dec-2017, users of OpenSSL 1.0.2 were advised to upgrade to 1.0.2n. OpenSSL versions 1.0.2m, 1.0.2k, and 1.1.0d address earlier security defects (CVE-2017-373[0-6]).
Since DACS and other web-based systems may use HTTP cookies for a variety of purposes, administrators should review CERT Vulnerability Note VU#804060 (24-Sep-2015). When deployed as recommended, all communication involving DACS-protected resources must be conducted over SSL/TLS connections, including those that send or return HTTP cookies.
In early 2011, Microsoft announced that it would not support CardSpace (aka, Infocards and Information Cards) starting with Windows 8. CardSpace has been the most widely available identity selector for using Information Cards. The implementation of Infocards support within DACS remains in the code base and is documented, but is no longer being actively tested and maintained (neither are the demos). Support for Information Cards within DACS will likely be removed eventually. You may find that other Infocard and CardSpace related projects have been terminated and their web pages are out of date or deleted. See: On the Demise of CardSpace // Open Cardspace opportunity // Personal Reflections on the CardSpace Journey // From CardSpace to Verified Claims // Change will come: the present is untenable // The Clay Feet of Giants? // RIP, Windows CardSpace. Hello, U-Prove // U-Prove.
A draft of a paper that describes some recent work, Time-Gated Mutual Authentication: System Architecture is occasionally revised.
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