This is the Sagan ruleset released 03/17/2011 to coincide with the 0.1.8 release.
You can download it from the following link: https://packetstormsecurity.com/files/download/99418/sagan-rules-03172011-r1.tar.gz
Source: https://packetstormsecurity.com/files/99418/Sagan-Rules-03172011-r1.html