Jeremy Harris: > > Semi-radical: provide an ACL, router, and transport modifier that > > checks some variable or content for dangerous contents > > We have that. All data provided by an untrusted source, described > as "tainted" for a shorthand.
Tainted variables contain potentially dangerous contents, not actually dangerous contents. Most of the time, the contents of tainted variables are not dangerous, but sometimes they are. I think that it would be useful for Exim to provide assistance in telling the two apart. I say this because I strongly believe that people are going to write Exim configuration code that de-taints variables in brute force ways (and the more that Exim doesn't provide mechanisms to do relatively arbitrary 'safe' de-tainting, the more that people are going to do so). I think it's relatively important to let people guard these de-taintings with safety checks, such as 'is there dangerous content here'. Also, even with relatively safe de-tainting, sometimes I would rather reject funny content immediately. This is actually a relatively popular thing to do today in ad-hoc ways; for example, the Debian 'split' Exim configuration has for years shipped with a set of checks for dangerous characters in local parts. Sysadmins can maybe write these checks in Exim configurations themselves, but in ad-hoc ways and sysadmins probably don't know as much about what things are dangerous (or valid) in various conditions as other people do. - cks -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/