> For that reason I've published another mitigation method
>
> # to be prepended to your mail acl (the ACL referenced
> # by the acl_smtp_mail main config option)
> deny condition = ${if eq{\\}{${substr{-1}{1}{$tls_in_sni}}}}
> deny condition = ${if eq{\\}{${substr{-1}{1}{$tls_in_peerdn}}}}
Thanks very much for that! Works fine on 4.86 (as shipped with Ubuntu
16.04).
On 4.82 as shipped with Ubuntu 14.04 (ick) on a host I unfortunately
can't upgrade quickly, the second deny condition (checking $tls_in_peerdn)
works fine but the first one complains that $tls_in_sni is an unknown
variable:
failed to expand ACL string "${if eq{\\}{${substr{-1}{1}{$tls_in_sni}}}}": unknown variable name "tls_in_sni"
I've compared the documentation for SNI-related variables in the two
versions and see no obvious relevant difference. Am I missing something
obvious?
Jay