diff options
Diffstat (limited to 'doc/doc-docbook/spec.xfpt')
| -rw-r--r-- | doc/doc-docbook/spec.xfpt | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 37bfeb3f3..ab13a427b 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -25761,7 +25761,11 @@ See &<<SECTresumption>>& for details. .cindex "TLS" SNI .cindex SNI "setting in client" .vindex "&$tls_sni$&" -If this option is set then it sets the $tls_out_sni variable and causes any +If this option is set +.new +and the connection is not DANE-validated +.wen +then it sets the $tls_out_sni variable and causes any TLS session to pass this value as the Server Name Indication extension to the remote side, which can be used by the remote side to select an appropriate certificate and private key for the session. @@ -29395,6 +29399,11 @@ nothing more to it. Choosing a sensible value not derived insecurely is the only point of caution. The &$tls_out_sni$& variable will be set to this string for the lifetime of the client connection (including during authentication). +.new +If DAVE validated the connection attempt then the value of the &%tls_sni%& option +is forced to the domain part of the recipient address. +.wen + Except during SMTP client sessions, if &$tls_in_sni$& is set then it is a string received from a client. It can be logged with the &%log_selector%& item &`+tls_sni`&. @@ -29692,7 +29701,7 @@ by (a) is thought to be smaller than that of the set of root CAs. It also allows the server to declare (implicitly) that connections to it should use TLS. An MITM could simply fail to pass on a server's STARTTLS. -DANE scales better than having to maintain (and side-channel communicate) copies of server certificates +DANE scales better than having to maintain (and communicate via side-channel) copies of server certificates for every possible target server. It also scales (slightly) better than having to maintain on an SMTP client a copy of the standard CAs bundle. It also means not having to pay a CA for certificates. @@ -29837,6 +29846,7 @@ If DANE is requested and useable (see above) the following transport options are tls_verify_certificates tls_crl tls_verify_cert_hostnames + tls_sni .endd If DANE is not usable, whether requested or not, and CA-anchored |