X-Git-Url: https://git.exim.org/users/heiko/exim.git/blobdiff_plain/8c8b8274fc537766da72eab2f79a62d1603d6638..4466248715466b6f251454283642b74de65e9d9a:/doc/doc-txt/experimental-spec.txt diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt index d0503d9e8..1ec323433 100644 --- a/doc/doc-txt/experimental-spec.txt +++ b/doc/doc-txt/experimental-spec.txt @@ -69,7 +69,8 @@ starts retrying to fetch an OCSP proof some time before its current proof expires. The downside is that it requires server support. If Exim is built with EXPERIMENTAL_OCSP and it was built with OpenSSL, -then it gains a new global option: "tls_ocsp_file". +or with GnuTLS 3.1.3 or later, then it gains a new global option: +"tls_ocsp_file". The file specified therein is expected to be in DER format, and contain an OCSP proof. Exim will serve it as part of the TLS handshake. This @@ -83,14 +84,21 @@ contents are always valid. Exim will expand the "tls_ocsp_file" option on each connection, so a new file will be handled transparently on the next connection. -Exim will check for a valid next update timestamp in the OCSP proof; -if not present, or if the proof has expired, it will be ignored. +Under OpenSSL Exim will check for a valid next update timestamp in the +OCSP proof; if not present, or if the proof has expired, it will be +ignored. -Also, given EXPERIMENTAL_OCSP and OpenSSL, the smtp transport gains -a "hosts_require_ocsp" option; a host-list for which an OCSP Stapling -is requested and required for the connection to proceed. The host(s) -should also be in "hosts_require_tls", and "tls_verify_certificates" -configured for the transport. +Also, given EXPERIMENTAL_OCSP, the smtp transport gains two options: +- "hosts_require_ocsp"; a host-list for which an OCSP Stapling +is requested and required for the connection to proceed. The default +value is empty. +- "hosts_request_ocsp"; a host-list for which (additionally) an OCSP +Stapling is requested (but not necessarily verified). The default +value is "*" meaning that requests are made unless configured +otherwise. + +The host(s) should also be in "hosts_require_tls", and +"tls_verify_certificates" configured for the transport. For the client to be able to verify the stapled OCSP the server must also supply, in its stapled information, any intermediate @@ -99,6 +107,9 @@ of the server certificate. There may be zero or one such. These intermediate certificates should be added to the server OCSP stapling file (named by tls_ocsp_file). +Note that the proof only covers the terminal server certificate, +not any of the chain from CA to it. + At this point in time, we're gathering feedback on use, to determine if it's worth adding complexity to the Exim daemon to periodically re-fetch OCSP files and somehow handling multiple files. @@ -107,8 +118,8 @@ OCSP files and somehow handling multiple files. OCSP server is supplied. The server URL may be included in the server certificate, if the CA is helpful. - One fail mode seen was the OCSP Signer cert expiring before the end - of vailidity of the OCSP proof. The checking done by Exim/OpenSSL + One failure mode seen was the OCSP Signer cert expiring before the end + of validity of the OCSP proof. The checking done by Exim/OpenSSL noted this as invalid overall, but the re-fetch script did not. @@ -460,9 +471,13 @@ which the spf condition should succeed. Valid strings are: processing, including Exim's SPF processing. You may defer messages when this occurs. (Changed in 4.83) + o err_temp Same as permerror, deprecated in 4.83, will be + removed in a future release. + o err_perm Same as temperror, deprecated in 4.83, will be + removed in a future release. You can prefix each string with an exclamation mark to invert -is meaning, for example "!fail" will match all results but +its meaning, for example "!fail" will match all results but "fail". The string list is evaluated left-to-right, in a short-circuit fashion. When a string matches the outcome of the SPF check, the condition succeeds. If none of the listed @@ -1083,10 +1098,16 @@ Proxy Protocol server at 192.168.1.2 will look like this: 3. In the ACL's the following expansion variables are available. -proxy_host_address The src IP of the proxy server making the connection -proxy_host_port The src port the proxy server is using -proxy_session Boolean, yes/no, the connected host is required to use - Proxy Protocol. +proxy_host_address The (internal) src IP of the proxy server + making the connection to the Exim server. +proxy_host_port The (internal) src port the proxy server is + using to connect to the Exim server. +proxy_target_address The dest (public) IP of the remote host to + the proxy server. +proxy_target_port The dest port the remote host is using to + connect to the proxy server. +proxy_session Boolean, yes/no, the connected host is required + to use Proxy Protocol. There is no expansion for a failed proxy session, however you can detect it by checking if $proxy_session is true but $proxy_host is empty. As @@ -1106,6 +1127,13 @@ an example, in my connect ACL, I have: [$sender_host_address] through proxy protocol \ host $proxy_host_address + # Possibly more clear + warn logwrite = Remote Source Address: $sender_host_address:$sender_host_port + logwrite = Proxy Target Address: $proxy_target_address:$proxy_target_port + logwrite = Proxy Internal Address: $proxy_host_address:$proxy_host_port + logwrite = Internal Server Address: $received_ip_address:$received_port + + 4. Runtime issues to be aware of: - Since the real connections are all coming from your proxy, and the per host connection tracking is done before Proxy Protocol is