X-Git-Url: https://git.exim.org/users/heiko/exim.git/blobdiff_plain/eb57651e8badf0b65af0371732e42f2ee5c7772c..4466248715466b6f251454283642b74de65e9d9a:/doc/doc-txt/experimental-spec.txt diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt index f21609662..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.