X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/c1e794ba50d0d5a73529412929228ae5c5d09073..1f6d19d2743e5243b1a71302d8044ea7fa90cf89:/doc/doc-txt/NewStuff?ds=inline diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 3ca10e84f..e33d2858c 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -6,17 +6,149 @@ Before a formal release, there may be quite a lot of detail so that people can test from the snapshots or the CVS before the documentation is updated. Once the documentation is updated, this file is reduced to a short list. -Version 4.78 +Version 4.81 +------------ + + 1. New command-line option -bI:sieve will list all supported sieve extensions + of this Exim build on standard output, one per line. + ManageSieve (RFC 5804) providers managing scripts for use by Exim should + query this to establish the correct list to include in the protocol's + SIEVE capability line. + + 2. If the -n option is combined with the -bP option, then the name of an + emitted option is not output, only the value (if visible to you). + For instance, "exim -n -bP pid_file_path" should just emit a pathname + followed by a newline, and no other text. + + 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now + has a "tls_dh_min_bits" option, to set the minimum acceptable number of + bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites) + acceptable for security. (Option accepted but ignored if using OpenSSL). + Defaults to 1024, the old value. May be lowered only to 512, or raised as + far as you like. Raising this may hinder TLS interoperability with other + sites and is not currently recommended. Lowering this will permit you to + establish a TLS session which is not as secure as you might like. + + Unless you really know what you are doing, leave it alone. + + 4. If not built with DISABLE_DNSSEC, Exim now has the main option + dns_use_dnssec; if set to 1 then Exim will initialise the resolver library + to send the DO flag to your recursive resolver. If you have a recursive + resolver, which can set the Authenticated Data (AD) flag in results, Exim + can now detect this. + + Current status: work-in-progress; $sender_host_dnssec variable added. + + 5. DSCP support for outbound connections: on a transport using the smtp driver, + set "dscp = ef", for instance, to cause the connections to have the relevant + DSCP (IPv4 TOS or IPv6 TCLASS) value in the header. Supported values depend + upon system libraries. "exim -bI:dscp" to list the ones Exim knows of. + You can also set a raw number 0..0x3F. + + +Version 4.80 ------------ 1. New authenticator driver, "gsasl". Server-only (at present). This is a SASL interface, licensed under GPL, which can be found at http://www.gnu.org/software/gsasl/. This system does not provide sources of data for authentication, so - careful use needs to be made of the conditions in Exim. Note that - this can not yet be used as a drop-in replacement for Cyrus SASL, as - Exim is currently unable to construct strings with embedded NULs for - use as keys in lookups against sasldb2. + careful use needs to be made of the conditions in Exim. + + 2. New authenticator driver, "heimdal_gssapi". Server-only. + A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME + is no longer honoured for setuid programs by Heimdal. Use the + "server_keytab" option to point to the keytab. + + 3. The "pkg-config" system can now be used when building Exim to reference + cflags and library information for lookups and authenticators, rather + than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and + "LOOKUP_LIBS" directly. Similarly for handling the TLS library support + without adjusting "TLS_INCLUDE" and "TLS_LIBS". + + In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to + find the headers and libraries for PCRE. + + 4. New expansion variable $tls_bits. + + 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will + be joined together with ASCII NUL characters to construct the key to pass + into the DBM library. Can be used with gsasl to access sasldb2 files as + used by Cyrus SASL. + + 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1. + + Avoid release 1.0.1a if you can. Note that the default value of + "openssl_options" is no longer "+dont_insert_empty_fragments", as that + increased susceptibility to attack. This may still have interoperability + implications for very old clients (see version 4.31 change 37) but + administrators can choose to make the trade-off themselves and restore + compatibility at the cost of session security. + + 7. Use of the new expansion variable $tls_sni in the main configuration option + tls_certificate will cause Exim to re-expand the option, if the client + sends the TLS Server Name Indication extension, to permit choosing a + different certificate; tls_privatekey will also be re-expanded. You must + still set these options to expand to valid files when $tls_sni is not set. + + The SMTP Transport has gained the option tls_sni, which will set a hostname + for outbound TLS sessions, and set $tls_sni too. + + A new log_selector, +tls_sni, has been added, to log received SNI values + for Exim as a server. + + 8. The existing "accept_8bitmime" option now defaults to true. This means + that Exim is deliberately not strictly RFC compliant. We're following + Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default. + Those who disagree, or know that they are talking to mail servers that, + even today, are not 8-bit clean, need to turn off this option. + + 9. Exim can now be started with -bw (with an optional timeout, given as + -bw). With this, stdin at startup is a socket that is + already listening for connections. This has a more modern name of + "socket activation", but forcing the activated socket to fd 0. We're + interested in adding more support for modern variants. + +10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix + for numbers indicates multiplication by 1024^3. + +11. The GnuTLS support has been revamped; the three options gnutls_require_kx, + gnutls_require_mac & gnutls_require_protocols are no longer supported. + tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority + string, documentation for which is at: + http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html + + SNI support has been added to Exim's GnuTLS integration too. + + For sufficiently recent GnuTLS libraries, ${randint:..} will now use + gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness. + +12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file + is now available. If the contents of the file are valid, then Exim will + send that back in response to a TLS status request; this is OCSP Stapling. + Exim will not maintain the contents of the file in any way: administrators + are responsible for ensuring that it is up-to-date. + + See "experimental-spec.txt" for more details. + +13. ${lookup dnsdb{ }} supports now SPF record types. They are handled + identically to TXT record lookups. + +14. New expansion variable $tod_epoch_l for higher-precision time. + +15. New global option tls_dh_max_bits, defaulting to current value of NSS + hard-coded limit of DH ephemeral bits, to fix interop problems caused by + GnuTLS 2.12 library recommending a bit count higher than NSS supports. + +16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier. + Option can now be a path or an identifier for a standard prime. + If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23". + Set to "historic" to get the old GnuTLS behaviour of auto-generated DH + primes. + +17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS). + Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL + install was not built with OPENSSL_NO_SSL2 ("no-ssl2"). Version 4.77