OpenSSL ======= The OpenSSL Project documents their supported releases at . The Exim Maintainers are unwilling to try to support Exim built with a version of a critical security library which is unmaintained. Thus as versions of OpenSSL become unsupported by OpenSSL, they become unsupported by Exim. Exim might build with older releases of OpenSSL, but that's risky behaviour. If your operating system vendor continues to ship an older version of OpenSSL and is diligently backporting security fixes, and they support Exim, then they will be backporting fixes to their packages of Exim too. If you wish to stick purely to packages of OpenSSL, then stick to packages of Exim too. If someone maintains "backports", that is worth exploring too. Note that a number of OSes use Exim with GnuTLS, not OpenSSL. Otherwise, assuming that your operating system has old OpenSSL, and you wish to use current Exim with OpenSSL, then you need to build and install your own, without interfering with the system libraries. Fortunately, this is easy. So this only applies if you build Exim yourself. Build ----- Extract the current source of OpenSSL. Change into that directory. This assumes that `/opt/openssl` is not in use. If it is, pick something else. `/opt/exim/openssl` perhaps. ./config --prefix=/opt/openssl --openssldir=/etc/ssl \ -L/opt/openssl/lib -Wl,-R/opt/openssl/lib \ enable-ssl-trace make make install You now have an installed OpenSSL under /opt/openssl which will not be used by any system programs. When you copy `src/EDITME` to `Local/Makefile` to make your build edits, choose the pkg-config approach in that file, but also tell Exim to add the relevant directory into the rpath stamped into the binary: SUPPORT_TLS=yes USE_OPENSSL_PC=openssl EXTRALIBS_EXIM=-ldl -Wl,-rpath,/opt/openssl/lib The -ldl is needed by OpenSSL 1.1+ on Linux and is not needed on most other platforms. Then tell pkg-config how to find the configuration files for your new OpenSSL install, and build Exim: export PKG_CONFIG_PATH=/opt/openssl/lib/pkgconfig make sudo make install (From Exim 4.89, you can put that `PKG_CONFIG_PATH` directly into your `Local/Makefile` file.) Confirming ---------- Run: exim -d-all+expand --version and look for the `Library version: OpenSSL:` lines. To look at the libraries _probably_ found by the linker, use: ldd $(which exim) # most platforms otool -L $(which exim) # MacOS although that does not correctly handle restrictions imposed upon executables which are setuid. If the `chrpath` package is installed, then: chrpath -l $(which exim) will show the DT_RPATH stamped into the binary. Your `binutils` package should come with `readelf`, so an alternative is to run: readelf -d $(which exim) | grep RPATH Very Advanced ------------- You can not use $ORIGIN for portably packing OpenSSL in with Exim with normal Exim builds, because Exim is installed setuid which causes the runtime linker to ignore $ORIGIN in DT_RPATH. _If_ following the steps for a non-setuid Exim, _then_ you can use: EXTRALIBS_EXIM=-ldl '-Wl,-rpath,$$ORIGIN/../lib' The doubled `$$` is needed for the make(1) layer and the quotes needed for the shell invoked by make(1) for calling the linker. Note that this is sufficiently far outside normal that the build-system doesn't support it by default; you'll want to drop a symlink to the lib directory into the Exim release top-level directory, so that lib exists as a sibling to the build-$platform directory.