X-Git-Url: https://git.exim.org/users/heiko/exim.git/blobdiff_plain/1922a912d23fc06ee7fb0d22d9cf3e633a4713dc..c85476e9d9f9002927fc3e2a6a12005423359ff1:/doc/doc-txt/openssl.txt?ds=sidebyside diff --git a/doc/doc-txt/openssl.txt b/doc/doc-txt/openssl.txt index e4f5d854c..7bcd47907 100644 --- a/doc/doc-txt/openssl.txt +++ b/doc/doc-txt/openssl.txt @@ -36,12 +36,23 @@ 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. +If you pick a location shared amongst various local packages, such as +`/usr/local` on Linux, then the new OpenSSL will be used by all of those +packages. If that's what you want, great! If instead you want to +ensure that only software you explicitly set to use the newer OpenSSL +will try to use the new OpenSSL, then stick to something like +`/opt/openssl`. + ./config --prefix=/opt/openssl --openssldir=/etc/ssl \ -L/opt/openssl/lib -Wl,-R/opt/openssl/lib \ enable-ssl-trace shared make make install +On some systems, the linker uses `-rpath` instead of `-R`; on such systems, +replace the parameter starting `-Wl` with: `-Wl,-rpath,/opt/openssl/lib`. +There are more variations on less common systems. + You now have an installed OpenSSL under /opt/openssl which will not be used by any system programs. @@ -94,6 +105,22 @@ is to run: readelf -d $(which exim) | grep RPATH +It is important to use `RPATH` and not `RUNPATH`! + +The gory details about `RUNPATH` (skip unless interested): +The OpenSSL library might be opened indirectly by some other library +which Exim depends upon. If the executable does have `RUNPATH` then +that will inhibit using either of `RPATH` or `RUNPATH` from the +executable for finding the OpenSSL library when that other library tries +to load it. +In fact, if the intermediate library has a `RUNPATH` stamped into it, +then this will block `RPATH` too, and will create problems with Exim. +If you're in such a situation, and those libraries were supplied to you +instead of built by you, then you're reaching the limits of sane +repairability and it's time to prioritize rebuilding your mail-server +hosts to be a current OS release which natively pulls in an +upstream-supported OpenSSL, or stick to the OS releases of Exim. + Very Advanced -------------