I have spent some time searching online but none of what I found seems to help.

I'm running CentOS 6 64bit and would like to compile Apache with mod_ssl and need to link it to my own OpenSSL build (which is newer than the OS provided version).

OpenSSL 1.1.0i is configured with:

./config --prefix=/opt/openssl-1.1.0 --openssldir=/opt/openssl-1.1.0 shared

Apache 2.4 is configured with:

./configure --enable-layout=mycustomlayout \
    --prefix=/opt/httpd-2.4.34 \
    --exec-prefix=/opt/httpd-2.4.34 \
    --with-mpm=prefork \
    --enable-so \
    --enable-ssl \
    --with-ssl=/opt/openssl-1.1.0 \
    --enable-cgi \
    --enable-http2 \
    --enable-proxy-http2 \

It appears to compile just fine but mod_ssl isn't aware of where OpenSSL 1.1.0 is installed:

[root@host .libs]# ldd ./mod_ssl.so | grep -iP 'ssl|crypto'
    libssl.so.1.1 => not found
    libcrypto.so.1.1 => not found

And so only works when you explicitly tell it where to look:

[root@host .libs]# export LD_LIBRARY_PATH=/opt/openssl-1.1.0/lib:$LD_LIBRARY_PATH
[root@host .libs]# ldd ./mod_ssl.so | grep -iP 'ssl|crypto'
    libssl.so.1.1 => /opt/openssl-1.1.0/lib/libssl.so.1.1 (0x00007f069149a000)
    libcrypto.so.1.1 => /opt/openssl-1.1.0/lib/libcrypto.so.1.1 (0x00007f069100a000)

Even building mod_ssl statically into httpd binary with --enable-mods-static=ssl doesn't help.

I tried --enable-ssl, --enable-ssl --enable-ssl-staticlib-deps, and --enable-ssl --enable-ssl-staticlib-deps --enable-mods-static=ssl and still the same result:

    libssl.so.1.1 => not found
    libcrypto.so.1.1 => not found

Also tried, without luck, setting these variables before ./configure:

export PKG_CONFIG_PATH=/opt/openssl-1.1.0/lib/pkgconfig:$PKG_CONFIG_PATH \
       LD_LIBRARY_PATH=/opt/openssl-1.1.0/lib:$LD_LIBRARY_PATH \

I know I can just add to /etc/ld.so.conf.d to autoload the new OpenSSL library or adjust Apache's init script to add to LD_LIBRARY_PATH but I'd much prefer to have it working properly, have the program where to look for libssl.so / libcrypto.so, just like my PHP build:

[root@host php]# export PKG_CONFIG_PATH=/opt/openssl-1.1.0/lib/pkgconfig:$PKG_CONFIG_PATH \
       LD_LIBRARY_PATH=/opt/openssl-1.1.0/lib:$LD_LIBRARY_PATH \
       LDFLAGS="-L/opt/openssl-1.1.0/lib" \
       PHP_PREFIX=/opt/php-7.2.9 \
[root@host php]# ./configure […] \
    --with-imap=shared \
    --with-imap-ssl \
    --with-openssl=shared \

[root@host php]# make

[root@host modules]# ldd ./openssl.so | grep -iP 'ssl|crypto'
    libssl.so.1.1 => /opt/openssl-1.1.0/lib/libssl.so.1.1 (0x00007fc2220a6000)
    libcrypto.so.1.1 => /opt/openssl-1.1.0/lib/libcrypto.so.1.1 (0x00007fc221c17000)

What am I doing wrong? Could this be a bug?

  • The problem may be related to the shared keyword, did you try another way? Aug 31 '18 at 1:39
  • Did you find a solution to this? Having the same problem and came to all the same conclusions.
    – user194553
    Jul 27 '19 at 22:20
  • 1
    I'm afraid I wasn't able to figure it out. Ended up having to load it via /etc/ld.so.conf.d/.
    – E-71
    Jul 28 '19 at 0:46
  • Thanks, I found another solution which is to add the library path to the envvars file in httpd's bin directory, which apachectl uses when controlling stuff. Basically the same thing, and still doesn't explain why this is neccesary, but avoids any risk of it interfering with other stuff.
    – user194553
    Jul 30 '19 at 4:55

Try adding the following to your LDFLAGS env variable:

-Bstatic -lssl -lcrypto

Also, make sure that you don't have any .so file on your openssl libdir, only the static .a ones. This ideally can be done by passing the no-shared parameter to openssl configure.

I am still unsure why sometimes the linker still prefers the shared version if it's present, even when we explicitly require the static ones, but probably it has to do with the way the ./configure script from httpd is handling library dependency.

While a patch on the configure script would probably be cleaner, just not having .so files seems to be enough for the linker to pick up the static version instead.

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