Compiling Coreutils with LibreSSL (instead of OpenSSL)

[Assaf Gordon]

Hi,

Just a quick note (to myself and others who try this):

Using "./configure --with-openssl=yes" uses the system's default
libcrypto library.

If one wants to use a non-default library (e.g. LibreSSL installed
in a non-default location), these are possible steps:

Download/Build/Install libreSSL:

    git clone https://github.com/libressl-portable/portable.git \
              libressl-portable
    cd libressl-portable/
    ./autogen.sh
    ./configure --prefix /opt/libressl/
    make
    sudo make install

Build coreutils with the custom library:

    export LD_LIBRARY_PATH=/opt/libressl/lib/
    cd coreutils-8.28
    ./configure --with-openssl=yes \
                CPPFLAGS=-I/opt/libressl/include/ \
                LDFLAGS=-L/opt/libressl/lib
    make

An alternative to LD_LIBRARY_PATH on GNU/Linux
is adding /opt/libressl/lib to /etc/ld.so.conf
and rerun 'ldconfig'.

Compiling the 'coreutils' binaries does not actually need to access
to the shared object (LD_LIBRARY_PATH), but as part
of the 'make' process the man pages are generated by running 'md5sum 
--help' which will fail if the shared library isn't found.

====

To the best of my understanding, CPPFLAGS/LDFLAGS are needed because
gnulib's gl-openssl.m4 [1] does not accept any external envvars or
checks pkg-config for the location of the library.
It assumes <openssl/md5.h> is available in the default header path,
and libcrypto is available on the default library path.

[1] https://opengrok.housegordon.com/source/xref/gnulib/m4/gl-openssl.m4

====

On systems which use LibreSSL by default using
"./configure --with-openssl=yes" just works.
E.g. On Alpine Linux:

    sudo apk add libressl libressl-dev
    cd coreutils-8.28
    ./configure --with-openssl=yes
    make

====


regards,
 - assaf