SSH into the box as root.
cd /volume1/@tmp
wget http://ipkg.nslu2-linux.org/feeds/optware/syno-i686/cross/unstable/syno-i686-bootstrap_1.2-7_i686.xsh
chmod +x syno-i686-bootstrap_1.2-7_i686.xsh
./syno-i686-bootstrap_1.2-7_i686.xsh
ipkg update
Add this to /etc/profile
PATH=/opt/bin:/opt/sbin:$PATH
Remove these lines from /root/.profile
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/syno/sbin:/usr/syno/bin:/usr/local/sbin:/usr/local/bin
export PATH
Continue with installing OpenSSL 1.0.1g.
ipkg install perl
ipkg install gcc
ipkg install make
wget http://www.openssl.org/source/openssl-1.0.1g.tar.gz
tar zxvf openssl-1.0.1g.tar.gz
cd openssl-1.0.1g
MACHINE=i686 ./config
make install
does not work for me
edit:
I've moved from ipkg to opkg (entware) and installed "OpenSSL 1.0.2n-fips 7 Dec 2017" using one command.