I am trying to install Stunnel 4.21 on a 1&1 shared Linux server.  PHP Settings claims that OpenSSL 0.9.6g is installed.  I unpacked the tar file and ran "./configure" using --prefix to override the /usr/local/ install directory.  I had one warning: "configure: WARNING: Openssl engine header not found".  In terms of threading model, I got "configure: PTHREAD thread model detected".

When I tried to run "make", I got "common.h:318: #error OpenSSL library compiled without thread support".  Is there a way around this?  I tried running "./configure" with --with-threads=ucontext/fork, but that gave a bunch of "OCSP_" undeclared variables and "Error 1".
        Thanks, Norbert