I'm trying to run the Jynx userlevel rootkit in different distros in VirtualBox (just out of curiosity), but I'm having trouble compiling it.

alex@virtualbox:~/jynx2$ make
gcc -m64 jynx2.c -Wall -shared -fPIC -ldl -lssl -o jynx2.so
jynx2.c:16:25: fatal error: openssl/ssh.h: No such file or directory
compilation terminated
make: *** [jynx2.so] Error 1
I have a very basic understanding of C, but I still don't understand why this header isn't available. It's coming from this line in jynx2.c:

#include <openssl/ssl.h>
I looked through the CoC and couldn't find anything against this btw, but correct me if I'm wrong. I'm not trying to use this for malicious purposes.