The development of libssh is made using Berlios subversion servers.
svn co svn://svn.berlios.de/libssh/trunk
cd <path where you've commited trunk> svn update
You've made some modifications to libssh and want to post them on the mailing list or preferably the bug tracker.
Make sure you have edited the latest version by doing svn update before hacking the code.
Change as needed.
svn diff > /path/to/mypatch.patch
Firstly, checkout the last revision as writen previously.
Then :
cd trunk/ ./autogen.sh
you can then use the configure script