Hi all,

How can I tell what version of libssh2 I have on my Linux machine?

In addition to this, I am experiencing difficulties installing libssh 0.18. I installed openssl0.9.8g and zlib1.2.3 but when I try to build libssh I get this error:

/usr/lib64/gcc/x86_64-suse-linux/4.1.2/../../../../x86_64-suse-linux/bin/ld: /usr/local/ssl/lib/libcrypto.a(md5_dgst.o): relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC
/usr/local/ssl/lib/libcrypto.a: could not read symbols: Bad value
collect2: ld returned 1 exit status
make[2]: *** [libssh2.la] Error 1

and I have no idea what to do next. Any advice would be appreciated.

Thanks!

On certain architectures (e.g., amd64), you can’t create shared object files which are position dependent. So in creating a shared library, you must link object files which have been compiled with the flag “-fPIC” (which ensures position independent code). It seems your target shared library is trying to incorporate a static archive of libcrypto. To remedy the problem, install a shared version of libcrypto. Alternatively, you might forgo building a shared libssh.

I built both openssl (which generates libcrypto.a) and libssh2 (which uses that library) with the -fPIC flag. It seems to make no difference (at not one I can see) since the build crashes with the very same error message.

Even if your static archive (libcrypto.a) has none of those relocations (obviously, it still does, even if you think you got rid of them. to check this is the case, try “readelf -r /usr/lib/libcrypto.a”), the recommended practice is to linked shared objects to shared objects. So you have two such solutions:

1. Install the shared version of libcrypto. When building openssl, specify “--enable-shared” as a configure parameter.
2. Don’t try to create a shared version of libssh. When building libssh, specify “--disable-shared” as a configure parameter.

…and it’s just that simple.