How to use the latest crypt lib without update glibc ?

[Andy <hewanxiang at gmail dot com>]

Hi all,
I got that, glibc can support SHA in crypt lib since v2.7.

There is a requirement in my application to use SHA, but update the
whole glibc is too risky. So I want to build a specific crypt lib for
the module using crypt function in my application.

Now the calling graph seems like this, from a simple view.

crypt_user.c  ---->  call crypt() function in libcrypt.so

myutil.c  -----> call functions in crypt_user.c, and it will be build
to a shared lib, libmyutil.so

Executable program : server -----> need to use libmyutil.so to work.

Now I can only use the latest static lib  libcrypt.a from the new
glibc. How should I use it ï Link it when build libmyutil.so or build
server ?

I tried to update my Makefile to link the libcrypt.a, but seems that
the called crypt function is not I expected still from the old glibc?

Any reply will be appreciated!

Thanks,
-Andy