How to install Asterisk with SRTP support?

I’m rather new to Asterisk, and I need my server to support WebRTC. As far as I know, Asterisk version in Asterisk Now is compiled without SRTP support, which is necessary for WebRTC.

So, I try to compile Asterisk 11.5.0 with SRTP on my Ubuntu server 13.04. I execute ./configure command with –with-srtp option. Here is this command:

./configure --with-crypto --with-ssl --with-srtp

But I get a warning:

checking for the ability of -lsrtp to be linked in a shared object... no
configure: WARNING: ***
configure: WARNING: *** libsrtp could not be linked as a shared object.
configure: WARNING: *** Try compiling libsrtp manually. Configure libsrtp
configure: WARNING: *** with ./configure CFLAGS=-fPIC --prefix=/usr
configure: WARNING: *** replacing /usr with the prefix of your choice.
configure: WARNING: *** After re-installing libsrtp
configure: WARNING: *** configure script.
configure: WARNING: ***
configure: WARNING: *** If you do not need SRTP support re-run configure
configure: WARNING: *** with the --without-srtp option.

My libsrtp (v 1.4.4) is already compiled with the options, mentioned above! I’ve also tried to set location of libsrtp, while configuring Asterisk:

./configure --with-crypto --with-ssl --with-srtp=/usr/include/srtp

but this changes nothing.

Can you help me with WebRTC support in Asterisk?

UPD: I think, there is a problem in SRTP library, because it does not pass runtest properly: Error 254.
They write, changing “RTPW=rtpw” to “RTPW=./rtpw” in rtpw_test.sh will fix this error, but it doesn’t.

make uninstall
make clean
./configure CFLAGS=-fPIC --prefix=/usr/local/lib
make
make runtest
make install

apt-cache search libsrtp