[Sipp-devel] [PATCH] Remove dependency on OpenSSL for authentication (& merge other authentication fixes)

[Rob D. <rk...@rk...>]

Hi all,

You may be aware that the OpenSSL license is incompatible with the GPL
(http://people.gnome.org/~markmc/openssl-and-the-gpl.html) and so SIPp,
which is licensed under the GPL, can't be distributed if linked against
it. See https://sourceforge.net/mailarchive/message.php?msg_id=27062924
for an example of how this is causing problems - the Debian SIPp
package, which lacks this OpenSSL support, can't do authentication nor
TLS.

It seemed to me that we shouldn't really need to link with OpenSSL for
authentication - all we're doing there is an MD5 digest. So I've created
a patch, which does the following:

* Includes md5.h and md5.c from
https://sourceforge.net/projects/libmd5-rfc/ (which is zlib-licensed and
GPL-compatible)
* Updates auth.c to use these MD5 functions instead
* Updates the Makefile to use these files for authentication support by
default
* Removed any #ifdef _USE_OPENSSL statements which related to
authentication
* Merged auth-username patch from Dmitry Semyonov (#2892694)
* Merged auth-int patch from Jordan Walbesser (#2776238)
* Reorganised the help text so that authentication parameters aren't in
a separate section along with TLS ones.

Note that for actual TLS transport support SIPp will still need to be
built against OpenSSL, but I think this is less mainstream and so I'm
more comfortable with its being excluded from Debian et al. That said, I
do want to try and move to GnuTLS at some point to eradicate the
licensing issue entirely.

I've tested this with a simple user/password pair ("alpha"/"beta") and
it generates identical responses to SIPp with OpenSSL for both MD5 and
AKAv1-MD5.

I'd like any comments on the patch itself, the desirability of this new
feature, and the merits of a move to GnuTLS.

Best,
Rob