[xmlsec] Using XMLSec with other crypto engines

[Aleksey Sanin]

Hi, All!

In the last few weeks I was asked by a number of people about
using XMLSec library with other (non OpenSSL) crypto engines
(NSS,  MS CryptoAPI, etc.). I kept this feature in mind from
the beginning and it looks like it is a right time to do this. Shortly
the plan is to move all the OpenSSL depended code into separate
folders (i.e. include/xmlsec/openssl and src/openssl). I don't expect
any major changes in the code (may be moving some functions around).

If you do not use any OpenSSL specific features of XMLSec (like,
xmlSecX509Data structure definition from xmsec/x509.h file) then
you should expect no changes in your code at all. Otherwise, you will
need to add some additional includes (for example, in the case above,
you'll need to add "#include <xmlsec/openssl/x509.h>"). The good
news is that all the changes could be spotted during compilation time :)
BTW, OpenSSL will still be a default crypto engine.

I am going to make this change in the next couple weeks. Most likely,
CVS builds be broken at some point. Please use the 0.0.10 version
instead.

If you have any questions, comments or problems because of the
proposed change then do not hesitate to write a message to the xmlsec
mailing list, please.

With best regards,
Aleksey