Add to support mbed TLS 2.1.x encryption backend
As you know, Zabbix 3.0.x and later support encrypted communication.
Zabbix currently support following encryption backends:
- mbed TLS (only 1.3.x)
But mbed TLS 1.3.x will drop to support by ARM soon
So, I made the patch to support mbed TLS 2.1.x.
This patch adds new "configure" script option:
Internally, adding a new preprocessor define (HAVE_MBEDTLS21) and keeping mbed TLS 1.3.x support (HAVE_POLARSSL)
If they keep API compatibility, It probably works with mbed TLS 2.x branch (eg: 2.6.0).
This patch is for "branches/3.0" revision 74336.