Configure the SRTP encryption in [general]

I checked some sip.conf files and I found that they put the “ecryption=yes” (to activate the SRTP) parameter under the user configuration like this

[demo-user] type=friend host=dynamic secret=secret avpf=yes encryption=yes

I m wondering if it’s possible to configure the “ecryption=yes” for all by setting it under the [general] config like this

[general] context=incoming_calls allowoverlap=yes allowtransfer=yes encryption=yes ...

No. (According to the source code of an approximately one year old trunk version of chan_sip.c.)