I don't think there is any free tool at the moment that will allow you to provision Cisco-based VPNs like CSM (for a large number of devices).
However you can use generic tools like Rancid, Kiwi Cat Tools, Nagios, OpenNMS, Zibbix etc. to achieve what you want. You could start with SDM/ASDM etc. to finish a few devices, and then use on of these tools to replicate it out to a large number of devices. Of course the configuraton on the branches/spokes would depend on the VPN technology you have chosen. Some technologies have an identical configuration on all spokes and others do not (e.g. GRE Tunnel IP in DMVPN).
However this would require some homework from your side.
Regards
Farrukh
