dnstoy 
a lightweight dns-over-tls proxy (WIP)
Project status
Not ready for production
TODO
- Basic functionality (accept query from UDP/TCP -> resolve query through dns-over-tls protocol -> forward answer to users)
- Reuse connection to prevent unnecessary handshake
- Select fastest remote dynamically
- Parallel resolve all queries
- Resolve query via mutliple remote servers (when idle)
- SSL session cache
- rfc7828 The edns-tcp-keepalive EDNS0 Option
- rfc7871 Client Subnet in DNS Queries
- rfc7830 The EDNS(0) Padding Option
- Cache
- Support TCP/UDP foreign server
- Select foreign server by rule
Know more about dns-over-tls
https://en.wikipedia.org/wiki/DNS_over_TLS
https://developers.cloudflare.com/1.1.1.1/dns-over-tls/
https://developers.google.com/speed/public-dns/docs/dns-over-tls