Add priv. key support for ecdsa
Add priv. key support for ecdsa

ezoic/dns,Git-Host/dns,josephyzhou/dns,asergeyev/dns,tonnerre/golang-dns,flebarbe/dns,modulexcite/dns,rolandshoemaker/dns,skyportsystems/dns,curtiszimmerman/dns,hugozhu/dns,bboreham/dns,letsencrypt/dns,tempbottle/dns,miekg/dns,michaelharo/dns,cloudflare/dns,ErikDubbelboer/dns,ym/go-dns,janstk/dns,skynet/dns,FiloSottile/dns,AlexCheong/dns,bragr/dns,jmhodges/dns,Psiphon-Inc/dns,tsenart/dns,benbearchen/dns,jdef/dns