awl/query/HTTPS.go

54 lines
1.3 KiB
Go

package query
import (
"bytes"
"fmt"
"io"
"net/http"
"time"
"github.com/miekg/dns"
)
// Resolve a DNS-over-HTTPS query
//
// Currently only supports POST requests
func ResolveHTTPS(msg *dns.Msg, server string) (*dns.Msg, time.Duration, error) {
httpR := &http.Client{}
buf, err := msg.Pack()
if err != nil {
return nil, 0, err
}
// query := server + "?dns=" + base64.RawURLEncoding.EncodeToString(buf)
req, err := http.NewRequest("POST", server, bytes.NewBuffer(buf))
if err != nil {
return nil, 0, fmt.Errorf("DoH: %s", err.Error())
}
req.Header.Set("Content-Type", "application/dns-message")
req.Header.Set("Accept", "application/dns-message")
now := time.Now()
res, err := httpR.Do(req)
rtt := time.Since(now)
if err != nil {
return nil, 0, fmt.Errorf("DoH HTTP request error: %s", err.Error())
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return nil, 0, fmt.Errorf("DoH server responded with HTTP %d", res.StatusCode)
}
fullRes, err := io.ReadAll(res.Body)
if err != nil {
return nil, 0, fmt.Errorf("DoH body read error: %s", err.Error())
}
response := dns.Msg{}
err = response.Unpack(fullRes)
if err != nil {
return nil, 0, fmt.Errorf("DoH dns message unpack error: %s", err.Error())
}
return &response, rtt, nil
}