awl/util/dns.go

90 lines
2.0 KiB
Go

package util
import (
"encoding/base64"
"errors"
"fmt"
"io"
"net"
"net/http"
"strings"
"time"
"github.com/c-robinson/iplib"
"github.com/miekg/dns"
)
type Response struct {
Answers Answers `json:"Response"` //
}
// The Answers struct is the basic structure of a DNS request
// to be returned to the user upon making a request
type Answers struct {
Server string `json:"Server"` // The server to make the DNS request from
Request uint16 `json:"Request"` // The type of request
Name string `json:"Name"` // The domain name to make a DNS request for
RTT time.Duration `json:"RTT"` // When AWL was ran
}
func ReverseDNS(dom string, q string) (string, error) {
if q == "PTR" {
if strings.Contains(dom, ".") {
// It's an IPv4 address
ip := net.ParseIP(dom)
if ip != nil {
return iplib.IP4ToARPA(ip), nil
} else {
return "", errors.New("error: Could not parse IPv4 address")
}
} else if strings.Contains(dom, ":") {
// It's an IPv6 address
ip := net.ParseIP(dom)
if ip != nil {
return iplib.IP6ToARPA(ip), nil
} else {
return "", errors.New("error: Could not parse IPv6 address")
}
}
}
return "", errors.New("error: -x flag given but no IP found")
}
func ResolveHTTPS(msg *dns.Msg, server string) (*dns.Msg, error) {
httpR := &http.Client{}
buf, err := msg.Pack()
if err != nil {
return nil, err
}
query := server + "?dns=" + base64.RawURLEncoding.EncodeToString(buf)
req, err := http.NewRequest("GET", query, nil)
if err != nil {
return nil, err
}
req.Header.Set("Accept", "application/dns-message")
res, err := httpR.Do(req)
if err != nil {
return nil, err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return nil, fmt.Errorf("bad HTTP Request: %d", res.StatusCode)
}
fullRes, err := io.ReadAll(res.Body)
if err != nil {
return nil, err
}
response := dns.Msg{}
err = response.Unpack(fullRes)
if err != nil {
return nil, err
}
return &response, nil
}