56 lines
1.0 KiB
Go
56 lines
1.0 KiB
Go
package utils
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import (
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"fmt"
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"strconv"
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"strings"
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"time"
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"github.com/miekg/dns"
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)
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type WrongAnswerError struct {
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Message string
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}
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func (e *WrongAnswerError) Error() string {
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return fmt.Sprintf("Wrong Answer: %s", e.Message)
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}
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func SendQuery(addr string, dn string) (string, error) {
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var (
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domain string
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rdns_ip string
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)
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if dn == "timestamp" {
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timestamp := strconv.FormatInt(time.Now().UnixNano(), 10)
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domain = strings.Join([]string{timestamp, "-scan.echodns.xyz."}, "")
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} else {
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domain = strings.Join([]string{dn, ".echodns.xyz."}, "")
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}
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//fmt.Println(domain)
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m := new(dns.Msg)
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m.SetQuestion(domain, dns.TypeA)
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m.RecursionDesired = true
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res, err := dns.Exchange(m, addr)
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if err == nil {
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if len(res.Answer) == 1 {
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if a, ok := res.Answer[0].(*dns.A); ok {
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rdns_ip = a.A.String()
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} else {
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rdns_ip = ""
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err = &WrongAnswerError{
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Message: "Wrong Record Type",
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}
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}
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} else {
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rdns_ip = ""
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err = &WrongAnswerError{
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Message: "Wrong Answer Section",
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}
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}
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}
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return rdns_ip, err
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}
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