Update Lego

vendor/github.com/xenolf/lego/providers/dns/duckdns/client.go

@@ -0,0 +1,68 @@
+package duckdns
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/miekg/dns"
+	"github.com/xenolf/lego/challenge/dns01"
+)
+
+// updateTxtRecord Update the domains TXT record
+// To update the TXT record we just need to make one simple get request.
+// In DuckDNS you only have one TXT record shared with the domain and all sub domains.
+func (d *DNSProvider) updateTxtRecord(domain, token, txt string, clear bool) error {
+	u, _ := url.Parse("https://www.duckdns.org/update")
+
+	mainDomain := getMainDomain(domain)
+	if len(mainDomain) == 0 {
+		return fmt.Errorf("unable to find the main domain for: %s", domain)
+	}
+
+	query := u.Query()
+	query.Set("domains", mainDomain)
+	query.Set("token", token)
+	query.Set("clear", strconv.FormatBool(clear))
+	query.Set("txt", txt)
+	u.RawQuery = query.Encode()
+
+	response, err := d.config.HTTPClient.Get(u.String())
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+
+	bodyBytes, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return err
+	}
+
+	body := string(bodyBytes)
+	if body != "OK" {
+		return fmt.Errorf("request to change TXT record for DuckDNS returned the following result (%s) this does not match expectation (OK) used url [%s]", body, u)
+	}
+	return nil
+}
+
+// DuckDNS only lets you write to your subdomain
+// so it must be in format subdomain.duckdns.org
+// not in format subsubdomain.subdomain.duckdns.org
+// so strip off everything that is not top 3 levels
+func getMainDomain(domain string) string {
+	domain = dns01.UnFqdn(domain)
+
+	split := dns.Split(domain)
+	if strings.HasSuffix(strings.ToLower(domain), "duckdns.org") {
+		if len(split) < 3 {
+			return ""
+		}
+
+		firstSubDomainIndex := split[len(split)-3]
+		return domain[firstSubDomainIndex:]
+	}
+
+	return domain[split[len(split)-1]:]
+}