fix: Fix username extraction in the TLS handler

internal/dns/username.go

@@ -0,0 +1,15 @@
+package dns
+
+import "strings"
+
+// Extract the username from the domain name @domain that we're processing
+// at the moment.
+func ExtractUsername(pagesDomain, domain string) string {
+	suffixlessDomain := strings.TrimSuffix(domain, "."+pagesDomain)
+	usernameParts := strings.Split(suffixlessDomain, ".")
+	if len(usernameParts) == 1 {
+		return usernameParts[0]
+	}
+
+	return strings.Join(usernameParts, ".")
+}

internal/dns/username_test.go

@@ -0,0 +1,23 @@
+package dns
+
+import "testing"
+
+func TestExtractUsernameSimple(t *testing.T) {
+	username := ExtractUsername(
+		"pages.local",
+		"papatutuwawa.pages.local",
+	)
+	if username != "papatutuwawa" {
+		t.Fatalf("Unexpected username: '%s'", username)
+	}
+}
+
+func TestExtractUsernameDot(t *testing.T) {
+	username := ExtractUsername(
+		"pages.local",
+		"polynom.me.pages.local",
+	)
+	if username != "polynom.me" {
+		t.Fatalf("Unexpected username: '%s'", username)
+	}
+}

internal/server/tls.go

@@ -44,7 +44,6 @@ func unlockDomain(domain string) {
 }
 
 func buildDomainList(domain, pagesDomain string) []string {
-	// TODO: For wildcards, we MUST use DNS01
 	if domain == pagesDomain || strings.HasSuffix(domain, pagesDomain) {
 		return []string{
 			pagesDomain,
@@ -56,7 +55,6 @@ func buildDomainList(domain, pagesDomain string) []string {
 }
 
 func getDomainKey(domain, pagesDomain string) string {
-	// TODO: For wildcards, we MUST use DNS01
 	if domain == pagesDomain || strings.HasSuffix(domain, pagesDomain) {
 		return "*." + pagesDomain
 	}
@@ -64,10 +62,6 @@ func getDomainKey(domain, pagesDomain string) string {
 	return domain
 }
 
-func usernameFromDomain(domain string) string {
-	return strings.Split(domain, ".")[0]
-}
-
 func getUsername(sni, pagesDomain string) (string, error) {
 	if !strings.HasSuffix(sni, pagesDomain) {
 		log.Debugf("'%s' is not a subdomain of '%s'", sni, pagesDomain)
@@ -81,10 +75,10 @@ func getUsername(sni, pagesDomain string) (string, error) {
 			return "", errors.New("CNAME does not resolve to subdomain of pages domain")
 		}
 
-		return usernameFromDomain(query), nil
+		return dns.ExtractUsername(pagesDomain, query), nil
 	}
 
-	return usernameFromDomain(sni), nil
+	return dns.ExtractUsername(pagesDomain, sni), nil
 }
 
 func MakeTlsConfig(pagesDomain, cachePath string, cache *certificates.CertificatesCache, acmeClient *lego.Client, giteaClient *repo.GiteaClient) *tls.Config {