[chore]: Bump github.com/miekg/dns from 1.1.55 to 1.1.56 (#2204)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/vendor/github.com/miekg/dns/defaults.go b/vendor/github.com/miekg/dns/defaults.go
index c1558b79c..6d7e17605 100644
--- a/vendor/github.com/miekg/dns/defaults.go
+++ b/vendor/github.com/miekg/dns/defaults.go
@@ -5,6 +5,7 @@ import (
 	"net"
 	"strconv"
 	"strings"
+	"unicode"
 )
 
 const hexDigit = "0123456789abcdef"
@@ -330,8 +331,18 @@ func Fqdn(s string) string {
 
 // CanonicalName returns the domain name in canonical form. A name in canonical
 // form is lowercase and fully qualified. See Section 6.2 in RFC 4034.
+// According to the RFC all uppercase US-ASCII letters in the owner name of the
+// RR areeplaced by the corresponding lowercase US-ASCII letters.
 func CanonicalName(s string) string {
-	return strings.ToLower(Fqdn(s))
+	var result strings.Builder
+	for _, ch := range s {
+		if unicode.IsUpper(ch) && (ch >= 0x00 && ch <= 0x7F) {
+			result.WriteRune(unicode.ToLower(ch))
+		} else {
+			result.WriteRune(ch)
+		}
+	}
+	return Fqdn(result.String())
 }
 
 // Copied from the official Go code.