Update chi/middleware to chi/v5/middleware (#17888)

Fix #17880


Co-authored-by: Lauris BH <lauris@nix.lv>

vendor/github.com/go-chi/chi/v5/middleware/basic_auth.go

@@ -0,0 +1,33 @@
+package middleware
+
+import (
+	"crypto/subtle"
+	"fmt"
+	"net/http"
+)
+
+// BasicAuth implements a simple middleware handler for adding basic http auth to a route.
+func BasicAuth(realm string, creds map[string]string) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			user, pass, ok := r.BasicAuth()
+			if !ok {
+				basicAuthFailed(w, realm)
+				return
+			}
+
+			credPass, credUserOk := creds[user]
+			if !credUserOk || subtle.ConstantTimeCompare([]byte(pass), []byte(credPass)) != 1 {
+				basicAuthFailed(w, realm)
+				return
+			}
+
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+func basicAuthFailed(w http.ResponseWriter, realm string) {
+	w.Header().Add("WWW-Authenticate", fmt.Sprintf(`Basic realm="%s"`, realm))
+	w.WriteHeader(http.StatusUnauthorized)
+}