[v8.3.x] Sync security changes (#45067)

* "Release: Updated versions in package to 8.3.5"

* [v8.3.x] Fix for CVE-2022-21702 (#225)

Fix for CVE-2022-21702

* Update yarn.lock for 8.3.5

* resolve conflicts

(cherry picked from commit bb38cfcba4b4f824060ff385d858c63f50b72d74)

* csrf checks for v8.3.5 (#234)

* Fix lint

* Cherry pick e2e test server changes

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>
Co-authored-by: Kevin Minehart <kmineh0151@gmail.com>
Co-authored-by: Serge Zaitsev <serge.zaitsev@grafana.com>

pkg/middleware/csrf.go

@@ -0,0 +1,39 @@
+package middleware
+
+import (
+	"errors"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+func CSRF(loginCookieName string) func(http.Handler) http.Handler {
+	// As per RFC 7231/4.2.2 these methods are idempotent:
+	// (GET is excluded because it may have side effects in some APIs)
+	safeMethods := []string{"HEAD", "OPTIONS", "TRACE"}
+
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// If request has no login cookie - skip CSRF checks
+			if _, err := r.Cookie(loginCookieName); errors.Is(err, http.ErrNoCookie) {
+				next.ServeHTTP(w, r)
+				return
+			}
+			// Skip CSRF checks for "safe" methods
+			for _, method := range safeMethods {
+				if r.Method == method {
+					next.ServeHTTP(w, r)
+					return
+				}
+			}
+			// Otherwise - verify that Origin matches the server origin
+			host := strings.Split(r.Host, ":")[0]
+			origin, err := url.Parse(r.Header.Get("Origin"))
+			if err != nil || (origin.String() != "" && origin.Hostname() != host) {
+				http.Error(w, "origin not allowed", http.StatusForbidden)
+				return
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}