Fix Broken User Authentication in Iris

Broken User Authentication in Iris typically involves manual, insecure cookie management or predictable session identifiers. Attackers exploit this by forging cookies or intercepting unencrypted session tokens to impersonate users. This guide moves from raw cookie handling to Iris's hardened session middleware.

The Vulnerable Pattern

func Login(ctx iris.Context) {
	userID := ctx.FormValue("id")
	// VULNERABILITY: Setting a raw, unsigned cookie. 
	// An attacker can change 'user_id' in their browser to any value.
	ctx.SetCookieKV("user_id", userID)
}
func Dashboard(ctx iris.Context) {
uid := ctx.GetCookie(“user_id”)
if uid == "" {
ctx.StopWithStatus(401)
return
}
ctx.Writef(“User ID: %s”, uid)
}

The Secure Implementation

The vulnerable code relies on client-side state that is easily manipulated. By using ctx.SetCookieKV without signing, the application trusts user input for identity. The secure implementation utilizes the Iris Sessions manager, which generates a cryptographically strong, random session ID stored in a cookie. Security is further hardened by: 1. CookieHTTPOnly: Prevents JavaScript access (XSS mitigation). 2. CookieSecure: Ensures tokens are only sent over HTTPS. 3. SameSite: Mitigates CSRF. The actual user data is stored server-side, indexed by the session ID, making impersonation via cookie editing impossible.

var sess = sessions.New(sessions.Config{
	Cookie: "__Host-session-id",
	Expires: 30 * time.Minute,
	CookieSecure: true,
	CookieHTTPOnly: true,
	SameSite: "Lax",
})
func Login(ctx iris.Context) {
s := sess.Start(ctx)
// In a real app, verify credentials first
s.Set(“authenticated”, true)
s.Set(“uid”, “12345”)
}
func Dashboard(ctx iris.Context) {
s := sess.Start(ctx)
if auth, _ := s.GetBoolean(“authenticated”); !auth {
ctx.StopWithStatus(iris.StatusUnauthorized)
return
}
uid := s.GetString(“uid”)
ctx.Writef(“Authenticated UID: %s”, uid)
}