2年以上面试必问的面试题，SSO核心机制实战分析 Token验证与跨域登录？

【IT老齐615】理解单点登录SSO

🔐 Single Sign-On (SSO) — One Login, Multiple Services Single Sign-On lets users authenticate once and securely access multiple applications without logging in again and again. Here’s how the SSO flow works in practice: • User requests access to an application (Service Provider A) • The app redirects the user to an Identity Provider (IdP) • IdP prompts the user to sign in • User provides credentials once • IdP verifies credentials securely • A signed token is issued and sent back • Access is gra