A user token (token) is an encrypted string used for authentication and authorization, typically used to authenticate users across a network. In many applications and systems, users are required to log in with a username and password to access protected resources and functions. In order to avoid the user having to provide the username and password again in each request, the system generates a unique token (token) and returns it to the client. This allows the client to carry the token (token) in subsequent requests to verify its identity without having to re-provide login credentials.
User tokens are usually short-lived and need to be re-applied after expiration to ensure security. Some popular authentication and authorization protocols such as OAuth and OpenID Connect also use tokens for authentication and authorization. In these protocols, a user token (token) usually contains information such as authorized access rights between the user and the application.
Some common types of user tokens include JSON Web Token (JWT), OAuth Access Token, Bearer Token, SAML Assertion, and Kerberos Ticket, among others. Each type of token (token) has a different structure and purpose.
Generally, the method of requesting and using token when logging in is as follows:
The user provides login credentials (username and password, etc.) to the server.
The server verifies the correctness of the login credentials, generates a token, and returns it to the client in the HTTP response.
The client saves this token, usually in a browser cookie or local storage.
In subsequent requests, the client adds the token in the HTTP request header, such as using Bearer Schema (eg Bearer {token}) in the Authorization header, to verify the user's identity.
The server parses the token from the request header and verifies its validity. If the verification is successful, it returns the requested resource or operation result to the client.
It should be noted that since the token contains sensitive information, such as user identity and access rights, it is necessary to use a secure transmission protocol such as HTTPS to ensure the security of the transmission. In addition, the validity period of the token should be as short as possible, and the expiration time should be set appropriately to reduce security risks. At the same time, the token needs to be updated or refreshed in time.
In actual development, some mature authentication and authorization frameworks (such as Spring Security, OAuth2, etc.) can be used to generate, verify and manage tokens, avoid repeated development and maintenance work, and improve development efficiency and security.
To set the effective time of Token needs to be judged according to specific application scenarios and security requirements. Generally speaking, the effective time of Token should not be set too long or too short, as it is easy to be attacked if it is too long, and it will cause bad experience for users to log in frequently if it is too short.
The following are some common Token valid time setting suggestions:
Short-term Token: Applicable to some scenarios that require high security, such as banking, finance and other fields. It is recommended that the valid time of Token be controlled within 30 minutes to 1 hour. This ensures that the user's information automatically expires after a certain period of time, thereby improving security.
Long-term Token: Applicable to some relatively safe scenarios, such as social networks and other fields. It is recommended that the valid time of the Token be controlled within 1 to 7 days, so as to ensure that the user's Token is valid for a period of time, and at the same time reduce the frequent re-login operations of the user and improve the user experience.
Permanent Token: Applicable to scenarios that do not require users to log in frequently, such as remembering passwords. However, this kind of Token has low security, so additional security protection measures are required, such as using two-factor authentication and other measures to strengthen security.
In practice, you can flexibly set the effective time of Token according to your own application scenarios and security requirements. At the same time, you need to adjust and optimize it in time according to the actual situation to ensure the security of Token.