Ssh is used to remotely log in to the Linux server to manage and maintain the system. SSH is a protocol designed to provide security for remote login sessions and other network services; using the ssh service (referring to software that implements the SSH protocol), you can remotely log in to the server to manage and maintain the system, preventing information leakage during remote management.
#The operating environment of this tutorial: linux5.9.8 system, Dell G3 computer.
(1) ssh is a protocol
SSH (Secure Shell) is more reliable and designed for remote login sessions and Other network services provide security protocols, and the use of the SSH protocol can effectively prevent information leakage during remote management.
(2) ssh service
Linux is generally used as a server. We usually use the ssh service (referring to the software that implements the SSH protocol) to log in remotely. Go to the Linux server to manage and maintain the system.
You need to create a pair of keys and put the public key on the server. When connecting to the SSH server, the client sends a request to the server and uses your public key for security verification. After the server receives the request, it first searches for your public key in your home directory on the server, and then compares it with yours. The public key sent is compared. If the two keys match, the server encrypts the "challenge" with the public key and sends it to the client software. After the client software receives the "challenge", it can decrypt it with your private key.
(1) Symmetric encryption
The same key (secret) is used for encryption and decryption key). Highly efficient, a major drawback of symmetric encryption is the management and distribution of keys. During the process of sending keys, there is a great risk that the keys will be intercepted by hackers. The common practice in reality is to asymmetrically encrypt the symmetric encryption key and then transmit it to the person who needs it.
(2) Asymmetric encryption
Asymmetric encryption provides a very secure method for data encryption and decryption. It uses A pair of keys, public key and private key. The private key can only be kept securely by one party and cannot be leaked, while the public key can be sent to anyone who requests it. Asymmetric encryption uses one of the keys in the pair for encryption, while decryption requires the other key. Currently the most commonly used asymmetric encryption algorithm is the RSA algorithm. Although asymmetric encryption is very secure, it is very slow compared to symmetric encryption, so we still have to use symmetric encryption to transmit messages, but the key used in symmetric encryption can be sent out through asymmetric encryption.
(1) Encryption: public key encryption private key decryption
Mainly used to encrypt data to prevent it from being illegally obtained by others to ensure data security. The data is encrypted using the public key, and only the private key can decrypt it. Even if the ciphertext is obtained by a third party on the Internet, it cannot be decrypted without the private key, thus ensuring data security.
(2) Authentication: Private key encryption and public key decryption
is mainly used for identity verification to determine the authenticity of a certain identity sex. After encrypting with the private key, decrypt it with the corresponding public key to verify the authenticity of the identity.
SSH public key login uses the second function.
(1) Quick login configuration
You can define some shortcut key login configurations under ~/.ssh/. The configuration is in ~/.ssh/config
config structure is as follows:
Host kafka_broker_01 #定义主机别名 ServerAliveInterval 30 HostName 122.22.222.102 #主机ip Port 33033 #ssh 端口 User bila #用户名 IdentityFile /Users/bila/.ssh/id_rsa #私钥 ProxyCommand ssh w_x_bastion -C -W %h:%p #设置跳板机
(2) Login
Specify user login
ssh bila@192.168.0.103
Specify port number login
ssh ssh 192.168.0.103 -p 2022
Related recommendations: "Linux Video Tutorial"
The above is the detailed content of What is the use of linux ssh?. For more information, please follow other related articles on the PHP Chinese website!