Key Authentication Login Host

Learning Précis-writers

There are two types of keys: symmetric key and asymmetric key
two key types
According to the cryptographic keys used by the cipher algorithm and the encryption key is the same, whether the decryption process can be deduced from the encryption process (or by the decryption process to derive the encryption process), the cryptosystem can be divided into symmetric cryptography (also known as single-key cryptography, secret key cryptography, symmetric key cryptography) and asymmetric cryptosystem ( Also known as dual-key cryptosystem, public key cryptosystem, asymmetric key cryptosystem).
symmetric key Encryption, also known as private key encryption or session key encryption algorithm, that is, the sender and receiver of the information use the same key to encrypt and decrypt data. Its biggest advantage is the fast encryption/decryption speed, which is suitable for encrypting large data volumes, but key management is difficult.

• Key Login Configuration Flow
  1. key generation open Puttygen, click Generate, Generate key
  650) this.width=650; "src=" Http://i3.tietuku.com/a7f7b7add4c91ca3.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>

  2. Post-generated public key
  650) this.width=650; "src=" Http://i3.tietuku.com/483c27542af30973.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>

  3. private key, write password, save to local directory
  650) this.width=650; "src=" Http://i3.tietuku.com/e14002976e1feaa0.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>

  650) this.width=650; "src=" Http://i3.tietuku.com/f2024536600fd910.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>
  4. save public key refers to server host
  Open the Linux terminal and/root/Created under Directory .ssh/authorized_keys File and glue the generated public key in. Save exit.
  650) this.width=650; "src=" Http://i3.tietuku.com/bf11521b477fc9b5.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>
  5. Change file Permissions

  [Email protected] ~]# chmod 700/root/.ssh/
  [Email protected] ~]# chmod 600/root/.ssh/authorized_keys

  6. Changing firewall rules

  [[email protected] ~]# setenforce 0[[email protected] ~]# vi /etc/ Selinux/config# this file controls the state of selinux on the  system.# SELINUX= can take one of these three values:#      enforcing - SELinux security policy is enforced.#      permissive - SELinux prints warnings instead of  Enforcing.#     disabled - no selinux policy is loaded. selinux=disabled   ## #原来的enforcing改为disabled, and is permanently active after reboot. # selinuxtype= can take one of these two values:#      targeted - Targeted processes are protected,#      mls - multi level security protection. Selinuxtype=targeted~ "/etc/selinux/config"  13l, 457c[[email protected] ~]# iptables - f  # #临时清楚防火墙规则, reload [[email protected] ~]# service iptables save  after reboot  ##  firewall rules write to save iptables: Save firewall rules to  /etc/sysconfig/iptables:     [OK]

  7.  Configure Telnet client
  650) this.width=650, "src=" Http://i3.tietuku.com/0c0e5c12fb4e8338.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>
  650 ) this.width=650; "src=" Http://i3.tietuku.com/617e2bdb1631f5ff.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>

  650) this.width=650; "src=" Http://i3.tietuku.com/b6585af0740ba773.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>
  After clicking on the session, click Save to save the configuration and click Open to enter the login screen.
  650) this.width=650; "src=" Http://i3.tietuku.com/21f06ce9bc110816.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>
  Enter your user name, enter your password when you save the private key (that is, save to local to confirm the password passphrase) when you generate the key.
  650) this.width=650; "src=" Http://i3.tietuku.com/8738eac27da22932.png "style=" padding:0px;margin:0px;border:0px; Vertical-align:middle; "/>

  
  

Key Authentication Login Host