Use OpenSSH to build more effective security performance (1)

Old Linux administrators know the SSH Secure shell Protocol), which is the most convenient and useful tool in their software toolbox. In the workstation X Windows environment, you can use multi-terminal competition or use Screen utility, Linux server administrator, or other Unix-based server administrator to easily manage several systems at the same time. The Network Management shell or Perl script can use SSH to automatically execute work on multiple servers in a simple and secure manner.
The Network shell effect RSH is longer than SSh. However, SSH adds powerful encryption and Data Compression functions to its functions, and most modern SSH implementations provide SFTP and SCP in the same package, which are used for secure file transmission in the network.
The most popular SSH implementation is in the form of OpenSSH, which is a project conceived and maintained by the OpenBSD community. OpenSSH is imported to every operating system platform, including Microsoft Windows. Although it is most widely used in the Window environment, it is used as a client for OpenSSH servers on Unix systems. These Unix-based systems include Linux, Solaris, and OpenBSD.
SSH responsibilities
SSH uses powerful encryption to protect remote meetings from malicious hacker attacks. End-to-end security is provided from the terminal, including the connection between the client and the host, and the establishment of a session-specific Password Key Exchange before the user name and password are transmitted between computers. It can use a variety of different cryptographic solutions: AES, 3DES, Blowfish and other solutions. Trusted Host Authentication Schemes and key-value exchanges between systems improve security. OpenSSH creates secure and encrypted remote meetings without the need for security certificates or priority key exchanges.
In addition, SSH can solve some types of network congestion and significantly accelerate the network, because it compresses the data before transmitting data. It uses SFTP encryption to provide FTP-like interactive file transmission capabilities. Therefore, the transmission of passwords and user names over the network is not blocked. For file transfer operations, SCP also provides a secure and convenient way to complete this work-the encrypted file copy command, which operates on network connections and is a part of SSH implementation.
SSH is a well-known network protocol in encrypted communication. It is developed to replace the RSH utility. RSH is encrypted, but not secure. SSH not only inherits the functions of RSH, but also extends and enhances its functions, especially in terms of security.
OpenSSH for Linux
It is easy to install OpenSSH on Linux. For example, in Debian GNU/Linux, when OpenSSH is installed, log on as the root user and enter the command apt-get install ssh. Similarly, on the Fedora Core Linux system, when OpenSSH is installed, log on as the root user and enter the command yum install ssh. You don't even need to do this, because in Debian and Fedora Core, their default installation configurations include OpenSSH. For Linux systems, to determine whether OoenSSH is installed on the system, you only need to enter the command: ssh. If OpenSSH is installed in the system, A simple user guide is provided. Listing ):

Listing A$ sshusage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec][-D port] [-e escape_char] [-F configfile][-iidentity_file] [-L [bind_address:]port:host:hostport][-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port][-R [bind_address:]port:host:hostport] [-S ctl_path][user@]hostname [command]

Provide more complete use information in the OpenSSH manual. This manual is part of the traditional UNIX file manual system. In command line mode, enter the man ssh command to access the OpenSSH manual. The manual provides command line options of the OpenSSH client, associated configuration file information, known Bug information of the current version, information about shell environment variables that affect the operation, and a list of related instructions. As shown in the list, there are sshd instructions, ssh-agent instructions, and other application instructions in the OpenSSH tool set.