tailieunhanh - .Pro OpenSSH phần 5

Rhosts. Nếu máy tin tưởng B Một máy, sau đó máy cũng phải tin tưởng các cơ chế xác thực của máy B. Điều này có thể dẫn đến nhiều thú vị Xác thực khóa công khai có thể cung cấp chứng thực là noninteractive, đó là lý tưởng cho người dùng kết nối với máy chủ từ xa và | CHAPTER 5 THE OPENSSH CLIENT 101 warnings about host key changes. By default host keys for the localhost are checked as demonstrated in the following code NoHostAuthenticationForLocalhost no NumberOfPasswordPrompts This keyword requires an integer as an argument. It specifies how many password attempts should be made before the client gives up. By default this is 3 as shown in the following example NumberOfPasswordsPrompts 3 PasswordAuthentication This token instructs the ssh client to attempt or not to attempt password-based authentication via a yes no argument. When using key-based authentication for automated jobs or system activity it is often a good idea to set PasswordAuthentication to no. This is covered in more detail in Chapter 6. PasswordAuthentication yes Port This keyword tells the client what port on the remote server should be used for the SSH connection. The default is 22 as shown in the following example Port 22 PreferredAuthentications This keyword tells ssh the order of preference for authentication techniques. By default this uses hostbased publickey keyboard-interactive password. As you see in the example that follows I often take out hostbased authentication because of my fondness for user-specified security. This option only applies to protocol 2. PreferredAuthentications publickey keyboard-interactive password Protocol This argument tells the client which protocol should be used. The default is 2 1 meaning that protocol 2 will be attempted and if it fails protocol 1 will be used. Normally I explicitly specify protocol 2 only as in the following code line. Multiple arguments are comma separated. Protocol 2 ProxyCommand When using a proxy the command string can be specified with a few expandable parameters. h is used for hostname and p is used for port. The command can be any appropriate string for your proxy. Setting the command to none will disable this option. 102 CHAPTER 5 THE OPENSSH CLIENT PubkeyAuthentication This keyword tells the ssh .