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| faq_su 2005-07-13 | faq_su 2024-09-09 (current) | ||
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| - | ====== How do I change a user after login (e.g. su root)? ====== | + | ====== How do I change user after login (e.g. su root)? ====== |
| - | [[protocols#sftp_ssh_file_transfer_protocol|SFTP protocol]] does not allow this. | + | None of the protocols ([[sftp|SFTP]], [[ftp|FTP]] and [[scp|SCP]]) supported by WinSCP allow the user to be changed in the middle of file transfer session. You need to start the session with the correct user. |
| - | With [[protocols#scp_secure_copy_protocol|SCP protocol]] it is possible, but only if you are allowed to do ''sudo su'' without being prompted with password. See ''sudo'' documentation to learn how to do that. Then you can specify ''sudo su'' (or ''sudo su <username>'') as custom shell on //[[ui_login_scp#shell|SCP tab]]// of Login dialog. | + | ===== Direct Login ===== |
| - | MORE: in the Environment setting, SCP screen. Change the shell from default to ENTER. then type: /bin/bash -c "sudo su" | + | Easiest way is to allow direct login with the user account you need, if it is not allowed already. For accounts such as ''root'', the direct login is typically disabled by default for security reasons. So when enabling it, have security in mind. |
| - | You must have the dash C and the quotes to make this work. Try and copy/paste the line as I typed it. | + | Particularly with SSH, you may want to keep password authentication (the most vulnerable one) disabled and use e.g. [[public_key|public key authentication]] instead. With OpenSSH server, you can do that by setting ''[[https://man.openbsd.org/sshd_config|sshd_config]]'' keyword ''PermitRootLogin'' to ''without-password''.((Even more restrictive option ''forced-commands-only'' may work with SFTP protocol, but it has not been tested.)) |
| - | Hit SAVE and call it: sudo session | + | ===== [[sudo]] Use sudo on Login ===== |
| + | In some cases (with Unix/Linux server) you may be able to use ''[[&man_ref(8,sudo)|sudo]]'' command straight after login to change a user, before file transfer session starts. | ||
| - | Now open the saved sesssion called: sudo session and enter the hostname or IP address and hit save again. give it the name of your server and add the word sudo at the end to identify this session as a sudo connection. | + | [[ftp|FTP]] protocol does not allow this. |
| + | |||
| + | The [[scp|SFTP]] and [[scp|SCP]] protocols allow for this, but the actual method is platform dependent. | ||
| + | |||
| + | * With SFTP protocol, you can use //[[ui_login_sftp#protocol_options|SFTP server]]// option on //SFTP page// of Advanced Site Settings dialog to execute SFTP binary under a different user. With OpenSSH server, you can specify: \\ <code> | ||
| + | sudo /bin/sftp-server | ||
| + | </code> Note that SFTP server binary may be located elsewhere((You can see path to SFTP binary in ''Subsystem sftp'' clause in ''/etc/ssh/sshd_config'', unless keyword ''internal-sftp'' is used instead of a path. You may also use ''whereis sftp-server'' command to locate the binary.)) (e.g. in ''/usr/lib/sftp-server'', ''/usr/lib/openssh/sftp-server'' or ''/usr/libexec/openssh/sftp-server''). | ||
| + | |||
| + | * With SCP protocol, you can specify the following command as custom shell on the //[[ui_login_scp#shell|SCP/Shell page]]// of Advanced Site Settings dialog: \\ <code> | ||
| + | sudo -s | ||
| + | </code> | ||
| + | |||
| + | However you will not be able to provide a password for ''su'' (see [[remote_command#limitations|remote command execution limitations]]). So you may be able to do the above only if you are allowed to do ''sudo su'' without being prompted with password. See ''[[&man_ref(8,sudo)|sudo]]'' documentation to learn how to do that. For example you can add following line to ''[[&man_ref(5,sudoers)|sudoers]]'' file (''/etc/sudoers''): | ||
| + | |||
| + | yourusername ALL=NOPASSWD: ALL | ||
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| + | The above line is very permissive, it allows user ''yourusername'' connected from anywhere (the first ''ALL'') to run any command (the second ''ALL'') as a ''root'' without being asked for password. So you should restrict it as much as possible. | ||
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| + | For example with OpenSSH you may restrict it only to SFTP session by: | ||
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| + | yourusername ALL=NOPASSWD: /bin/sftp-server | ||
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| + | Note that as WinSCP cannot implement terminal emulation, you need to have ''sudoers'' option ''requiretty'' turned off (which is default). | ||
| - | If you have all the correct rights in the sudoers file to run sudo su without a password, then this configuration will get you into the linux box and give you full rights while in WINSCP. Happy Copying :) | ||