Security of Credentials

If you are using public key authentication, you can use Pageant authentication agent to avoid entering your passphrase for every connection.

If you want to store your password in site to avoid entering them for every connection, it is recommended to protect them with master password.

By default, when you enter your password on authentication window, it is used only for that single authentication. When WinSCP needs to authenticate again, such as when reconnecting, opening additional connection for background transfer or opening separate shell session, you are prompted for your password again.

You can choose to keep the password in memory, to allow its reuse, on password prompt. You can also opt to remember the password for all sessions using preference option Remember password for duration of the session.1

In the latest beta version, the password is remembered by default.

The same effect (just per-session, not global) has entering your password already to a Password box on the Login dialog. For a stored site you can achieve that by cloning it.

If you have your password stored in site, it’s remembered implicitly.

Keeping password in memory can be dangerous, in case a malware gains access to the WinSCP process or the memory is swapped out to disk or written into a crash dump file. However, it is still unavoidably very dangerous if malicious software is in a position to read the memory of your WinSCP processes: there is still a lot of sensitive data in there which cannot be wiped because it’s still being used, e.g. session keys. Also Pageant retains decrypted private keys in memory for long periods on purpose if you use it. So turning the option off somewhat mitigates the risks of malicious access to your WinSCP processes’ memory, but it cannot eliminate those risks completely.2

Enable preference option Remember session password and pass it to PuTTY to make WinSCP keep password in memory and pass it to PuTTY, when opening a session in PuTTY.

Note that the password is passed to PuTTY using command-line parameter -pw. It is rather easy for other processes (possibly malicious) on your computer to retrieve command-line used to start PuTTY, hence to discover your password. So you should avoid using this option, unless you are confident about security of your computer. Preferred alternative approach is to use public key authentication together with Pageant (PuTTY can use Pageant too).

The least recommended method of handling passwords conveniently is to store them unprotected with your site.

Saved passwords (unless protected by master password) are stored in a manner that they can easily be recovered. It is not possible to securely encrypt passwords in a way that still allows for automatic use. Do not use the save password feature if you are not absolutely sure of the physical and electronic security of the system on which you are storing passwords.

Also note that you need to request storing your password unprotected explicitly on Save session as dialog.

System administrators can restrict password storing altogether.

Learn how to protect credentials used for automation.