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ssh

Configuring SSH On Windows

ssh comes with both Cygwin and MSYS. (Cygwin note: you need to ask for package openssh (not ssh) in the Cygwin list of packages; or use the ghc-depends package -- see Installing and configuring Cygwin.)

There are several strange things about ssh on Windows that you need to know.

  • The programs ssh-keygen1, ssh1, and cvs, seem to lock up bash entirely if they try to get user input (e.g. if they ask for a password). To solve this, start up cmd.exe and run it as follows:

    c:\tmp> set CYGWIN32=tty
c:\tmp> c:/user/local/bin/ssh-keygen1

  • (Cygwin-only problem, I think.) ssh needs to access your directory .ssh, in your home directory.
    To determine your home directory ssh first looks in c:/cygwin/etc/passwd (or wherever you have Cygwin installed). If there's an entry there with your userid, it'll use that entry to determine your home directory, ignoring the setting of the environment variable $HOME. If the home directory is bogus, ssh fails horribly. The best way to see what is going on is to say

    ssh -v cvs.haskell.org

    which makes ssh print out information about its activity.

    You can fix this problem, either by correcting the home-directory field in c:/cygwin/etc/passwd, or by simply deleting the entire entry for your userid. If you do that, ssh uses the $HOME environment variable instead.

  • To protect your .ssh from access by anyone else, right-click your .ssh directory, and select Properties. If you are not on the access control list, add yourself, and give yourself full permissions (the second panel). Remove everyone else from the access control list. Don't leave them there but deny them access, because 'they' may be a list that includes you!

  • In fact ssh 3.6.1 now seems to require you to have Unix permissions 600 (read/write for owner only) on the .ssh/identity file, else it bombs out. For your local C drive, it seems that chmod 600 identity works, but on Windows NT/XP, it doesn't work on a network drive (exact dteails obscure).
    The solution seems to be to set the $CYGWIN environment variable to "ntsec neta". The $CYGWIN environment variable is discussed in the Cygwin User's Guide, and there are more details in the Cygwin FAQ.