ssh-keygen does not find ssh_askpass

Question

I'm trying to generate SSH keys for Git on Windows (I just installed 2.18.0), but it's not finding something called ssh_askpass:

d:\src\py\>ssh-keygen -b 4096 -C [email protected]
Generating public/private rsa key pair.
Enter file in which to save the key (/d//.ssh/id_rsa): D:\.ssh\id_rsa_new
ssh_askpass: exec(/usr/lib/ssh/ssh-askpass): No such file or directory
ssh_askpass: exec(/usr/lib/ssh/ssh-askpass): No such file or directory
.
.pub.

The ssh-keygen binary is the one that comes with git, in C:\Program Files\Git\usr\bin, but that directory does not have a ssh_askpass file.

Where can I get this 'ssh_askpass' ? What is the consequence of not finding it ?

Answer 1

Answering my own question, for the benefit of others who might stumble onto this, now that I actually understand what was going: this command was typed inside an emacs subshell, which does not have the full terminal capabilities (it's considered a "dumb" terminal).

Then ssh-keygen considers that it is not running inside a terminal, so it can't read the passphrase, and it tries to run an X Window program instead, and fails because this is Windows.

The solution is to run ssh-keygen (or ssh-add) inside Git Bash, or in the Windows command line tool, where it will be able to prompt for the passphrase, and work as expected.

Answer 2

As in this issue, check if you have an environment variable DISPLAY=localhost:0.0 was set.

If so, unset it with:

set DISPLAY=

Then try again your ssh-keygen command.

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Make sure also, for testing, to try and generate a key without passphrase:

ssh-keygen -t rsa -P "" -b 4096 -C [email protected]

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Finally, check your %PATH% and make sure ssh-keygen called is the one you are thinking about (from Git installation)

where ssh-keygen

Sometimes, it can be overshadowed by one from Cygwin for instance.