1st of all, as the Windows maintainer for X2Go Client, I intend to either add support for using PuTTY private keys, or at least update X2Go Client to give a meaningful error message about PuTTY private keys not being supported. I currently have no ETA on when I will implement this.
2nd, if Pageant support is not working for you in x2goclient 4.0.1.3 or 4.0.1.3+build2, upgrade to x2goclient 4.0.2.0. This is bug 448.
3rd, as Stefan briefly mentioned, With PuTTYGen (0.63), a workaround is available. Basically you are just exporting your private key from PuTTY format to OpenSSH format. This workaround is the intended design of PuTTY suite. Here are full instructions.
Step 4 isn't required, but I strongly encourage you to follow it. Step 5 only applies to if you wish to use cygwin.
- Generate or load your putty private key with PuTTYGen
- Select Conversions -> export OpenSSH key
- Save the private key file to a file. I strongly encourage you to save it with the standard openSSH filename. The standard filename would be, depending upon what type of key your generated,: id_rsa id_dsa
- Copy the "Public key for pasting into OpenSSH authorized_keys file" into a new file in your favorite text editor; notepad will suffice. Save it as one of the standard filenames in the same folder: id_rsa.pub id_dsa.pub When saving it, make sure you do not put .txt on the end of the filename!
- If you have cygwin installed on your Windows client, copy or move both files to: ~/.ssh/ . Create ~/.ssh/ if it does not exist. Make sure you set the correct permissions though: chmod 700 ~/.ssh && chmod 600 ~/.ssh/*
- Configure your X2Go Client to use your id_rsa or id_dsa file.