"Bad owner or permissions" error using Cygwin's ssh.exe

If you are an IT administrator, you may have encountered the dreaded “Bad owner or permissions on .ssh/config” error when trying to use Cygwin’s ssh.exe. This error is caused by the ssh.exe utility not having the correct permissions to access the .ssh/config file. This can be a frustrating issue, as the error message itself can be rather vague and unhelpful in determining the cause of the problem.

Fortunately, the solution to this problem is fairly straightforward. The first step is to ensure that the user running the ssh.exe utility has the correct permissions to access the .ssh/config file. To do this, you will need to open the Windows Explorer and navigate to the folder containing the .ssh/config file. Right-click the file and select Properties. In the Properties window, switch to the Security tab. In the Group or user names list, select the user that is running the ssh.exe utility and verify that they have Read and Execute permissions. If not, click the Edit… button and set the permissions accordingly.

Once the user has the correct permissions, the second step is to ensure that the file itself is not corrupted. To do this, you will need to open a command prompt and navigate to the folder where the .ssh/config file is located. Once there, type the command “md5sum .ssh/config” to calculate the MD5 checksum of the file. Compare the result with the MD5 checksum of a known good version of the file. If the checksums do not match, the file has been corrupted and will need to be replaced with a valid version.

Finally, the third step is to ensure that the ssh.exe utility is running with the correct command-line parameters. To do this, open the Task Manager and find the process “ssh.exe”. Right-click the process and select “Go to details”. In the Details tab, right-click the process “ssh.exe” and select “Properties”. In the Properties window, switch to the “Command-line” tab. Verify that the command-line parameters are correct. If not, click the “Change…” button and set the parameters accordingly.

Once all three steps have been completed, the “Bad owner or permissions on .ssh/config” error should no longer occur when using Cygwin’s ssh.exe. It is important to note that if the user running the ssh.exe utility does not have the correct permissions, the ssh connection will still succeed but the configuration file will not be used. It is also important to note that if the file itself is corrupted, the ssh connection may still succeed but the configuration file will not be used. In either case, the user may not be able to access certain services or perform certain tasks due to the missing or corrupted configuration file.