Windows SSH: Permissions for 'private-key' are too open

Question

I've OpenSSH 7.6 installed in Windows 7 for testing purposes. SSH client & server work just fine till I tried to access one of my AWS EC2 box from this windows.

It seems like I need to change the permission on the private key file. This can be easily done on unix/linux with chmod command.

What about windows?

private-key.ppm is copied directly from AWS and I guess the permission too.

C:\>ssh -V
OpenSSH_7.6p1, LibreSSL 2.5.3

C:\>ver

Microsoft Windows [Version 6.1.7601]

C:\>


C:\>ssh ubuntu@192.168.0.1 -i private-key.ppk
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions for 'private-key.ppk' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
Load key "private-key.ppk": bad permissions
ubuntu@192.168.0.1: Permission denied (publickey).

C:\>
C:\>
C:\>ssh ubuntu@192.168.0.1 -i private-key.ppm
Warning: Identity file private-key.ppm not accessible: No such file or directory.
ubuntu@192.168.0.1: Permission denied (publickey).

C:\>

Answer 1

You locate the file in Windows Explorer, right-click on it then select "Properties". Navigate to the "Security" tab and click "Advanced".

Change the owner to you, disable inheritance and delete all permissions. Then grant yourself "Full control" and save the permissions. Now SSH won't complain about file permission too open anymore.

It should end up looking like this:

Answer 2

Keys must only be accessible to the user they're intended for and no other account, service, or group.

• GUI:
  • [File] Properties - Security - Advanced
    1. Set Owner to the key's user
    2. Remove all users, groups, and services, except for the key's user, under Permission Entries
    3. Set key's user to Full Control

• CLI:

  :: # Set Variable ::
  Set Key="C:\Path\to\key"
  
  :: # Remove Inheritance ::
  Cmd /c Icacls %Key% /c /t /Inheritance:d
  
  :: # Set Ownership to Owner ::
  Cmd /c Icacls %Key% /c /t /Grant %UserName%:F
  
  :: # Remove All Users, except for Owner ::
  Cmd /c Icacls %Key% /c /t /Remove Administrator "Authenticated Users" BUILTIN\Administrators BUILTIN Everyone System Users
  
  :: # Verify ::
  Cmd /c Icacls %Key%
  

Answer 3

In addition to the answer provided by ibug. Since i was using the ubuntu system inside windows to to run the ssh command. It still was not working. So i did

sudo ssh ...

and then it worked

Answer 4

I had the same problem, and it seems to be related to the version of SSH you're running.

If I type

where ssh

I get...

C:\Windows\System32\OpenSSH\ssh.exe
C:\Program Files\Git\usr\bin\ssh.exe

When I run ssh -V in both locations, I get

OpenSSH_7.5p1, without OpenSSL
OpenSSH_7.3p1, OpenSSL 1.0.2k  26 Jan 2017

...respectively

So, when I run ssh from the git/bin directory, it works fine and doesn't complain about the permissions, but running the same command line, using the former installation of SSH, it comes back with this.

Load key "t:\\mykeys\\rich-private.ppk": invalid format
banana@127.0.0.127: Permission denied (publickey).

ps. the permissions on the file are just full access for myself, and nothing else.

Answer 5

use below command on your key it works on windows

icacls .\private.key /inheritance:r
icacls .\private.key /grant:r "%username%":"(R)"

Answer 6

I had a similar issue but I was at work and don't have the ability to change file permissions on my work computer. What you need to do is install WSL then copy the your key to the hidden ssh directory in WSL:

cp <path to your key> ~/.ssh/<name of your key>

Now you should be able to modify the permissions normally.

sudo chmod 600 ~/.ssh/<your key's name>

Then ssh using WSL:

ssh -i ~/.ssh/<name of your key> <username>@<ip address>

Answer 7

You need jsut 2 things:

1) Disable inheritance

2) Convert inherited permissions to explicit permissions

3) Remove Users group

4) You will end up with no Users can access private files, this should be enough to add id_rsa.

Answer 8

You can use icacls in windows instead of chmod to adjust file permission. To give the current user read permission and remove everything else,

icacls <file name> /inheritance:r
icacls <file name> /grant:r "%username%":"(R)"

Answer 9

This is just a scripted version of @JW0914's CLI answer, so upvote him first and foremost. Also, it is my first PowerShell script, so suggestions welcome.

# DO the following in powerhsell if not already done:
# Set-ExecutionPolicy RemoteSigned


# NOTE: edit the path in this command if needed
$sshFiles=Get-ChildItem -Path C:\DevContainerHome\.ssh -Force

$sshFiles | % {
  $key = $_
  & icacls $key /c /t /inheritance:d
  & icacls $key /c /t /grant %username%:F
  & icacls $key  /c /t /remove Administrator "Authenticated Users" BUILTIN\Administrators BUILTIN Everyone System Users
}

# Verify:
$sshFiles | % {
  icacls $_
}

Answer 10

A single line in CMD might do the trick (as described here: https://serverfault.com/a/883338/550334), i.e. adding the key from stdin instead of changing the permissons:

cat /path/to/permission_file | ssh-add -k 

To check if key has been added:

ssh-add -l

Answer 11

Use Mingw-w64.

Infos: http://mingw-w64.org/doku.php

Download with Git for Windows, or directly.

Available here: https://github.com/mirror/mingw-w64

git clone https://github.com/mirror/mingw-w64

It also has other useful Linux commands like tar and gzip.

Answer 12

I'm a Window user, using the Windows's bash and followed all the steps to set permission using Windows GUI, and it still doesn't work and it complains:

Permissions 0555 for 'my_ssh.pem' are too open.
It is required that your private key files are NOT accessible by others.

The I added sudo at the front of the ssh command and it just works. Hope this is helpful to others.

Answer 13

I couldn't get any of these answers working for me due to permission issues, so I'll share my solution:

1. Go to C:\Users\UserName.ssh

2. Copy and paste the id_rsa file

3. Rename it to something else, eg. example

4. Open the renamed file example and replace the key with your own private key

5. cd to that directory

6. Do ssh -i example example@127.0.0.1 and enter your password.

Answer 14

Answer by iBug works fine! You can follow that and get rid of this issue.

But there are few things which are needed to be cleared as I faced issues during setting up permissions and it took few minutes for me to figure out the problem!

Following iBug's answer, you'll remove all the permissions but how do you set Full Control permission to yourself? that's where I got stuck at first as I didn't knew how to do that.

After Disabling Inheritance, you'll be able to delete all allowed users or groups.

Once Done with that,

Click on Add then click on Set a Principal then enter System and Administrators and your email addredd in the field at bottom then click on check names.

It'll load the name if user exists. Then, Click on OK > Type Allow > Basic Permisisons Full Control > Okay

This will setup Full Control permission to SYSTEM, Administrators and Your User.

After that try to ssh using that key. It should be solved now.

I had same issue and I solved that using this method. If there's any user or group with that name then it'll load that.

-Screenshots-

Permission Entries Select a Principal/ Select User or Groups