How to generate ssh keys (ecdsa) on Win10 for native ssh into Win10

Question

All,

I'm quite adept at key generation and public/private key authentication on Linux, but am basically a fish out of water on windows. I have Win10 with Ubuntu bash installed and I've had no problem with the ssh-keygen from within bash and setting up outbound passwordless ssh access to all Linux hosts. That is not what this questions asks.

This is about generating keys natively within Win10 OS so that I can ssh into Win10 w/o a password. (not the WSL bash instance, Win10 itself) For example, I can sit on my arch host and ssh into Win10 as follows:

Arch Host valhalla to Win10 host elite (HP elite workstation):

20:04 valhalla:~> uname -a
Linux valhalla 4.8.3-1-ARCH #1 SMP PREEMPT Thu Oct 20 19:53:59 CEST 2016 x86_64 GNU/Linux
20:04 valhalla:~> ssh elite
david@elite's password:

Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.

C:\Users\david>dir /a
Volume in drive C is Windows
Volume Serial Number is EA64-6B82

Directory of C:\Users\david

10/23/2016  03:38 PM    <DIR>          .
10/23/2016  03:38 PM    <DIR>          ..
10/22/2016  05:40 AM    <DIR>          AppData
10/22/2016  05:40 AM    <JUNCTION>     Application Data [C:\Users\david\AppData\Roaming]
10/22/2016  07:35 AM    <DIR>          Contacts
10/22/2016  05:40 AM    <JUNCTION>     Cookies [C:\Users\david\AppData\Local\Microsoft\Windows\INetCookies]
10/22/2016  07:35 AM    <DIR>          Desktop
10/23/2016  04:17 PM    <DIR>          Documents
10/23/2016  02:53 AM    <DIR>          Downloads
10/22/2016  11:40 PM    <DIR>          Favorites
10/22/2016  07:35 AM    <DIR>          Links
10/22/2016  05:40 AM    <JUNCTION>     Local Settings [C:\Users\david\AppData\Local]
10/22/2016  07:35 AM    <DIR>          Music
10/22/2016  05:40 AM    <JUNCTION>     My Documents [C:\Users\david\Documents]
10/22/2016  05:40 AM    <JUNCTION>     NetHood [C:\Users\david\AppData\Roaming\Microsoft\Windows\Network Shortcuts]
10/23/2016  03:37 PM         1,572,864 NTUSER.DAT
10/22/2016  05:40 AM           163,840 ntuser.dat.LOG1
10/22/2016  05:40 AM           131,072 ntuser.dat.LOG2
10/23/2016  03:38 PM         1,048,576 NTUSER.DAT{de890eec-984b-11e6-b234-9452f8984253}.TxR.0.regtrans-ms
<snip>
C:\Users\david>exit
Connection to elite closed.
20:04 valhalla:~>

The question is "is there a way to generate ssh keys (ecdsa) on Win10 natively?" (e.g. id_ecdsa and id_ecdsa.pub) and "if so, where do you put them on windows"? (is there a user .ssh directory, where they go?)

Worst case, "can I generate a key-pair on Linux and move the pair to Win10 and tell windows to use it?" (if so, same question "where would they go?")

(as a side note, it was just impressive as heck to be able to ssh into a windows OS, something I've taken for granted on Linux for 16 years, but was somewhat surprised when it worked into Win10 :)

Answer 1

You might need to wait patiently ...

The native Windows SSH service (as opposed to the sshd in WSL) doesn't seem to have much documentation published for it. It seems to have appeared along with WSL but, so far as I can tell, is somewhat separate.

See Win32 OpenSSH RoadMap

Rough timeline on when the key tasks would be accomplished:

Date        Task 
3/31/2016   Reliability Enhancements    
5/15/2016   Security Enhancements   
10/15/2016  Code Prep for integration   
10/30/2016  Integration in main repo    

Following Windows specific feature/work items are not in scope for this deadline:

• MINGW build support
• Use MS CNG (instead of OpenSSL)
• Key management using MS CNG
• Xterm, VT220 terminal modes
• ETW Logging (syslog alternative in Windows)

(my emphasis)

---

But note you can now/soon run native Windows executables from Bash under Ubuntu under Windows (WSL). Using the sshd in WSL might therefore suit some use cases that were hitherto problematic.

• Running Win32 program from Bash for Windows 10