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Andrew Wharton

WSE16 client backup errors after disabling TLS 1.0/1.1?

I would like to secure my WSE16 by removing TLS 1.0 & 1.1 as recommended by ssllabs. However, after I do so via SCHANNEL\Protocols registry keys, client backups fail with error ‘cannot contact server’. Are there additional steps I must take on WSE2016 as so not to break any core services?   I would very much appreciate some direction.

asked05/07/2020 17:19
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Last Activity 05/29/2020 02:59

1 Answer(s)

  • Mariette Knap
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    Andrew Wharton

    Thank you for your exceptionally speedy response Mariette.   I did find some additional regkeys to make .net use more secure channels. But I wasn’t sure if they were applicable.   Making .net use TLS 1.2 won’t be of any use to me, no?

    Host

    It requires a code update of the Essentials Dashboard and as that is closed source by Microsoft there is nothing you can do about this. It will not take long before the Essentials Dashboard stops working with Office 365 integration because Office 365 will require TLS 1.2 only. Integration in the dashboard will therefor stop working.


    replied 05/08/2020 07:09
    Andrew Wharton

    Thank you greatly for your time in helping me to understand.

     

    Would you know if it’s just TLS 1.0/1.1 that WSE16 relies on. Could I go ahead and add SSL & RC4 regkeys to harden my box the best I can, or will doing so break core services too?


    replied 05/08/2020 07:30
    Joe Mills

    I found the addition of  "SchUseStrongCrypto" to all .NET subkeys worked for me.  My servers are currently supporting TLS 1.2 only.  Refer to the following:

    https://support.microsoft.com/en-us/help/4022913/how-to-resolve-azure-backup-agent-issues-when-disabling-tls-1-0-for-pc

    Hope this helps!

     


    replied 05/08/2020 13:51
    Mariette Knap

    Joe, thanks for this. Did you implement that on a Windows Server 2016 + Essentials Experience role? Or is it just Standard or Datacenter?


    replied 05/08/2020 14:15
    Andrew Wharton

    Thanks Joe. I had already read this information, and thought it may have been useful after learning here that the Dashboard is .net driven.

     

    Have you tested connector wizards etc to ensure nothing else is broken?


    replied 05/08/2020 14:23
    Joe Mills

    Yes, I ran it on Windows Server 2016 Essentials up until lat week when I upgraded to Windows Server 2019 Standard with the added (unsupported but working) Essentials role.  :-)  Works in both.


    replied 05/08/2020 14:26
    Andrew Wharton

    I was reading about applying TLS conditions to specific domains this morning. However, after poking around it appears the information was only applicable to WSE2019


    replied 05/08/2020 14:28
    Andrew Wharton

    Adding SchUseStrongCrypto regkeys as directed in the link provided here did not work. The directions did not specify 32bit or 64bit DWORD entries, so I have used 32-bit. Do you think this would have made any difference?

     The regkeys I am using to harden WSE16 are as follows:

    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 2.0\Client]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 2.0\Server]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 3.0\Client]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\SSL 3.0\Server]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.0\Client]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.0\Server]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Client]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000
    
    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.1\Server]
    "DisabledByDefault"=dword:00000001
    "Enabled"=dword:00000000

     Any ideas welcomed!


    replied 05/08/2020 16:30
    Joe Mills

    Did you add the "SchUseStrongCrypto" to registry on the Clients and Server?  I found it is required on the Clients after disabling TLS 1.0 and 1.1 on the server.


    replied 05/08/2020 17:06
    Andrew Wharton

    A response to my Technet post seems to confirm what Mariette has already stated; it isn’t possible.

     

    I have, however, been given a link to a workaround script: https://www.hass.de/content/setup-microsoft-windows-or-iis-ssl-perfect-forward-secrecy-and-tls-12

     

    I will look into this after my WSE16 has finished restoring.

     

    Thank you for your time. You're the best!


    replied 05/08/2020 17:07
    Andrew Wharton

    I only added the .net keys to the server. All of my clients are Win10, and I assumed they would use TLS 1.2 when necessary. I guess now that was wrong to assume.

     

    On the other forum I was told that disabling TLS 1.0 will break other functions of the server. So, I’m inclined to review the mentioned script to harden my box.

     

    If I am unhappy to proceed with the script for any reason, I will almost certainly come back to your solution Joe. With thanks!


    replied 05/08/2020 17:21
    Joe Mills

    I haven't found anything broken yet on my servers after disabling TLS 1.0 & 1.1 and adding the keys to the Servers and Clients.  I can't vouch for that script as I have NOT tried it.....  IMO I would try adding the keys to the clients first as it should be a quick and easy test; and easily reversed if it doesn't work for you.  Good luck!


    replied 05/08/2020 17:31
    Andrew Wharton

    I didn’t find any reasons not to use the mentioned script, and every reason to use it. The script does need to be run on both server and clients. And, I found that it adds the SCHANNEL and .net regkeys which leads me to believe that Joe’s advice is sound.

     

    But with that said, the script is most convenient, and addresses the other security issues too. For me, it was the perfect solution. Instead of various tasks spread across numerous notes, its everything I need in one place.

     

    This has been an enlightening ride. I hope that the information in this thread helps others on the same path.

     

    Many thanks!


    replied 05/09/2020 07:40
    Eugene Palmer

    So far so good with the script!  Now to get it out to remote clients.


    replied 05/29/2020 02:59

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    replied 05/07/2020 17:46
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