Additional menu

Tachytelic.net

Remote Desktop CredSSP encryption Oracle remediation Registry fix

by 13 Comments

This is a quick credssp registry fix for the following error when trying to connect to a machine using RDP (Remote Desktop):

Image showing RDP CredSSP Authentication Error when connecting to a host with RDP
An authentication error has occurred. The function requested is not supported

This is because the server you are connecting to is not patched up to date, and the machine you are connecting from is. Modify the registry to allow your machine to connect to it:

  1. Open Regedit.
  2. Navigate to the following registry key, or create it if it does not exist: 
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters
  3. Create a new DWORD value called “AllowEncryptionOracle“
  4. Set the new registry entry to have a value of 2:

    Image showing AllowEncryptionOracle registry entry being set to a value of 2
    Set the value of AllowEncryptionOracle to 2
  5. Connect to the server that you were unable to connect to before.

Run this from an elevated command prompt to achieve the same result:

REG ADD "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters" /v AllowEncryptionOracle /t REG_DWORD /d 2

This registry entry is a temporary workaround until you have patched your server, when you have done that, remove the setting with this command.

REG Delete "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\CredSSP\Parameters" /v AllowEncryptionOracle

Reader Interactions

Comments

  1. shreyash says

    Wow Thats straight forward simple and effective.
    Thanks for making simple and easy steps.
    thaks alot

  7. Jose Castineiras says

    Amazing, if the creddssp\parameters folder does not exist create it and it work.

  10. nalin says

    Thanks it worked I had a typo in the Reg key.. What a quick fix. Will it get over wirtten the next time it updates GPO from the domain?

Leave a Reply