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0600 Credential Delegation Issue

Malcolm Stewart edited this page Nov 3, 2020 · 12 revisions

0600 Credential Delegation (double Hop) Issue

0600.1 Is this the correct workflow?

Does the issue only affect database connections, or does it affect web and file share connections, too?

0600.1.1 Typical Error Messages

  • Cannot generate SSPI Context
  • Login failed for user '(null)'
  • Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'

0600.1.1 Is there a better workflow?

0600.2 Moving Parts

The initial goal is to try to isolate whether the web server or the SQL Server is not accepting Kerberos credentials. If there are problems after that, we have additional troubleshooting steps.

Here is the conceptual diagram of Kerberos delegation.

Kerberos Diagram

0600.3 Pre-Work

0600.3.1 Please perform the initial data collection and narrowing steps: 0100 Initial Data Collection and Scoping Questions. This will help get a macro perspective of the scope of an issue, such as whether the issue affects multiple computers or just one, or whether only those computers in a specific data center are facing issues. This can help focus the troubleshooting steps. It will also make you prepared for discussing the issue with Microsoft Support should you choose to do so.

0600.3.2 Make sure you understand the application architecture. Make a summary in a succinct form, similar to the below description:

  • There are two domains involved: CONTOSO and FABRIKAM.
  • The client (SPARKY.CONTOSO.COM) is Windows 2012.
  • The user (CONTOSO\JOHNDOE) runs EDGE and connects to a web server (_HTTP://WEB01.CONTOSO.COM/Accounting) using Integrated security.
  • The IIS app pool runs as (CONTOSO\WEB_SVC).
  • The web server connects to SQL Server 2014 (SQLProd01.FABRIKAM.COM\Accounting on port 1433) using the SqlClient .NET 4.6.2 Provider and delegates the user credentials to SQL Server via integrated security.
  • The SQL Server service account is FABRIKAM\SQL_SVC_01.

0600.3.3 Collect the SPN information based on the service accounts identified in the description. e.g.

SETSPN -L CONTOSO\WEB_SVC > c:\temp\spns.txt             > creates a new file
SETSPN -L FABRIKAM\SQL_SVC_01 >> c:\temp\spns.txt        >> appends to a file

0600.4 Alternate Delegation Scenarios to be Aware of

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