Async/Await with Entity Framework 6.1.1 and impersonation

问题:

I have a WCF service hosted in IIS that is retrieving data from multiple sources (all SQL Server). With each data source, I have to impersonate a different Active Directory user to connect to the database. I am using Entity Framework v6.1.1 for two of the data sources. Integrated Security is set to True in the connection strings, too.

I use the example below to set the impersonated user, where the impersonated user is a System.Security.Principal.WindowsImpersonationContext that I set from configuration:

internal async Task<List<string>> GetItemsByLookupItemsAsync(List<string> lookupItems)  {     var result = new List<string>();      using (var db = new EntityFrameworkDb())      {          var query = from item in db.Table                     where lookupItems.Contains(item.LookupColumn)                     select item.StringColumn;          var queryResult = new List<string>();         using (GetImpersonatedUser())         {             queryResult.AddRange(await query.ToListAsync());         }          result.AddRange(queryResult.OrderBy(e => e));     }      return result; } 

The problem is that the previous code throws a SqlException saying that the account running the web service can not log on to the database. It appears that when I hit the await I lose the impersonation context.

What are some suggestions to solve this problem?

回答1:

Set the legacyImpersonationPolicy to false and alwaysFlowImpersonationPolicy to true inside your web.config and restart IIS

<configuration>    <runtime>      <legacyImpersonationPolicy enabled="false"/>     <alwaysFlowImpersonationPolicy enabled="true"/>      </runtime> </configuration> 

文章来源: Async/Await with Entity Framework 6.1.1 and impersonation