What is the difference between Integrated Security = True and Integrated Security = SSPI?

Question

I have two apps that use Integrated Security. One assigns Integrated Security = true in the connection string, and the other sets Integrated Security = SSPI.

What is the difference between SSPI and true in the context of Integrated Security?

Solution 1

According to Microsoft they are the same thing.

When false, User ID and Password are specified in the connection. When true, the current Windows account credentials are used for authentication.
Recognized values are true, false, yes, no, and sspi (strongly recommended), which is equivalent to true.

Solution 2

Integrated Security=true; doesn't work in all SQL providers, it throws an exception when used with the OleDb provider.

So basically Integrated Security=SSPI; is preferred since works with both SQLClient & OleDB provider.

Here's the full set of syntaxes according to MSDN - Connection String Syntax (ADO.NET)

Solution 3

Using Windows Authentication

To connect to the database server is recommended to use Windows Authentication, commonly known as integrated security. To specify the Windows authentication, you can use any of the following two key-value pairs with the data provider. NET Framework for SQL Server:

 Integrated Security = true;
 Integrated Security = SSPI;

However, only the second works with the data provider .NET Framework OleDb. If you set Integrated Security = true for ConnectionString an exception is thrown.

To specify the Windows authentication in the data provider. NET Framework for ODBC, you should use the following key-value pair.

Trusted_Connection = yes;

Source: MSDN: Working with Connection Strings

Solution 4

Many questions get answers if we use .Net Reflector to see the actual code of SqlConnection :) true and sspi are the same:

internal class DbConnectionOptions

...

internal bool ConvertValueToIntegratedSecurityInternal(string stringValue)
{
    if ((CompareInsensitiveInvariant(stringValue, "sspi") || CompareInsensitiveInvariant(stringValue, "true")) || CompareInsensitiveInvariant(stringValue, "yes"))
    {
        return true;
    }
}

...

EDIT 20.02.2018 Now in .Net Core we can see its open source on github! Search for ConvertValueToIntegratedSecurityInternal method:

https://github.com/dotnet/corefx/blob/fdbb160aeb0fad168b3603dbdd971d568151a0c8/src/System.Data.SqlClient/src/System/Data/Common/DbConnectionOptions.cs

Solution 5

Integrated Security = False : User ID and Password are specified in the connection. Integrated Security = true : the current Windows account credentials are used for authentication.

Integrated Security = SSPI : this is equivalant to true.

We can avoid the username and password attributes from the connection string and use the Integrated Security

View more solutions

Comments

[Pranav Singh]

The accepted answer is not the best one, its not fully correct either. Integrated Security = True or SSPI are not same. Integrated Security=true; doesn't work in all SQL providers, it throws an exception when used with the OleDb provider. So basically Integrated Security=SSPI; is preferred since works with both SQLClient & OleDB provider. I have added an answer for better clarification.

[Mark]

@PranavSingh has the right idea, this question is incomplete unless you specify which provider you are using. Different providers accept and/or translate various strings into internal states.

[Hassan Faghihi]

Although they are same, I believe that there was a very old document in one of websites, at the time i was curious same as you, that said if you are developing for windows mobile (not what you see today, the old devices which i don't remember the OS suffix since i never had one), you should use SSPI, and User Password together. but since i never wrote one, and i don't remember the source of that document, i cannot guarantee it.

[ATL_DEV]

What is SSPI short for? The "SS" hopefully means SQL Server, but not sure what SI means.

[eugened]

Originally, I think there was a difference in that "True" used NTLM and "SSPI" used Kerberos, but they're now interchangeable.

[JD.]

Thanks for the response. Any reason why it works with one and not the other? In fact, if recall correctly, the error obtained when I used "true" was about some driver (on a 2003 windows server with sql server express). JD.

[Johnny_D]

Didn't check last comment, but if true, should be as answer, but not the comment

[Barış Velioğlu]

@RodneyFoley I use SSPI with wrong username and password, but it doesnt care and connected successfully in net4.0. Is this expected result ?

[Kirk Broadhurst]

@RodneyFoley Do you have a source for that statement? This seems unusual as integrated is preferred over SQL authentication, so a system that defaults to SQL auth seems unlikely.

[Rodney S. Foley]

@KirkBroadhurst MSDN Doc's for connection strings, and real world usage.

[Kirk Broadhurst]

@RodneyFoley sorry, wasn't clear enough. Can you provide a source for that statement? I'm googling it and can't find any such advice.

[Kirk Broadhurst]

@RodneyFoley sorry, my tests confirm that this answer is correct and your comment is not. Maybe it worked that way once, but it doesn't now, and you can't provide any reference to a Microsoft doc that supports your opinion.

[Amit Shishodia]

social.msdn.microsoft.com/Forums/en-US/…

[Alex des Pelagos]

Agree with Kirk. User / password is ignored when SSPI specified - .net 4.0, SQL server 2012.

[Jason Goemaat]

@RodneyFoley and @KirkBroadhurst: Looking at other answers it looks like it might depend on the provider used. If talking about System.Data.SqlClient, I did find this article which says True means that User Id and Password will be ignored and SSPI means that they will be be used if present, but Windows Security will be used if not. This link says true will ignore them but doesn't mention SSPI.

[Zé Carlos]

So if they "are the same thing" why is SSPI "strongly recommended" rather than "true" or "yes? That's the reason why I came to this question...

[underscore_d]

The connection string is not necessarily visible to any employee.

[Zé Carlos]

@PranavSingh: It's not me who is saying they are the same. Is the current answer which we are commenting...

[Pranav Singh]

@ZéCarlos Ok, Got it. Somehow that is accepted answer with highest votes :) . I added answer for same clarification

[Pranav Singh]

That part of code is property only for one case that is explainable by name ConvertValueToIntegratedSecurityInternal. That property is used only when provider is SqlClient so in SqlClient, SSPI &true are same but not when client is OleDb or OracleClient. I have clarified that in stackoverflow.com/a/23637478/704008 with msdn reference

[Kelly]

If it is only used to say you are using Windows Authentication, wonder why they didn't just call the setting/property "Windows Authentication" instead of Integrated Security?

[Yola]

Isn't this answer repeats the third rated one?

[interDist]

@Yola this answer is a bit more complete and also links to a still-valid Microsoft Docs page (the link in the other answer now brings you to a page suggesting to download Visual Studio 2005 Retired docs).