What is my choice on MS Windows platforms for the SUID equivalent of Unix based platforms?

Question

To understand what I'm asking, it's important to distinguish between one of several uses of SUID on Unix.

I have a project that uses an executable in a user PATH that belongs to the project and which has the SUID bit. Thus, when it is executed, it is executed in the context of the owner of the file, not the caller. Thus, he has access to those things that the user does not do, and thereby these things are protected from the user by the usual file system protections. This works quite well. Plans are to move the project to a client-server architecture, but it will take some time. At the same time, how can I repeat this type of behavior on Windows systems?

Please note that project executables do not call the SETUID library, although, frankly, this would be a great opportunity to add, in my opinion, what the project does. The project does not need root privileges. The first security problem is that it must protect its own files from the user (which is just any user other than the owner of the file), and it would be very nice if he had the opportunity to switch to the "user context" to access to the file as if it were the calling user. (In this way, he could more easily determine what is appropriate for the project and what is not.)

The project is written in a combination of C and Java - a C program with a set of SUID calls Java code ...

I really want to know all such mechanisms and especially focus on those that:

• Suitable for C and Java and
• Easy to implement for non-Windows programmers and;
• Require minimum encoding unique to Windows.

If some solutions are superior, please share your thoughts on what you know in this regard.

NOTES:

• LogonUser: A plain text password is required. How can this be the answer?
• RunAs: you need to enter a password in PROMPT! ... As with LogonUser it is only worse; I do not understand how this is the answer.

Answer 1

Cygwin perfectly discusses how they do this without requiring a user password here: Using Windows Security in Cygwin

They basically install the LSA user authentication package, which provides security tokens without requiring a password. As a backup, when the authentication package is not installed, they use the undocumented NtCreateToken API.

An application that wants to impersonate itself can make a call to cygwin setuid before calling java.

Answer 2

I don’t think that on Windows there is the equivalent of SETUID, but you can start the process as another user. If you use C, there really are only two main Windows Specific features that you need to learn:

Logonuser

CreateProcessAsUser

The docs for these features are pretty good, so this should not be a huge problem. Basically you will use LogonUser to impersonate the user, and then CreateProcessAsUser to start the JVM as that user.

You can also watch RUNAS , but I'm not sure if this will meet your needs or not.