Determine if user has administrator rights (windows)

szh1

Maybe I should just try to edit the registry, and if it fails, I assume the user lacks the correct privileges?

ixSci

You don't understand what are you talking about. You don't need privileges to access registry you need rights. Maybe you just explain what is the your main goal in common?

szh1

Sorry about my lack of knowledge about the innards of the Windows operating system. What exactly is the difference between privileges and rights? And if I changed my previous post to:

Maybe I should just try to edit the registry, and if it fails, I assume the user lacks the correct rights?

Would that work better?

By the way, I don't work for Microsoft, and I didn't build Windows either.

szh1

Why does the MSDN code sample not work in Qt?

ixSci

What exactly is the difference between privileges and rights?
It is a really big topic and I'd recommend you to read some articles or books(e.g. Jeffrey Richter) about it if you really have an interest. Shortly - rights is the object specific term and privilege is the system wide term.
Maybe I should just try to edit the registry, and if it fails, I assume the user lacks the correct rights?
You can only check if the user has a particular right against a particular registry entry.
Really you'd better tell us what is your end goal because security in windows isn't the easy topic to explain it in the forum.

szh1

My application requires registry editing, and in main() I want to make sure the user has the rights to edit the registry so I don't get errors when I try to do it.

DenisKormalev

< offtopic >
Oh, such a lot of tags for only twelve comments.
< /offtopic >

ixSci

Ok, presume you want to check if the user has a right to change some registry entry. You should:
@
if(RegOpenKeyEx(XXX, XXX, XXX, KEY_WRITE, XXX) == ERROR_ACCESS_DENIED)
//user has no right to write in this registry key
@
It's just a pseudo-code but I think you'll grasp the idea

szh1

Thanks! I think I'll try that. But I am still wondering why the MSDN sample code didn't work.

ixSci

I don't know, may be some troubles with Windows SDK? Check the headers which you had included whether they have that function declaration.

szh1

It says I need to include Windows.h, and I did. I also tried including Winbase.h. Still doesn't work.

szh1

[quote author="ixSci" date="1287770694"]Ok, presume you want to check if the user has a right to change some registry entry. You should:
@
if(RegOpenKeyEx(XXX, XXX, XXX, KEY_WRITE, XXX) == ERROR_ACCESS_DENIED)
//user has no right to write in this registry key
@
It's just a pseudo-code but I think you'll grasp the idea[/quote]

You can actually use QSettings to edit the registry.

szh1

I just got it working! Here's my code:
@
// get ready to attempt to edit the registry
QSettings adminTest("HKEY_LOCAL_MACHINE", QSettings::NativeFormat);
// get the current value and put it back
QVariant currentValue = adminTest.value("(Default)");
adminTest.setValue("(Default)", currentValue);
adminTest.sync();
// see if there was an error
if (adminTest.status() == QSettings::AccessError)
return false;
else
return true;
@

Thanks a lot for the help everyone! I definitely learned a lot from this.

szh1

By the way, I checked, and the above code puts in another "(Default)" Value Name with a Value Data of "@Invalid()". I am not sure if this is good or bad, but it hasn't causes me any problems. You do it at your own risk.

terma.aba

It is a valid question because: QSettings::Scope allows writes at QSettings::SystemScope - but only if you have sufficient rights (in the general sense of the English word rather than the Microsoft one).

The remaining posts seems to be Win API based, so I guess the answer is "no"?