Troubles with User Permission

16 Dec 2006 1:09 PM

CharlyE

Hi!

I am working with VB6 and XP Home Edition.

I experience trouble when trying to access the windows registry and my app
databases when the user has limited permission (i.e., has not system
administrator permission).
The databases, which are common for all users, are not accessible because
they are locked in read-only mode (so I can't write on them), and the windows
registry will not let me write on the HKEY_LOCAL_MACHINE key (where I need to
write user-independent information for my app).

Can anybody help and give some guidance on working with user permission from
within VB6 code?

Thanks in advance

Carlos

PS: I hope my explanation is clear... I'm sorry if it's not... I'm a newbie!!

16 Dec 2006 2:45 PM

MikeD

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"CharlyE" <Char***@discussions.microsoft.com> wrote in message
news:745C11B2-89AE-45B2-B8AA-2D11992E214C@microsoft.com...
> Hi!
>
> I am working with VB6 and XP Home Edition.
>
> I experience trouble when trying to access the windows registry and my app
> databases when the user has limited permission (i.e., has not system
> administrator permission).
> The databases, which are common for all users, are not accessible because
> they are locked in read-only mode (so I can't write on them), and the
> windows
> registry will not let me write on the HKEY_LOCAL_MACHINE key (where I need
> to
> write user-independent information for my app).
>
> Can anybody help and give some guidance on working with user permission
> from
> within VB6 code?
>

Well, not sure about the database being read-only. That may or may not have
anything to do with permissions or user privileges. You'd need to provide
more information about this. For example, what is the database? Is it your
own file format (i.e. you're using VB's file I/O statements and functions to
read/write it). Is it an Access database? Some other RDMS? Where are the
database files located? Regular users do not have permissions for many
folders. For example, they may not have write permissions even to the
application folder (the folder where your app is installed). This is why
each user account has an Application Data (and other) folders under
Documents and Settings. You might want to save your database files there.
Since they are common for all users, you'd want them saved to "\Documents
and Settings\All Users\Application Data" or perhaps "\Documents and
Settings\All Users\Documents" (or a subfolder under either of these). Do
NOT hard-code either of these paths in your app. Use the
SHGetSpecialFolderPath Win32API function (and either CSIDL_COMMON_APPDATA or
CSIDL_COMMON_DOCUMENTS) to get it. Search www.google.com if you need help
or code examples for this function. If you need to support any Win9x
systems, there will be alternate considerations.

As far as the Registry, if these are "user-independent" settings, you're
saving them to the wrong place. You need to save them to HKEY_CURRENT_USER.
HKEY_LOCAL_MACHINE is for system-wide settings and only admins and power
users have write permissions to anything under it (Power users aren't very
common under WinXP because it's not an "available" user account type..a user
must be specifically added to the Power Users group). Regular users can
read from HKEY_LOCAL_MACHINE, but not write to it. Also, when opening
Registry keys, never use KEY_ALL_ACCESS. This does not "grant" permissions
that a user doesn't have. Use KEY_READ or KEY_WRITE as appropriate for the
operation you need to perform.

--
Mike
Microsoft MVP Visual Basic

16 Dec 2006 4:47 PM

CharlyE

Mike, thank you for your answer!

About the databases, they are Access databases located at the C:\Program
files (don't know the exact english name for that folder... in spanish it's
C:\Archivos de programa... i.e., the "default" installation folder).
I'll try the "\Documents and Settings\All Users\Application Data" or
"\Documents and Settings\All Users\Documents" approach.

For the registry, I'll use the HKEY_CURRENT_USER. I thought that beeing
"user-independent" settings, HKEY_LOCAL_MACHINE was the place... I was wrong!

Thank you very much for your help!

Carlos

Show quoteHide quote

"MikeD" wrote:

>
> "CharlyE" <Char***@discussions.microsoft.com> wrote in message
> news:745C11B2-89AE-45B2-B8AA-2D11992E214C@microsoft.com...
> > Hi!
> >
> > I am working with VB6 and XP Home Edition.
> >
> > I experience trouble when trying to access the windows registry and my app
> > databases when the user has limited permission (i.e., has not system
> > administrator permission).
> > The databases, which are common for all users, are not accessible because
> > they are locked in read-only mode (so I can't write on them), and the
> > windows
> > registry will not let me write on the HKEY_LOCAL_MACHINE key (where I need
> > to
> > write user-independent information for my app).
> >
> > Can anybody help and give some guidance on working with user permission
> > from
> > within VB6 code?
> >
>
>
> Well, not sure about the database being read-only. That may or may not have
> anything to do with permissions or user privileges. You'd need to provide
> more information about this. For example, what is the database? Is it your
> own file format (i.e. you're using VB's file I/O statements and functions to
> read/write it). Is it an Access database? Some other RDMS? Where are the
> database files located? Regular users do not have permissions for many
> folders. For example, they may not have write permissions even to the
> application folder (the folder where your app is installed). This is why
> each user account has an Application Data (and other) folders under
> Documents and Settings. You might want to save your database files there.
> Since they are common for all users, you'd want them saved to "\Documents
> and Settings\All Users\Application Data" or perhaps "\Documents and
> Settings\All Users\Documents" (or a subfolder under either of these). Do
> NOT hard-code either of these paths in your app. Use the
> SHGetSpecialFolderPath Win32API function (and either CSIDL_COMMON_APPDATA or
> CSIDL_COMMON_DOCUMENTS) to get it. Search www.google.com if you need help
> or code examples for this function. If you need to support any Win9x
> systems, there will be alternate considerations.
>
> As far as the Registry, if these are "user-independent" settings, you're
> saving them to the wrong place. You need to save them to HKEY_CURRENT_USER.
> HKEY_LOCAL_MACHINE is for system-wide settings and only admins and power
> users have write permissions to anything under it (Power users aren't very
> common under WinXP because it's not an "available" user account type..a user
> must be specifically added to the Power Users group). Regular users can
> read from HKEY_LOCAL_MACHINE, but not write to it. Also, when opening
> Registry keys, never use KEY_ALL_ACCESS. This does not "grant" permissions
> that a user doesn't have. Use KEY_READ or KEY_WRITE as appropriate for the
> operation you need to perform.
>
> --
> Mike
> Microsoft MVP Visual Basic
>
>

16 Dec 2006 4:57 PM

Bob Butler

"CharlyE" <Char***@discussions.microsoft.com> wrote in message
news:330CB91C-3D46-4C0E-8CD1-5072E51C149D@microsoft.com
> For the registry, I'll use the HKEY_CURRENT_USER. I thought that
> beeing "user-independent" settings, HKEY_LOCAL_MACHINE was the
> place... I was wrong!

No, you were correct, but non-admins can't generally write to HKLM and those
users shouldn't be modifying system-wide settings.

IMO the registry is the wrong place for application settings anyway. It
makes much more sense to store them in your database (since you have that
available anyway) or in an INI, XML or other file format of your choosing
and put that file in the same place you put the database.

--
Reply to the group so all can participate
VB.Net: "Fool me once..."

16 Dec 2006 5:13 PM

CharlyE

Bob, thanks for your contribution!

I thought about using the registry because I want some data to be
"persistent", even in the case my app is unistalled... Considering this, in
the case I used an INI file, where should I store it?

Thanks

Carlos

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"Bob Butler" wrote:

> "CharlyE" <Char***@discussions.microsoft.com> wrote in message
> news:330CB91C-3D46-4C0E-8CD1-5072E51C149D@microsoft.com
> > For the registry, I'll use the HKEY_CURRENT_USER. I thought that
> > beeing "user-independent" settings, HKEY_LOCAL_MACHINE was the
> > place... I was wrong!
>
> No, you were correct, but non-admins can't generally write to HKLM and those
> users shouldn't be modifying system-wide settings.
>
> IMO the registry is the wrong place for application settings anyway. It
> makes much more sense to store them in your database (since you have that
> available anyway) or in an INI, XML or other file format of your choosing
> and put that file in the same place you put the database.
>
> --
> Reply to the group so all can participate
> VB.Net: "Fool me once..."
>
>