Re: [GENERAL] SET Role doesn't work from Security Definer Function...

2010-02-23 Thread dipti shah
You are correct Tom that I want to perform some portion of function as
postgres user and other portion as current user.

As per you suggestion I did refactor and separated the portion that needs to
be executed as superuser to another function. But the thing is PostGreSQL
recognize when I call this separated funtion from my original SECURITY
DEFINER function and gives the same error. :(

For your reference I did something like this:

1. Create Function foo1  (this is without SECURITY DEFINER where I am
using SET ROLE to current user).

2. Create Function foo2 with SECURITY DEFINER ...
 spi_exe_query(select foo1()); == Here it throws the error.

I am helpless now. Could you tell me what could be done in this situation?

Thanks,
Dipti
On Tue, Feb 23, 2010 at 2:04 AM, Tom Lane t...@sss.pgh.pa.us wrote:

 dipti shah shahdipti1...@gmail.com writes:
  I have just noticed that SET ROLE doesn't work from security definer
  function. I don;t know why but it clearly gives the error that SET role
  doesn;t work in security definer context.

 This is intentional because allowing it creates security holes.

  If I create function in postgres user with Security Definer enabled, it
 will
  allow to create any table with any foreign references etc...So I am
 setting
  role to current_user in my function and then creating a table to make
 sure
  that user has the appropriate privilege.

 Well, if you are trying to set the role back to current, why don't you
 just not have the function be security definer in the first place?

 I suppose the answer to that is that you want it to do some things as
 superuser and some things not.  In which case, you need to refactor so
 that those two classes of things are done by different functions.

regards, tom lane



Re: [GENERAL] SET Role doesn't work from Security Definer Function...

2010-02-23 Thread Alvaro Herrera
dipti shah escribió:

 For your reference I did something like this:
 
 1. Create Function foo1  (this is without SECURITY DEFINER where I am
 using SET ROLE to current user).
 
 2. Create Function foo2 with SECURITY DEFINER ...
  spi_exe_query(select foo1()); == Here it throws the error.

Shouldn't it be the other way around?  The normal function calls the
security-definer one.

-- 
Alvaro Herrerahttp://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

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Re: [GENERAL] SET Role doesn't work from Security Definer Function...

2010-02-23 Thread dipti shah
No, I tried that but that can't be done in my requirements because my
function has to be run in super user context to create the table in schema
where normal users have only USAGE permissions. If I remove SECURITY DEFINER
then my stored procedure will be failed for all users by saying permission
denied on schema myschema.

Moreover, I want to run only create table code in normal user context and
other things in stored procedure should be done in super user context.

I tried all possible ways but couldn't find to get out of this yet.

Thanks,
Dipti

On Tue, Feb 23, 2010 at 8:36 PM, Alvaro Herrera
alvhe...@commandprompt.comwrote:

 dipti shah escribió:

  For your reference I did something like this:
 
  1. Create Function foo1  (this is without SECURITY DEFINER where I am
  using SET ROLE to current user).
 
  2. Create Function foo2 with SECURITY DEFINER ...
   spi_exe_query(select foo1()); == Here it throws the error.

 Shouldn't it be the other way around?  The normal function calls the
 security-definer one.

 --
 Alvaro Herrera
 http://www.CommandPrompt.com/
 PostgreSQL Replication, Consulting, Custom Development, 24x7 support



Re: [GENERAL] SET Role doesn't work from Security Definer Function...

2010-02-23 Thread dipti shah
This issue is driving me crazy. Could any one please suggest me any
workaround?

For summary of issue,

   1. I don't want any users to perform any action on mydb schema without
using my stored procedure. So I revoke ALL permissions from mydb schema and
assigned only USAGE permissions.
   2. As my stored procedure allows creating table in mydb schema and users
have only USAGE permissions on mydb schama, I have to defined my stored
procedure with SECURITY DEFINER so that it allows to create table in mydb
schema.
   3. To prevent creating unauthenticated foreign references to other
tables, I want to make sure that current user has the required permissions
to create table before creating table. For this I have to use SET ROLE to
current user but it is not allowed in SECURITY DEFINER context.

Any help would be much appreciated.

Thanks,
Dipti
On Tue, Feb 23, 2010 at 10:51 PM, dipti shah shahdipti1...@gmail.comwrote:

 No, I tried that but that can't be done in my requirements because my
 function has to be run in super user context to create the table in schema
 where normal users have only USAGE permissions. If I remove SECURITY DEFINER
 then my stored procedure will be failed for all users by saying permission
 denied on schema myschema.

 Moreover, I want to run only create table code in normal user context and
 other things in stored procedure should be done in super user context.

 I tried all possible ways but couldn't find to get out of this yet.

 Thanks,
 Dipti


 On Tue, Feb 23, 2010 at 8:36 PM, Alvaro Herrera 
 alvhe...@commandprompt.com wrote:

 dipti shah escribió:

  For your reference I did something like this:
 
  1. Create Function foo1  (this is without SECURITY DEFINER where I
 am
  using SET ROLE to current user).
 
  2. Create Function foo2 with SECURITY DEFINER ...
   spi_exe_query(select foo1()); == Here it throws the error.

 Shouldn't it be the other way around?  The normal function calls the
 security-definer one.

 --
 Alvaro Herrera
 http://www.CommandPrompt.com/ http://www.commandprompt.com/
 PostgreSQL Replication, Consulting, Custom Development, 24x7 support





Re: [GENERAL] SET Role doesn't work from Security Definer Function...

2010-02-22 Thread Tom Lane
dipti shah shahdipti1...@gmail.com writes:
 I have just noticed that SET ROLE doesn't work from security definer
 function. I don;t know why but it clearly gives the error that SET role
 doesn;t work in security definer context.

This is intentional because allowing it creates security holes.

 If I create function in postgres user with Security Definer enabled, it will
 allow to create any table with any foreign references etc...So I am setting
 role to current_user in my function and then creating a table to make sure
 that user has the appropriate privilege.

Well, if you are trying to set the role back to current, why don't you
just not have the function be security definer in the first place?

I suppose the answer to that is that you want it to do some things as
superuser and some things not.  In which case, you need to refactor so
that those two classes of things are done by different functions.

regards, tom lane

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