Re: retrieving information about password from MS Access front-end - Mailing list pgsql-interfaces

From Volkan YAZICI
Subject Re: retrieving information about password from MS Access front-end
Date
Msg-id 7104a737050612234734ffc2a5@mail.gmail.com
Whole thread Raw
In response to retrieving information about password from MS Access front-end  (Zlatko Matić <zlatko.matic1@sb.t-com.hr>)
List pgsql-interfaces
Hi,

On 6/13/05, Zlatko Matić <zlatko.matic1@sb.t-com.hr> wrote:
> I want to create VBA procedure that compares value in text box with actual
> password to determine if it is the same. As the password is encrypted (md5)
> I can't read it from pg_shaddow system table. How to retrieve decrypted
> value from pg_shaddow?

It's (practically) impossible to decrypt a MD5 hashed password.

> Or at least, how to transfer value from text-box (MS Access) to Postgres
> so that Postgres can determine whether those two values
> are the same ?

You need to MD5 hash the input passsword and compare hashed input
password with the one in pg_shadow. For instance:

-- $1 for password input.
SELECT usernm FROM recs WHERE passwd = md5($1)

Furthermore, it'll bring some potential security problems to be able
to access pg_shadow which requires db admin permissions.

Regards.

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