Re: role passwords and md5()

I thought I read this be for I sent it. :-(

What I meant to say was:
Does the password hash change (and how?) Or is the original username kept
somewhere is the system tables?

Regards,

Ben

"Ben Trewern" <ben(dot)trewern(at)_nospam_mowlem(dot)com> wrote in message
news:evnpgi$md3$1(at)news(dot)hub(dot)org(dot)(dot)(dot)
> How does this work when you rename a role? Does the is the password hash
> changed (and how?) or is the original username kept somewhere in the
> system tables?
>
> Regards,
>
> Ben
>
> "Andrew Kroeger" <andrew(at)sprocks(dot)gotdns(dot)com> wrote in message
> news:461E27BA(dot)7020001(at)sprocks(dot)gotdns(dot)com(dot)(dot)(dot)
>> Lutz Broedel wrote:
>>> Dear list,
>>>
>>> I am trying to verify the password given by a user against the system
>>> catalog. Since I need the password hash later on, I can not just use the
>>> authentication mechanism for verification, but need to do this in SQL
>>> statements.
>>> Unfortunately, even if I set passwords to use MD5 encryption in
>>> pg_hba.conf, the SQL function MD5() returns a different hash.
>>>
>>> A (shortened) example:
>>> CREATE ROLE my_user WITH ENCRYPTED PASSWORD 'my_password';
>>>
>>> SELECT * FROM pg_authid
>>> WHERE rolname='my_user' AND rolpassword=MD5('my_password');
>>>
>>> Any ideas, what to do to make this work?
>>> Best regards,
>>> Lutz Broedel
>>
>> A quick look at the source shows that the hashed value stored in
>> pg_authid uses the role name as a salt for the hashing of the password.
>> Moreover, the value in pg_authid has the string "md5" prepended to the
>> hash value (I imagine to allow different hash algorithms to be used, but
>> I haven't personally seen anything but "md5").
>>
>> Given your example above, the following statement should do what you are
>> looking for:
>>
>> SELECT * FROM pg_authid WHERE rolname='my_user' AND rolpassword = 'md5'
>> || md5('my_password' || 'my_user');
>>
>> Hope this helps.
>>
>> Andrew
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 5: don't forget to increase your free space map settings
>>
>
>