Well for the user salt I was just going to randomly generate an 8 character
string using alphanumerics..

What is the best way to generate a UUID?

On Wed, May 12, 2010 at 1:52 PM, Peter J. Farrell <[email protected]> wrote:

> It might be overkill to have a sitewide salt in the mix.  If somebody gains
> access to your system, more than likely they can read the sitewide salt from
> a source file.
>
> Usually, SHA(pwd + salt)  is fine.  The algorithm is important so sha 512
> is good but slow as well.  The longer the salt; the better.  The more random
> the salt; the better. I tend to use UUIDs for salt because it's important to
> use unique salt values.
>
> Adding in a sitewide salt is no different than just using a longer user
> salt except that the site wide is mostly static (bad).  The more characters
> in the salt means that computing rainbow tables takes longer because more
> bytes have to be crunched.  Just be sure to store the salt in the database
> in plain text.
>
> .pjf
>
> Jason Allen said the following on 12/05/10 13:26:
>
> Ok,
>>
>> I'm going to use SHA-512 just because I can.
>>
>> When the user submits their password (when creating an account)
>>
>> I will (in crude mockup code)
>>
>> set usersalt = rand(0-9,a-z)
>>
>> set pw_pre_hash = 'form.password + sitewidesalt + usersalt'
>>
>> set pw_hash = hash(pw_pre_hash, "SHA-512")
>>
>> insert into user table
>>
>> pw_hash, usersalt
>>
>>
>> This way, when I need to chekc their password I just fetch their hash
>> and usersalt then combine their submitted password with the usersalt
>> and sitewidesalt, and compare it to the hash.
>>
>> Good enough?
>>
>>
>>
>
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