hashing and unhashing

[Anon]

I have a slight issue with md5 hashing

I can happliy has a password and put it in the database. However when i want to update the password i need to pull the hashed pwd from the database and convert it back to it's original state (i.e unhashed)

Been rackinh my brains. But to not avail

i.e. if password is 'gary' it goes into the database as
1d5b9bc9f82aa7c6f5e70e245e05cdd4
.

When i wish to update the pwd i need the original pwd (gary) to appear not the hashed version.

Any help would be greatly received.

Thanks

Gary

[Anon]

You can't do it: md5 is (by design) a one-way function.

But why do you need the original password? It's not
clear from your explanation--once it's in the database
in hashed form, all you need to do is to hash the user-
entered password and see if it matches the hashed
value as retrieved from the database.

If you really do need encryption rather than hashing,
then you need to enable mcrypt support and use
that instead. Caution--there's only one specific
version of mcrypt that works with PHP; there's an
message here about this that describes what you
need to do:

http://www.phpbuilder.com/forum/read.php3?num=3&id=100285&loc=0&thread=100285