This module implements a data type
chkpass that is designed for storing encrypted
passwords. Each password is automatically converted to encrypted
form upon entry, and is always stored encrypted. To compare, simply
compare against a clear text password and the comparison function
will encrypt it before comparing.
There are provisions in the code to report an error if the password is determined to be easily crackable. However, this is currently just a stub that does nothing.
If you precede an input string with a colon, it is assumed to be an already-encrypted password, and is stored without further encryption. This allows entry of previously-encrypted passwords.
On output, a colon is prepended. This makes it possible to dump
and reload passwords without re-encrypting them. If you want the
encrypted password without the colon then use the
raw() function. This allows you to use the type
with things like Apache's
The encryption uses the standard Unix function
crypt(), and so it suffers from all the usual
limitations of that function; notably that only the first eight
characters of a password are considered.
Note that the
chkpass data type is not
test=# create table test (p chkpass); CREATE TABLE test=# insert into test values ('hello'); INSERT 0 1 test=# select * from test; p ---------------- :dVGkpXdOrE3ko (1 row) test=# select raw(p) from test; raw --------------- dVGkpXdOrE3ko (1 row) test=# select p = 'hello' from test; ?column? ---------- t (1 row) test=# select p = 'goodbye' from test; ?column? ---------- f (1 row)
D'Arcy J.M. Cain (
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