-- -- crypt() and gen_salt(): md5 -- SELECT crypt('', '$1$Szzz0yzz'); ERROR: crypt(3) returned NULL SELECT crypt('foox', '$1$Szzz0yzz'); ERROR: crypt(3) returned NULL CREATE TABLE ctest (data text, res text, salt text); INSERT INTO ctest VALUES ('password', '', ''); UPDATE ctest SET salt = gen_salt('md5'); UPDATE ctest SET res = crypt(data, salt); ERROR: crypt(3) returned NULL SELECT res = crypt(data, res) AS "worked" FROM ctest; ERROR: invalid salt DROP TABLE ctest;