CREATE OR REPLACE FUNCTION verify_function
(username varchar2,
password varchar2,
old_password varchar2)
RETURN boolean IS
n boolean;
m integer;
differ integer;
isdigit boolean;
ischar boolean;
ispunct boolean;
db_name varchar2(40);
digitarray varchar2(20);
punctarray varchar2(25);
chararray varchar2(52);
i_char varchar2(10);
simple_password varchar2(10);
reverse_user varchar2(32);
BEGIN
digitarray:= '0123456789';
chararray:= 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
-- Check for the minimum length of the password
IF length(password) < 8 THEN
raise_application_error(-20001, 'Password length less than 8');
END IF;
-- Check if the password is same as the username or username(1-100)
IF NLS_LOWER(password) = NLS_LOWER(username) THEN
raise_application_error(-20002, 'Password same as or similar to user');
END IF;
FOR i IN 1..100 LOOP
i_char := to_char(i);
if NLS_LOWER(username)|| i_char = NLS_LOWER(password) THEN
raise_application_error(-20005, 'Password same as or similar to user name ');
END IF;
END LOOP;
-- Check if the password is same as the username reversed
FOR i in REVERSE 1..length(username) LOOP
reverse_user := reverse_user || substr(username, i, 1);
END LOOP;
IF NLS_LOWER(password) = NLS_LOWER(reverse_user) THEN
raise_application_error(-20003, 'Password same as username reversed');
END IF;
-- Check if the password is the same as server name and or servername(1-100)
select name into db_name from sys.v$database;
if NLS_LOWER(db_name) = NLS_LOWER(password) THEN
raise_application_error(-20004, 'Password same as or similar to server name');
END IF;
FOR i IN 1..100 LOOP
i_char := to_char(i);
if NLS_LOWER(db_name)|| i_char = NLS_LOWER(password) THEN
raise_application_error(-20005, 'Password same as or similar to server name ');
END IF;
END LOOP;
-- Check if the password is too simple. A dictionary of words may be
-- maintained and a check may be made so as not to allow the words
-- that are too simple for the password.
IF NLS_LOWER(password) IN ('welcome1', 'database1', 'account1', 'user1234', 'password1', 'oracle123', 'computer1', 'abcdefg1', 'change_on_install') THEN
raise_application_error(-20006, 'Password too simple');
END IF;
-- Check if the password is the same as oracle (1-100)
simple_password := 'oracle';
FOR i IN 1..100 LOOP
i_char := to_char(i);
if simple_password || i_char = NLS_LOWER(password) THEN
raise_application_error(-20007, 'Password too simple ');
END IF;
END LOOP;
-- Check if the password contains at least one letter, one digit
-- 1. Check for the digit
isdigit:=FALSE;
m := length(password);
FOR i IN 1..10 LOOP
FOR j IN 1..m LOOP
IF substr(password,j,1) = substr(digitarray,i,1) THEN
isdigit:=TRUE;
GOTO findchar;
END IF;
END LOOP;
END LOOP;
IF isdigit = FALSE THEN
raise_application_error(-20008, 'Password must contain at least one digit, one character');
END IF;
-- 2. Check for the character
<<findchar>>
ischar:=FALSE;
FOR i IN 1..length(chararray) LOOP
FOR j IN 1..m LOOP
IF substr(password,j,1) = substr(chararray,i,1) THEN
ischar:=TRUE;
GOTO endsearch;
END IF;
END LOOP;
END LOOP;
IF ischar = FALSE THEN
raise_application_error(-20009, 'Password must contain at least one \
digit, and one character');
END IF;