oracle用户口令复杂要求

通过sys执行$ORACLE_HOME/rdbms/admin/utlpwdmg.sql，可以建立相应的verify_function function,通过修改用户的profile，可以对用户口令进行校验，建议对该SQL文件进行适当修改，以免
使用不便。
Rem $Header: utlpwdmg.sql 31-aug-2000.11:00:47 nireland Exp $
Rem
Rem utlpwdmg.sql
Rem
Rem  Copyright (c) Oracle Corporation 1996, 2000. All Rights Reserved.
Rem
Rem    NAME
Rem      utlpwdmg.sql - script for Default Password Resource Limits
Rem
Rem    DESCRIPTION
Rem      This is a script for enabling the password management features
Rem      by setting the default password resource limits.
Rem
Rem    NOTES
Rem      This file contains a function for minimum checking of password
Rem      complexity. This is more of a sample function that the customer
Rem      can use to develop the function for actual complexity checks that the
Rem      customer wants to make on the new password.
Rem
Rem    MODIFIED   (MM/DD/YY)
Rem    nireland    08/31/00 - Improve check for username=password. #1390553
Rem    nireland    06/28/00 - Fix null old password test. #1341892
Rem    asurpur     04/17/97 - Fix for bug479763
Rem    asurpur     12/12/96 - Changing the name of password_verify_function
Rem    asurpur     05/30/96 - New script for default password management
Rem    asurpur     05/30/96 - Created
Rem

-- This script sets the default password resource parameters
-- This script needs to be run to enable the password features.
-- However the default resource parameters can be changed based
-- on the need.
-- A default password complexity function is also provided.
-- This function makes the minimum complexity checks like
-- the minimum length of the password, password not same as the
-- username, etc. The user may enhance this function according to
-- the need.
-- This function must be created in SYS schema.
-- connect sys/ as sysdba before running the script

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;
   digitarray varchar2(20);
   punctarray varchar2(25);
   chararray varchar2(52);

BEGIN
   digitarray:= '0123456789';
   chararray:= 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
   punctarray:='!"#$%&()``*+,-/:;<=>?_';

   -- Check if the password is same as the username
   IF NLS_LOWER(password) = NLS_LOWER(username) THEN
     raise_application_error(-20001, 'Password same as or similar to user');
   END IF;

   -- Check for the minimum length of the password
   IF length(password) < 6 THEN
      raise_application_error(-20002, 'Password length less than 4');
   END IF;

   -- 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 ('welcome', 'database', 'account', 'user', 'password', 'oracle', 'computer', 'abcd') THEN
      raise_application_error(-20002, 'Password too simple');
   END IF;

   -- Check if the password contains at least one letter, one digit and one
   -- punctuation mark.
   -- 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(-20003, 'Password should contain at least one digit, one character and one punctuation');
   END IF;
   -- 2. Check for the character
   <>
   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 findpunct;
         END IF;
      END LOOP;
   END LOOP;
   IF ischar = FALSE THEN
      raise_application_error(-20003, 'Password should contain at least one \
              digit, one character and one punctuation');
   END IF;
   -- 3. Check for the punctuation
   <>
   ispunct:=FALSE;
   FOR i IN 1..length(punctarray) LOOP
      FOR j IN 1..m LOOP
         IF substr(password,j,1) = substr(punctarray,i,1) THEN
            ispunct:=TRUE;
             GOTO endsearch;
         END IF;
      END LOOP;
   END LOOP;
   IF ispunct = FALSE THEN
      raise_application_error(-20003, 'Password should contain at least one \
              digit, one character and one punctuation');
   END IF;

   <>
   -- Check if the password differs from the previous password by at least
   -- 3 letters
   IF old_password IS NOT NULL THEN
     differ := length(old_password) - length(password);

     IF abs(differ) < 3 THEN
       IF length(password) < length(old_password) THEN
         m := length(password);
       ELSE
         m := length(old_password);
       END IF;

       differ := abs(differ);
       FOR i IN 1..m LOOP
         IF substr(password,i,1) != substr(old_password,i,1) THEN
           differ := differ + 1;
         END IF;
       END LOOP;

       IF differ < 3 THEN
         raise_application_error(-20004, 'Password should differ by at \
         least 3 characters');
       END IF;
     END IF;
   END IF;
   -- Everything is fine; return TRUE ;   
   RETURN(TRUE);
END;
/

-- This script alters the default parameters for Password Management
-- This means that all the users on the system have Password Management
-- enabled and set to the following values unless another profile is
-- created with parameter values set to different value or UNLIMITED
-- is created and assigned to the user.

执行完后，ALTER PROFILE PROFILE LIMIT  PASSWORD_VERIFY_FUNCTION verify_function;
即可，对默认profile进行限制，可以通过查询dba_profikes进行查询。