While installing OEM 13c, the following warning might occur from checking OEM repository database:
“Oracle strongly recommends that you disable the password verification function in your database before proceeding any further”

Let’s check and disable password verification function if any.
SQL>select username, profile from dba_users where username like 'SYSMAN%';
USERNAME PROFILE
------------------------------ ------------------------------
SYSMAN_TYPES DEFAULT
SYSMAN_RO MGMT_INTERNAL_USER_PROFILE
SYSMAN_OPSS MGMT_INTERNAL_USER_PROFILE
SYSMAN_STB MGMT_INTERNAL_USER_PROFILE
SYSMAN_BIPLATFORM MGMT_INTERNAL_USER_PROFILE
SYSMAN MGMT_INTERNAL_USER_PROFILE
SYSMAN_MDS MGMT_INTERNAL_USER_PROFILE
7 rows selected.
SQL> select PROFILE,RESOURCE_NAME,LIMIT from dba_profiles
where PROFILE in ('DEFAULT','MGMT_INTERNAL_USER_PROFILE')
and RESOURCE_NAME='PASSWORD_VERIFY_FUNCTION';
PROFILE RESOURCE_NAME LIMIT
-------------------------- ------------------------ ---------------------
DEFAULT PASSWORD_VERIFY_FUNCTION NULL
MGMT_INTERNAL_USER_PROFILE PASSWORD_VERIFY_FUNCTION GMT_INTERNAL_PASS_VERIFY
SQL>
SQL> alter profile MGMT_INTERNAL_USER_PROFILE limit
PASSWORD_VERIFY_FUNCTION null;
Profile altered.
SQL> select PROFILE,RESOURCE_NAME,LIMIT
from dba_profiles
where PROFILE in ('DEFAULT','MGMT_INTERNAL_USER_PROFILE')
and RESOURCE_NAME='PASSWORD_VERIFY_FUNCTION';
PROFILE RESOURCE_NAME LIMIT
-------------------------- ------------------------ ------------------
DEFAULT PASSWORD_VERIFY_FUNCTION NULL
MGMT_INTERNAL_USER_PROFILE PASSWORD_VERIFY_FUNCTION NULL
SQL>