Checking for Accounts Using Case-Insensitive Password Version

Use these procedures to identify if the Oracle Database that you want to upgrade has accounts or configuration parameters that are using a case-insensitive password version.

By default, in Oracle Database 12c release 2 (12.2) and later releases, the 10G password version is not generated or allowed.

If you do not set SQLNET.ALLOWED_LOGON_VERSION_SERVER to a permissive authentication protocol that permits case-insensitive versions, and you do not want user accounts authenticated with case-insensitive password versions to be locked out of the database, then you must identify affected accounts, and ensure that they are using case-sensitive password versions.

Example 2-1 Finding User Accounts That Use Case-Insensitive (10G) Version

SELECT USERNAME,PASSWORD_VERSIONS FROM DBA_USERS;

The following result shows password versions for the accounts:

USERNAME                       PASSWORD_VERSIONS
------------------------------ -----------------
JONES                          10G 11G 12C
ADAMS                          10G 11G
CLARK                          10G 11G
PRESTON                        11G
BLAKE                          10G

In this example, the backgrounds for each user account password verification version in use are different:

JONES was created in Oracle Database 10G, and the password for JONES was reset in Oracle Database 12C when the setting for the SQLNET.ALLOWED_LOGON_VERSION_SERVER parameter was set to 8. As a result, this password reset created all three versions. 11G and 12C use case-sensitive passwords.
ADAMS and CLARK were originally created with the 10G version, and then 11G, after they were imported from an earlier release. These account passwords were then reset in 11G, with the deprecated parameter SEC_CASE_SENSITIVE_LOGON set to TRUE.
The password for BLAKE was created with the 10G version, and the password has not been reset. As a result, user BLAKE continues to use the 10G password version, which uses a case-insensitive password.

The user BLAKE has only the 10G password version before upgrade:

SQL> SELECT USERNAME,PASSWORD_VERSIONS FROM DBA_USERS;

USERNAME PASSWORD_VERSIONS
------------------------------ -----------------
BLAKE 10G

If you upgrade to a new Oracle Database release without taking any further action, then this account becomes inaccessible. Ensure that the system is not configured in Exclusive Mode (by setting the SQLNET.ORA parameter SQLNET.ALLOWED_LOGON_VERSION_SERVER to a more permissive authentication mode) before the upgrade.

Example 2-2 Fixing Accounts with Case-Insensitive Passwords

Complete the following procedure:

Use the following SQL query to find the accounts that only have the 10G password version:

      select USERNAME
         from DBA_USERS
        where ( PASSWORD_VERSIONS = '10G '
               or PASSWORD_VERSIONS = '10G HTTP ')
          and USERNAME <> 'ANONYMOUS';

Configure the system so that it is not running in Exclusive Mode by editing the setting of the SQLNET.ORA parameter SQLNET.ALLOWED_LOGON_VERSION_SERVER to a level appropriate for affected accounts. For example:
```
SQLNET.ALLOWED_LOGON_VERSION_SERVER=11
```
After you make this change, proceed with the upgrade.
After the upgrade completes, use the following command syntax to expire the accounts you found in step 1, where username is the name of a user returned from the query in step 1:

ALTER USER username PASSWORD EXPIRE;
Ask the users for whom you have expired the passwords to log in.
When these users log in, they are prompted to reset their passwords. The system internally generates the missing 11G and 12C password versions for their account, in addition to the 10G password version. The 10G password version is still present, because the system is running in the permissive mode.
Ensure that the client software with which users are connecting has the O5L_NP capability flag.

Note:

All Oracle Database release 11.2.0.4 and later clients, and all Oracle Database release 12.1 and later clients have the O5L_NP capability. Other clients require the CPUOct2012 patch to acquire the O5L_NP capability.

The O5L_NP capability flag is documented in Oracle Database Net Services Reference, in the section on the parameter SQLNET.ALLOWED_LOGON_VERSION_SERVER.
After all clients have the O5L_NP capability, raise the server security back to Exclusive Mode by using the following procedure:
1. Remove the SEC_CASE_SENSITIVE_LOGON setting from the instance initialization file, or set the SEC_CASE_SENSITIVE_LOGON instance initialization parameter to TRUE. For example:
  
  SEC_CASE_SENSITIVE_LOGON = TRUE
2. Remove the SQLNET.ALLOWED_LOGON_VERSION_SERVER parameter from the server SQLNET.ORA file, or set it back to Exclusive Mode by changing the value of SQLNET.ALLOWED_LOGON_VERSION_SERVER in the server SQLNET.ORA file back to 12. For example:
  
  SQLNET.ALLOWED_LOGON_VERSION_SERVER = 12

Use the following SQL query to find the accounts that still have the 10G password version:

       select USERNAME
         from DBA_USERS
        where PASSWORD_VERSIONS like '%10G%'
          and USERNAME <> 'ANONYMOUS';

Use the list of accounts returned from the query in step 8 to expire all the accounts that still have the 10G password version. Expire the accounts using the following syntax, where username is a name on the list returned by the query:

ALTER USER username PASSWORD EXPIRE;
Request the users whose accounts you expired to log in to their accounts.

When the users log in, they are prompted to reset their password. The system internally generates only the 11G and 12C password versions for their account. Because the system is running in Exclusive Mode, the 10G password version is no longer generated.
Check that the system is running in a secure mode by rerunning the query from step 1. Ensure that no users are found. When the query finds no users, this result means that no 10G password version remains present in the system.

Example 2-3 Checking for the Presence of SEC_CASE_SENSITIVE_LOGON Set to FALSE

Oracle Database does not prevent the use of the FALSE setting for SEC_CASE_SENSITIVE_LOGON when the SQLNET.ALLOWED_LOGON_VERSION_SERVER parameter is set to 12 or 12a. This setting can result in all accounts in the upgraded database becoming inaccessible.

SQL> SHOW PARAMETER SEC_CASE_SENSITIVE_LOGON

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
sec_case_sensitive_logon             boolean     FALSE

You can change this parameter by using the following command:

SQL> ALTER SYSTEM SET SEC_CASE_SENSITIVE_LOGON = TRUE;

System altered.

Note:

Unless the value for the parameter SQLNET.ALLOWED_LOGON_VERSION_SERVER is changed to a version that is more permissive than 12, such as 11, do not set the SEC_CASE_SENSITIVE_LOGON parameter to FALSE.