Authentication, Authorization, and Accounting Configuration Guide, Cisco IOS Release 15SY
Password Strength and Management for Common Criteria
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Password Strength and Management for Common Criteria

Password Strength and Management for Common Criteria

Last Updated: November 13, 2012

The Password Strength and Management for Common Criteria feature is used to specify password policies and security mechanisms for storing, retrieving, and providing rules to specify user passwords.

For local users, the user profile and the password information with the key parameters are stored on the Cisco device, and this profile is used for local authentication of users. The user can be an administrator (terminal access) or a network user (for example, PPP users being authenticated for network access).

For remote users, where the user profile information is stored in a remote server, a third-party authentication, authorization, and accounting (AAA) server may be used for providing AAA services, both for administrative and network access.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Restrictions for Password Strength and Management for Common Criteria

Only four concurrent users can log on to the system by using vty at any moment.

Information About Password Strength and Management for Common Criteria

Password Composition Policy

The password composition policy allows you to create passwords of any combination of upper and lowercase characters, numbers, and special characters that include "!", "@", "#", "$", "%","^", "&", "*", "(", and ")".

Password Length Policy

The administrator has the flexibility to set the password's minimum and maximum length. The recommended minimum password length is 8 characters. The administrator can specify both the minimum (1) and the maximum (64) length for the password.

Password Lifetime Policy

The security administrator can provide a configurable option for a password to have a maximum lifetime. If the lifetime parameter is not configured, the configured password will never expire. The maximum lifetime can be configured by providing the configurable value in years, months, days, hours, minutes, and seconds. The lifetime configuration will survive across reloads as it is a part of the configuration, but every time the system reboots, the password creation time will be updated to the new time. For example, if a password is configured with a lifetime of one month and on the 29th day, the system reboots, then the password will be valid for one month after the system reboots.

Password Expiry Policy

If the user attempts to log on and if the user's password credentials have expired, then the following happens:

  1. The user is prompted to set the new password after successfully entering the expired password.
  2. When the user enters the new password, the password is validated against the password security policy.
  3. If the new password matches the password security policy, then the AAA database is updated, and the user is authenticated with the new password.
  4. If the new password does not match the password security policy, then the user is prompted again for the password. From AAA perspective, there is no restriction on the number of retries. The number of retries for password prompt in case of unsuccessful authentication is controlled by the respective terminal access interactive module. For example, for telnet, after three unsuccessful attempts, the session will be terminated.

If the password's lifetime is not configured for a user and the user has already logged on and if the security administrator configures the lifetime for that user, then the lifetime will be set in the database. When the same user is authenticated the next time, the system will check for password expiry. The password expiry is checked only during the authentication phase.

If the user has been already authenticated and logged on to the system and if the password expires, then no action will be taken. The user will be prompted to change the password only during the next authentication for the same user.

Password Change Policy

The new password must contain a minimum of 4 character changes from the previous password. A password change can be triggered by the following scenarios:

  • The security administrator wants to change the password.
  • The user is trying to get authenticated using a profile, and the password for that profile has expired.

When the security administrator changes the password security policy and the existing profile does not meet the password security policy rules, no action will be taken if the user has already logged on to the system. The user will be prompted to change the password only when the user tries to get authenticated using the profile that does not meet the password security restriction.

When the user changes the password, the lifetime parameters set by the security administrator for the old profile will be the lifetime parameters for the new password.

For noninteractive clients such as dot1x, when the password expires, appropriate error messages will be sent to the clients, and the clients must contact the security administrator to renew the password.

User Reauthentication Policy

Users are reauthenticated when they change their passwords.

When users change their passwords on expiry, they will be authenticated against the new password. In such cases, the actual authentication happens based on the previous credentials, and the new password is updated in the database.


Note


Users can change their passwords only when they are logging on and after the expiry of the old password; however, a security administrator can change the user's password at any time.

Support for Framed (noninteractive) Session

When a client such as dot1x uses the local database for authentication, the Password Strength and Management for Common Criteria feature will be applicable; however, upon password expiry, clients will not be able to change the password. An appropriate failure message will be sent to such clients, and the user must request the security administrator to change the password.

How to Configure Password Strength and Management for Common Criteria

Configuring the Password Security Policy

Perform this task to create a password security policy and to apply the policy to a specific user profile.

SUMMARY STEPS

1.    enable

2.   configure terminal

3.   aaa new-model

4.   aaa common-criteria policy policy-name

5.   char-changes number

6.   max-length number

7.   min-length number

8.   numeric-count number

9.   special-case number

10.   exit

11.   username username common-criteria-policy policy-name password password

12.   end


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Device> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Device# configure terminal

 

Enters global configuration mode.

 
Step 3
aaa new-model


Example:

Device(config)# aaa new-model

 

Enables AAA globally.

 
Step 4
aaa common-criteria policy policy-name


Example:

Device(config)# aaa common-criteria policy policy1

 

Creates the AAA security password policy and enters common criteria configuration policy mode.

 
Step 5
char-changes number


Example:

Device(config-cc-policy)# char-changes 4

 

(Optional) Specifies the number of changed characters between old and new passwords.

 
Step 6
max-length number


Example:

Device(config-cc-policy)# max-length 25

 

(Optional) Specifies the maximum length of the password.

 
Step 7
min-length number


Example:

Device(config-cc-policy)# min-length 8

 

(Optional) Specifies the minimum length of the password.

 
Step 8
numeric-count number


Example:

Device(config-cc-policy)# numeric-count 4

 

(Optional) Specifies the number of numeric characters in the password.

 
Step 9
special-case number


Example:

Device(config-cc-policy)# special-case 3

 

(Optional) Specifies the number of special characters in the password.

 
Step 10
exit


Example:

Device(config-cc-policy)# exit

 

(Optional) Exits common criteria configuration policy mode and returns to global configuration mode.

 
Step 11
username username common-criteria-policy policy-name password password


Example:

Device(config)# username user1 common-criteria-policy policy1 password password1

 

(Optional) Applies a specific policy and password to a user profile.

 
Step 12
end


Example:

Device(config)# end

 

Returns to privileged EXEC mode.

 

Verifying the Common Criteria Policy

Perform this task to verify all the common criteria security policies.

SUMMARY STEPS

1.   enable

2.   show aaa common-criteria policy name policy-name

3.   show aaa common-criteria policy all


DETAILED STEPS
Step 1   enable

Enables privileged EXEC mode.



Example:
Device> enable
          
Step 2   show aaa common-criteria policy name policy-name

Displays the password security policy information for a specific policy.



Example:
Device# show aaa common-criteria policy name policy1

Policy name: policy1
Minimum length: 1
Maximum length: 64
Upper Count: 20
Lower Count: 20
Numeric Count: 5
Special Count: 2
Number of character changes 4
Valid forever. User tied to this policy will not expire.
Step 3   show aaa common-criteria policy all

Displays password security policy information for all the configured policies.



Example:
Device# show aaa common-criteria policy all
====================================================================
Policy name: policy1
Minimum length: 1
Maximum length: 64
Upper Count: 20
Lower Count: 20
Numeric Count: 5
Special Count: 2
Number of character changes 4
Valid forever. User tied to this policy will not expire.
====================================================================
Policy name: policy2
Minimum length: 1
Maximum length: 34
Upper Count: 10
Lower Count: 5
Numeric Count: 4
Special Count: 2
Number of character changes 2
Valid forever. User tied to this policy will not expire.
=====================================================================

Troubleshooting Tips

Use the debug aaa common-criteria command to troubleshoot AAA common criteria.

Configuration Example for the Password Strength and Management for Common Criteria Feature

Example: Password Strength and Management for Common Criteria

The following example shows how to create a common criteria security policy and apply the specific policy to a user profile:

Device> enable
Device# configure terminal
Device(config)# aaa new-model
Device(config)# aaa common-criteria policy policy1
Device(config-cc-policy)# char-changes 4
Device(config-cc-policy)# max-length 20
Device(config-cc-policy)# min-length 6
Device(config-cc-policy)# numeric-count 2
Device(config-cc-policy)# special-case 2
Device(config-cc-policy)# exit
Device(config)# username user1 common-criteria-policy policy1 password password1
Device(config)# end
      

Additional References

Technical Assistance

Description Link

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http://www.cisco.com/cisco/web/support/index.html

Feature Information for Password Strength and Management for Common Criteria

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1 Feature Information for Password Strength and Management for Common Criteria
Feature Name Releases Feature Information

Password Strength and Management for Common Criteria

15.0(2)SE

15.1(1)SY

The Password Strength and Management for Common Criteria feature is used to specify password policies and security mechanisms for storing, retrieving, and providing rules to specify user passwords.

The following commands were introduced or modified: aaa common-criteria policy, debug aaa common-criteria, and show aaa common-criteria policy.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2012 Cisco Systems, Inc. All rights reserved.