Cisco ASR 9000 Series Aggregation Services Router System Security Configuration Guide, Release 4.2.x
Implementing Keychain Management
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Implementing Keychain Management

Implementing Keychain Management

This module describes how to implement keychain management on. Keychain management is a common method of authentication to configure shared secrets on all entities that exchange secrets such as keys, before establishing trust with each other. Routing protocols and network management applications on Cisco IOS XR software often use authentication to enhance security while communicating with peers.

Feature History for Implementing Keychain Management

Release

Modification

Release 3.7.2

This feature was introduced.

Prerequisites for Configuring Keychain Management

You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Restrictions for Implementing Keychain Management

You must be aware that changing the system clock impacts the validity of the keys in the existing configuration.

Information About Implementing Keychain Management

The keychain by itself has no relevance; therefore, it must be used by an application that needs to communicate by using the keys (for authentication) with its peers. The keychain provides a secure mechanism to handle the keys and rollover based on the lifetime. Border Gateway Protocol (BGP), Open Shortest Path First (OSPF), and Intermediate System-to-Intermediate System (IS-IS) use the keychain to implement a hitless key rollover for authentication. BGP uses TCP authentication, which enables the authentication option and sends the Message Authentication Code (MAC) based on the cryptographic algorithm configured for the keychain. For information about BGP, OSPF, and IS-IS keychain configurations, see

  • Resource Reservation Protocol (RSVP) uses keychain for authentication. For more information about RSVP, see the Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide.
  • IP Service Level Agreements (IP SLAs) use a keychain for MD5 authentication for the IP SLA control message. For more information about IP SLAs, see the Cisco ASR 9000 Series Aggregation Services Router System Monitoring Configuration Guide and the key-chain command in the Cisco ASR 9000 Series Aggregation Services Router System Monitoring Comand Reference.

To implement keychain management, you must understand the concept of key lifetime, which is explained in the next section.

Lifetime of a Key

If you are using keys as the security method, you must specify the lifetime for the keys and change the keys on a regular basis when they expire. To maintain stability, each party must be able to store and use more than one key for an application at the same time. A keychain is a sequence of keys that are collectively managed for authenticating the same peer, peer group, or both.

Keychain management groups a sequence of keys together under a keychain and associates each key in the keychain with a lifetime.


Note


Any key that is configured without a lifetime is considered invalid; therefore, the key is rejected during configuration.


The lifetime of a key is defined by the following options:

  • Start-time—Specifies the absolute time.
  • End-time—Specifies the absolute time that is relative to the start-time or infinite time.

Each key definition within the keychain must specify a time interval for which that key is activated; for example, lifetime. Then, during a given key's lifetime, routing update packets are sent with this activated key. Keys cannot be used during time periods for which they are not activated. Therefore, we recommend that for a given keychain, key activation times overlap to avoid any period of time for which no key is activated. If a time period occurs during which no key is activated, neighbor authentication cannot occur; therefore, routing updates can fail.

Multiple keychains can be specified.

How to Implement Keychain Management

This section contains the following procedures:

Configuring a Keychain

This task configures a name for the keychain.

You can create or modify the name of the keychain.

SUMMARY STEPS

    1.    configure

    2.    key chain key-chain-name

    3.    Use the commit or end command.

    4.    show key chain key-chain-name


DETAILED STEPS
     Command or ActionPurpose
    Step 1 configure


    Example:
    RP/0/RSP0/CPU0:router# configure
     

    Enters global configuration mode.

     
    Step 2key chain key-chain-name


    Example:
    RP/0/RSP0/CPU0:router(config)# key chain isis-keys
    RP/0/RSP0/CPU0:router(config-isis-keys)#
    
     

    Creates a name for the keychain.

    Note   

    Configuring only the keychain name without any key identifiers is considered a nonoperation. When you exit the configuration, the router does not prompt you to commit changes until you have configured the key identifier and at least one of the global configuration mode attributes or keychain-key configuration mode attributes (for example, lifetime or key string).

     
    Step 3 Use the commit or end command.  

    commit—Saves the configuration changes, and remains within the configuration session.

    end—Prompts user to take one of these actions:
    • Yes— Saves configuration changes and exits the configuration session.
    • No—Exits the configuration session without committing the configuration changes.
    • Cancel—Remains in the configuration mode, without committing the configuration changes.
     
    Step 4show key chain key-chain-name


    Example:
    RP/0/RSP0/CPU0:router# show key chain isis-keys
    
     

    (Optional) Displays the name of the keychain.

    Note   

    The key-chain-name argument is optional. If you do not specify a name for the key-chain-name argument, all the keychains are displayed.

     
    What to Do Next

    After completing keychain configuration, see the Configuring a Tolerance Specification to Accept Keys section.

    Configuring a Tolerance Specification to Accept Keys

    This task configures the tolerance specification to accept keys for a keychain to facilitate a hitless key rollover for applications, such as routing and management protocols.

    SUMMARY STEPS

      1.    configure

      2.    key chain key-chain-name

      3.    accept-tolerance value [infinite]

      4.    Use the commit or end command.


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 configure


      Example:
      RP/0/RSP0/CPU0:router# configure
       

      Enters global configuration mode.

       
      Step 2key chain key-chain-name


      Example:
      RP/0/RSP0/CPU0:router(config)# key chain isis-keys
      
       

      Creates a name for the keychain.

       
      Step 3accept-tolerance value [infinite]


      Example:
      RP/0/RSP0/CPU0:router(config-isis-keys)# accept-tolerance infinite
      
       

      Configures a tolerance value to accept keys for the keychain.

      • Use the value argument to set the tolerance range in seconds. The range is from 1 to 8640000.
      • Use the infinite keyword to specify that the tolerance specification is infinite.
       
      Step 4 Use the commit or end command.  

      commit—Saves the configuration changes, and remains within the configuration session.

      end—Prompts user to take one of these actions:
      • Yes— Saves configuration changes and exits the configuration session.
      • No—Exits the configuration session without committing the configuration changes.
      • Cancel—Remains in the configuration mode, without committing the configuration changes.
       

      Configuring a Key Identifier for the Keychain

      This task configures a key identifier for the keychain.

      You can create or modify the key for the keychain.

      SUMMARY STEPS

        1.    configure

        2.    key chain key-chain-name

        3.    key key-id

        4.    Use the commit or end command.


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 configure


        Example:
        RP/0/RSP0/CPU0:router# configure
         

        Enters global configuration mode.

         
        Step 2key chain key-chain-name


        Example:
        RP/0/RSP0/CPU0:router(config)# key chain isis-keys
        
         

        Creates a name for the keychain.

         
        Step 3key key-id


        Example:
        RP/0/RSP0/CPU0:router(config-isis-keys)# key 8
        
         

        Creates a key for the keychain. The key ID number is translated from decimal to hexadecimal to create the command mode subprompt.

        • Use the key-id argument as a 48-bit integer.
         
        Step 4 Use the commit or end command.  

        commit—Saves the configuration changes, and remains within the configuration session.

        end—Prompts user to take one of these actions:
        • Yes— Saves configuration changes and exits the configuration session.
        • No—Exits the configuration session without committing the configuration changes.
        • Cancel—Remains in the configuration mode, without committing the configuration changes.
         
        What to Do Next

        After configuring a key identifier for the keychain, see the Configuring the Text for the Key String section.

        Configuring the Text for the Key String

        This task configures the text for the key string.

        SUMMARY STEPS

          1.    configure

          2.    key chain key-chain-name

          3.    key key-id

          4.    key-string [clear | password] key-string-text

          5.    Use the commit or end command.


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 configure


          Example:
          RP/0/RSP0/CPU0:router# configure
           

          Enters global configuration mode.

           
          Step 2key chain key-chain-name


          Example:
          RP/0/RSP0/CPU0:router(config)# key chain isis-keys
          
           

          Creates a name for the keychain.

           
          Step 3key key-id


          Example:
          RP/0/RSP0/CPU0:router(config-isis-keys)# key 8
          RP/0/RSP0/CPU0:router(config-isis-keys-0x8)#
          
           

          Creates a key for the keychain.

           
          Step 4key-string [clear | password] key-string-text


          Example:
          RP/0/RSP0/CPU0:router(config-isis-keys-0x8)# key-string password 8
          
           

          Specifies the text string for the key.

          • Use the clear keyword to specify the key string in clear text form; use the password keyword to specify the key in encrypted form.
          • For a string to be a valid password, it must comply with the following rules:
            • It must contain an even number of characters.
            • The minumum length is 4.
            • The first two digits must be decimal numbers and the others must be hexadecimal numbers.
            • The first two digits must not be greater than 53.
            Examples of valid passwords are:
            • 12abcd
            • 32986510
           
          Step 5 Use the commit or end command.  

          commit—Saves the configuration changes, and remains within the configuration session.

          end—Prompts user to take one of these actions:
          • Yes— Saves configuration changes and exits the configuration session.
          • No—Exits the configuration session without committing the configuration changes.
          • Cancel—Remains in the configuration mode, without committing the configuration changes.
           
          What to Do Next

          After configuring the text for the key string, see the Configuring the Keys to Generate Authentication Digest for the Outbound Application Traffic section.

          Determining the Valid Keys

          This task determines the valid keys for local applications to authenticate the remote peers.

          SUMMARY STEPS

            1.    configure

            2.    key chain key-chain-name

            3.    key key-id

            4.    accept-lifetime start-time [duration duration-value | infinite | end-time]

            5.    Use the commit or end command.


          DETAILED STEPS
             Command or ActionPurpose
            Step 1 configure


            Example:
            RP/0/RSP0/CPU0:router# configure
             

            Enters global configuration mode.

             
            Step 2key chain key-chain-name


            Example:
            RP/0/RSP0/CPU0:router(config)# key chain isis-keys
            
             

            Creates a a name for the keychain.

             
            Step 3key key-id


            Example:
            RP/0/RSP0/CPU0:router(config-isis-keys)# key 8
            RP/0/RSP0/CPU0:router(config-isis-keys-0x8)#
            
             

            Creates a key for the keychain.

             
            Step 4accept-lifetime start-time [duration duration-value | infinite | end-time]


            Example:
            RP/0/RSP0/CPU0:router(config-isis-keys-0x8)# accept-lifetime 1:00:00 october 24 2005 infinite
            
            
             

            (Optional) Specifies the validity of the key lifetime in terms of clock time.

             
            Step 5 Use the commit or end command.  

            commit—Saves the configuration changes, and remains within the configuration session.

            end—Prompts user to take one of these actions:
            • Yes— Saves configuration changes and exits the configuration session.
            • No—Exits the configuration session without committing the configuration changes.
            • Cancel—Remains in the configuration mode, without committing the configuration changes.
             

            Configuring the Keys to Generate Authentication Digest for the Outbound Application Traffic

            This task configures the keys to generate authentication digest for the outbound application traffic.

            SUMMARY STEPS

              1.    configure

              2.    key chain key-chain-name

              3.    key key-id

              4.    send-lifetime start-time [duration duration-value | infinite | end-time]

              5.    Use the commit or end command.


            DETAILED STEPS
               Command or ActionPurpose
              Step 1 configure


              Example:
              RP/0/RSP0/CPU0:router# configure
               

              Enters global configuration mode.

               
              Step 2key chain key-chain-name


              Example:
              RP/0/RSP0/CPU0:router(config)# key chain isis-keys
              
               

              Creates a name for the keychain.

               
              Step 3key key-id


              Example:
              RP/0/RSP0/CPU0:router(config-isis-keys)# key 8
              RP/0/RSP0/CPU0:router(config-isis-keys-0x8)#
              
               

              Creates a key for the keychain.

               
              Step 4send-lifetime start-time [duration duration-value | infinite | end-time]


              Example:
              RP/0/RSP0/CPU0:router(config-isis-keys-0x8)# send-lifetime 1:00:00 october 24 2005 infinite
              
              
               

              (Optional) Specifies the set time period during which an authentication key on a keychain is valid to be sent. You can specify the validity of the key lifetime in terms of clock time.

              In addition, you can specify a start-time value and one of the following values:

              • duration keyword (seconds)
              • infinite keyword
              • end-time argument

              If you intend to set lifetimes on keys, Network Time Protocol (NTP) or some other time synchronization method is recommended.

               
              Step 5 Use the commit or end command.  

              commit—Saves the configuration changes, and remains within the configuration session.

              end—Prompts user to take one of these actions:
              • Yes— Saves configuration changes and exits the configuration session.
              • No—Exits the configuration session without committing the configuration changes.
              • Cancel—Remains in the configuration mode, without committing the configuration changes.
               

              Configuring the Cryptographic Algorithm

              This task allows the keychain configuration to accept the choice of the cryptographic algorithm.

              SUMMARY STEPS

                1.    configure

                2.    key chain key-chain-name

                3.    key key-id

                4.    cryptographic-algorithm [HMAC-MD5 | HMAC-SHA1-12 | HMAC-SHA1-20 | MD5 | SHA-1]

                5.    Use the commit or end command.


              DETAILED STEPS
                 Command or ActionPurpose
                Step 1 configure


                Example:
                RP/0/RSP0/CPU0:router# configure
                 

                Enters global configuration mode.

                 
                Step 2key chain key-chain-name


                Example:
                RP/0/RSP0/CPU0:router(config)# key chain isis-keys
                RP/0/RSP0/CPU0:router(config-isis-keys)#
                
                 

                Creates a name for the keychain.

                 
                Step 3key key-id


                Example:
                RP/0/RSP0/CPU0:router(config-isis-keys)# key 8
                RP/0/RSP0/CPU0:router(config-isis-keys-0x8)#
                
                 

                Creates a key for the keychain.

                 
                Step 4cryptographic-algorithm [HMAC-MD5 | HMAC-SHA1-12 | HMAC-SHA1-20 | MD5 | SHA-1]


                Example:
                RP/0/RSP0/CPU0:router(config-isis-keys-0x8)# cryptographic-algorithm MD5
                
                 

                Specifies the choice of the cryptographic algorithm. You can choose from the following list of algorithms:

                • HMAC-MD5
                • HMAC-SHA1-12
                • HMAC-SHA1-20
                • MD5
                • SHA-1

                The routing protocols each support a different set of cryptographic algorithms:

                • Border Gateway Protocol (BGP) supports only HMAC-MD5 and HMAC-SHA1-12.
                • Intermediate System-to-Intermediate System (IS-IS) supports only HMAC-MD5.
                • Open Shortest Path First (OSPF) supports only MD5 and HMAC-MD5.
                 
                Step 5 Use the commit or end command.  

                commit—Saves the configuration changes, and remains within the configuration session.

                end—Prompts user to take one of these actions:
                • Yes— Saves configuration changes and exits the configuration session.
                • No—Exits the configuration session without committing the configuration changes.
                • Cancel—Remains in the configuration mode, without committing the configuration changes.
                 

                Configuration Examples for Implementing Keychain Management

                This section provides the following configuration example:

                Configuring Keychain Management: Example

                The following example shows how to configure keychain management:

                configure
                key chain isis-keys
                accept-tolerance infinite
                key 8
                key-string mykey91abcd
                cryptographic-algorithm MD5
                send-lifetime 1:00:00 june 29 2006 infinite
                accept-lifetime 1:00:00 june 29 2006 infinite
                end
                
                Uncommitted changes found, commit them? [yes]: yes
                
                show key chain isis-keys
                
                Key-chain: isis-keys/ -
                
                accept-tolerance -- infinite
                Key 8 -- text "1104000E120B520005282820"
                  cryptographic-algorithm -- MD5
                  Send lifetime:   01:00:00, 29 Jun 2006 - Always valid  [Valid now]
                  Accept lifetime: 01:00:00, 29 Jun 2006 - Always valid [Valid now]
                

                Additional References

                The following sections provide references related to implementing keychain management.

                Related Documents

                Related Topic

                Document Title

                Keychain management commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

                Keychain Management Commands in the Cisco ASR 9000 Series Aggregation Services Router System Security Command Reference  

                Standards

                Standards

                Title

                No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

                MIBs

                MIBs

                MIBs Link

                To locate and download MIBs using Cisco IOS XR software, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http:/​/​cisco.com/​public/​sw-center/​netmgmt/​cmtk/​mibs.shtml

                RFCs

                RFCs

                Title

                No new or modified RFCs are supported by this feature.

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