Contents

Configuring keychains· 1

About keychains· 1

Restrictions and guidelines: Keychain configuration· 1

Configuring a keychain· 1

Display and maintenance commands for keychain· 2

Keychain configuration example· 2

Example: Configuring keychains· 2

 

Configuring keychains

About keychains

A keychain, a sequence of keys, provides dynamic authentication to ensure secure communication by periodically changing the key and authentication algorithm without service interruption.

A keychain operates in absolute time mode. In this mode, each time point during a key's lifetime is the UTC time and is not affected by the system's time zone or daylight saving time.

Each key in a keychain has a key string, authentication algorithm, sending lifetime, and receiving lifetime. When the system time is within the lifetime of a key in a keychain, an application uses the key to authenticate incoming and outgoing packets. The keys in the keychain take effect one by one according to the sequence of the configured lifetimes. In this way, the authentication algorithms and keys are dynamically changed to implement dynamic authentication.

Restrictions and guidelines: Keychain configuration

To make sure only one key in a keychain is used at a time to authenticate packets to a peer, set non-overlapping sending lifetimes for the keys in the keychain.

The keys used by the local device and the peer device must have the same authentication algorithm and key string.

Configuring a keychain

1.        Enter system view.

system-view

2.        Create a keychain and enter keychain view.

keychain keychain-name mode absolute

3.        (Optional.) Configure TCP authentication.

¡  Set the kind value in the TCP Enhanced Authentication Option.

tcp-kind kind-value

By default, the kind value is 254.

¡  Set an algorithm ID for a TCP authentication algorithm.

tcp-algorithm-id { hmac-md5 | md5 } algorithm-id

By default, the algorithm ID is 3 for the MD5 authentication algorithm and 5 for the HMAC-MD5 authentication algorithm.

When the local device uses TCP to communicate with a peer device from another vendor, make sure both devices have the same kind value and algorithm ID settings. If they do not, modify the settings on the local device.

4.        (Optional.) Set a tolerance time for accept keys in the keychain.

accept-tolerance { value | infinite }

By default, no tolerance time is configured for accept keys in a keychain.

If authentication information is changed, information mismatch occurs on the local and peer devices, and the service might be interrupted. Use this command to ensure continuous packet authentication.

5.        Create a key and enter key view.

key key-id

6.        Configure the key.

¡  Specify an authentication algorithm for the key.

authentication-algorithm { hmac-md5 | hmac-sha-256 | md5 }

By default, no authentication algorithm is specified for a key.

¡  Configure a key string for the key.

key-string { cipher | plain } string

By default, no key string is configured.

¡  Set the sending lifetime in UTC mode for the key.

send-lifetime utc start-time start-date { duration { duration-value | infinite } | to end-time end-date }

By default, the sending lifetime is not configured for a key.

¡  Set the receiving lifetime in UTC mode for the key.

accept-lifetime utc start-time start-date { duration { duration-value | infinite } | to end-time end-date }

By default, the receiving lifetime is not configured for a key.

¡  (Optional.) Specify the key as the default send key.

default-send-key

You can specify only one key as the default send key in a keychain.

Display and maintenance commands for keychain

Execute display commands in any view.

 

Task	Command
Display keychain information.	display keychain [ name keychain-name [ key key-id ] ]

 

Keychain configuration example

Example: Configuring keychains

Network configuration

As shown in Figure 1, establish an OSPF neighbor relationship between Switch A and Switch B, and use a keychain to authenticate packets between the switches. Configure key 1 and key 2 for the keychain and make sure key 2 is used immediately when key 1 expires.

Figure 1 Network diagram

 

Procedure

1.        Configure Switch A:

# Configure IP addresses for interfaces. (Details not shown.)

# Configure OSPF.

<SwitchA> system-view

[SwitchA] ospf 1 router-id 1.1.1.1

[SwitchA-ospf-1] area 0

[SwitchA-ospf-1-area-0.0.0.0] network 192.1.1.0 0.0.0.255

[SwitchA-ospf-1-area-0.0.0.0] quit

[SwitchA-ospf-1] quit

# Create a keychain named abc, and specify the absolute time mode for it.

[SwitchA] keychain abc mode absolute

# Create key 1 for keychain abc, specify an authentication algorithm, and configure a key string and the sending and receiving lifetimes for the key.

[SwitchA-keychain-abc] key 1

[SwitchA-keychain-abc-key-1] authentication-algorithm md5

[SwitchA-keychain-abc-key-1] key-string plain 123456

[SwitchA-keychain-abc-key-1] send-lifetime utc 10:00:00 2015/02/06 to 11:00:00 2015/02/06

[SwitchA-keychain-abc-key-1] accept-lifetime utc 10:00:00 2015/02/06 to 11:00:00 2015/02/06

[SwitchA-keychain-abc-key-1] quit

# Create key 2 for keychain abc, specify an authentication algorithm, and configure a key string and the sending and receiving lifetimes for the key.

[SwitchA-keychain-abc] key 2

[SwitchA-keychain-abc-key-2] authentication-algorithm hmac-md5

[SwitchA-keychain-abc-key-2] key-string plain pwd123

[SwitchA-keychain-abc-key-2] send-lifetime utc 11:00:00 2015/02/06 to 12:00:00 2015/02/06

[SwitchA-keychain-abc-key-2] accept-lifetime utc 11:00:00 2015/02/06 to 12:00:00 2015/02/06

[SwitchA-keychain-abc-key-2] quit

[SwitchA-keychain-abc] quit

# Configure VLAN-interface 100 to use keychain abc for authentication.

[SwitchA] interface vlan-interface 100

[SwitchA-Vlan-interface100] ospf authentication-mode keychain abc

[SwitchA-Vlan-interface100] quit

2.        Configure Switch B:

# Configure IP addresses for interfaces. (Details not shown.)

# Configure OSPF.

[SwitchB] ospf 1 router-id 2.2.2.2

[SwitchB-ospf-1] area 0

[SwitchB-ospf-1-area-0.0.0.0] network 192.1.1.0 0.0.0.255

[SwitchB-ospf-1-area-0.0.0.0] quit

[SwitchB-ospf-1] quit

# Create a keychain named abc, and specify the absolute time mode for it.

[SwitchB] keychain abc mode absolute

# Create key 1 for keychain abc, specify an authentication algorithm, and configure a key string and the sending and receiving lifetimes for the key.

[SwitchB-keychain-abc] key 1

[SwitchB-keychain-abc-key-1] authentication-algorithm md5

[SwitchB-keychain-abc-key-1] key-string plain 123456

[SwitchB-keychain-abc-key-1] send-lifetime utc 10:00:00 2015/02/06 to 11:00:00 2015/02/06

[SwitchB-keychain-abc-key-1] accept-lifetime utc 10:00:00 2015/02/06 to 11:00:00 2015/02/06

[SwitchB-keychain-abc-key-1] quit

# Create key 2 for keychain abc, specify an authentication algorithm, and configure a key string and the sending and receiving lifetimes for the key.

[SwitchB-keychain-abc] key 2

[SwitchB-keychain-abc-key-2] authentication-algorithm hmac-md5

[SwitchB-keychain-abc-key-2] key-string plain pwd123

[SwitchB-keychain-abc-key-2] send-lifetime utc 11:00:00 2015/02/06 to 12:00:00 2015/02/06

[SwitchB-keychain-abc-key-2] accept-lifetime utc 11:00:00 2015/02/06 to 12:00:00 2015/02/06

[SwitchB-keychain-abc-key-2] quit

[SwitchB-keychain-abc] quit

# Configure VLAN-interface 100 to use keychain abc for authentication.

[SwitchB] interface vlan-interface 100

[SwitchB-Vlan-interface100] ospf authentication-mode keychain abc

[SwitchB-Vlan-interface100] quit

Verifying the configuration

1.        When the system time is within the lifetime from 10:00:00 to 11:00:00 on the day 2015/02/06, verify the status of the keys in keychain abc.

# Display keychain information on Switch A. The output shows that key 1 is the valid key.

[SwitchA] display keychain

 

 Keychain name          : abc

   Mode                 : absolute

   Accept tolerance     : 0

   TCP kind value       : 254

   TCP algorithm value

     HMAC-MD5           : 5

     MD5                : 3

   Default send key ID  : None

   Active send key ID   : 1

   Active accept key IDs: 1

 

   Key ID               : 1

     Key string         : $c$3$dYTC8QeOKJkwFwP2k/rWL+1p6uMTw3MqNg==

     Algorithm          : md5

     Send lifetime      : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Send status        : Active

     Accept lifetime    : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Accept status      : Active

 

   Key ID               : 2

     Key string         : $c$3$7TSPbUxoP1ytOqkdcJ3K3x0BnXEWl4mOEw==

     Algorithm          : hmac-md5

     Send lifetime      : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Send status        : Inactive

     Accept lifetime    : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Accept status      : Inactive

# Display keychain information on Switch B. The output shows that key 1 is the valid key.

[SwitchB]display keychain

 

 Keychain name          : abc

   Mode                 : absolute

   Accept tolerance     : 0

   TCP kind value       : 254

   TCP algorithm value

     HMAC-MD5           : 5

     MD5                : 3

   Default send key ID  : None

   Active send key ID   : 1

   Active accept key IDs: 1

 

   Key ID               : 1

     Key string         : $c$3$/G/Shnh6heXWprlSQy/XDmftHa2JZJBSgg==

     Algorithm          : md5

     Send lifetime      : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Send status        : Active

     Accept lifetime    : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Accept status      : Active

 

   Key ID               : 2

     Key string         : $c$3$t4qHAw1hpZYN0JKIEpXPcMFMVT81u0hiOw==

     Algorithm          : hmac-md5

     Send lifetime      : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Send status        : Inactive

     Accept lifetime    : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Accept status      : Inactive

2.        When the system time is within the lifetime from 11:00:00 to 12:00:00 on the day 2015/02/06, verify the status of the keys in keychain abc.

# Display keychain information on Switch A. The output shows that key 2 becomes the valid key.

[SwitchA]display keychain

 

 Keychain name          : abc

   Mode                 : absolute

   Accept tolerance     : 0

   TCP kind value       : 254

   TCP algorithm value

     HMAC-MD5           : 5

     MD5                : 3

   Default send key ID  : None

   Active send key ID   : 2

   Active accept key IDs: 2

 

   Key ID               : 1

     Key string         : $c$3$dYTC8QeOKJkwFwP2k/rWL+1p6uMTw3MqNg==

     Algorithm          : md5

     Send lifetime      : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Send status        : Inactive

     Accept lifetime    : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Accept status      : Inactive

 

   Key ID               : 2

     Key string         : $c$3$7TSPbUxoP1ytOqkdcJ3K3x0BnXEWl4mOEw==

     Algorithm          : hmac-md5

     Send lifetime      : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Send status        : Active

     Accept lifetime    : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Accept status      : Active

# Display keychain information on Switch B. The output shows that key 2 becomes the valid key.

[SwitchB]display keychain

 

 Keychain name          : abc

   Mode                 : absolute

   Accept tolerance     : 0

   TCP kind value       : 254

   TCP algorithm value

     HMAC-MD5           : 5

     MD5                : 3

   Default send key ID  : None

   Active send key ID   : 1

   Active accept key IDs: 1

 

   Key ID               : 1

     Key string         : $c$3$/G/Shnh6heXWprlSQy/XDmftHa2JZJBSgg==

     Algorithm          : md5

     Send lifetime      : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Send status        : Inactive

     Accept lifetime    : 10:00:00 2015/02/06 to 11:00:00 2015/02/06

     Accept status      : Inactive

 

   Key ID               : 2

     Key string         : $c$3$t4qHAw1hpZYN0JKIEpXPcMFMVT81u0hiOw==

     Algorithm          : hmac-md5

     Send lifetime      : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Send status        : Active

     Accept lifetime    : 11:00:00 2015/02/06 to 12:00:00 2015/02/06

     Accept status      : Active