System Administration Guide: IP Services

Keying Utilities

The IKE protocol is the automatic keying utility for IPv4 addresses. See Chapter 21, Internet Key Exchange for how to set up IKE. The manual keying utility is the ipseckey(1M) command.

You use the ipseckey command to manually manipulate the security association databases with the ipsecah(7P) and ipsecesp(7P) protection mechanisms. You can also use the ipseckey command to set up security associations between communicating parties when automated key management is not available. An example is communicating parties that have IPv6 addresses.

While the ipseckey command has only a limited number of general options, it supports a rich command language. You can specify that requests should be delivered by means of a programmatic interface specific for manual keying. See the pf_key(7P) man page for additional information. When you invoke ipseckey with no arguments, it enters an interactive mode that displays a prompt that enables you to make entries. Some commands require an explicit security association (SA) type, while others permit you to specify the SA type and act on all SA types.

Security Considerations

The ipseckey command enables a privileged user to enter sensitive cryptographic keying information. If an adversary gains access to this information, the adversary can compromise the security of IPsec traffic. You should consider the following issues when you handle keying material and use the ipseckey command:

  1. Have you refreshed the keying material? Periodic key refreshment is a fundamental security practice. Changing keys guards against potential weaknesses of the algorithm and keys, and limits the damage of an exposed key.

  2. Is the TTY going over a network (interactive mode)?

    • If the TTY is in interactive mode, then the security of the keying material is the security of the network path for this TTY's traffic. You should avoid using the ipseckey command over a clear-text telnet or rlogin session.

    • Even local windows might be vulnerable to attacks by a concealed program that reads window events.

  3. Is the file accessed over the network or readable to the world (-f option)?

    • An adversary can read a network-mounted file as it is being read. You should avoid using a world-readable file with keying material in it.

    • If your source address is a host that can be looked up over the network, and your naming system is compromised, then any names used are no longer trustworthy.

Security weaknesses often lie in misapplication of tools, not the tools themselves. You should be cautious when using the ipseckey command. Use a console or other hard-connected TTY for the safest mode of operation.