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IP Security Architecture (Reference)
This chapter contains the following reference information:
For instructions on how to implement IPsec on your network, see Chapter 20, Configuring IPsec (Tasks). For an overview of IPsec, see Chapter 19, IP Security Architecture (Overview).
ipsecconf Command
You use the ipsecconf command to configure the IPsec policy for a host. When you run the command to configure the policy, the system creates the IPsec policy entries in the kernel. The system uses these entries to check the policy on all outbound and inbound IP datagrams. Forwarded datagrams are not subjected to policy checks that are added by using this command. The ipsecconf command also configures the security policy database (SPD).
For information on how to protect forwarded packets, see the ifconfig(1M) and tun(7M) man pages.
For IPsec policy options, see the ipsecconf(1M) man page.
For instructions on how to use the ipsecconf command to protect traffic between systems, see Configuring IKE (Task Map).
You must become superuser or assume an equivalent role to invoke the ipsecconf command. The command accepts entries that protect traffic in both directions. The command also accepts entries that protect traffic in only one direction.
Policy entries with a format of local address and remote address can protect traffic in both directions with a single policy entry. For example, entries that contain the patterns laddr host1 and raddr host2 protect traffic in both directions, if no direction is specified for the named host. Thus, you need only one policy entry for each host.
Policy entries with a format of source address to destination address protect traffic in only one direction. For example, a policy entry of the pattern saddr host1 daddr host2 protects inbound traffic or outbound traffic, not both directions. Thus, to protect traffic in both directions, you need to pass the ipsecconf command another entry, as in saddr host2 daddr host1.
The ipsecpolicy.conf file is deleted when the system shuts down. To ensure that the IPsec policy is active when the machine boots, you can create an IPsec policy file, /etc/inet/ipsecinit.conf. This file is read when the network services are started. For instructions on how to create an IPsec policy file, see Protecting Traffic With IPsec (Task Map).
ipsecinit.conf File
To invoke IPsec security policies when you start the Solaris Operating System, you create a configuration file to initialize IPsec with your specific IPsec policy entries. You should name the file /etc/inet/ipsecinit.conf. See the ipsecconf(1M) man page for details about policy entries and their format. After policies are configured, you can use the ipsecconf command to view or modify the existing configuration.
Sample ipsecinit.conf File
The Solaris software includes a sample IPsec policy file, ipsecinit.sample. You can use the file as a template to create your own ipsecinit.conf file. The ipsecinit.sample file contains the following examples:
#
# For example,
#
# {rport 23} ipsec {encr_algs des encr_auth_algs md5}
#
# will protect the telnet traffic originating from the host with ESP using
# DES and MD5. Also:
#
# {raddr 10.5.5.0/24} ipsec {auth_algs any}
#
# will protect traffic to or from the 10.5.5.0 subnet with AH
# using any available algorithm.
#
#
# To do basic filtering, a drop rule may be used. For example:
#
# {lport 23 dir both} drop {}
# will disallow any remote system from telnetting in.
#
# If you are using IPv6, it may be useful to bypass neighbor discovery
# to allow in.iked to work properly with on-link neighbors. To do that,
# add the following lines:
#
# {ulp ipv6-icmp type 133-137 dir both } pass { }
#
# This will allow neighbor discovery to work normally.
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Security Considerations for ipsecinit.conf and ipsecconf
Use extreme caution if transmitting a copy of the ipsecinit.conf file over a network. An adversary can read a network-mounted file as the file is being read. If, for example, the /etc/inet/ipsecinit.conf file is accessed or is copied from an NFS-mounted file system, an adversary can change the policy that is contained in the file.
Ensure that you set up IPsec policies before starting any communications, because existing connections might be affected by the addition of new policy entries. Similarly, do not change policies in the middle of a communication.
Specifically, IPsec policy cannot be changed for SCTP, TCP, or UDP sockets on which a connect() or accept() function call has been issued. A socket whose policy cannot be changed is called a latched socket. New policy entries do not protect sockets that are already latched. For more information, see the connect(3SOCKET) and accept(3SOCKET) man pages.
Protect your naming system. If the following two conditions are met, then your host names are no longer trustworthy:
Your source address is a host that can be looked up over the network.
Your naming system is compromised.
Security weaknesses often arise from the misapplication of tools, not from the actual tools. You should be cautious when using the ipsecconf command. Use a console or other hard-connected TTY for the safest mode of operation.
ipsecalgs Command
The Solaris cryptographic framework provides authentication and encryption algorithms to IPsec. You use the ipsecalgs command to query and modify the list of protocols and the list of algorithms that IPsec supports. The ipsecalgs command stores this information in tabular format in the IPsec protocols and algorithms file, /etc/inet/ipsecalgs. This file must never be edited manually.
The valid IPsec protocols and algorithms are described by the ISAKMP domain of interpretation (DOI), which is covered by RFC 2407. In a general sense, a DOI defines data formats, network traffic exchange types, and conventions for naming security-relevant information. Security policies, cryptographic algorithms, and cryptographic modes are examples of security-relevant information.
Specifically, the ISAKMP DOI defines the naming and numbering conventions for the valid IPsec algorithms and for their protocols, PROTO_IPSEC_AH and PROTO_IPSEC_ESP. Each algorithm is associated with exactly one protocol. These ISAKMP DOI definitions are in the /etc/inet/ipsecalgs file. The algorithm and protocol numbers are defined by the Internet Assigned Numbers Authority (IANA). The ipsecalgs command makes the list of algorithms for IPsec extensible.
For more information on the algorithms, refer to the ipsecalgs(1M) man page. For more information on the Solaris cryptographic framework, see Chapter 12, "Solaris Cryptographic Framework (Overview)," in System Administration Guide: Security Services.