SKIP (Simple Key Management for Internet Protocols) is an IP layer encryption package. It provides a system with the ability to efficiently encrypt any protocol within the TCP/IP protocol suite. Once installed, any two (or more) systems running SKIP have the ability to transparently encrypt and/or authenticate all traffic between them.
SKIP's access control is based on the requesting system's IP address. To provide access for mobile remote users, SKIP has provided users with the ability to separate an entity from it's physical address through the use of a key identifier. When a system tries to connect to a host running SKIP, the order of processing is as follows:
SKIP provides users with the ability to separate the identity of an entity from it's physical address. This means that each person (sender/receiver) participating in a transfer of encrypted data over a computer network can be identified by an NSID/Local KeyID pair. The KeyID is used for key lookup, not for routing. By default, the NSID is set to 0 and a KeyID is not sent. However, with the KeyID feature activated, key names are no longer tied to IP addresses. This means that regardless of their physical location on the network or on the Internet, sales, marketing, and support personnel have the ability to communicate with each other and corporate using encryption. Corporate data remains secured regardless of the location of a sales rep or system engineer at customer sites or trade shows.
The Name Space Identifiers (NSID). The NSID's supported by SKIP are:
NSID 0 (Not present)
NSID 1 (IPv4 address)
NSID 8 (MD5 of Diffie-Hellman Public Values)
Keys and certificates are handled by the key manager. Local key information is managed using the skiplocal command and CA information is managed using the skipca command.
The algorithms used by SKIP are:
There are times when it is useful to allow a system to have more than one public/private key pair. For example, different key sizes may be required when communicating with subsidiaries in other countries due to local regulations. To meet these user requirement's, Sun's SKIP implementation allows a system to possess as many local keys as required. Similarly, the SKIP system can also be configured with the details of several Certification Authorities so that certificates signed by different CAs can be checked for authenticity.
http://www.incog.com
For more information on SKIP, please see the SKIP web page:
http://skip.incog.com
The software must be unpacked before it can be installed. To extract the files, complete the following steps:
example# zcat directoryname/skip.tar.z|tar -xvf -
example# cd /usr/skip
example# ./install.skip
example# set path = ( /usr/skip/bin $path )
# skiplocal keygen
Even when using skiplocal export, make sure you both verify the other party's keyid over the phone with the other party to make sure someone is not impersonating them.
example# skipif -a
On a machine with multiple network interfaces, you should specify the interface :
example# skipif -i zp0 -a
setenv MANPATH /usr/share/man:/usr/skip/man
example# reboot
X509 Certificates without proper signatures are not be added to the database. Therefore, the CAs certificate must be added to the CA Certificate database using the skipca command prior to adding certificates signed by that CA to the database.
skipd services encryption and decryption requests from the kernel and acts as a certificate server. The encryption/decryption requests are received and answered via /dev/skip_key. When acting as a certificate server, skipd answers CDP requests from remote hosts as well as issuing requests for certificates from remote Certificate Discovery servers when necessary.
# skipd_restart
To start SKIP, complete the following steps:
skiptool Main Menu
Hosts are added to the Authorized System list using the Add button, located at the bottom left of the Authorized Systems list on the skiptool Main Window. When setting up SKIP, be sure to include any NFS servers and NIS name servers on the Authorized Systems list, otherwise your system hangs. To determine the servers your system communicates with, use the following commands:
It could be usefull also to verify the current routing entries used by the local system with ``netstat -rn'' and add specific network ACL entries.
When adding entities to your access control list, valid types are:
When you click on the Add button, the Add popup window appears. Here you select the Type of connection: Host, Network, or Nomadic. Next, set the Security level. After any level of security has been selected, the Properties window becomes available. The Add system Properties window is used to set up the options for the type of encryption used by the host, network, or nomadic system being authorized. On the Add system Properties window, the following button is not implemented at this time: Compression.
To authorize a system, complete the following steps:
None
The following namespaces are listed in this menu:
To communicate with a Sunscreen(TM) SPF-100 you must use the SKIP V1 Protocol and install the proper key. Call SunService for help in obtaining the key. Appendix A of this manual describes how to install the key.
When accessing a SunScreen, the Node ID, Tunnel address, Key encryption, and Traffic encryption fields must be set up.
Use the Unauthorized Systems button on the main window to select what action SKIP should take when an unidentified system attempts access. There are three possible actions which SKIP may take when an unidentified system attempts to connect to your system when the default entry has been removed from these lists:
If a Default authorized system resides on either the Authorized or Excluded Systems lists, this option does not take affect.
Once SKIP has been configured on your system, you are ready to configure it on the other systems which you will be communicating with either in the clear or through one of the encryption methods available in SKIP. Once both parties have installed and configured SKIP, SKIP should be enabled and your data protected.
To configure SKIP using the skiphost command, one entry is required for each system/host being set up in the access control list. Before enabling SKIP, any hosts needed for operation of the local system must be present in the ACL. Verify that any NFS file servers, NIS servers, or any local broadcast addresses for your network are on the ACL. Then skiphost must be run one final time to enable SKIP. See the man page for skiphost for details
Enabling SKIP
This windows now adds also the ``ALL-SYSTEMS'' and ``ALL-ROUTERS'' multicast addresses.
The Authorized Systems area lists all the hosts allowed access. The Excluded Systems area shows all those known hosts which are explicitly denied access.The graphic preceding the host name or IP address depicts what type of security is being used with that host.
Note that if the default system entry remains, it is unnecessary to add any entity with the OFF security option. Further, if the default system entry remains, the option set by the Unauthorized Systems button never goes into effect.
If you quit the application, SKIP stays in whatever mode it was last in (enabled or disabled). The Unauthorized Systems policy automatically changes to No Access, since there is no longer any way to notify you if an unauthorized system is attempting to gain access.
SKIP Icon showing both the Enabled and Disabled states
To verify that SKIP is operating properly on your system, complete one or more of the following procedures:
SKIP Network Interface Statistics
Selecting File - SKIP Statistics-Network Interface Stats displays the SKIP Network Interface Statistics window.SKIP Header Statistics
Selecting File - SKIP Statistics-Header Stats displays the SKIP Header Statistics window.In the field descriptions below, V1 refers to SKIP v1 compatibility mode.SKIP Key Statistics
Selecting File - SKIP Statistics-Key Stats displays the SKIP Key Statistics window (Figure 3-7).
SKIP Encryption Statistics
Selecting File - SKIP Statistics-Encryption Stats (SKIP V1 or IPSP) displays the SKIP Algorithm Statistics window.SKIP Authentication Stats
Selecting File - SKIP Statistics-Authentication Stats displays the SKIP Authentication Stats window which provides information on MAC's (Message Authentication Code). Using skipstat
The alternative method of viewing SKIP statistics is to use the skipstat command line interface. skipstat is a part of the skiptool GUI as well. skipstat provides statistical data on the following items for the local system:
Key and Certificate Management Using the Command Line Interface
When issuing any of the commands used in key and certificate management, you must be logged in as root. In addition, if you are running Solaris 2.x, you must issue the xhost + command to allow access to the X server. The key and management commands provided by SKIP are:Installing Certificates
The following procedure provides instructions for installing certificates from Sun Microsystems Internet Commerce Group's Certificate Authority.
example# install_skip_keys -icg /floppy/floppy0
example# eject floppy