This is Info file krb5-install.info, produced by Makeinfo version 1.68 from the input file install.texinfo.  File: krb5-install.info, Node: Create a kadmind Keytab, Next: Start the Kerberos Daemons, Prev: Add Administrators to the Kerberos Database, Up: Install the Master KDC Create a kadmind Keytab ....................... The kadmind keytab is the key that kadmind will use to decrypt administrators' Kerberos tickets to determine whether or not it should give them access to the database. You need to create the kadmin keytab with entries for the principals `kadmin/admin' and `kadmin/changepw'. (These principals are placed in the Kerberos database automatically when you create it.) To create the kadmin keytab, run `kadmin.local' and use the `ktadd' command, as in the following example. (The line beginning with => is a continuation of the previous line.): shell% /usr/local/sbin/kadmin.local kadmin.local: ktadd -k /usr/local/var/krb5kdc/kadm5.keytab => kadmin/admin kadmin/changepw Entry for principal kadmin/admin@ATHENA.MIT.EDU with kvno 3, encryption type DES-CBC-CRC added to keytab WRFILE:/usr/local/var/krb5kdc/kadm5.keytab. Entry for principal kadmin/changepw@ATHENA.MIT.EDU with kvno 3, encryption type DES-CBC-CRC added to keytab WRFILE:/usr/local/var/krb5kdc/kadm5.keytab. kadmin.local: quit shell% As specified in the `-k' argument, `ktadd' will save the extracted keytab as `/usr/local/var/krb5kdc/kadm5.keytab'. The filename you use must be the one specified in your `kdc.conf' file.  File: krb5-install.info, Node: Start the Kerberos Daemons, Prev: Create a kadmind Keytab, Up: Install the Master KDC Start the Kerberos Daemons on the Master KDC ............................................ At this point, you are ready to start the Kerberos daemons on the Master KDC. To do so, type: shell% /usr/local/sbin/krb5kdc shell% /usr/local/sbin/kadmind Each daemon will fork and run in the background. Assuming you want these daemons to start up automatically at boot time, you can add them to the KDC's `/etc/rc' or `/etc/inittab' file. You need to have a stash file in order to do this. You can verify that they started properly by checking for their startup messages in the logging locations you defined in `/etc/krb5.conf' (see *Note Edit the Configuration Files::). For example: shell% tail /var/log/krb5kdc.log Dec 02 12:35:47 beeblebrox krb5kdc[3187](info): commencing operation shell% tail /var/log/kadmin.log Dec 02 12:35:52 beeblebrox kadmind[3189](info): starting Any errors the daemons encounter while starting will also be listed in the logging output.  File: krb5-install.info, Node: Install the Slave KDCs, Next: Back on the Master KDC, Prev: Install the Master KDC, Up: Installing KDCs Install the Slave KDCs ---------------------- You are now ready to start configuring the slave KDCs. Assuming you are setting the KDCs up so that you can easily switch the master KDC with one of the slaves, you should perform each of these steps on the master KDC as well as the slave KDCs, unless these instructions specify otherwise. * Menu: * Create Host Keys for the Slave KDCs:: * Extract Host Keytabs for the KDCs:: * Set Up the Slave KDCs for Database Propagation::  File: krb5-install.info, Node: Create Host Keys for the Slave KDCs, Next: Extract Host Keytabs for the KDCs, Prev: Install the Slave KDCs, Up: Install the Slave KDCs Create Host Keys for the Slave KDCs ................................... Each KDC needs a host principal in the Kerberos database. You can enter these from any host, once the `kadmind' daemon is running. For example, if your master KDC were called kerberos.mit.edu, and you had two KDC slaves named kerberos-1.mit.edu and kerberos-2.mit.edu, you would type the following: shell% /usr/local/sbin/kadmin kadmin: addprinc -randkey host/kerberos.mit.edu WARNING: no policy specified for "host/kerberos.mit.edu@ATHENA.MIT.EDU"; defaulting to no policy. Principal "host/kerberos.mit.edu@ATHENA.MIT.EDU" created. kadmin: addprinc -randkey host/kerberos-1.mit.edu WARNING: no policy specified for "host/kerberos-1.mit.edu@ATHENA.MIT.EDU"; defaulting to no policy. Principal "host/kerberos-1.mit.edu@ATHENA.MIT.EDU" created. kadmin: addprinc -randkey host/kerberos-2.mit.edu WARNING: no policy specified for "host/kerberos-2.mit.edu@ATHENA.MIT.EDU"; defaulting to no policy. Principal "host/kerberos-2.mit.edu@ATHENA.MIT.EDU" created. kadmin: It is not actually necessary to have the master KDC server in the Kerberos database, but it can be handy if: * anyone will be logging into the machine as something other than root * you want to be able to swap the master KDC with one of the slaves if necessary.  File: krb5-install.info, Node: Extract Host Keytabs for the KDCs, Next: Set Up the Slave KDCs for Database Propagation, Prev: Create Host Keys for the Slave KDCs, Up: Install the Slave KDCs Extract Host Keytabs for the KDCs ................................. Each KDC (including the master) needs a keytab to decrypt tickets. Ideally, you should extract each keytab locally on its own KDC. If this is not feasible, you should use an encrypted session to send them across the network. To extract a keytab on a KDC called kerberos.mit.edu, you would execute the following command: kadmin: ktadd host/kerberos.mit.edu kadmin: Entry for principal host/kerberos.mit.edu@ATHENA.MIT.EDU with kvno 1, encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5.keytab. kadmin: Note that the principal must exist in the Kerberos database in order to extract the keytab.  File: krb5-install.info, Node: Set Up the Slave KDCs for Database Propagation, Prev: Extract Host Keytabs for the KDCs, Up: Install the Slave KDCs Set Up the Slave KDCs for Database Propagation .............................................. The database is propagated from the master KDC to the slave KDCs via the `kpropd' daemon. To set up propagation, create a file on each KDC, named `/usr/local/var/krb5kdc/kpropd.acl', containing the principals for each of the KDCs. For example, if the master KDC were `kerberos.mit.edu', the slave KDCs were `kerberos-1.mit.edu' and `kerberos-2.mit.edu', and the realm were `ATHENA.MIT.EDU', then the file's contents would be: host/kerberos.mit.edu@ATHENA.MIT.EDU host/kerberos-1.mit.edu@ATHENA.MIT.EDU host/kerberos-2.mit.edu@ATHENA.MIT.EDU Then, add the following lines to `/etc/inetd.conf' file on each KDC (the line beginnng with => is a continuation of the previous line): krb5_prop stream tcp nowait root /usr/local/sbin/kpropd kpropd eklogin stream tcp nowait root /usr/local/sbin/klogind => klogind -k -c -e The first line sets up the `kpropd' database propagation daemon. The second line sets up the `eklogin' daemon, allowing Kerberos-authenticated, encrypted rlogin to the KDC. You also need to add the following lines to `/etc/services' on each KDC: kerberos 88/udp kdc # Kerberos authentication (udp) kerberos 88/tcp kdc # Kerberos authentication (tcp) krb5_prop 754/tcp # Kerberos slave propagation kerberos-adm 749/tcp # Kerberos 5 admin/changepw (tcp) kerberos-adm 749/udp # Kerberos 5 admin/changepw (udp) eklogin 2105/tcp # Kerberos encrypted rlogin  File: krb5-install.info, Node: Back on the Master KDC, Next: Finish Installing the Slave KDCs, Prev: Install the Slave KDCs, Up: Installing KDCs Back on the Master KDC ---------------------- Now that the slave KDCs are able to accept database propagation, you'll need to propagate the database to each of them. * Menu: * Propagate the Database to Each Slave KDC::  File: krb5-install.info, Node: Propagate the Database to Each Slave KDC, Prev: Back on the Master KDC, Up: Back on the Master KDC Propagate the Database to Each Slave KDC ........................................ First, create a dump of the database on the master KDC, as follows: shell% /usr/local/sbin/kdb5_util dump /usr/local/var/krb5kdc/slave_datatrans shell% Next, you need to manually propagate the database to each slave KDC, as in the following example. (The lines beginning with => are continuations of the previous line.): /usr/local/sbin/kprop -f /usr/local/var/krb5kdc/slave_datatrans => kerberos-1.mit.edu /usr/local/sbin/kprop -f /usr/local/var/krb5kdc/slave_datatrans => kerberos-2.mit.edu You will need a script to dump and propagate the database. The following is an example of a bourne shell script that will do this. (Note that the line that begins with => is a continuation of the previous line. Remember that you need to replace /usr/local with the name of the directory in which you installed Kerberos V5.) #!/bin/sh kdclist = "kerberos-1.mit.edu kerberos-2.mit.edu" /usr/local/sbin/kdb5_util -R "dump => /usr/local/var/krb5kdc/slave_datatrans" for kdc in $kdclist do /usr/local/sbin/kprop -f /usr/local/var/krb5kdc/slave_datatrans $kdc done You will need to set up a cron job to run this script at the intervals you decided on earlier (*Note Database Propagation::.)  File: krb5-install.info, Node: Finish Installing the Slave KDCs, Next: Add Kerberos Principals to the Database, Prev: Back on the Master KDC, Up: Installing KDCs Finish Installing the Slave KDCs -------------------------------- Now that the slave KDCs have copies of the Kerberos database, you can create stash files for them and start the `krb5kdc' daemon. * Menu: * Create Stash Files on the Slave KDCs:: * Start the krb5kdc Daemon on Each KDC::  File: krb5-install.info, Node: Create Stash Files on the Slave KDCs, Next: Start the krb5kdc Daemon on Each KDC, Prev: Finish Installing the Slave KDCs, Up: Finish Installing the Slave KDCs Create Stash Files on the Slave KDCs .................................... Create stash files, by issuing the following commands on each slave KDC: shell% kdb5_util stash kdb5_util: Cannot find/read stored master key while reading master key kdb5_util: Warning: proceeding without master key Enter KDC database master key: <= Enter the database master key. shell% As mentioned above, the stash file is necessary for your KDCs to be able authenticate to themselves, such as when they reboot. You could run your KDCs without stash files, but you would then need to type in the Kerberos database master key by hand every time you start a KDC daemon.  File: krb5-install.info, Node: Start the krb5kdc Daemon on Each KDC, Prev: Create Stash Files on the Slave KDCs, Up: Finish Installing the Slave KDCs Start the krb5kdc Daemon on Each KDC .................................... The final step in configuing your slave KDCs is to run the KDC daemon: shell% /usr/local/sbin/krb5kdc As with the master KDC, you will probably want to add this command to the KDCs' `/etc/rc' or `/etc/inittab' files, so they will start the krb5kdc daemon automatically at boot time.  File: krb5-install.info, Node: Add Kerberos Principals to the Database, Next: Limit Access to the KDCs, Prev: Finish Installing the Slave KDCs, Up: Installing KDCs Add Kerberos Principals to the Database --------------------------------------- Once your KDCs are set up and running, you are ready to use `kadmin' to load principals for your users, hosts, and other services into the Kerberos database. This procedure is described fully in the "Adding or Modifying Principals" section of the Kerberos V5 System Administrator's Guide. (*Note Create Host Keys for the Slave KDCs:: for a brief description.) The keytab is generated by running `kadmin' and issuing the `ktadd' command.  File: krb5-install.info, Node: Limit Access to the KDCs, Next: Switching Master and Slave KDCs, Prev: Add Kerberos Principals to the Database, Up: Installing KDCs Limit Access to the KDCs ------------------------ To limit the possibility that your Kerberos database could be compromised, MIT recommends that each KDC be a dedicated host, with limited access. If your KDC is also a file server, FTP server, Web server, or even just a client machine, someone who obtained root access through a security hole in any of those areas could gain access to the Kerberos database. MIT recommends that your KDCs use the following `/etc/inetd.conf' file. (Note: each line beginning with => is a continuation of the previous line.): # # Configuration file for inetd(1M). See inetd.conf(4). # # To re-configure the running inetd process, edit this file, then # send the inetd process a SIGHUP. # # Syntax for socket-based Internet services: # => # # Syntax for TLI-based Internet services: # # tli # # Ftp and telnet are standard Internet services. # # This machine is a secure Kerberos Key Distribution Center (KDC). # Services are limited. # # # Time service is used for clock synchronization. # time stream tcp nowait root internal time dgram udp wait root internal # # Limited Kerberos services # krb5_prop stream tcp nowait root /usr/local/sbin/kpropd kpropd eklogin stream tcp nowait root /usr/local/sbin/klogind => klogind -5 -c -e  File: krb5-install.info, Node: Switching Master and Slave KDCs, Prev: Limit Access to the KDCs, Up: Installing KDCs Switching Master and Slave KDCs ------------------------------- You may occasionally want to use one of your slave KDCs as the master. This might happen if you are upgrading the master KDC, or if your master KDC has a disk crash. Assuming you have configured all of your KDCs to be able to function as either the master KDC or a slave KDC (as this document recommends), all you need to do to make the changeover is: If the master KDC is still running, do the following on the *old* master KDC: 1. Kill the `kadmind' process. 2. Disable the cron job that propagates the database. 3. Run your database propagation script manually, to ensure that the slaves all have the latest copy of the database. (*Note Propagate the Database to Each Slave KDC::.) On the *new* master KDC: 1. Create a database keytab. (*Note Create a kadmind Keytab::.) 2. Start the `kadmind' daemon. (*Note Start the Kerberos Daemons::.) 3. Set up the cron job to propagate the database. (*Note Propagate the Database to Each Slave KDC::.) 4. Switch the CNAMEs of the old and new master KDCs. (If you don't do this, you'll need to change the `krb5.conf' file on every client machine in your Kerberos realm.)  File: krb5-install.info, Node: Installing and Configuring UNIX Client Machines, Next: UNIX Application Servers, Prev: Installing KDCs, Up: Installing Kerberos V5 Installing and Configuring UNIX Client Machines =============================================== Client machine installation is much more straightforward than installation of the KDCs. * Menu: * Client Programs:: * Client Machine Configuration Files::  File: krb5-install.info, Node: Client Programs, Next: Client Machine Configuration Files, Prev: Installing and Configuring UNIX Client Machines, Up: Installing and Configuring UNIX Client Machines Client Programs --------------- The Kerberized client programs are `login.krb5', `rlogin', `telnet', `ftp', `rcp', `rsh', `kinit', `klist', `kdestroy', `kpasswd', `ksu', and `krb524init'. All of these programs are in the directory `/usr/local/bin', except for `login.krb5' which is in `/usr/local/sbin'. You will probably want to have your users put `/usr/local/bin' ahead of `/bin' and `/usr/bin' in their paths, so they will by default get the Kerberos V5 versions of `rlogin', `telnet', `ftp', `rcp', and `rsh'. MIT recommends that you use `login.krb5' in place of `/bin/login' to give your users a single-sign-on system. You will need to make sure your users know to use their Kerberos passwords when they log in. You will also need to educate your users to use the ticket management programs `kinit', `klist', `kdestroy', and to use the Kerberos programs `ksu', and `kpasswd' in place of their non-Kerberos counterparts `su', `passwd', and `rdist'.  File: krb5-install.info, Node: Client Machine Configuration Files, Prev: Client Programs, Up: Installing and Configuring UNIX Client Machines Client Machine Configuration Files ---------------------------------- Each machine running Kerberos must have a `/etc/krb5.conf' file. (*Note krb5.conf::) Also, for most UNIX systems, you must add the appropriate Kerberos services to each client machine's `/etc/services' file. If you are using the default configuration for Kerberos V5, you should be able to just insert the following code: # # Note --- if you are using Kerberos V4 and you either: # # (a) haven't converted all your master or slave KDCs to V5, or # # (b) are worried about inter-realm interoperability with other KDC's # that are still using V4 # # you will need to switch the "kerberos" service to port 750 and create a # "kerberos-sec" service on port 88. # kerberos 88/udp kdc # Kerberos V5 KDC kerberos 88/tcp kdc # Kerberos V5 KDC klogin 543/tcp # Kerberos authenticated rlogin kshell 544/tcp cmd # and remote shell kerberos-adm 749/tcp # Kerberos 5 admin/changepw kerberos-adm 749/udp # Kerberos 5 admin/changepw krb5_prop 754/tcp # Kerberos slave propagation eklogin 2105/tcp # Kerberos auth. & encrypted rlogin krb524 4444/tcp # Kerberos 5 to 4 ticket translator As described in the comments in the above code, if your master KDC or any of your slave KDCs is running Kerberos V4, (or if you will be authenticating to any Kerberos V4 KDCs in another realm) you will need to switch the port number for `kerberos' to 750 and create a `kerberos-sec' service (tcp and udp) on port 88, so the Kerberos V4 KDC(s) will continue to work properly. * Menu: * Mac OS X Configuration::  File: krb5-install.info, Node: Mac OS X Configuration, Prev: Client Machine Configuration Files, Up: Client Machine Configuration Files Mac OS X Configuration ...................... To install Kerberos V5 on Mac OS X and Mac OS X Server, follow the directions for generic Unix-based OS's, except for the `/etc/services' updates described above. Mac OS X and Mac OS X Server use a database called NetInfo to store the contents of files normally found in `/etc'. Instead of modifying `/etc/services', you should run the following commands to add the Kerberos service entries to NetInfo: $ niutil -create . /services/kerberos $ niutil -createprop . /services/kerberos name kerberos kdc $ niutil -createprop . /services/kerberos port 750 $ niutil -createprop . /services/kerberos protocol tcp udp $ niutil -create . /services/krbupdate $ niutil -createprop . /services/krbupdate name krbupdate kreg $ niutil -createprop . /services/krbupdate port 760 $ niutil -createprop . /services/krbupdate protocol tcp $ niutil -create . /services/kpasswd $ niutil -createprop . /services/kpasswd name kpasswd kpwd $ niutil -createprop . /services/kpasswd port 761 $ niutil -createprop . /services/kpasswd protocol tcp $ niutil -create . /services/klogin $ niutil -createprop . /services/klogin port 543 $ niutil -createprop . /services/klogin protocol tcp $ niutil -create . /services/eklogin $ niutil -createprop . /services/eklogin port 2105 $ niutil -createprop . /services/eklogin protocol tcp $ niutil -create . /services/kshell $ niutil -createprop . /services/kshell name kshell krcmd $ niutil -createprop . /services/kshell port 544 $ niutil -createprop . /services/kshell protocol tcp In addition to adding services to NetInfo, you must also modify the resolver configuration in NetInfo so that the machine resolves its own hostname as a FQDN (fully qualified domain name). By default, Mac OS X and Mac OS X Server machines query NetInfo to resolve hostnames before falling back to DNS. Because NetInfo has an unqualified name for all the machines in the NetInfo database, the machine's own hostname will resolve to an unqualified name. Kerberos needs a FQDN to look up keys in the machine's keytab file. Fortunately, you can change the `lookupd' caching order to query DNS first. Run the following NetInfo commands and reboot the machine: $ niutil -create . /locations/lookupd/hosts $ niutil -createprop . /locations/lookupd/hosts LookupOrder CacheAgent DNSAgent NIAgent NILAgent Once you have rebooted, you can verify that the resolver now behaves correctly. Compile the Kerberos 5 distribution and run: $ cd .../src/tests/resolve $ ./resolve This will tell you whether or not your machine returns FQDNs on name lookups. If the test still fails, you can also try turning off DNS caching. Run the following commands and reboot: $ niutil -create . /locations/lookupd/hosts $ niutil -createprop . /locations/lookupd/hosts LookupOrder DNSAgent CacheAgent NIAgent NILAgent The remainder of the setup of a Mac OS X client machine or application server should be the same as for other UNIX-based systems.  File: krb5-install.info, Node: UNIX Application Servers, Prev: Installing and Configuring UNIX Client Machines, Up: Installing Kerberos V5 UNIX Application Servers ======================== An application server is a host that provides one or more services over the network. Application servers can be "secure" or "insecure." A "secure" host is set up to require authentication from every client connecting to it. An "insecure" host will still provide Kerberos authentication, but will also allow unauthenticated clients to connect. If you have Kerberos V5 installed on all of your client machines, MIT recommends that you make your hosts secure, to take advantage of the security that Kerberos authentication affords. However, if you have some clients that do not have Kerberos V5 installed, you can run an insecure server, and still take advantage of Kerberos V5's single sign-on on capability. * Menu: * Server Programs:: * Server Configuration Files:: * The Keytab File:: * Some Advice about Secure Hosts::  File: krb5-install.info, Node: Server Programs, Next: Server Configuration Files, Prev: UNIX Application Servers, Up: UNIX Application Servers Server Programs --------------- Just as Kerberos V5 provided its own Kerberos-enhanced versions of client UNIX network programs, Kerberos V5 also provides Kerberos-enhanced versions of server UNIX network daemons. These are `ftpd', `klogind', `kshd', and `telnetd'. These programs are installed in the directory `/usr/local/sbin'. You may want to add this directory to root's path.  File: krb5-install.info, Node: Server Configuration Files, Next: The Keytab File, Prev: Server Programs, Up: UNIX Application Servers Server Configuration Files -------------------------- For a *secure* server, make the following changes to `/etc/inetd.conf': Find and comment out any lines for the services `ftp', `telnet', `shell', `login', and `exec'. Add the following lines. (Note: each line beginning with => is a continuation of the previous line.) klogin stream tcp nowait root /usr/local/sbin/klogind => klogind -k -c eklogin stream tcp nowait root /usr/local/sbin/klogind => klogind -k -c -e kshell stream tcp nowait root /usr/local/sbin/kshd => kshd -k -c -A ftp stream tcp nowait root /usr/local/sbin/ftpd => ftpd -a telnet stream tcp nowait root /usr/local/sbin/telnetd => telnetd -a valid For an *insecure* server, make the following changes instead to `/etc/inetd.conf': Find and comment out any lines for the services `ftp' and `telnet'. Add the following lines. (Note: each line beginning with => is a continuation of the previous line.) klogin stream tcp nowait root /usr/local/sbin/klogind => klogind -k -c eklogin stream tcp nowait root /usr/local/sbin/klogind => klogind -k -c -e kshell stream tcp nowait root /usr/local/sbin/kshd => kshd -k -c -A ftp stream tcp nowait root /usr/local/sbin/ftpd => ftpd telnet stream tcp nowait root /usr/local/sbin/telnetd => telnetd -a none  File: krb5-install.info, Node: The Keytab File, Next: Some Advice about Secure Hosts, Prev: Server Configuration Files, Up: UNIX Application Servers The Keytab File --------------- All Kerberos server machines need a "keytab" file, called `/etc/krb5.keytab', to authenticate to the KDC. The keytab file is an encrypted, local, on-disk copy of the host's key. The keytab file, like the stash file (*Note Create the Database::) is a potential point-of-entry for a break-in, and if compromised, would allow unrestricted access to its host. The keytab file should be readable only by root, and should exist only on the machine's local disk. The file should not be part of any backup of the machine, unless access to the backup data is secured as tightly as access to the machine's root password itself. In order to generate a keytab for a host, the host must have a principal in the Kerberos database. The procedure for adding hosts to the database is described fully in the "Adding or Modifying Principals" section of the `Kerberos V5 System Administrator's Guide'. *Note Create Host Keys for the Slave KDCs:: for a brief description.) The keytab is generated by running `kadmin' and issuing the `ktadd' command. For example, to generate a keytab file to allow the host trillium.mit.edu to authenticate for the services `host', `ftp', and `pop', the administrator `joeadmin' would issue the command (on trillium.mit.edu): trillium% /usr/local/sbin/kadmin kadmin5: ktadd host/trillium.mit.edu ftp/trillium.mit.edu => pop/trillium.mit.edu kadmin: Entry for principal host/trillium.mit.edu@ATHENA.MIT.EDU with kvno 3, encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5.keytab. kadmin: Entry for principal ftp/trillium.mit.edu@ATHENA.MIT.EDU with kvno 3, encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5.keytab. kadmin: Entry for principal pop/trillium.mit.edu@ATHENA.MIT.EDU with kvno 3, encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5.keytab. kadmin5: quit trillium% If you generate the keytab file on another host, you need to get a copy of the keytab file onto the destination host (`trillium', in the above example) without sending it unencrypted over the network. If you have installed the Kerberos V5 client programs, you can use encrypted `rcp'.  File: krb5-install.info, Node: Some Advice about Secure Hosts, Prev: The Keytab File, Up: UNIX Application Servers Some Advice about Secure Hosts ------------------------------ Kerberos V5 can protect your host from certain types of break-ins, but it is possible to install Kerberos V5 and still leave your host vulnerable to attack. Obviously an installation guide is not the place to try to include an exhaustive list of countermeasures for every possible attack, but it is worth noting some of the larger holes and how to close them. As stated earlier in this section, MIT recommends that on a secure host, you disable the standard `ftp', `login', `telnet', `shell', and `exec' services in `/etc/inetd.conf'. We also recommend that secure hosts have an empty `/etc/hosts.equiv' file and that there not be a `.rhosts' file in `root''s home directory. You can grant Kerberos-authenticated root access to specific Kerberos principals by placing those principals in the file `.k5login' in root's home directory. We recommend that backups of secure machines exclude the keytab file (`/etc/krb5.keytab'). If this is not possible, the backups should at least be done locally, rather than over a network, and the backup tapes should be physically secured. Finally, the keytab file and any programs run by root, including the Kerberos V5 binaries, should be kept on local disk. The keytab file should be readable only by root.  File: krb5-install.info, Node: Upgrading Existing Kerberos V5 Installations, Next: Bug Reports for Kerberos V5, Prev: Installing Kerberos V5, Up: Top Upgrading Existing Kerberos V5 Installations ******************************************** If you already have an existing Kerberos database that you created with a prior release of Kerberos 5, you can upgrade it to work with the current release with the `kdb5_util' command. The process for upgrading a Master KDC involves the following steps (the lines beginning with => indicate a continuation of the previous line): 1. Stopping your current KDC and administration server processes, if any. 2. Dumping your existing Kerberos database to an ASCII file with `kdb5_util''s "dump" command: shell% kdb5_util -r ATHENA.MIT.EDU dump => /usr/local/var/krb5kdc/old-kdb-dump shell% 3. Creating a new Master KDC installation (*Note Install the Master KDC::). If you have a stash file for your current database, choose any new master password but then copy your existing stash file to the location specified by your kdc.conf; if you do not have a stash file for your current database, you must choose the same master password. 4. Load your old Kerberos database into the new system with `kdb5_util''s "load" command: shell% kdb5_util load /usr/local/var/krb5kdc/old-kdb-dump shell% To update a Slave KDC, you must stop the old server processes on the Slave KDC, install the new server binaries, reload the most recent slave dump file, and re-start the server processes.  File: krb5-install.info, Node: Bug Reports for Kerberos V5, Next: Files, Prev: Upgrading Existing Kerberos V5 Installations, Up: Top Bug Reports for Kerberos V5 *************************** In any complex software, there will be bugs. If you have successfully built and installed Kerberos V5, please use the `krb5-send-pr' program to fill out a Problem Report. Bug reports that include proposed fixes are especially welcome. If you do include fixes, please send them using either context diffs or unified diffs (using `diff -c' or `diff -u', respectively). The `krb5-send-pr' program is installed in the directory `/usr/local/sbin'. The `krb5-send-pr' program enters the problem report into our Problem Report Management System (PRMS), which automatically assigns it to the engineer best able to help you with problems in the assigned category. The `krb5-send-pr' program will try to intelligently fill in as many fields as it can. You need to choose the "category", "class", "severity", and "priority" of the problem, as well as giving us as much information as you can about its exact nature. The PR category will be one of: krb5-admin krb5-appl krb5-build krb5-clients krb5-doc krb5-kdc krb5-libs krb5-misc pty telnet test Choose the category that best describes the area under which your problem falls. The class can be "sw-bug", "doc-bug", "change-request", or "support". The first two are exactly as their names imply. Use change-request when the software is behaving according to specifications, but you want to request changes in some feature or behavior. The support class is intended for more general questions about building or using Kerberos V5. The severity of the problem indicates the problem's impact on the usability of Kerberos V5. If a problem is "critical", that means the product, component or concept is completely non-operational, or some essential functionality is missing, and no workaround is known. A "serious" problem is one in which the product, component or concept is not working properly or significant functionality is missing. Problems that would otherwise be considered critical are rated serious when a workaround is known. A "non-critical" problem is one that is indeed a problem, but one that is having a minimal effect on your ability to use Kerberos V5. E.g., The product, component or concept is working in general, but lacks features, has irritating behavior, does something wrong, or doesn't match its documentation. The default severity is serious. The priority indicates how urgent this particular problem is in relation to your work. Note that low priority does not imply low importance. A priority of "high" means a solution is needed as soon as possible. A priority of "medium" means the problem should be solved no later than the next release. A priority of "low" means the problem should be solved in a future release, but it is not important to your work how soon this happens. The default priority is medium. Note that a given severity does not necessarily imply a given priority. For example, a non-critical problem might still have a high priority if you are faced with a hard deadline. Conversely, a serious problem might have a low priority if the feature it is disabling is one that you do not need. It is important that you fill in the release field and tell us what changes you have made, if any. Bug reports that include proposed fixes are especially welcome. If you include proposed fixes, please send them using either context diffs (`diff -c') or unified diffs (`diff -u'). A sample filled-out form from a company named "Toasters, Inc." might look like this: To: krb5-bugs@mit.edu Subject: misspelled "Kerberos" in title of installation guide From: jcb Reply-To: jcb Cc: X-send-pr-version: 3.99 >Submitter-Id: mit >Originator: Jeffrey C. Gilman Bigler >Organization: mit >Confidential: no >Synopsis: Misspelled "Kerberos" in title of installation guide >Severity: non-critical >Priority: low >Category: krb5-doc >Class: doc-bug >Release: 1.0-development >Environment: System: ULTRIX imbrium 4.2 0 RISC Machine: mips >Description: Misspelled "Kerberos" in title of "Kerboros V5 Installation Guide" >How-To-Repeat: N/A >Fix: Correct the spelling. If the `krb5-send-pr' program does not work for you, or if you did not get far enough in the process to have an installed and working `krb5-send-pr', you can generate your own form, using the above as an example.  File: krb5-install.info, Node: Files, Prev: Bug Reports for Kerberos V5, Up: Top Files ***** * Menu: * krb5.conf:: * kdc.conf::  File: krb5-install.info, Node: krb5.conf, Next: kdc.conf, Prev: Files, Up: Files krb5.conf ========= Here is an example `krb5.conf' file: [libdefaults] ticket_lifetime = 600 default_realm = ATHENA.MIT.EDU default_tkt_enctypes = des-cbc-crc default_tgs_enctypes = des-cbc-crc [realms] ATHENA.MIT.EDU = { kdc = kerberos.mit.edu:88 kdc = kerberos-1.mit.edu:88 kdc = kerberos-2.mit.edu:88 admin_server = kerberos.mit.edu:749 default_domain = mit.edu } [domain_realm] .mit.edu = ATHENA.MIT.EDU mit.edu = ATHENA.MIT.EDU For the KDCs, add a section onto the end of the `krb5.conf' file telling how logging information should be stored, as in the following example: [logging] kdc = FILE:/var/log/krb5kdc.log admin_server = FILE:/var/log/kadmin.log default = FILE:/var/log/krb5lib.log  File: krb5-install.info, Node: kdc.conf, Prev: krb5.conf, Up: Files kdc.conf ======== Here's an example of a kdc.conf file: [kdcdefaults] kdc_ports = 88,750 [realms] ATHENA.MIT.EDU = { database_name = /usr/local/var/krb5kdc/principal admin_keytab = /usr/local/var/krb5kdc/kadm5.keytab acl_file = /usr/local/var/krb5kdc/kadm5.acl dict_file = /usr/local/var/krb5kdc/kadm5.dict key_stash_file = /usr/local/var/krb5kdc/.k5.ATHENA.MIT.EDU kadmind_port = 749 max_life = 10h 0m 0s max_renewable_life = 7d 0h 0m 0s master_key_type = des-cbc-crc supported_enctypes = des-cbc-crc:normal } To add Kerberos V4 support, change the `supported_enctypes' line to: supported_enctypes = des-cbc-crc:normal des-cbc-crc:v4 * Menu: * Encryption Types and Salt Types::  File: krb5-install.info, Node: Encryption Types and Salt Types, Prev: kdc.conf, Up: kdc.conf Encryption Types and Salt Types ------------------------------- Currently, Kerberos V5 supports only DES and triple-DES encryption; however, triple-DES is currently supported only for service keys, not for user keys or session keys. The encoding types include `des-cbc-crc' and `des3-cbc-sha1'. The "salt" is additional information encoded within the key that tells what kind of key it is. The only salts that you will be likely to encounter are: * "normal", which MIT recommends using for all of your Kerberos V5 keys * "v4", which is necessary only for compatibility with a v4 KDC * "afs", which you will never need to generate, and which you will encounter only if you dump an AFS database into a Kerberos database Support for additional encryption types is planned in the future.