MIT krb5

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Download Source: http://web.mit.edu/kerberos/www/dist/krb5/1.7/krb5-1.7-signed.tar

Contents

Introduction to MIT krb5

Kerberos is a network authentication protocol. It is designed to provide strong authentication for client/server applications by using secret-key cryptography. A free implementation of this protocol is available from the Massachusetts Institute of Technology.

Project Homepage: http://web.mit.edu/Kerberos/

Dependencies

 !!!HIGHLY RECOMMENDED!!!

Optional

  • xinetd (services servers only)
  • Linux-PAM (for xdm based logins)
  • OpenLDAP (alternative for krb5kdc password database)
Caution.png

Note

A time synchronization facility of some sort (like NTP) is needed on your system if you're going to be using Kerberos. Kerberos won't authenticate if the time differential between a kerberized client and the KDC server is more than 5 minutes. And since you'll probably want Kerberos to be able to authenticate, you'll want to synchronize the time between teh client and the server.

Non-Multilib

Build the packge:

cd src &&  CPPFLAGS="-DEAI_NODATA=EAI_NONAME" \
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var/lib \
   --enable-dns-for-realm --mandir=/usr/share/man &&
make

Install the package:

make install &&
chmod -v 755 /usr/lib/lib{krb5support,com_err,k5crypto,krb5}.so* &&
chmod -v 755 /usr/lib/lib{gssapi_krb5,gssrpc,kdb5,kadm5clnt,kadm5srv}.so* &&
chmod -v 755 /usr/lib/krb5/plugins/*/*.so &&
mv -v /usr/lib/libcom_err.so.3* /lib &&
mv -v /usr/lib/libgssapi_krb5.so.2* /lib &&
mv -v /usr/lib/libgssrpc.so.4* /lib &&
mv -v /usr/lib/libk5crypto.so.3* /lib &&
mv -v /usr/lib/libkadm5clnt.so.6* /lib &&
mv -v /usr/lib/libkadm5srv.so.6* /lib &&
mv -v /usr/lib/libkdb5.so.4* /lib &&
mv -v /usr/lib/libkrb5.so.3* /lib &&
mv -v /usr/lib/libkrb5support.so.0* /lib &&
ln -v -sf ../../lib/libcom_err.so.3 /usr/lib/libcom_err.so &&
ln -v -sf ../../lib/libgssapi_krb5.so.2 /usr/lib/libgssapi_krb5.so &&
ln -v -sf ../../lib/libgssrpc.so.4 /usr/lib/libgssrpc.so &&
ln -v -sf ../../lib/libk5crypto.so.3 /usr/lib/libk5crypto.so &&
ln -v -sf ../../lib/libkadm5clnt.so.6 /usr/lib/libkadm5clnt.so &&
ln -v -sf ../../lib/libkadm5srv.so.6 /usr/lib/libkadm5srv.so &&
ln -v -sf ../../lib/libkdb5.so.4 /usr/lib/libkdb5.so &&
ln -v -sf ../../lib/libkrb5.so.3 /usr/lib/libkrb5.so &&
ln -v -sf ../../lib/libkrb5support.so.0 /usr/lib/libkrb5support.so &&
mv -v /usr/bin/ksu /bin &&
ldconfig

Multilib

32Bit

Build the packge:

cd src &&
CPPFLAGS="-DEAI_NODATA=EAI_NONAME" CC="gcc ${BUILD32}" USE_ARCH=32 \
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var/lib \
   --enable-dns-for-realm --mandir=/usr/share/man &&
make

Install the package:

make install &&
chmod -v 755 /usr/lib/lib{krb5support,com_err,k5crypto,krb5}.so* &&
chmod -v 755 /usr/lib/lib{gssapi_krb5,gssrpc,kdb5,kadm5clnt,kadm5srv}.so* &&
chmod -v 755 /usr/lib/krb5/plugins/*/*.so &&
mv -v /usr/lib/libcom_err.so.3* /lib &&
mv -v /usr/lib/libgssapi_krb5.so.2* /lib &&
mv -v /usr/lib/libgssrpc.so.4* /lib &&
mv -v /usr/lib/libk5crypto.so.3* /lib &&
mv -v /usr/lib/libkadm5clnt.so.6* /lib &&
mv -v /usr/lib/libkadm5srv.so.6* /lib &&
mv -v /usr/lib/libkdb5.so.4* /lib &&
mv -v /usr/lib/libkrb5.so.3* /lib &&
mv -v /usr/lib/libkrb5support.so.0* /lib &&
ln -v -sf ../../lib/libcom_err.so.3 /usr/lib/libcom_err.so &&
ln -v -sf ../../lib/libgssapi_krb5.so.2 /usr/lib/libgssapi_krb5.so &&
ln -v -sf ../../lib/libgssrpc.so.4 /usr/lib/libgssrpc.so &&
ln -v -sf ../../lib/libk5crypto.so.3 /usr/lib/libk5crypto.so &&
ln -v -sf ../../lib/libkadm5clnt.so.6 /usr/lib/libkadm5clnt.so &&
ln -v -sf ../../lib/libkadm5srv.so.6 /usr/lib/libkadm5srv.so &&
ln -v -sf ../../lib/libkdb5.so.4 /usr/lib/libkdb5.so &&
ln -v -sf ../../lib/libkrb5.so.3 /usr/lib/libkrb5.so &&
ln -v -sf ../../lib/libkrb5support.so.0 /usr/lib/libkrb5support.so &&
mv -v /usr/bin/ksu /bin &&
mv -v /usr/bin/krb5-config{,-32} &&
ldconfig

N32

Build the packge:

cd src &&
CPPFLAGS="-DEAI_NODATA=EAI_NONAME" CC="gcc ${BUILDN32}" USE_ARCH=n32 \
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var/lib \
   --enable-dns-for-realm --mandir=/usr/share/man --libdir=/usr/lib32 &&
make

Install the package:

make install &&
chmod -v 755 /usr/lib32/lib{krb5support,com_err,k5crypto,krb5}.so* &&
chmod -v 755 /usr/lib32/lib{gssapi_krb5,gssrpc,kdb5,kadm5clnt,kadm5srv}.so* &&
chmod -v 755 /usr/lib32/krb5/plugins/*/*.so &&
mv -v /usr/lib32/libcom_err.so.3* /lib32 &&
mv -v /usr/lib32/libgssapi_krb5.so.2* /lib32 &&
mv -v /usr/lib32/libgssrpc.so.4* /lib32 &&
mv -v /usr/lib32/libk5crypto.so.3* /lib32 &&
mv -v /usr/lib32/libkadm5clnt.so.6* /lib32 &&
mv -v /usr/lib32/libkadm5srv.so.6* /lib32 &&
mv -v /usr/lib32/libkdb5.so.4* /lib32 &&
mv -v /usr/lib32/libkrb5.so.3* /lib32 &&
mv -v /usr/lib32/libkrb5support.so.0* /lib32 &&
ln -v -sf ../../lib32/libcom_err.so.3 /usr/lib32/libcom_err.so &&
ln -v -sf ../../lib32/libgssapi_krb5.so.2 /usr/lib32/libgssapi_krb5.so &&
ln -v -sf ../../lib32/libgssrpc.so.4 /usr/lib32/libgssrpc.so &&
ln -v -sf ../../lib32/libk5crypto.so.3 /usr/lib32/libk5crypto.so &&
ln -v -sf ../../lib32/libkadm5clnt.so.6 /usr/lib32/libkadm5clnt.so &&
ln -v -sf ../../lib32/libkadm5srv.so.6 /usr/lib32/libkadm5srv.so &&
ln -v -sf ../../lib32/libkdb5.so.4 /usr/lib32/libkdb5.so &&
ln -v -sf ../../lib32/libkrb5.so.3 /usr/lib32/libkrb5.so &&
ln -v -sf ../../lib32/libkrb5support.so.0 /usr/lib32/libkrb5support.so &&
mv -v /usr/bin/ksu /bin &&
mv -v /usr/bin/krb5-config{,-n32} &&
ldconfig

64Bit

Build the packge:

cd src &&
CPPFLAGS="-DEAI_NODATA=EAI_NONAME" CC="gcc ${BUILD64}" USE_ARCH=64 \
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var/lib \
   --enable-dns-for-realm --mandir=/usr/share/man --libdir=/usr/lib64 &&
make

Install the package:

make install &&
chmod -v 755 /usr/lib64/lib{krb5support,com_err,k5crypto,krb5}.so* &&
chmod -v 755 /usr/lib64/lib{gssapi_krb5,gssrpc,kdb5,kadm5clnt,kadm5srv}.so* &&
chmod -v 755 /usr/lib64/krb5/plugins/*/*.so &&
mv -v /usr/lib64/libcom_err.so.3* /lib64 &&
mv -v /usr/lib64/libgssapi_krb5.so.2* /lib64 &&
mv -v /usr/lib64/libgssrpc.so.4* /lib64 &&
mv -v /usr/lib64/libk5crypto.so.3* /lib64 &&
mv -v /usr/lib64/libkadm5clnt.so.6* /lib64 &&
mv -v /usr/lib64/libkadm5srv.so.6* /lib64 &&
mv -v /usr/lib64/libkdb5.so.4* /lib64 &&
mv -v /usr/lib64/libkrb5.so.3* /lib64 &&
mv -v /usr/lib64/libkrb5support.so.0* /lib64 &&
ln -v -sf ../../lib64/libcom_err.so.3 /usr/lib64/libcom_err.so &&
ln -v -sf ../../lib64/libgssapi_krb5.so.2 /usr/lib64/libgssapi_krb5.so &&
ln -v -sf ../../lib64/libgssrpc.so.4 /usr/lib64/libgssrpc.so &&
ln -v -sf ../../lib64/libk5crypto.so.3 /usr/lib64/libk5crypto.so &&
ln -v -sf ../../lib64/libkadm5clnt.so.6 /usr/lib64/libkadm5clnt.so &&
ln -v -sf ../../lib64/libkadm5srv.so.6 /usr/lib64/libkadm5srv.so &&
ln -v -sf ../../lib64/libkdb5.so.4 /usr/lib64/libkdb5.so &&
ln -v -sf ../../lib64/libkrb5.so.3 /usr/lib64/libkrb5.so &&
ln -v -sf ../../lib64/libkrb5support.so.0 /usr/lib64/libkrb5support.so &&
mv -v /usr/bin/ksu /bin &&
mv -v /usr/bin/krb5-config{,-64} &&
ln -sfv multiarch_wrapper /usr/bin/krb5-config &&
ldconfig

Configuring

Caution.png

Note

login.krb5 does not support shadow passwords. So, when the Kerberos server is unavailable, the default use of /etc/passwd will not work because the passwords are now in /etc/shadow (where they were put while building CLFS). Entering the following commands without moving the passwords back to /etc/passwd could prevent any logins.

If you have Linux-PAM installed then you can authenticate using the login provided by shadow through the Pam-krb5 module (Recommended). If you understand the above warning and Linux-PAM is not installed, the following commands can be used:

mv -v /bin/login /bin/login.shadow &&
cp -v /usr/sbin/login.krb5 /bin/login

The information in the sections below are based off information from the following pages:

http://www.bayour.com/LDAPv3-HOWTO.html
http://aput.net/~jheiss/krbldap/

Creating a Kerberos Realm

Caution.png

Note

At this point it is strongly recommended that you have a working DNS Server. After setting up a login with Kerberos failure to resolve the name of the KDC server will result in login failures.

Create the db directory exists with the following command:

install -dv -m755 /var/lib/krb5kdc

Create the Kerberos configuration with the following command. It's recommended that the Kerberos Realm be all uppercase.

cat > /etc/krb5.conf << "EOF"
# Begin /etc/krb5.conf

[libdefaults]
    default_realm = <REALMNAME.COM>
    encrypt = true

[kdc]
    profile = /var/lib/krb5kdc/kdc.conf

[appdefaults]
    pam = {
        <REALMNAME.COM> = {
            minimum_uid = 5000
        }
    }

[realms]
    <REALMNAME.COM> = {
        kdc = <servername.realmname.com>
        admin_server = <servername.realmname.com>
        dict_file = /usr/share/dict/words
    }

[domain_realm]
    .<realmname.com> = <REALMNAME.COM>
    <realmname.com> = <REALMNAME.COM>

[logging]
    kdc = SYSLOG[:INFO[:AUTH]]
    admin_server = SYSLOG[INFO[:AUTH]]
    default = SYSLOG[[:SYS]]

# End /etc/krb5.conf
EOF

On the Kerberos Server create the KDC Configuration File:

cat > /var/lib/krb5kdc/kdc.conf << "EOF"
# Begin /var/lib/krb5kdc/kdc.conf

[kdcdefaults]
    kdc_ports = 750,88

[realms]
    <REALMNAME.COM> = {
        database_name = /var/lib/krb5kdc/principal
        admin_keytab = FILE:/var/lib/krb5kdc/kadm5.keytab
        acl_file = /var/lib/krb5kdc/krb5_adm.acl
        key_stash_file = /var/lib/krb5kdc/.k5.<REALMNAME.COM>
        kdc_ports = 750,88
        max_life = 10h 0m 0s
        max_renewable_life = 7d 0h 0m 0s
    }

# End /var/lib/krb5kdc/kdc.conf
EOF

Execute the following command to initialize the Krb5 database:

kdb5_util create -r REALMNAME.COM -s

Create the Admin Service Keytab:

kadmin.local -q "ktadd -k /var/lib/krb5kdc/kadm5.keytab kadmin/admin" &&
kadmin.local -q "ktadd -k /var/lib/krb5kdc/kadm5.keytab kadmin/changepw" &&
chmod 600 /var/lib/krb5kdc/kadm5.keytab

Create a user to administer Kerberos with:

kadmin.local -q "addprinc krbadm@<REALMNAME.COM>"
kadmin.local -q "addprinc krbadm/admin@<REALMNAME.COM>"

Create a basic acl file:

cat > /var/lib/krb5kdc/krb5_adm.acl << "EOF"
kadmin/admin@<REALMNAME.COM>   *
*/admin@<REALMNAME.COM>        *
krbadm@<REALMNAME.COM>         *
*/*@<REALMNAME.COM>            i
EOF

Testing

Start the kdc service with the following command:

/usr/sbin/krb5kdc &

The following command will simulate a login:

kinit <principle name>

To list your current tickets:

klist

Bootscript

Install the init script included in the bootscripts package.

make install-kerberos

Configuring Kerberos Clients

Securly copy /etc/krb5.conf from one of the Kerberos Servers to each of the clients. You should now be able to get a ticket from the KDC. Now would be a good time to test this:

kinit <principal name>

List your tickets with the following command:

klist

Contents

Installed Programs: compile-et, ftp, ftpd, gss-client, gss-server, k5srvutil, kadmin, kadmin.local, kadmind, kadmind4, kdb5_util, kdestroy, kinit, klist, klogind, kpasswd, kprop, kpropd, krb5-send-pr, krb5-config, krb524d, krb524init, krb5kdc, kshd, ksu, ktutil, kvno, login.krb5, rcp, rlogin, rsh, sclient, sim_client, sim_server, sserver, telnet, telnetd, uuclient, uuserver, v5passwd, and v5passwdd
Installed Libraries: libcom_err.{so,a}, libdes425.{so,a}, libgssapi.{so,a}, libgssrpc.{so,a}, libkadm5clnt.{so,a}, libkadm5srv.{so,a}, libkdb5.{so,a}, libkrb5.{so,a}, and libkrb4.{so,a}
Installed Directory: /usr/include/kerberosIV and /var/lib/krb5kdc

Short Descriptions

compile_et converts the table listing error-code names into a C source file.
ftp is a kerberized FTP client.
ftpd is a kerberized FTP daemon.
k5srvutil is a host keytable manipulation utility.
kadmin is an utility used to make modifications to the Kerberos database.
kadmind is a server for administrative access to a Kerberos database.
kdb5_util is the KDC database utility.
kdestroy removes the current set of tickets.
kinit is used to authenticate to the Kerberos server as a principal and acquire a ticket granting ticket that can later be used to obtain tickets for other services.
klist reads and displays the current tickets in the credential cache.
klogind is the server that responds to rlogin requests.
kpasswd is a program for changing Kerberos 5 passwords.
kprop takes a principal database in a specified format and converts it into a stream of database records.
kpropd receives a database sent by kprop and writes it as a local database.
krb5-config gives information on how to link programs against libraries.
krb5kdc is a Kerberos 5 server.
kshd is the server that responds to rsh requests.
ksu is the super user program using Kerberos protocol. Requires a properly configured /etc/shells and ~/.k5login containing principals authorized to become super users.
ktutil is a program for managing Kerberos keytabs.
kvno prints keyversion numbers of Kerberos principals.
login.krb5 is a kerberized login program.
rcp is a kerberized rcp client program.
rlogin is a kerberized rlogin client program.
rsh is a kerberized rsh client program.
telnet is a kerberized telnet client program.
telnetd is a kerberized telnet server.
libcom_err.{so,a} implements the Kerberos library error code.
libgssapi.{so,a} contain the Generic Security Service Application Programming Interface (GSSAPI) functions which provides security services to callers in a generic fashion, supportable with a range of underlying mechanisms and technologies and hence allowing source-level portability of applications to different environments.
libkadm5clnt.{so,a} contains the administrative authentication and password checking functions required by Kerberos 5 client-side programs.
libkadm5srv.{so,a} contain the administrative authentication and password checking functions required by Kerberos 5 servers.
libkdb5.{so,a} is a Kerberos 5 authentication/authorization database access library.
libkrb5.{so,a} is an all-purpose Kerberos 5 library.
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