freeradius-config 3.0.16+dfsg-1ubuntu3 / etc / freeradius / 3.0 / certs / README

  This directory contains scripts to create the server certificates.
To make a set of default (i.e. test) certificates, simply type:

$ ./bootstrap

  The "openssl" command will be run against the sample configuration
files included here, and will make a self-signed certificate authority
(i.e. root CA), and a server certificate.  This "root CA" should be
installed on any client machine needing to do EAP-TLS, PEAP, or
EAP-TTLS.

  The Microsoft "XP Extensions" will be automatically included in the
server certificate.  Without those extensions Windows clients will
refuse to authenticate to FreeRADIUS.

  The root CA and the "XP Extensions" file also contain a crlDistributionPoints
attribute. The latest release of Windows Phone needs this to be present
for the handset to validate the RADIUS server certificate. The RADIUS
server must have the URI defined but the CA need not have...however it
is best practice for a CA to have a revocation URI. Note that whilst
the Windows Mobile client cannot actually use the CRL when doing 802.1X
it is recommended that the URI be an actual working URL and contain a
revocation format file as there may be other OS behaviour at play and
future OSes that may do something with that URI.

  In general, you should use self-signed certificates for 802.1x (EAP)
authentication.  When you list root CAs from other organisations in
the "ca_file", you permit them to masquerade as you, to authenticate
your users, and to issue client certificates for EAP-TLS.

  If FreeRADIUS was configured to use OpenSSL, then simply starting
the server in root in debugging mode should also create test
certificates, i.e.:

$ radiusd -X

  That will cause the EAP-TLS module to run the "bootstrap" script in
this directory.  The script will be executed only once, the first time
the server has been installed on a particular machine.  This bootstrap
script SHOULD be run on installation of any pre-built binary package
for your OS.  In any case, the script will ensure that it is not run
twice, and that it does not over-write any existing certificates.

  If you already have CA and server certificates, rename (or delete)
this directory, and create a new "certs" directory containing your
certificates.  Note that the "make install" command will NOT
over-write your existing "raddb/certs" directory, which means that the
"bootstrap" command will not be run.


		NEW INSTALLATIONS OF FREERADIUS


  We suggest that new installations use the test certificates for
initial tests, and then create real certificates to use for normal
user authentication.  See the instructions below for how to create the
various certificates.  The old test certificates can be deleted by
running the following command:

$ rm -f *.pem *.der *.csr *.crt *.key *.p12 serial* index.txt*

  Then, follow the instructions below for creating real certificates.

  Once the final certificates have been created, you can delete the
"bootstrap" command from this directory, and delete the
"make_cert_command" configuration from the "tls" sub-section of
eap.conf.

  If you do not want to enable EAP-TLS, PEAP, or EAP-TTLS, then delete
the relevant sub-sections from the "eap.conf" file.


		MAKING A ROOT CERTIFICATE


$ vi ca.cnf

  Edit the "input_password" and "output_password" fields to be the
  password for the CA certificate.

  Edit the [certificate_authority] section to have the correct values
  for your country, state, etc.

$ make ca.pem

  This step creates the CA certificate.

$ make ca.der

  This step creates the DER format of the self-signed certificate,
  which is can be imported into Windows.


		MAKING A SERVER CERTIFICATE


The following steps will let you create a server certificate for use
with TLS-based EAP methods, such as EAP-TLS, PEAP, and TTLS.  Follow
similar steps to create an "inner-server.pem" file, for use with
EAP-TLS that is tunneled inside of another TLS-based EAP method.

$ vi server.cnf

  Edit the "input_password" and "output_password" fields to be the
  password for the server certificate.

  Edit the [server] section to have the correct values for your
  country, state, etc.  Be sure that the commonName field here is
  different from the commonName for the CA certificate.

$ make server.pem

  This step creates the server certificate.

  If you have an existing certificate authority, and wish to create a
  certificate signing request for the server certificate, edit
  server.cnf as above, and type the following command.

$ make server.csr

  You will have to ensure that the certificate contains the XP
  extensions needed by Microsoft clients.



		MAKING A CLIENT CERTIFICATE


  Client certificates are used by EAP-TLS, and optionally by EAP-TTLS
and PEAP.  The following steps outline how to create a client
certificate that is signed by the server certificate created above.
You will have to have the password for the server certificate in the
"input_password" and "output_password" fields of the server.cnf file.


$ vi client.cnf

  Edit the "input_password" and "output_password" fields to be the
  password for the client certificate.  You will have to give these
  passwords to the end user who will be using the certificates.

  Edit the [client] section to have the correct values for your
  country, state, etc.  Be sure that the commonName field here is
  the User-Name that will be used for logins!

$ make client.pem

  The users certificate will be in "emailAddress.pem",
  i.e. "user@example.com.pem".

  To create another client certificate, just repeat the steps for
  making a client certificate, being sure to enter a different login
  name for "commonName", and a different password.


		PERFORMANCE


  EAP performance for EAP-TLS, TTLS, and PEAP is dominated by SSL
  calculations.  That is, a normal system can handle PAP
  authentication at a rate of 10k packets/s.  However, SSL involves
  RSA calculations, which are very expensive.  To benchmark your system,
  do:

$ openssl speed rsa

  or

$ openssl speed rsa2048

  to test 2048 bit keys.

  A 1GHz system will likely do 30 calculations/s.  A 2GHz system may
  do 50 calculations/s, or more.  That number is also the number of
  authentications/s that can be done for EAP-TLS (or TTLS, or PEAP).


		COMPATIBILITY

The certificates created using this method are known to be compatible
with ALL operating systems.  Some common issues are:

  - Windows requires certain OIDs in the certificates.  If it doesn't
    see them, it will stop doing EAP.  The most visible effect is
    that the client starts EAP, gets a few Access-Challenge packets,
    and then a little while later re-starts EAP.  If this happens, see
    the FAQ, and the comments in raddb/eap.conf for how to fix it.

  - Windows requires the root certificates to be on the client PC.
    If it doesn't have them, you will see the same issue as above.

  - Windows XP post SP2 has a bug where it has problems with
    certificate chains.  i.e. if the server certificate is an
    intermediate one, and not a root one, then authentication will
    silently fail, as above.

  - Some versions of Windows CE cannot handle 4K RSA certificates.
    They will (again) silently fail, as above.

  - In none of these cases will Windows give the end user any
    reasonable error message describing what went wrong.  This leads
    people to blame the RADIUS server.  That blame is misplaced.

  - Certificate chains of more than 64K bytes are known to not work.
    This is a problem in FreeRADIUS.  However, most clients cannot
    handle 64K certificate chains.  Most Access Points will shut down
    the EAP session after about 50 round trips, while 64K certificate
    chains will take about 60 round trips.  So don't use large
    certificate chains.  They will only work after everyone upgrade
    everything in the network.

  - All other operating systems are known to work with EAP and
    FreeRADIUS.  This includes Linux, *BSD, Mac OS X, Solaris,
    Symbian, along with all known embedded systems, phones, WiFi
    devices, etc.

  - Someone needs to ask Microsoft to please stop making life hard for
    their customers.


		SECURITY CONSIDERATIONS

The default certificate configuration files uses MD5 for message
digests, to maintain compatibility with network equipment that
supports only this algorithm.

MD5 has known weaknesses and is discouraged in favour of SHA1 (see
http://www.kb.cert.org/vuls/id/836068 for details). If your network
equipment supports the SHA1 signature algorithm, we recommend that you
change the "ca.cnf", "server.cnf", and "client.cnf" files to specify
the use of SHA1 for the certificates. To do this, change the
'default_md' entry in those files from 'md5' to 'sha1'.