How to use smartcards with OpenSSH?

OpenSSH contains experimental support for authentication using
Cyberflex smartcards and TODOS card readers, in addition to the cards
with PKCS#15 structure supported by OpenSC. To enable this you
need to:

Using libsectok:

(1) enable sectok support in OpenSSH:

	$ ./configure --with-sectok

(2) If you have used a previous version of ssh with your card, you
    must remove the old applet and keys.

	$ sectok
	sectok> login -d
	sectok> junload Ssh.bin
	sectok> delete 0012
	sectok> delete sh
	sectok> quit

(3) load the Java Cardlet to the Cyberflex card and set card passphrase:

	$ sectok
	sectok> login -d
	sectok> jload /usr/libdata/ssh/Ssh.bin
	sectok> setpass
	Enter new AUT0 passphrase:
	Re-enter passphrase:
	sectok> quit

	Do not forget the passphrase.  There is no way to
	recover if you do.

	IMPORTANT WARNING: If you attempt to login with the
	wrong passphrase three times in a row, you will
	destroy your card.

(4) load a RSA key to the card:

	$ ssh-keygen -f /path/to/rsakey -U 1
	(where 1 is the reader number, you can also try 0)

	In spite of the name, this does not generate a key.
	It just loads an already existing key on to the card.

(5) Optional: If you don't want to use a card passphrase, change the
    acl on the private key file:

	$ sectok
	sectok> login -d
	sectok> acl 0012 world: w
	 world: w
	 AUT0: w inval
	sectok> quit

	If you do this, anyone who has access to your card
	can assume your identity.  This is not recommended.


Using OpenSC:

(1) install OpenSC:

	Sources and instructions are available from
	http://www.opensc.org/

(2) enable OpenSC support in OpenSSH:

	$ ./configure --with-opensc[=/path/to/opensc] [options]

(3) load a RSA key to the card:

	Not supported yet.


Common operations:

(1) tell the ssh client to use the card reader:

	$ ssh -I 1 otherhost

(2) or tell the agent (don't forget to restart) to use the smartcard:

	$ ssh-add -s 1


-markus,
Tue Jul 17 23:54:51 CEST 2001

$OpenBSD: README.smartcard,v 1.9 2003/11/21 11:57:02 djm Exp $