2001-09-18 05:06:21 +00:00
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How to use smartcards with OpenSSH?
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OpenSSH contains experimental support for authentication using
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Cyberflex smartcards and TODOS card readers. To enable this you
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need to:
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(1) install sectok
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2001-09-18 05:44:34 +00:00
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Sources are instructions are available from
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http://www.citi.umich.edu/projects/smartcard/sectok.html
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2001-09-18 05:06:21 +00:00
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(2) enable SMARTCARD support in OpenSSH:
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2001-09-18 05:44:34 +00:00
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$ ./configure --with-smartcard [options]
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You can also specify a path to libsectok:
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$ ./configure --with-smartcard=/path/to/libsectok [options]
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2001-09-18 05:06:21 +00:00
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(3) load the Java Cardlet to the Cyberflex card:
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$ sectok
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sectok> login -d
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sectok> jload /usr/libdata/ssh/Ssh.bin
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sectok> quit
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(4) load a RSA key to the card:
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please don't use your production RSA keys, since
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with the current version of sectok/ssh-keygen
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the private key file is still readable
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$ ssh-keygen -f /path/to/rsakey -U 1
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(where 1 is the reader number, you can also try 0)
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In spite of the name, this does not generate a key.
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It just loads an already existing key on to the card.
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(5) optional:
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Change the card password so that only you can
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read the private key:
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$ sectok
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sectok> login -d
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sectok> setpass
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sectok> quit
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This prevents reading the key but not use of the
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key by the card applet.
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Do not forget the passphrase. There is no way to
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recover if you do.
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IMPORTANT WARNING: If you attempt to login with the
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wrong passphrase three times in a row, you will
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destroy your card.
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(6) tell the ssh client to use the card reader:
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$ ssh -I 1 otherhost
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(7) or tell the agent (don't forget to restart) to use the smartcard:
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$ ssh-add -s 1
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-markus,
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Tue Jul 17 23:54:51 CEST 2001
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