 4667619269
			
		
	
	
		4667619269
		
	
	
	
	
		
			
			Buglink: https://gitlab.com/qemu-project/qemu/-/issues/527 Signed-off-by: Lucas Ramage <lucas.ramage@infinite-omicron.com> Message-Id: <20220405142906.21382-1-oxr463@gmx.us> Reviewed-by: Damien Hedde <damien.hedde@greensocs.com> [thuth: Added some cosmetic fixes] Signed-off-by: Thomas Huth <thuth@redhat.com>
		
			
				
	
	
		
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			172 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			ReStructuredText
		
	
	
	
	
	
| Chip Card Interface Device (CCID)
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| =================================
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| 
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| USB CCID device
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| ---------------
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| The USB CCID device is a USB device implementing the CCID specification, which
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| lets one connect smart card readers that implement the same spec. For more
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| information see the specification::
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| 
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|   Universal Serial Bus
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|   Device Class: Smart Card
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|   CCID
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|   Specification for
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|   Integrated Circuit(s) Cards Interface Devices
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|   Revision 1.1
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|   April 22rd, 2005
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| 
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| Smartcards are used for authentication, single sign on, decryption in
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| public/private schemes and digital signatures. A smartcard reader on the client
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| cannot be used on a guest with simple usb passthrough since it will then not be
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| available on the client, possibly locking the computer when it is "removed". On
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| the other hand this device can let you use the smartcard on both the client and
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| the guest machine. It is also possible to have a completely virtual smart card
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| reader and smart card (i.e. not backed by a physical device) using this device.
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| 
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| Building
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| --------
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| The cryptographic functions and access to the physical card is done via the
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| libcacard library, whose development package must be installed prior to
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| building QEMU:
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| 
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| In redhat/fedora::
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| 
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|   yum install libcacard-devel
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| 
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| In ubuntu::
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| 
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|   apt-get install libcacard-dev
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| 
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| Configuring and building::
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| 
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|   ./configure --enable-smartcard && make
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| 
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| Using ccid-card-emulated with hardware
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| --------------------------------------
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| Assuming you have a working smartcard on the host with the current
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| user, using libcacard, QEMU acts as another client using ccid-card-emulated::
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| 
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|   qemu -usb -device usb-ccid -device ccid-card-emulated
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| 
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| Using ccid-card-emulated with certificates stored in files
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| ----------------------------------------------------------
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| You must create the CA and card certificates. This is a one time process.
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| We use NSS certificates::
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| 
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|   mkdir fake-smartcard
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|   cd fake-smartcard
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|   certutil -N -d sql:$PWD
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|   certutil -S -d sql:$PWD -s "CN=Fake Smart Card CA" -x -t TC,TC,TC -n fake-smartcard-ca
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|   certutil -S -d sql:$PWD -t ,, -s "CN=John Doe" -n id-cert -c fake-smartcard-ca
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|   certutil -S -d sql:$PWD -t ,, -s "CN=John Doe (signing)" --nsCertType smime -n signing-cert -c fake-smartcard-ca
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|   certutil -S -d sql:$PWD -t ,, -s "CN=John Doe (encryption)" --nsCertType sslClient -n encryption-cert -c fake-smartcard-ca
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| 
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| Note: you must have exactly three certificates.
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| 
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| You can use the emulated card type with the certificates backend::
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| 
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|   qemu -usb -device usb-ccid -device ccid-card-emulated,backend=certificates,db=sql:$PWD,cert1=id-cert,cert2=signing-cert,cert3=encryption-cert
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| 
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| To use the certificates in the guest, export the CA certificate::
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| 
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|   certutil -L -r -d sql:$PWD -o fake-smartcard-ca.cer -n fake-smartcard-ca
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| 
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| and import it in the guest::
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| 
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|   certutil -A -d /etc/pki/nssdb -i fake-smartcard-ca.cer -t TC,TC,TC -n fake-smartcard-ca
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| 
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| In a Linux guest you can then use the CoolKey PKCS #11 module to access
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| the card::
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| 
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|   certutil -d /etc/pki/nssdb -L -h all
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| 
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| It will prompt you for the PIN (which is the password you assigned to the
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| certificate database early on), and then show you all three certificates
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| together with the manually imported CA cert::
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| 
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|   Certificate Nickname                        Trust Attributes
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|   fake-smartcard-ca                           CT,C,C
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|   John Doe:CAC ID Certificate                 u,u,u
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|   John Doe:CAC Email Signature Certificate    u,u,u
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|   John Doe:CAC Email Encryption Certificate   u,u,u
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| 
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| If this does not happen, CoolKey is not installed or not registered with
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| NSS. Registration can be done from Firefox or the command line::
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| 
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|   modutil -dbdir /etc/pki/nssdb -add "CAC Module" -libfile /usr/lib64/pkcs11/libcoolkeypk11.so
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|   modutil -dbdir /etc/pki/nssdb -list
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| 
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| Using ccid-card-passthru with client side hardware
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| --------------------------------------------------
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| On the host specify the ccid-card-passthru device with a suitable chardev::
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| 
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|   qemu -chardev socket,server=on,host=0.0.0.0,port=2001,id=ccid,wait=off \
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|        -usb -device usb-ccid -device ccid-card-passthru,chardev=ccid
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| 
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| On the client run vscclient, built when you built QEMU::
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| 
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|   vscclient <qemu-host> 2001
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| 
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| Using ccid-card-passthru with client side certificates
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| ------------------------------------------------------
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| This case is not particularly useful, but you can use it to debug
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| your setup.
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| 
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| Follow instructions above, except run QEMU and vscclient as follows.
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| 
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| Run qemu as per above, and run vscclient from the "fake-smartcard"
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| directory as follows::
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| 
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|   qemu -chardev socket,server=on,host=0.0.0.0,port=2001,id=ccid,wait=off \
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|        -usb -device usb-ccid -device ccid-card-passthru,chardev=ccid
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|   vscclient -e "db=\"sql:$PWD\" use_hw=no soft=(,Test,CAC,,id-cert,signing-cert,encryption-cert)" <qemu-host> 2001
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| 
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| 
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| Passthrough protocol scenario
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| -----------------------------
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| This is a typical interchange of messages when using the passthru card device.
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| usb-ccid is a usb device. It defaults to an unattached usb device on startup.
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| usb-ccid expects a chardev and expects the protocol defined in
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| cac_card/vscard_common.h to be passed over that.
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| The usb-ccid device can be in one of three modes:
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| 
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| * detached
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| * attached with no card
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| * attached with card
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| 
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| A typical interchange is (the arrow shows who started each exchange, it can be client
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| originated or guest originated)::
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| 
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|   client event        |    vscclient           |    passthru    |    usb-ccid  |  guest event
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|   ------------------------------------------------------------------------------------------------
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|                       |    VSC_Init            |                |              |
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|                       |    VSC_ReaderAdd       |                |    attach    |
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|                       |                        |                |              |  sees new usb device.
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|     card inserted ->  |                        |                |              |
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|                       |    VSC_ATR             |   insert       |    insert    |  see new card
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|                       |                        |                |              |
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|                       |    VSC_APDU            |   VSC_APDU     |              | <- guest sends APDU
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|   client <-> physical |                        |                |              |
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|    card APDU exchange |                        |                |              |
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|    client response -> |    VSC_APDU            |   VSC_APDU     |              |  receive APDU response
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|                                                       ...
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|                                       [APDU<->APDU repeats several times]
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|                                                       ...
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|      card removed  -> |                        |                |              |
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|                       |    VSC_CardRemove      |   remove       |   remove     |   card removed
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|                                                       ...
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|                                       [(card insert, apdu's, card remove) repeat]
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|                                                       ...
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|     kill/quit         |                        |                |              |
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|       vscclient       |                        |                |              |
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|                       |    VSC_ReaderRemove    |                |   detach     |
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|                       |                        |                |              |   usb device removed.
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| 
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| libcacard
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| ---------
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| Both ccid-card-emulated and vscclient use libcacard as the card emulator.
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| libcacard implements a completely virtual CAC (DoD standard for smart
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| cards) compliant card and uses NSS to retrieve certificates and do
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| any encryption. The backend can then be a real reader and card, or
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| certificates stored in files.
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