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			The official spelling is QEMU. Signed-off-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
		
			
				
	
	
		
			136 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| QEMU CCID Device Documentation.
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| 
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| Contents
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| 1. USB CCID device
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| 2. Building
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| 3. Using ccid-card-emulated with hardware
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| 4. Using ccid-card-emulated with certificates
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| 5. Using ccid-card-passthru with client side hardware
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| 6. Using ccid-card-passthru with client side certificates
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| 7. Passthrough protocol scenario
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| 8. libcacard
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| 
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| 1. 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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| Smartcard 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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| 2. Building
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| 
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| The cryptographic functions and access to the physical card is done via NSS.
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| 
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| Installing NSS:
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| 
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| In redhat/fedora:
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|     yum install nss-devel
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| In ubuntu/debian:
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|     apt-get install libnss3-dev
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|     (not tested on ubuntu)
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| 
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| Configuring and building:
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|     ./configure --enable-smartcard && make
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| 
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| 3. 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 NSS, qemu acts as another NSS client using ccid-card-emulated:
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| 
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|     qemu -usb -device usb-ccid -device ccid-card-emualated
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| 
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| 4. Using ccid-card-emulated with certificates
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| 
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| You must create the certificates. This is a one time process. We use NSS
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| certificates:
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| 
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|     certutil -d /etc/pki/nssdb -x -t "CT,CT,CT" -S -s "CN=cert1" -n cert1
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| 
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| Note: you must have exactly three certificates.
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| 
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| Assuming the current user can access the certificates (use certutil -L to
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| verify), 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,cert1=cert1,cert2=cert2,cert3=cert3
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| 
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| 5. 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,host=0.0.0.0,port=2001,id=ccid,nowait -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 the libcacard library:
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|     libcacard/vscclient <qemu-host> 2001
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| 
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| 6. Using ccid-card-passthru with client side certificates
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| 
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| Run qemu as per #5, and run vscclient as follows:
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| (Note: vscclient command line interface is in a state of change)
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| 
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|     libcacard/vscclient -e "db=\"/etc/pki/nssdb\" use_hw=no soft=(,Test,CAC,,cert1,cert2,cert3)" <qemu-host> 2001
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| 
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| 7. 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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|  * 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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| 
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| 8. libcacard
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| 
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| ccid-card-passthru and vscclient use libcacard as the card emulator.
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| libcacard implements a completely virtual CAC (DoD standard for smart cards)
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| compliant card and uses NSS to actually retrive certificates and do any
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| encryption using the backend (real reader + card or file backed certificates).
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| 
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| For documentation of cac_card see README in libcacard subdirectory.
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| 
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