136 lines
5.7 KiB
Plaintext
136 lines
5.7 KiB
Plaintext
QEMU CCID Device Documentation.
|
|
|
|
Contents
|
|
1. USB CCID device
|
|
2. Building
|
|
3. Using ccid-card-emulated with hardware
|
|
4. Using ccid-card-emulated with certificates
|
|
5. Using ccid-card-passthru with client side hardware
|
|
6. Using ccid-card-passthru with client side certificates
|
|
7. Passthrough protocol scenario
|
|
8. libcacard
|
|
|
|
1. USB CCID device
|
|
|
|
The USB CCID device is a USB device implementing the CCID specification, which
|
|
lets one connect smart card readers that implement the same spec. For more
|
|
information see the specification:
|
|
|
|
Universal Serial Bus
|
|
Device Class: Smart Card
|
|
CCID
|
|
Specification for
|
|
Integrated Circuit(s) Cards Interface Devices
|
|
Revision 1.1
|
|
April 22rd, 2005
|
|
|
|
Smartcard are used for authentication, single sign on, decryption in
|
|
public/private schemes and digital signatures. A smartcard reader on the client
|
|
cannot be used on a guest with simple usb passthrough since it will then not be
|
|
available on the client, possibly locking the computer when it is "removed". On
|
|
the other hand this device can let you use the smartcard on both the client and
|
|
the guest machine. It is also possible to have a completely virtual smart card
|
|
reader and smart card (i.e. not backed by a physical device) using this device.
|
|
|
|
2. Building
|
|
|
|
The cryptographic functions and access to the physical card is done via NSS.
|
|
|
|
Installing NSS:
|
|
|
|
In redhat/fedora:
|
|
yum install nss-devel
|
|
In ubuntu/debian:
|
|
apt-get install libnss3-dev
|
|
(not tested on ubuntu)
|
|
|
|
Configuring and building:
|
|
./configure --enable-smartcard && make
|
|
|
|
3. Using ccid-card-emulated with hardware
|
|
|
|
Assuming you have a working smartcard on the host with the current
|
|
user, using NSS, qemu acts as another NSS client using ccid-card-emulated:
|
|
|
|
qemu -usb -device usb-ccid -device ccid-card-emualated
|
|
|
|
4. Using ccid-card-emulated with certificates
|
|
|
|
You must create the certificates. This is a one time process. We use NSS
|
|
certificates:
|
|
|
|
certutil -d /etc/pki/nssdb -x -t "CT,CT,CT" -S -s "CN=cert1" -n cert1
|
|
|
|
Note: you must have exactly three certificates.
|
|
|
|
Assuming the current user can access the certificates (use certutil -L to
|
|
verify), you can use the emulated card type with the certificates backend:
|
|
|
|
qemu -usb -device usb-ccid -device ccid-card-emulated,backend=certificates,cert1=cert1,cert2=cert2,cert3=cert3
|
|
|
|
5. Using ccid-card-passthru with client side hardware
|
|
|
|
on the host specify the ccid-card-passthru device with a suitable chardev:
|
|
|
|
qemu -chardev socket,server,host=0.0.0.0,port=2001,id=ccid,nowait -usb -device usb-ccid -device ccid-card-passthru,chardev=ccid
|
|
|
|
on the client run vscclient, built when you built the libcacard library:
|
|
libcacard/vscclient <qemu-host> 2001
|
|
|
|
6. Using ccid-card-passthru with client side certificates
|
|
|
|
Run qemu as per #5, and run vscclient as follows:
|
|
(Note: vscclient command line interface is in a state of change)
|
|
|
|
libcacard/vscclient -e "db=\"/etc/pki/nssdb\" use_hw=no soft=(,Test,CAC,,cert1,cert2,cert3)" <qemu-host> 2001
|
|
|
|
7. Passthrough protocol scenario
|
|
|
|
This is a typical interchange of messages when using the passthru card device.
|
|
usb-ccid is a usb device. It defaults to an unattached usb device on startup.
|
|
usb-ccid expects a chardev and expects the protocol defined in
|
|
cac_card/vscard_common.h to be passed over that.
|
|
The usb-ccid device can be in one of three modes:
|
|
* detached
|
|
* attached with no card
|
|
* attached with card
|
|
|
|
A typical interchange is: (the arrow shows who started each exchange, it can be client
|
|
originated or guest originated)
|
|
|
|
client event | vscclient | passthru | usb-ccid | guest event
|
|
----------------------------------------------------------------------------------------------
|
|
| VSC_Init | | |
|
|
| VSC_ReaderAdd | | attach |
|
|
| | | | sees new usb device.
|
|
card inserted -> | | | |
|
|
| VSC_ATR | insert | insert | see new card
|
|
| | | |
|
|
| VSC_APDU | VSC_APDU | | <- guest sends APDU
|
|
client<->physical | | | |
|
|
card APDU exchange| | | |
|
|
client response ->| VSC_APDU | VSC_APDU | | receive APDU response
|
|
...
|
|
[APDU<->APDU repeats several times]
|
|
...
|
|
card removed -> | | | |
|
|
| VSC_CardRemove | remove | remove | card removed
|
|
...
|
|
[(card insert, apdu's, card remove) repeat]
|
|
...
|
|
kill/quit | | | |
|
|
vscclient | | | |
|
|
| VSC_ReaderRemove | | detach |
|
|
| | | | usb device removed.
|
|
|
|
|
|
8. libcacard
|
|
|
|
ccid-card-passthru and vscclient use libcacard as the card emulator.
|
|
libcacard implements a completely virtual CAC (DoD standard for smart cards)
|
|
compliant card and uses NSS to actually retrive certificates and do any
|
|
encryption using the backend (real reader + card or file backed certificates).
|
|
|
|
For documentation of cac_card see README in libcacard subdirectory.
|
|
|