wi(4) and shared authmode

Hi all

I have wi-based wireless nic.

[(19:59)(82.06%)(p0):~ ] dmesg|grep wi0
wi0: <Intersil Prism2.5> mem 0xf8000000-0xf8000fff at device 2.0 on pci2
wi0: [GIANT-LOCKED]
wi0: using RF:PRISM2.5 MAC:ISL3874A(Mini-PCI)
wi0: Intersil Firmware: Primary (1.1.0), Station (1.4.3)
wi0: Ethernet address: 00:d0:59:49:12:52
wi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps

My AP works in 'Shared key' WEP mode, it means only encrypted
connections allowed.
But I can't configure wi0 to make authmode 'shared':

[(20:00)(81.59%)(p0):~ ] ifconfig wi0
wi0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 10.0.0.2 netmask 0xff000000 broadcast 10.255.255.255
        ether 00:d0:59:49:12:52
        media: IEEE 802.11 Wireless Ethernet autoselect (DS/2Mbps)
        status: no carrier
        ssid toxawlan 1:toxawlan
        stationname "FreeBSD_ToxaWlan_Station"
        channel -1 authmode OPEN powersavemode OFF powersavesleep 100
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        rtsthreshold 2312 protmode CTS
        wepmode MIXED weptxkey 1
        wepkey 1:104-bit

When I try to swith authmode to shared mode I get this error:

[(20:00)(81.53%)(p0):~ ] ifconfig wi0 authmode shared
ifconfig: SIOCS80211: Invalid argument
        
And 'ifconfig wi0 wepmode on' does nothing, card still stays in MIXED
mode

I guess wi(4) doesn't support authmode shared, does it?