/* FIXME: split and cleanup */
int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
struct wusb_ckhdid *ck)
{
int result = -ENOMEM;
struct usb_device *usb_dev = wusb_dev->usb_dev;
struct device *dev = &usb_dev->dev;
u32 tkid;
__le32 tkid_le;
struct usb_handshake *hs;
struct aes_ccm_nonce ccm_n;
u8 mic[8];
struct wusb_keydvt_in keydvt_in;
struct wusb_keydvt_out keydvt_out;
hs = kzalloc(3*sizeof(hs[0]), GFP_KERNEL);
if (hs == NULL) {
dev_err(dev, "can't allocate handshake data\n");
goto error_kzalloc;
}
/* We need to turn encryption before beginning the 4way
* hshake (WUSB1.0[.3.2.2]) */
result = wusb_dev_set_encryption(usb_dev, 1);
if (result < 0)
goto error_dev_set_encryption;
tkid = wusbhc_next_tkid(wusbhc, wusb_dev);
tkid_le = cpu_to_le32(tkid);
hs[0].bMessageNumber = 1;
hs[0].bStatus = 0;
memcpy(hs[0].tTKID, &tkid_le, sizeof(hs[0].tTKID));
hs[0].bReserved = 0;
memcpy(hs[0].CDID, &wusb_dev->cdid, sizeof(hs[0].CDID));
get_random_bytes(&hs[0].nonce, sizeof(hs[0].nonce));
memset(hs[0].MIC, 0, sizeof(hs[0].MIC)); /* Per WUSB1.0[T7-22] */
result = usb_control_msg(
usb_dev, usb_sndctrlpipe(usb_dev, 0),
USB_REQ_SET_HANDSHAKE,
USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1, 0, &hs[0], sizeof(hs[0]), 1000 /* FIXME: arbitrary */);
if (result < 0) {
dev_err(dev, "Handshake1: request failed: %d\n", result);
goto error_hs1;
}
/* Handshake 2, from the device -- need to verify fields */
result = usb_control_msg(
usb_dev, usb_rcvctrlpipe(usb_dev, 0),
USB_REQ_GET_HANDSHAKE,
USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
2, 0, &hs[1], sizeof(hs[1]), 1000 /* FIXME: arbitrary */);
if (result < 0) {
dev_err(dev, "Handshake2: request failed: %d\n", result);
goto error_hs2;
}
result = -EINVAL;
if (hs[1].bMessageNumber != 2) {
dev_err(dev, "Handshake2 failed: bad message number %u\n",
hs[1].bMessageNumber);
goto error_hs2;
}
if (hs[1].bStatus != 0) {
dev_err(dev, "Handshake2 failed: bad status %u\n",
hs[1].bStatus);
goto error_hs2;
}
if (memcmp(hs[0].tTKID, hs[1].tTKID, sizeof(hs[0].tTKID))) {
dev_err(dev, "Handshake2 failed: TKID mismatch "
"(#1 0x%02x%02x%02x vs #2 0x%02x%02x%02x)\n",
hs[0].tTKID[0], hs[0].tTKID[1], hs[0].tTKID[2],
hs[1].tTKID[0], hs[1].tTKID[1], hs[1].tTKID[2]);
goto error_hs2;
}
if (memcmp(hs[0].CDID, hs[1].CDID, sizeof(hs[0].CDID))) {
dev_err(dev, "Handshake2 failed: CDID mismatch\n");
goto error_hs2;
}
/* Setup the CCM nonce */
memset(&ccm_n.sfn, 0, sizeof(ccm_n.sfn)); /* Per WUSB1.0[6.5.2] */
memcpy(ccm_n.tkid, &tkid_le, sizeof(ccm_n.tkid));
ccm_n.src_addr = wusbhc->uwb_rc->uwb_dev.dev_addr;
ccm_n.dest_addr.data[0] = wusb_dev->addr;
ccm_n.dest_addr.data[1] = 0;
/* Derive the KCK and PTK from CK, the CCM, H and D nonces */
memcpy(keydvt_in.hnonce, hs[0].nonce, sizeof(keydvt_in.hnonce));
memcpy(keydvt_in.dnonce, hs[1].nonce, sizeof(keydvt_in.dnonce));
result = wusb_key_derive(&keydvt_out, ck->data, &ccm_n, &keydvt_in);
if (result < 0) {
dev_err(dev, "Handshake2 failed: cannot derive keys: %d\n",
result);
goto error_hs2;
}
/* Compute MIC and verify it */
result = wusb_oob_mic(mic, keydvt_out.kck, &ccm_n, &hs[1]);
if (result < 0) {
dev_err(dev, "Handshake2 failed: cannot compute MIC: %d\n",
result);
goto error_hs2;
}
if (memcmp(hs[1].MIC, mic, sizeof(hs[1].MIC))) {
dev_err(dev, "Handshake2 failed: MIC mismatch\n");
goto error_hs2;
}
/* Send Handshake3 */
hs[2].bMessageNumber = 3;
hs[2].bStatus = 0;
memcpy(hs[2].tTKID, &tkid_le, sizeof(hs[2].tTKID));
hs[2].bReserved = 0;
memcpy(hs[2].CDID, &wusb_dev->cdid, sizeof(hs[2].CDID));
memcpy(hs[2].nonce, hs[0].nonce, sizeof(hs[2].nonce));
result = wusb_oob_mic(hs[2].MIC, keydvt_out.kck, &ccm_n, &hs[2]);
if (result < 0) {
dev_err(dev, "Handshake3 failed: cannot compute MIC: %d\n",
result);
goto error_hs2;
}
result = usb_control_msg(
usb_dev, usb_sndctrlpipe(usb_dev, 0),
USB_REQ_SET_HANDSHAKE,
USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
3, 0, &hs[2], sizeof(hs[2]), 1000 /* FIXME: arbitrary */);
if (result < 0) {
dev_err(dev, "Handshake3: request failed: %d\n", result);
goto error_hs3;
}
result = wusbhc->set_ptk(wusbhc, wusb_dev->port_idx, tkid,
keydvt_out.ptk, sizeof(keydvt_out.ptk));
if (result < 0)
goto error_wusbhc_set_ptk;
result = wusb_dev_set_gtk(wusbhc, wusb_dev);
if (result < 0) {
dev_err(dev, "Set GTK for device: request failed: %d\n",
result);
goto error_wusbhc_set_gtk;
}
/* Update the device's address from unauth to auth */
if (usb_dev->authenticated == 0) {
result = wusb_dev_update_address(wusbhc, wusb_dev);
if (result < 0)
goto error_dev_update_address;
}
result = 0;
dev_info(dev, "device authenticated\n");
error_dev_update_address:
error_wusbhc_set_gtk:
error_wusbhc_set_ptk:
error_hs3:
error_hs2:
error_hs1:
memset(hs, 0, 3*sizeof(hs[0]));
memset(&keydvt_out, 0, sizeof(keydvt_out));
memset(&keydvt_in, 0, sizeof(keydvt_in));
memset(&ccm_n, 0, sizeof(ccm_n));
memset(mic, 0, sizeof(mic));
if (result < 0)
wusb_dev_set_encryption(usb_dev, 0);
error_dev_set_encryption:
kfree(hs);
error_kzalloc:
return result;
}
/* These come from WUSB1.0[A.1] + 2006/12 errata
* NOTE: can't make this const or global -- somehow it seems
* the scatterlists for crypto get confused and we get
* bad data. There is no doc on this... */
struct wusb_keydvt_in stv_keydvt_in_a1 = {
.hnonce = {
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f
},
.dnonce = {
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f
}
};
result = wusb_key_derive(&keydvt_out, stv_key_a1, &stv_keydvt_n_a1,
&stv_keydvt_in_a1);
if (result < 0)
printk(KERN_ERR "E: WUSB key derivation test: "
"derivation failed: %d\n", result);
if (memcmp(&stv_keydvt_out_a1, &keydvt_out, sizeof(keydvt_out))) {
printk(KERN_ERR "E: WUSB key derivation test: "
"mismatch between key derivation result "
"and WUSB1.0[A1] Errata 2006/12\n");
printk(KERN_ERR "E: keydvt in: key\n");
wusb_key_dump(stv_key_a1, sizeof(stv_key_a1));
printk(KERN_ERR "E: keydvt in: nonce\n");
wusb_key_dump( &stv_keydvt_n_a1, sizeof(stv_keydvt_n_a1));
printk(KERN_ERR "E: keydvt in: hnonce & dnonce\n");
wusb_key_dump(&stv_keydvt_in_a1, sizeof(stv_keydvt_in_a1));
printk(KERN_ERR "E: keydvt out: KCK\n");
wusb_key_dump(&keydvt_out.kck, sizeof(keydvt_out.kck));
