Staging: strip: delete the driver
[linux/fpc-iii.git] / drivers / usb / wusbcore / security.c
blobb60799b811c144e5513e9e201f2f6fb38b5a709b
1 /*
2 * Wireless USB Host Controller
3 * Security support: encryption enablement, etc
5 * Copyright (C) 2006 Intel Corporation
6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version
10 * 2 as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 * 02110-1301, USA.
23 * FIXME: docs
25 #include <linux/types.h>
26 #include <linux/slab.h>
27 #include <linux/usb/ch9.h>
28 #include <linux/random.h>
29 #include "wusbhc.h"
31 static void wusbhc_set_gtk_callback(struct urb *urb);
32 static void wusbhc_gtk_rekey_done_work(struct work_struct *work);
34 int wusbhc_sec_create(struct wusbhc *wusbhc)
36 wusbhc->gtk.descr.bLength = sizeof(wusbhc->gtk.descr) + sizeof(wusbhc->gtk.data);
37 wusbhc->gtk.descr.bDescriptorType = USB_DT_KEY;
38 wusbhc->gtk.descr.bReserved = 0;
40 wusbhc->gtk_index = wusb_key_index(0, WUSB_KEY_INDEX_TYPE_GTK,
41 WUSB_KEY_INDEX_ORIGINATOR_HOST);
43 INIT_WORK(&wusbhc->gtk_rekey_done_work, wusbhc_gtk_rekey_done_work);
45 return 0;
49 /* Called when the HC is destroyed */
50 void wusbhc_sec_destroy(struct wusbhc *wusbhc)
55 /**
56 * wusbhc_next_tkid - generate a new, currently unused, TKID
57 * @wusbhc: the WUSB host controller
58 * @wusb_dev: the device whose PTK the TKID is for
59 * (or NULL for a TKID for a GTK)
61 * The generated TKID consist of two parts: the device's authenicated
62 * address (or 0 or a GTK); and an incrementing number. This ensures
63 * that TKIDs cannot be shared between devices and by the time the
64 * incrementing number wraps around the older TKIDs will no longer be
65 * in use (a maximum of two keys may be active at any one time).
67 static u32 wusbhc_next_tkid(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
69 u32 *tkid;
70 u32 addr;
72 if (wusb_dev == NULL) {
73 tkid = &wusbhc->gtk_tkid;
74 addr = 0;
75 } else {
76 tkid = &wusb_port_by_idx(wusbhc, wusb_dev->port_idx)->ptk_tkid;
77 addr = wusb_dev->addr & 0x7f;
80 *tkid = (addr << 8) | ((*tkid + 1) & 0xff);
82 return *tkid;
85 static void wusbhc_generate_gtk(struct wusbhc *wusbhc)
87 const size_t key_size = sizeof(wusbhc->gtk.data);
88 u32 tkid;
90 tkid = wusbhc_next_tkid(wusbhc, NULL);
92 wusbhc->gtk.descr.tTKID[0] = (tkid >> 0) & 0xff;
93 wusbhc->gtk.descr.tTKID[1] = (tkid >> 8) & 0xff;
94 wusbhc->gtk.descr.tTKID[2] = (tkid >> 16) & 0xff;
96 get_random_bytes(wusbhc->gtk.descr.bKeyData, key_size);
99 /**
100 * wusbhc_sec_start - start the security management process
101 * @wusbhc: the WUSB host controller
103 * Generate and set an initial GTK on the host controller.
105 * Called when the HC is started.
107 int wusbhc_sec_start(struct wusbhc *wusbhc)
109 const size_t key_size = sizeof(wusbhc->gtk.data);
110 int result;
112 wusbhc_generate_gtk(wusbhc);
114 result = wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid,
115 &wusbhc->gtk.descr.bKeyData, key_size);
116 if (result < 0)
117 dev_err(wusbhc->dev, "cannot set GTK for the host: %d\n",
118 result);
120 return result;
124 * wusbhc_sec_stop - stop the security management process
125 * @wusbhc: the WUSB host controller
127 * Wait for any pending GTK rekeys to stop.
129 void wusbhc_sec_stop(struct wusbhc *wusbhc)
131 cancel_work_sync(&wusbhc->gtk_rekey_done_work);
135 /** @returns encryption type name */
136 const char *wusb_et_name(u8 x)
138 switch (x) {
139 case USB_ENC_TYPE_UNSECURE: return "unsecure";
140 case USB_ENC_TYPE_WIRED: return "wired";
141 case USB_ENC_TYPE_CCM_1: return "CCM-1";
142 case USB_ENC_TYPE_RSA_1: return "RSA-1";
143 default: return "unknown";
146 EXPORT_SYMBOL_GPL(wusb_et_name);
149 * Set the device encryption method
151 * We tell the device which encryption method to use; we do this when
152 * setting up the device's security.
154 static int wusb_dev_set_encryption(struct usb_device *usb_dev, int value)
156 int result;
157 struct device *dev = &usb_dev->dev;
158 struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
160 if (value) {
161 value = wusb_dev->ccm1_etd.bEncryptionValue;
162 } else {
163 /* FIXME: should be wusb_dev->etd[UNSECURE].bEncryptionValue */
164 value = 0;
166 /* Set device's */
167 result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
168 USB_REQ_SET_ENCRYPTION,
169 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
170 value, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
171 if (result < 0)
172 dev_err(dev, "Can't set device's WUSB encryption to "
173 "%s (value %d): %d\n",
174 wusb_et_name(wusb_dev->ccm1_etd.bEncryptionType),
175 wusb_dev->ccm1_etd.bEncryptionValue, result);
176 return result;
180 * Set the GTK to be used by a device.
182 * The device must be authenticated.
184 static int wusb_dev_set_gtk(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
186 struct usb_device *usb_dev = wusb_dev->usb_dev;
188 return usb_control_msg(
189 usb_dev, usb_sndctrlpipe(usb_dev, 0),
190 USB_REQ_SET_DESCRIPTOR,
191 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
192 USB_DT_KEY << 8 | wusbhc->gtk_index, 0,
193 &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
194 1000);
198 /* FIXME: prototype for adding security */
199 int wusb_dev_sec_add(struct wusbhc *wusbhc,
200 struct usb_device *usb_dev, struct wusb_dev *wusb_dev)
202 int result, bytes, secd_size;
203 struct device *dev = &usb_dev->dev;
204 struct usb_security_descriptor *secd;
205 const struct usb_encryption_descriptor *etd, *ccm1_etd = NULL;
206 const void *itr, *top;
207 char buf[64];
209 secd = kmalloc(sizeof(*secd), GFP_KERNEL);
210 if (secd == NULL) {
211 result = -ENOMEM;
212 goto out;
215 result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
216 0, secd, sizeof(*secd));
217 if (result < sizeof(*secd)) {
218 dev_err(dev, "Can't read security descriptor or "
219 "not enough data: %d\n", result);
220 goto out;
222 secd_size = le16_to_cpu(secd->wTotalLength);
223 secd = krealloc(secd, secd_size, GFP_KERNEL);
224 if (secd == NULL) {
225 dev_err(dev, "Can't allocate space for security descriptors\n");
226 goto out;
228 result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
229 0, secd, secd_size);
230 if (result < secd_size) {
231 dev_err(dev, "Can't read security descriptor or "
232 "not enough data: %d\n", result);
233 goto out;
235 bytes = 0;
236 itr = &secd[1];
237 top = (void *)secd + result;
238 while (itr < top) {
239 etd = itr;
240 if (top - itr < sizeof(*etd)) {
241 dev_err(dev, "BUG: bad device security descriptor; "
242 "not enough data (%zu vs %zu bytes left)\n",
243 top - itr, sizeof(*etd));
244 break;
246 if (etd->bLength < sizeof(*etd)) {
247 dev_err(dev, "BUG: bad device encryption descriptor; "
248 "descriptor is too short "
249 "(%u vs %zu needed)\n",
250 etd->bLength, sizeof(*etd));
251 break;
253 itr += etd->bLength;
254 bytes += snprintf(buf + bytes, sizeof(buf) - bytes,
255 "%s (0x%02x/%02x) ",
256 wusb_et_name(etd->bEncryptionType),
257 etd->bEncryptionValue, etd->bAuthKeyIndex);
258 if (etd->bEncryptionType == USB_ENC_TYPE_CCM_1)
259 ccm1_etd = etd;
261 /* This code only supports CCM1 as of now. */
262 /* FIXME: user has to choose which sec mode to use?
263 * In theory we want CCM */
264 if (ccm1_etd == NULL) {
265 dev_err(dev, "WUSB device doesn't support CCM1 encryption, "
266 "can't use!\n");
267 result = -EINVAL;
268 goto out;
270 wusb_dev->ccm1_etd = *ccm1_etd;
271 dev_dbg(dev, "supported encryption: %s; using %s (0x%02x/%02x)\n",
272 buf, wusb_et_name(ccm1_etd->bEncryptionType),
273 ccm1_etd->bEncryptionValue, ccm1_etd->bAuthKeyIndex);
274 result = 0;
275 out:
276 kfree(secd);
277 return result;
280 void wusb_dev_sec_rm(struct wusb_dev *wusb_dev)
282 /* Nothing so far */
286 * Update the address of an unauthenticated WUSB device
288 * Once we have successfully authenticated, we take it to addr0 state
289 * and then to a normal address.
291 * Before the device's address (as known by it) was usb_dev->devnum |
292 * 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.
294 int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
296 int result = -ENOMEM;
297 struct usb_device *usb_dev = wusb_dev->usb_dev;
298 struct device *dev = &usb_dev->dev;
299 u8 new_address = wusb_dev->addr & 0x7F;
301 /* Set address 0 */
302 result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
303 USB_REQ_SET_ADDRESS, 0,
304 0, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
305 if (result < 0) {
306 dev_err(dev, "auth failed: can't set address 0: %d\n",
307 result);
308 goto error_addr0;
310 result = wusb_set_dev_addr(wusbhc, wusb_dev, 0);
311 if (result < 0)
312 goto error_addr0;
313 usb_set_device_state(usb_dev, USB_STATE_DEFAULT);
314 usb_ep0_reinit(usb_dev);
316 /* Set new (authenticated) address. */
317 result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
318 USB_REQ_SET_ADDRESS, 0,
319 new_address, 0, NULL, 0,
320 1000 /* FIXME: arbitrary */);
321 if (result < 0) {
322 dev_err(dev, "auth failed: can't set address %u: %d\n",
323 new_address, result);
324 goto error_addr;
326 result = wusb_set_dev_addr(wusbhc, wusb_dev, new_address);
327 if (result < 0)
328 goto error_addr;
329 usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
330 usb_ep0_reinit(usb_dev);
331 usb_dev->authenticated = 1;
332 error_addr:
333 error_addr0:
334 return result;
341 /* FIXME: split and cleanup */
342 int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
343 struct wusb_ckhdid *ck)
345 int result = -ENOMEM;
346 struct usb_device *usb_dev = wusb_dev->usb_dev;
347 struct device *dev = &usb_dev->dev;
348 u32 tkid;
349 __le32 tkid_le;
350 struct usb_handshake *hs;
351 struct aes_ccm_nonce ccm_n;
352 u8 mic[8];
353 struct wusb_keydvt_in keydvt_in;
354 struct wusb_keydvt_out keydvt_out;
356 hs = kzalloc(3*sizeof(hs[0]), GFP_KERNEL);
357 if (hs == NULL) {
358 dev_err(dev, "can't allocate handshake data\n");
359 goto error_kzalloc;
362 /* We need to turn encryption before beginning the 4way
363 * hshake (WUSB1.0[.3.2.2]) */
364 result = wusb_dev_set_encryption(usb_dev, 1);
365 if (result < 0)
366 goto error_dev_set_encryption;
368 tkid = wusbhc_next_tkid(wusbhc, wusb_dev);
369 tkid_le = cpu_to_le32(tkid);
371 hs[0].bMessageNumber = 1;
372 hs[0].bStatus = 0;
373 memcpy(hs[0].tTKID, &tkid_le, sizeof(hs[0].tTKID));
374 hs[0].bReserved = 0;
375 memcpy(hs[0].CDID, &wusb_dev->cdid, sizeof(hs[0].CDID));
376 get_random_bytes(&hs[0].nonce, sizeof(hs[0].nonce));
377 memset(hs[0].MIC, 0, sizeof(hs[0].MIC)); /* Per WUSB1.0[T7-22] */
379 result = usb_control_msg(
380 usb_dev, usb_sndctrlpipe(usb_dev, 0),
381 USB_REQ_SET_HANDSHAKE,
382 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
383 1, 0, &hs[0], sizeof(hs[0]), 1000 /* FIXME: arbitrary */);
384 if (result < 0) {
385 dev_err(dev, "Handshake1: request failed: %d\n", result);
386 goto error_hs1;
389 /* Handshake 2, from the device -- need to verify fields */
390 result = usb_control_msg(
391 usb_dev, usb_rcvctrlpipe(usb_dev, 0),
392 USB_REQ_GET_HANDSHAKE,
393 USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
394 2, 0, &hs[1], sizeof(hs[1]), 1000 /* FIXME: arbitrary */);
395 if (result < 0) {
396 dev_err(dev, "Handshake2: request failed: %d\n", result);
397 goto error_hs2;
400 result = -EINVAL;
401 if (hs[1].bMessageNumber != 2) {
402 dev_err(dev, "Handshake2 failed: bad message number %u\n",
403 hs[1].bMessageNumber);
404 goto error_hs2;
406 if (hs[1].bStatus != 0) {
407 dev_err(dev, "Handshake2 failed: bad status %u\n",
408 hs[1].bStatus);
409 goto error_hs2;
411 if (memcmp(hs[0].tTKID, hs[1].tTKID, sizeof(hs[0].tTKID))) {
412 dev_err(dev, "Handshake2 failed: TKID mismatch "
413 "(#1 0x%02x%02x%02x vs #2 0x%02x%02x%02x)\n",
414 hs[0].tTKID[0], hs[0].tTKID[1], hs[0].tTKID[2],
415 hs[1].tTKID[0], hs[1].tTKID[1], hs[1].tTKID[2]);
416 goto error_hs2;
418 if (memcmp(hs[0].CDID, hs[1].CDID, sizeof(hs[0].CDID))) {
419 dev_err(dev, "Handshake2 failed: CDID mismatch\n");
420 goto error_hs2;
423 /* Setup the CCM nonce */
424 memset(&ccm_n.sfn, 0, sizeof(ccm_n.sfn)); /* Per WUSB1.0[6.5.2] */
425 memcpy(ccm_n.tkid, &tkid_le, sizeof(ccm_n.tkid));
426 ccm_n.src_addr = wusbhc->uwb_rc->uwb_dev.dev_addr;
427 ccm_n.dest_addr.data[0] = wusb_dev->addr;
428 ccm_n.dest_addr.data[1] = 0;
430 /* Derive the KCK and PTK from CK, the CCM, H and D nonces */
431 memcpy(keydvt_in.hnonce, hs[0].nonce, sizeof(keydvt_in.hnonce));
432 memcpy(keydvt_in.dnonce, hs[1].nonce, sizeof(keydvt_in.dnonce));
433 result = wusb_key_derive(&keydvt_out, ck->data, &ccm_n, &keydvt_in);
434 if (result < 0) {
435 dev_err(dev, "Handshake2 failed: cannot derive keys: %d\n",
436 result);
437 goto error_hs2;
440 /* Compute MIC and verify it */
441 result = wusb_oob_mic(mic, keydvt_out.kck, &ccm_n, &hs[1]);
442 if (result < 0) {
443 dev_err(dev, "Handshake2 failed: cannot compute MIC: %d\n",
444 result);
445 goto error_hs2;
448 if (memcmp(hs[1].MIC, mic, sizeof(hs[1].MIC))) {
449 dev_err(dev, "Handshake2 failed: MIC mismatch\n");
450 goto error_hs2;
453 /* Send Handshake3 */
454 hs[2].bMessageNumber = 3;
455 hs[2].bStatus = 0;
456 memcpy(hs[2].tTKID, &tkid_le, sizeof(hs[2].tTKID));
457 hs[2].bReserved = 0;
458 memcpy(hs[2].CDID, &wusb_dev->cdid, sizeof(hs[2].CDID));
459 memcpy(hs[2].nonce, hs[0].nonce, sizeof(hs[2].nonce));
460 result = wusb_oob_mic(hs[2].MIC, keydvt_out.kck, &ccm_n, &hs[2]);
461 if (result < 0) {
462 dev_err(dev, "Handshake3 failed: cannot compute MIC: %d\n",
463 result);
464 goto error_hs2;
467 result = usb_control_msg(
468 usb_dev, usb_sndctrlpipe(usb_dev, 0),
469 USB_REQ_SET_HANDSHAKE,
470 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
471 3, 0, &hs[2], sizeof(hs[2]), 1000 /* FIXME: arbitrary */);
472 if (result < 0) {
473 dev_err(dev, "Handshake3: request failed: %d\n", result);
474 goto error_hs3;
477 result = wusbhc->set_ptk(wusbhc, wusb_dev->port_idx, tkid,
478 keydvt_out.ptk, sizeof(keydvt_out.ptk));
479 if (result < 0)
480 goto error_wusbhc_set_ptk;
482 result = wusb_dev_set_gtk(wusbhc, wusb_dev);
483 if (result < 0) {
484 dev_err(dev, "Set GTK for device: request failed: %d\n",
485 result);
486 goto error_wusbhc_set_gtk;
489 /* Update the device's address from unauth to auth */
490 if (usb_dev->authenticated == 0) {
491 result = wusb_dev_update_address(wusbhc, wusb_dev);
492 if (result < 0)
493 goto error_dev_update_address;
495 result = 0;
496 dev_info(dev, "device authenticated\n");
498 error_dev_update_address:
499 error_wusbhc_set_gtk:
500 error_wusbhc_set_ptk:
501 error_hs3:
502 error_hs2:
503 error_hs1:
504 memset(hs, 0, 3*sizeof(hs[0]));
505 memset(&keydvt_out, 0, sizeof(keydvt_out));
506 memset(&keydvt_in, 0, sizeof(keydvt_in));
507 memset(&ccm_n, 0, sizeof(ccm_n));
508 memset(mic, 0, sizeof(mic));
509 if (result < 0)
510 wusb_dev_set_encryption(usb_dev, 0);
511 error_dev_set_encryption:
512 kfree(hs);
513 error_kzalloc:
514 return result;
518 * Once all connected and authenticated devices have received the new
519 * GTK, switch the host to using it.
521 static void wusbhc_gtk_rekey_done_work(struct work_struct *work)
523 struct wusbhc *wusbhc = container_of(work, struct wusbhc, gtk_rekey_done_work);
524 size_t key_size = sizeof(wusbhc->gtk.data);
526 mutex_lock(&wusbhc->mutex);
528 if (--wusbhc->pending_set_gtks == 0)
529 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
531 mutex_unlock(&wusbhc->mutex);
534 static void wusbhc_set_gtk_callback(struct urb *urb)
536 struct wusbhc *wusbhc = urb->context;
538 queue_work(wusbd, &wusbhc->gtk_rekey_done_work);
542 * wusbhc_gtk_rekey - generate and distribute a new GTK
543 * @wusbhc: the WUSB host controller
545 * Generate a new GTK and distribute it to all connected and
546 * authenticated devices. When all devices have the new GTK, the host
547 * starts using it.
549 * This must be called after every device disconnect (see [WUSB]
550 * section 6.2.11.2).
552 void wusbhc_gtk_rekey(struct wusbhc *wusbhc)
554 static const size_t key_size = sizeof(wusbhc->gtk.data);
555 int p;
557 wusbhc_generate_gtk(wusbhc);
559 for (p = 0; p < wusbhc->ports_max; p++) {
560 struct wusb_dev *wusb_dev;
562 wusb_dev = wusbhc->port[p].wusb_dev;
563 if (!wusb_dev || !wusb_dev->usb_dev || !wusb_dev->usb_dev->authenticated)
564 continue;
566 usb_fill_control_urb(wusb_dev->set_gtk_urb, wusb_dev->usb_dev,
567 usb_sndctrlpipe(wusb_dev->usb_dev, 0),
568 (void *)wusb_dev->set_gtk_req,
569 &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
570 wusbhc_set_gtk_callback, wusbhc);
571 if (usb_submit_urb(wusb_dev->set_gtk_urb, GFP_KERNEL) == 0)
572 wusbhc->pending_set_gtks++;
574 if (wusbhc->pending_set_gtks == 0)
575 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);