git.oblomov.eu Git - linux-2.6/blob - drivers/usb/wusbcore/security.c

   1 /*
   2  * Wireless USB Host Controller
   3  * Security support: encryption enablement, etc
   4  *
   5  * Copyright (C) 2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   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.
  11  *
  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.
  16  *
  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.
  21  *
  22  *
  23  * FIXME: docs
  24  */
  25 #include <linux/types.h>
  26 #include <linux/usb/ch9.h>
  27 #include <linux/random.h>
  28 #include "wusbhc.h"
  29
  30 /*
  31  * DEBUG & SECURITY WARNING!!!!
  32  *
  33  * If you enable this past 1, the debug code will weaken the
  34  * cryptographic safety of the system (on purpose, for debugging).
  35  *
  36  * Weaken means:
  37  *   we print secret keys and intermediate values all the way,
  38  */
  39 #undef D_LOCAL
  40 #define D_LOCAL 2
  41 #include <linux/uwb/debug.h>
  42
  43 static void wusbhc_set_gtk_callback(struct urb *urb);
  44 static void wusbhc_gtk_rekey_done_work(struct work_struct *work);
  45
  46 int wusbhc_sec_create(struct wusbhc *wusbhc)
  47 {
  48         wusbhc->gtk.descr.bLength = sizeof(wusbhc->gtk.descr) + sizeof(wusbhc->gtk.data);
  49         wusbhc->gtk.descr.bDescriptorType = USB_DT_KEY;
  50         wusbhc->gtk.descr.bReserved = 0;
  51
  52         wusbhc->gtk_index = wusb_key_index(0, WUSB_KEY_INDEX_TYPE_GTK,
  53                                            WUSB_KEY_INDEX_ORIGINATOR_HOST);
  54
  55         INIT_WORK(&wusbhc->gtk_rekey_done_work, wusbhc_gtk_rekey_done_work);
  56
  57         return 0;
  58 }
  59
  60
  61 /* Called when the HC is destroyed */
  62 void wusbhc_sec_destroy(struct wusbhc *wusbhc)
  63 {
  64 }
  65
  66
  67 /**
  68  * wusbhc_next_tkid - generate a new, currently unused, TKID
  69  * @wusbhc:   the WUSB host controller
  70  * @wusb_dev: the device whose PTK the TKID is for
  71  *            (or NULL for a TKID for a GTK)
  72  *
  73  * The generated TKID consist of two parts: the device's authenicated
  74  * address (or 0 or a GTK); and an incrementing number.  This ensures
  75  * that TKIDs cannot be shared between devices and by the time the
  76  * incrementing number wraps around the older TKIDs will no longer be
  77  * in use (a maximum of two keys may be active at any one time).
  78  */
  79 static u32 wusbhc_next_tkid(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
  80 {
  81         u32 *tkid;
  82         u32 addr;
  83
  84         if (wusb_dev == NULL) {
  85                 tkid = &wusbhc->gtk_tkid;
  86                 addr = 0;
  87         } else {
  88                 tkid = &wusb_port_by_idx(wusbhc, wusb_dev->port_idx)->ptk_tkid;
  89                 addr = wusb_dev->addr & 0x7f;
  90         }
  91
  92         *tkid = (addr << 8) | ((*tkid + 1) & 0xff);
  93
  94         return *tkid;
  95 }
  96
  97 static void wusbhc_generate_gtk(struct wusbhc *wusbhc)
  98 {
  99         const size_t key_size = sizeof(wusbhc->gtk.data);
 100         u32 tkid;
 101
 102         tkid = wusbhc_next_tkid(wusbhc, NULL);
 103
 104         wusbhc->gtk.descr.tTKID[0] = (tkid >>  0) & 0xff;
 105         wusbhc->gtk.descr.tTKID[1] = (tkid >>  8) & 0xff;
 106         wusbhc->gtk.descr.tTKID[2] = (tkid >> 16) & 0xff;
 107
 108         get_random_bytes(wusbhc->gtk.descr.bKeyData, key_size);
 109 }
 110
 111 /**
 112  * wusbhc_sec_start - start the security management process
 113  * @wusbhc: the WUSB host controller
 114  *
 115  * Generate and set an initial GTK on the host controller.
 116  *
 117  * Called when the HC is started.
 118  */
 119 int wusbhc_sec_start(struct wusbhc *wusbhc)
 120 {
 121         const size_t key_size = sizeof(wusbhc->gtk.data);
 122         int result;
 123
 124         wusbhc_generate_gtk(wusbhc);
 125
 126         result = wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid,
 127                                  &wusbhc->gtk.descr.bKeyData, key_size);
 128         if (result < 0)
 129                 dev_err(wusbhc->dev, "cannot set GTK for the host: %d\n",
 130                         result);
 131
 132         return result;
 133 }
 134
 135 /**
 136  * wusbhc_sec_stop - stop the security management process
 137  * @wusbhc: the WUSB host controller
 138  *
 139  * Wait for any pending GTK rekeys to stop.
 140  */
 141 void wusbhc_sec_stop(struct wusbhc *wusbhc)
 142 {
 143         cancel_work_sync(&wusbhc->gtk_rekey_done_work);
 144 }
 145
 146
 147 /** @returns encryption type name */
 148 const char *wusb_et_name(u8 x)
 149 {
 150         switch (x) {
 151         case USB_ENC_TYPE_UNSECURE:     return "unsecure";
 152         case USB_ENC_TYPE_WIRED:        return "wired";
 153         case USB_ENC_TYPE_CCM_1:        return "CCM-1";
 154         case USB_ENC_TYPE_RSA_1:        return "RSA-1";
 155         default:                        return "unknown";
 156         }
 157 }
 158 EXPORT_SYMBOL_GPL(wusb_et_name);
 159
 160 /*
 161  * Set the device encryption method
 162  *
 163  * We tell the device which encryption method to use; we do this when
 164  * setting up the device's security.
 165  */
 166 static int wusb_dev_set_encryption(struct usb_device *usb_dev, int value)
 167 {
 168         int result;
 169         struct device *dev = &usb_dev->dev;
 170         struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
 171
 172         if (value) {
 173                 value = wusb_dev->ccm1_etd.bEncryptionValue;
 174         } else {
 175                 /* FIXME: should be wusb_dev->etd[UNSECURE].bEncryptionValue */
 176                 value = 0;
 177         }
 178         /* Set device's */
 179         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 180                         USB_REQ_SET_ENCRYPTION,
 181                         USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 182                         value, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
 183         if (result < 0)
 184                 dev_err(dev, "Can't set device's WUSB encryption to "
 185                         "%s (value %d): %d\n",
 186                         wusb_et_name(wusb_dev->ccm1_etd.bEncryptionType),
 187                         wusb_dev->ccm1_etd.bEncryptionValue,  result);
 188         return result;
 189 }
 190
 191 /*
 192  * Set the GTK to be used by a device.
 193  *
 194  * The device must be authenticated.
 195  */
 196 static int wusb_dev_set_gtk(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 197 {
 198         struct usb_device *usb_dev = wusb_dev->usb_dev;
 199
 200         return usb_control_msg(
 201                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 202                 USB_REQ_SET_DESCRIPTOR,
 203                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 204                 USB_DT_KEY << 8 | wusbhc->gtk_index, 0,
 205                 &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
 206                 1000);
 207 }
 208
 209
 210 /* FIXME: prototype for adding security */
 211 int wusb_dev_sec_add(struct wusbhc *wusbhc,
 212                      struct usb_device *usb_dev, struct wusb_dev *wusb_dev)
 213 {
 214         int result, bytes, secd_size;
 215         struct device *dev = &usb_dev->dev;
 216         struct usb_security_descriptor secd;
 217         const struct usb_encryption_descriptor *etd, *ccm1_etd = NULL;
 218         void *secd_buf;
 219         const void *itr, *top;
 220         char buf[64];
 221
 222         d_fnstart(3, dev, "(usb_dev %p, wusb_dev %p)\n", usb_dev, wusb_dev);
 223         result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
 224                                     0, &secd, sizeof(secd));
 225         if (result < sizeof(secd)) {
 226                 dev_err(dev, "Can't read security descriptor or "
 227                         "not enough data: %d\n", result);
 228                 goto error_secd;
 229         }
 230         secd_size = le16_to_cpu(secd.wTotalLength);
 231         d_printf(5, dev, "got %d bytes of sec descriptor, total is %d\n",
 232                  result, secd_size);
 233         secd_buf = kmalloc(secd_size, GFP_KERNEL);
 234         if (secd_buf == NULL) {
 235                 dev_err(dev, "Can't allocate space for security descriptors\n");
 236                 goto error_secd_alloc;
 237         }
 238         result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
 239                                     0, secd_buf, secd_size);
 240         if (result < secd_size) {
 241                 dev_err(dev, "Can't read security descriptor or "
 242                         "not enough data: %d\n", result);
 243                 goto error_secd_all;
 244         }
 245         d_printf(5, dev, "got %d bytes of sec descriptors\n", result);
 246         bytes = 0;
 247         itr = secd_buf + sizeof(secd);
 248         top = secd_buf + result;
 249         while (itr < top) {
 250                 etd = itr;
 251                 if (top - itr < sizeof(*etd)) {
 252                         dev_err(dev, "BUG: bad device security descriptor; "
 253                                 "not enough data (%zu vs %zu bytes left)\n",
 254                                 top - itr, sizeof(*etd));
 255                         break;
 256                 }
 257                 if (etd->bLength < sizeof(*etd)) {
 258                         dev_err(dev, "BUG: bad device encryption descriptor; "
 259                                 "descriptor is too short "
 260                                 "(%u vs %zu needed)\n",
 261                                 etd->bLength, sizeof(*etd));
 262                         break;
 263                 }
 264                 itr += etd->bLength;
 265                 bytes += snprintf(buf + bytes, sizeof(buf) - bytes,
 266                                   "%s (0x%02x/%02x) ",
 267                                   wusb_et_name(etd->bEncryptionType),
 268                                   etd->bEncryptionValue, etd->bAuthKeyIndex);
 269                 if (etd->bEncryptionType == USB_ENC_TYPE_CCM_1)
 270                         ccm1_etd = etd;
 271         }
 272         /* This code only supports CCM1 as of now. */
 273         /* FIXME: user has to choose which sec mode to use?
 274          * In theory we want CCM */
 275         if (ccm1_etd == NULL) {
 276                 dev_err(dev, "WUSB device doesn't support CCM1 encryption, "
 277                         "can't use!\n");
 278                 result = -EINVAL;
 279                 goto error_no_ccm1;
 280         }
 281         wusb_dev->ccm1_etd = *ccm1_etd;
 282         dev_info(dev, "supported encryption: %s; using %s (0x%02x/%02x)\n",
 283                  buf, wusb_et_name(ccm1_etd->bEncryptionType),
 284                  ccm1_etd->bEncryptionValue, ccm1_etd->bAuthKeyIndex);
 285         result = 0;
 286         kfree(secd_buf);
 287 out:
 288         d_fnend(3, dev, "(usb_dev %p, wusb_dev %p) = %d\n",
 289                 usb_dev, wusb_dev, result);
 290         return result;
 291
 292
 293 error_no_ccm1:
 294 error_secd_all:
 295         kfree(secd_buf);
 296 error_secd_alloc:
 297 error_secd:
 298         goto out;
 299 }
 300
 301 void wusb_dev_sec_rm(struct wusb_dev *wusb_dev)
 302 {
 303         /* Nothing so far */
 304 }
 305
 306 static void hs_printk(unsigned level, struct device *dev,
 307                       struct usb_handshake *hs)
 308 {
 309         d_printf(level, dev,
 310                  "  bMessageNumber: %u\n"
 311                  "  bStatus:        %u\n"
 312                  "  tTKID:          %02x %02x %02x\n"
 313                  "  CDID:           %02x %02x %02x %02x %02x %02x %02x %02x\n"
 314                  "                  %02x %02x %02x %02x %02x %02x %02x %02x\n"
 315                  "  nonce:          %02x %02x %02x %02x %02x %02x %02x %02x\n"
 316                  "                  %02x %02x %02x %02x %02x %02x %02x %02x\n"
 317                  "  MIC:            %02x %02x %02x %02x %02x %02x %02x %02x\n",
 318                  hs->bMessageNumber, hs->bStatus,
 319                  hs->tTKID[2], hs->tTKID[1], hs->tTKID[0],
 320                  hs->CDID[0], hs->CDID[1], hs->CDID[2], hs->CDID[3],
 321                  hs->CDID[4], hs->CDID[5], hs->CDID[6], hs->CDID[7],
 322                  hs->CDID[8], hs->CDID[9], hs->CDID[10], hs->CDID[11],
 323                  hs->CDID[12], hs->CDID[13], hs->CDID[14], hs->CDID[15],
 324                  hs->nonce[0], hs->nonce[1], hs->nonce[2], hs->nonce[3],
 325                  hs->nonce[4], hs->nonce[5], hs->nonce[6], hs->nonce[7],
 326                  hs->nonce[8], hs->nonce[9], hs->nonce[10], hs->nonce[11],
 327                  hs->nonce[12], hs->nonce[13], hs->nonce[14], hs->nonce[15],
 328                  hs->MIC[0], hs->MIC[1], hs->MIC[2], hs->MIC[3],
 329                  hs->MIC[4], hs->MIC[5], hs->MIC[6], hs->MIC[7]);
 330 }
 331
 332 /**
 333  * Update the address of an unauthenticated WUSB device
 334  *
 335  * Once we have successfully authenticated, we take it to addr0 state
 336  * and then to a normal address.
 337  *
 338  * Before the device's address (as known by it) was usb_dev->devnum |
 339  * 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.
 340  */
 341 int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 342 {
 343         int result = -ENOMEM;
 344         struct usb_device *usb_dev = wusb_dev->usb_dev;
 345         struct device *dev = &usb_dev->dev;
 346         u8 new_address = wusb_dev->addr & 0x7F;
 347
 348         /* Set address 0 */
 349         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 350                                  USB_REQ_SET_ADDRESS, 0,
 351                                  0, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
 352         if (result < 0) {
 353                 dev_err(dev, "auth failed: can't set address 0: %d\n",
 354                         result);
 355                 goto error_addr0;
 356         }
 357         result = wusb_set_dev_addr(wusbhc, wusb_dev, 0);
 358         if (result < 0)
 359                 goto error_addr0;
 360         usb_ep0_reinit(usb_dev);
 361
 362         /* Set new (authenticated) address. */
 363         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 364                                  USB_REQ_SET_ADDRESS, 0,
 365                                  new_address, 0, NULL, 0,
 366                                  1000 /* FIXME: arbitrary */);
 367         if (result < 0) {
 368                 dev_err(dev, "auth failed: can't set address %u: %d\n",
 369                         new_address, result);
 370                 goto error_addr;
 371         }
 372         result = wusb_set_dev_addr(wusbhc, wusb_dev, new_address);
 373         if (result < 0)
 374                 goto error_addr;
 375         usb_ep0_reinit(usb_dev);
 376         usb_dev->authenticated = 1;
 377 error_addr:
 378 error_addr0:
 379         return result;
 380 }
 381
 382 /*
 383  *
 384  *
 385  */
 386 /* FIXME: split and cleanup */
 387 int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
 388                             struct wusb_ckhdid *ck)
 389 {
 390         int result = -ENOMEM;
 391         struct usb_device *usb_dev = wusb_dev->usb_dev;
 392         struct device *dev = &usb_dev->dev;
 393         u32 tkid;
 394         __le32 tkid_le;
 395         struct usb_handshake *hs;
 396         struct aes_ccm_nonce ccm_n;
 397         u8 mic[8];
 398         struct wusb_keydvt_in keydvt_in;
 399         struct wusb_keydvt_out keydvt_out;
 400
 401         hs = kzalloc(3*sizeof(hs[0]), GFP_KERNEL);
 402         if (hs == NULL) {
 403                 dev_err(dev, "can't allocate handshake data\n");
 404                 goto error_kzalloc;
 405         }
 406
 407         /* We need to turn encryption before beginning the 4way
 408          * hshake (WUSB1.0[.3.2.2]) */
 409         result = wusb_dev_set_encryption(usb_dev, 1);
 410         if (result < 0)
 411                 goto error_dev_set_encryption;
 412
 413         tkid = wusbhc_next_tkid(wusbhc, wusb_dev);
 414         tkid_le = cpu_to_le32(tkid);
 415
 416         hs[0].bMessageNumber = 1;
 417         hs[0].bStatus = 0;
 418         memcpy(hs[0].tTKID, &tkid_le, sizeof(hs[0].tTKID));
 419         hs[0].bReserved = 0;
 420         memcpy(hs[0].CDID, &wusb_dev->cdid, sizeof(hs[0].CDID));
 421         get_random_bytes(&hs[0].nonce, sizeof(hs[0].nonce));
 422         memset(hs[0].MIC, 0, sizeof(hs[0].MIC));        /* Per WUSB1.0[T7-22] */
 423
 424         d_printf(1, dev, "I: sending hs1:\n");
 425         hs_printk(2, dev, &hs[0]);
 426
 427         result = usb_control_msg(
 428                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 429                 USB_REQ_SET_HANDSHAKE,
 430                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 431                 1, 0, &hs[0], sizeof(hs[0]), 1000 /* FIXME: arbitrary */);
 432         if (result < 0) {
 433                 dev_err(dev, "Handshake1: request failed: %d\n", result);
 434                 goto error_hs1;
 435         }
 436
 437         /* Handshake 2, from the device -- need to verify fields */
 438         result = usb_control_msg(
 439                 usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 440                 USB_REQ_GET_HANDSHAKE,
 441                 USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 442                 2, 0, &hs[1], sizeof(hs[1]), 1000 /* FIXME: arbitrary */);
 443         if (result < 0) {
 444                 dev_err(dev, "Handshake2: request failed: %d\n", result);
 445                 goto error_hs2;
 446         }
 447         d_printf(1, dev, "got HS2:\n");
 448         hs_printk(2, dev, &hs[1]);
 449
 450         result = -EINVAL;
 451         if (hs[1].bMessageNumber != 2) {
 452                 dev_err(dev, "Handshake2 failed: bad message number %u\n",
 453                         hs[1].bMessageNumber);
 454                 goto error_hs2;
 455         }
 456         if (hs[1].bStatus != 0) {
 457                 dev_err(dev, "Handshake2 failed: bad status %u\n",
 458                         hs[1].bStatus);
 459                 goto error_hs2;
 460         }
 461         if (memcmp(hs[0].tTKID, hs[1].tTKID, sizeof(hs[0].tTKID))) {
 462                 dev_err(dev, "Handshake2 failed: TKID mismatch "
 463                         "(#1 0x%02x%02x%02x vs #2 0x%02x%02x%02x)\n",
 464                         hs[0].tTKID[0], hs[0].tTKID[1], hs[0].tTKID[2],
 465                         hs[1].tTKID[0], hs[1].tTKID[1], hs[1].tTKID[2]);
 466                 goto error_hs2;
 467         }
 468         if (memcmp(hs[0].CDID, hs[1].CDID, sizeof(hs[0].CDID))) {
 469                 dev_err(dev, "Handshake2 failed: CDID mismatch\n");
 470                 goto error_hs2;
 471         }
 472
 473         /* Setup the CCM nonce */
 474         memset(&ccm_n.sfn, 0, sizeof(ccm_n.sfn));       /* Per WUSB1.0[6.5.2] */
 475         memcpy(ccm_n.tkid, &tkid_le, sizeof(ccm_n.tkid));
 476         ccm_n.src_addr = wusbhc->uwb_rc->uwb_dev.dev_addr;
 477         ccm_n.dest_addr.data[0] = wusb_dev->addr;
 478         ccm_n.dest_addr.data[1] = 0;
 479
 480         /* Derive the KCK and PTK from CK, the CCM, H and D nonces */
 481         memcpy(keydvt_in.hnonce, hs[0].nonce, sizeof(keydvt_in.hnonce));
 482         memcpy(keydvt_in.dnonce, hs[1].nonce, sizeof(keydvt_in.dnonce));
 483         result = wusb_key_derive(&keydvt_out, ck->data, &ccm_n, &keydvt_in);
 484         if (result < 0) {
 485                 dev_err(dev, "Handshake2 failed: cannot derive keys: %d\n",
 486                         result);
 487                 goto error_hs2;
 488         }
 489         d_printf(2, dev, "KCK:\n");
 490         d_dump(2, dev, keydvt_out.kck, sizeof(keydvt_out.kck));
 491         d_printf(2, dev, "PTK:\n");
 492         d_dump(2, dev, keydvt_out.ptk, sizeof(keydvt_out.ptk));
 493
 494         /* Compute MIC and verify it */
 495         result = wusb_oob_mic(mic, keydvt_out.kck, &ccm_n, &hs[1]);
 496         if (result < 0) {
 497                 dev_err(dev, "Handshake2 failed: cannot compute MIC: %d\n",
 498                         result);
 499                 goto error_hs2;
 500         }
 501
 502         d_printf(2, dev, "MIC:\n");
 503         d_dump(2, dev, mic, sizeof(mic));
 504         if (memcmp(hs[1].MIC, mic, sizeof(hs[1].MIC))) {
 505                 dev_err(dev, "Handshake2 failed: MIC mismatch\n");
 506                 goto error_hs2;
 507         }
 508
 509         /* Send Handshake3 */
 510         hs[2].bMessageNumber = 3;
 511         hs[2].bStatus = 0;
 512         memcpy(hs[2].tTKID, &tkid_le, sizeof(hs[2].tTKID));
 513         hs[2].bReserved = 0;
 514         memcpy(hs[2].CDID, &wusb_dev->cdid, sizeof(hs[2].CDID));
 515         memcpy(hs[2].nonce, hs[0].nonce, sizeof(hs[2].nonce));
 516         result = wusb_oob_mic(hs[2].MIC, keydvt_out.kck, &ccm_n, &hs[2]);
 517         if (result < 0) {
 518                 dev_err(dev, "Handshake3 failed: cannot compute MIC: %d\n",
 519                         result);
 520                 goto error_hs2;
 521         }
 522
 523         d_printf(1, dev, "I: sending hs3:\n");
 524         hs_printk(2, dev, &hs[2]);
 525
 526         result = usb_control_msg(
 527                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 528                 USB_REQ_SET_HANDSHAKE,
 529                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 530                 3, 0, &hs[2], sizeof(hs[2]), 1000 /* FIXME: arbitrary */);
 531         if (result < 0) {
 532                 dev_err(dev, "Handshake3: request failed: %d\n", result);
 533                 goto error_hs3;
 534         }
 535
 536         d_printf(1, dev, "I: turning on encryption on host for device\n");
 537         d_dump(2, dev, keydvt_out.ptk, sizeof(keydvt_out.ptk));
 538         result = wusbhc->set_ptk(wusbhc, wusb_dev->port_idx, tkid,
 539                                  keydvt_out.ptk, sizeof(keydvt_out.ptk));
 540         if (result < 0)
 541                 goto error_wusbhc_set_ptk;
 542
 543         d_printf(1, dev, "I: setting a GTK\n");
 544         result = wusb_dev_set_gtk(wusbhc, wusb_dev);
 545         if (result < 0) {
 546                 dev_err(dev, "Set GTK for device: request failed: %d\n",
 547                         result);
 548                 goto error_wusbhc_set_gtk;
 549         }
 550
 551         /* Update the device's address from unauth to auth */
 552         if (usb_dev->authenticated == 0) {
 553                 d_printf(1, dev, "I: updating addres to auth from non-auth\n");
 554                 result = wusb_dev_update_address(wusbhc, wusb_dev);
 555                 if (result < 0)
 556                         goto error_dev_update_address;
 557         }
 558         result = 0;
 559         d_printf(1, dev, "I: 4way handshke done, device authenticated\n");
 560
 561 error_dev_update_address:
 562 error_wusbhc_set_gtk:
 563 error_wusbhc_set_ptk:
 564 error_hs3:
 565 error_hs2:
 566 error_hs1:
 567         memset(hs, 0, 3*sizeof(hs[0]));
 568         memset(&keydvt_out, 0, sizeof(keydvt_out));
 569         memset(&keydvt_in, 0, sizeof(keydvt_in));
 570         memset(&ccm_n, 0, sizeof(ccm_n));
 571         memset(mic, 0, sizeof(mic));
 572         if (result < 0) {
 573                 /* error path */
 574                 wusb_dev_set_encryption(usb_dev, 0);
 575         }
 576 error_dev_set_encryption:
 577         kfree(hs);
 578 error_kzalloc:
 579         return result;
 580 }
 581
 582 /*
 583  * Once all connected and authenticated devices have received the new
 584  * GTK, switch the host to using it.
 585  */
 586 static void wusbhc_gtk_rekey_done_work(struct work_struct *work)
 587 {
 588         struct wusbhc *wusbhc = container_of(work, struct wusbhc, gtk_rekey_done_work);
 589         size_t key_size = sizeof(wusbhc->gtk.data);
 590
 591         mutex_lock(&wusbhc->mutex);
 592
 593         if (--wusbhc->pending_set_gtks == 0)
 594                 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
 595
 596         mutex_unlock(&wusbhc->mutex);
 597 }
 598
 599 static void wusbhc_set_gtk_callback(struct urb *urb)
 600 {
 601         struct wusbhc *wusbhc = urb->context;
 602
 603         queue_work(wusbd, &wusbhc->gtk_rekey_done_work);
 604 }
 605
 606 /**
 607  * wusbhc_gtk_rekey - generate and distribute a new GTK
 608  * @wusbhc: the WUSB host controller
 609  *
 610  * Generate a new GTK and distribute it to all connected and
 611  * authenticated devices.  When all devices have the new GTK, the host
 612  * starts using it.
 613  *
 614  * This must be called after every device disconnect (see [WUSB]
 615  * section 6.2.11.2).
 616  */
 617 void wusbhc_gtk_rekey(struct wusbhc *wusbhc)
 618 {
 619         static const size_t key_size = sizeof(wusbhc->gtk.data);
 620         int p;
 621
 622         wusbhc_generate_gtk(wusbhc);
 623
 624         for (p = 0; p < wusbhc->ports_max; p++) {
 625                 struct wusb_dev *wusb_dev;
 626
 627                 wusb_dev = wusbhc->port[p].wusb_dev;
 628                 if (!wusb_dev || !wusb_dev->usb_dev | !wusb_dev->usb_dev->authenticated)
 629                         continue;
 630
 631                 usb_fill_control_urb(wusb_dev->set_gtk_urb, wusb_dev->usb_dev,
 632                                      usb_sndctrlpipe(wusb_dev->usb_dev, 0),
 633                                      (void *)wusb_dev->set_gtk_req,
 634                                      &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
 635                                      wusbhc_set_gtk_callback, wusbhc);
 636                 if (usb_submit_urb(wusb_dev->set_gtk_urb, GFP_KERNEL) == 0)
 637                         wusbhc->pending_set_gtks++;
 638         }
 639         if (wusbhc->pending_set_gtks == 0)
 640                 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
 641 }