u2f.c (10433B)
1 /* 2 * U2F USB device. 3 * 4 * Copyright (c) 2020 César Belley <cesar.belley@lse.epita.fr> 5 * Written by César Belley <cesar.belley@lse.epita.fr> 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 * THE SOFTWARE. 24 */ 25 26 #include "qemu/osdep.h" 27 #include "qemu/module.h" 28 #include "qapi/error.h" 29 #include "hw/usb.h" 30 #include "hw/usb/hid.h" 31 #include "migration/vmstate.h" 32 #include "desc.h" 33 34 #include "u2f.h" 35 36 /* U2F key Vendor / Product */ 37 #define U2F_KEY_VENDOR_NUM 0x46f4 /* CRC16() of "QEMU" */ 38 #define U2F_KEY_PRODUCT_NUM 0x0005 39 40 enum { 41 STR_MANUFACTURER = 1, 42 STR_PRODUCT, 43 STR_SERIALNUMBER, 44 STR_CONFIG, 45 STR_INTERFACE 46 }; 47 48 static const USBDescStrings desc_strings = { 49 [STR_MANUFACTURER] = "QEMU", 50 [STR_PRODUCT] = "U2F USB key", 51 [STR_SERIALNUMBER] = "0", 52 [STR_CONFIG] = "U2F key config", 53 [STR_INTERFACE] = "U2F key interface" 54 }; 55 56 static const USBDescIface desc_iface_u2f_key = { 57 .bInterfaceNumber = 0, 58 .bNumEndpoints = 2, 59 .bInterfaceClass = USB_CLASS_HID, 60 .bInterfaceSubClass = 0x0, 61 .bInterfaceProtocol = 0x0, 62 .ndesc = 1, 63 .descs = (USBDescOther[]) { 64 { 65 /* HID descriptor */ 66 .data = (uint8_t[]) { 67 0x09, /* u8 bLength */ 68 USB_DT_HID, /* u8 bDescriptorType */ 69 0x10, 0x01, /* u16 HID_class */ 70 0x00, /* u8 country_code */ 71 0x01, /* u8 num_descriptors */ 72 USB_DT_REPORT, /* u8 type: Report */ 73 0x22, 0, /* u16 len */ 74 }, 75 }, 76 }, 77 .eps = (USBDescEndpoint[]) { 78 { 79 .bEndpointAddress = USB_DIR_IN | 0x01, 80 .bmAttributes = USB_ENDPOINT_XFER_INT, 81 .wMaxPacketSize = U2FHID_PACKET_SIZE, 82 .bInterval = 0x05, 83 }, { 84 .bEndpointAddress = USB_DIR_OUT | 0x01, 85 .bmAttributes = USB_ENDPOINT_XFER_INT, 86 .wMaxPacketSize = U2FHID_PACKET_SIZE, 87 .bInterval = 0x05, 88 }, 89 }, 90 91 }; 92 93 static const USBDescDevice desc_device_u2f_key = { 94 .bcdUSB = 0x0100, 95 .bMaxPacketSize0 = U2FHID_PACKET_SIZE, 96 .bNumConfigurations = 1, 97 .confs = (USBDescConfig[]) { 98 { 99 .bNumInterfaces = 1, 100 .bConfigurationValue = 1, 101 .iConfiguration = STR_CONFIG, 102 .bmAttributes = USB_CFG_ATT_ONE, 103 .bMaxPower = 15, 104 .nif = 1, 105 .ifs = &desc_iface_u2f_key, 106 }, 107 }, 108 }; 109 110 static const USBDesc desc_u2f_key = { 111 .id = { 112 .idVendor = U2F_KEY_VENDOR_NUM, 113 .idProduct = U2F_KEY_PRODUCT_NUM, 114 .bcdDevice = 0, 115 .iManufacturer = STR_MANUFACTURER, 116 .iProduct = STR_PRODUCT, 117 .iSerialNumber = STR_SERIALNUMBER, 118 }, 119 .full = &desc_device_u2f_key, 120 .str = desc_strings, 121 }; 122 123 static const uint8_t u2f_key_hid_report_desc[] = { 124 0x06, 0xd0, 0xf1, /* Usage Page (FIDO) */ 125 0x09, 0x01, /* Usage (FIDO) */ 126 0xa1, 0x01, /* Collection (HID Application) */ 127 0x09, 0x20, /* Usage (FIDO data in) */ 128 0x15, 0x00, /* Logical Minimum (0) */ 129 0x26, 0xFF, 0x00, /* Logical Maximum (0xff) */ 130 0x75, 0x08, /* Report Size (8) */ 131 0x95, 0x40, /* Report Count (0x40) */ 132 0x81, 0x02, /* Input (Data, Variable, Absolute) */ 133 0x09, 0x21, /* Usage (FIDO data out) */ 134 0x15, 0x00, /* Logical Minimum (0) */ 135 0x26, 0xFF, 0x00, /* Logical Maximum (0xFF) */ 136 0x75, 0x08, /* Report Size (8) */ 137 0x95, 0x40, /* Report Count (0x40) */ 138 0x91, 0x02, /* Output (Data, Variable, Absolute) */ 139 0xC0 /* End Collection */ 140 }; 141 142 static void u2f_key_reset(U2FKeyState *key) 143 { 144 key->pending_in_start = 0; 145 key->pending_in_end = 0; 146 key->pending_in_num = 0; 147 } 148 149 static void u2f_key_handle_reset(USBDevice *dev) 150 { 151 U2FKeyState *key = U2F_KEY(dev); 152 153 u2f_key_reset(key); 154 } 155 156 static void u2f_key_handle_control(USBDevice *dev, USBPacket *p, 157 int request, int value, int index, int length, uint8_t *data) 158 { 159 U2FKeyState *key = U2F_KEY(dev); 160 int ret; 161 162 ret = usb_desc_handle_control(dev, p, request, value, index, length, data); 163 if (ret >= 0) { 164 return; 165 } 166 167 switch (request) { 168 case InterfaceRequest | USB_REQ_GET_DESCRIPTOR: 169 switch (value >> 8) { 170 case 0x22: 171 memcpy(data, u2f_key_hid_report_desc, 172 sizeof(u2f_key_hid_report_desc)); 173 p->actual_length = sizeof(u2f_key_hid_report_desc); 174 break; 175 default: 176 goto fail; 177 } 178 break; 179 case HID_GET_IDLE: 180 data[0] = key->idle; 181 p->actual_length = 1; 182 break; 183 case HID_SET_IDLE: 184 key->idle = (uint8_t)(value >> 8); 185 break; 186 default: 187 fail: 188 p->status = USB_RET_STALL; 189 break; 190 } 191 192 } 193 194 static void u2f_key_recv_from_guest(U2FKeyState *key, USBPacket *p) 195 { 196 U2FKeyClass *kc = U2F_KEY_GET_CLASS(key); 197 uint8_t packet[U2FHID_PACKET_SIZE]; 198 199 if (kc->recv_from_guest == NULL || p->iov.size != U2FHID_PACKET_SIZE) { 200 return; 201 } 202 203 usb_packet_copy(p, packet, p->iov.size); 204 kc->recv_from_guest(key, packet); 205 } 206 207 static void u2f_pending_in_add(U2FKeyState *key, 208 const uint8_t packet[U2FHID_PACKET_SIZE]) 209 { 210 uint8_t index; 211 212 if (key->pending_in_num >= U2FHID_PENDING_IN_NUM) { 213 return; 214 } 215 216 index = key->pending_in_end; 217 key->pending_in_end = (index + 1) % U2FHID_PENDING_IN_NUM; 218 ++key->pending_in_num; 219 220 memcpy(key->pending_in[index], packet, U2FHID_PACKET_SIZE); 221 } 222 223 static uint8_t *u2f_pending_in_get(U2FKeyState *key) 224 { 225 uint8_t index; 226 227 if (key->pending_in_num == 0) { 228 return NULL; 229 } 230 231 index = key->pending_in_start; 232 key->pending_in_start = (index + 1) % U2FHID_PENDING_IN_NUM; 233 --key->pending_in_num; 234 235 return key->pending_in[index]; 236 } 237 238 static void u2f_key_handle_data(USBDevice *dev, USBPacket *p) 239 { 240 U2FKeyState *key = U2F_KEY(dev); 241 uint8_t *packet_in; 242 243 /* Endpoint number check */ 244 if (p->ep->nr != 1) { 245 p->status = USB_RET_STALL; 246 return; 247 } 248 249 switch (p->pid) { 250 case USB_TOKEN_OUT: 251 u2f_key_recv_from_guest(key, p); 252 break; 253 case USB_TOKEN_IN: 254 packet_in = u2f_pending_in_get(key); 255 if (packet_in == NULL) { 256 p->status = USB_RET_NAK; 257 return; 258 } 259 usb_packet_copy(p, packet_in, U2FHID_PACKET_SIZE); 260 break; 261 default: 262 p->status = USB_RET_STALL; 263 break; 264 } 265 } 266 267 void u2f_send_to_guest(U2FKeyState *key, 268 const uint8_t packet[U2FHID_PACKET_SIZE]) 269 { 270 u2f_pending_in_add(key, packet); 271 usb_wakeup(key->ep, 0); 272 } 273 274 static void u2f_key_unrealize(USBDevice *dev) 275 { 276 U2FKeyState *key = U2F_KEY(dev); 277 U2FKeyClass *kc = U2F_KEY_GET_CLASS(key); 278 279 if (kc->unrealize != NULL) { 280 kc->unrealize(key); 281 } 282 } 283 284 static void u2f_key_realize(USBDevice *dev, Error **errp) 285 { 286 U2FKeyState *key = U2F_KEY(dev); 287 U2FKeyClass *kc = U2F_KEY_GET_CLASS(key); 288 Error *local_err = NULL; 289 290 usb_desc_create_serial(dev); 291 usb_desc_init(dev); 292 u2f_key_reset(key); 293 294 if (kc->realize != NULL) { 295 kc->realize(key, &local_err); 296 if (local_err != NULL) { 297 error_propagate(errp, local_err); 298 return; 299 } 300 } 301 key->ep = usb_ep_get(dev, USB_TOKEN_IN, 1); 302 } 303 304 const VMStateDescription vmstate_u2f_key = { 305 .name = "u2f-key", 306 .version_id = 1, 307 .minimum_version_id = 1, 308 .fields = (VMStateField[]) { 309 VMSTATE_USB_DEVICE(dev, U2FKeyState), 310 VMSTATE_UINT8(idle, U2FKeyState), 311 VMSTATE_UINT8_2DARRAY(pending_in, U2FKeyState, 312 U2FHID_PENDING_IN_NUM, U2FHID_PACKET_SIZE), 313 VMSTATE_UINT8(pending_in_start, U2FKeyState), 314 VMSTATE_UINT8(pending_in_end, U2FKeyState), 315 VMSTATE_UINT8(pending_in_num, U2FKeyState), 316 VMSTATE_END_OF_LIST() 317 } 318 }; 319 320 static void u2f_key_class_init(ObjectClass *klass, void *data) 321 { 322 DeviceClass *dc = DEVICE_CLASS(klass); 323 USBDeviceClass *uc = USB_DEVICE_CLASS(klass); 324 325 uc->product_desc = "QEMU U2F USB key"; 326 uc->usb_desc = &desc_u2f_key; 327 uc->handle_reset = u2f_key_handle_reset; 328 uc->handle_control = u2f_key_handle_control; 329 uc->handle_data = u2f_key_handle_data; 330 uc->handle_attach = usb_desc_attach; 331 uc->realize = u2f_key_realize; 332 uc->unrealize = u2f_key_unrealize; 333 dc->desc = "QEMU U2F key"; 334 dc->vmsd = &vmstate_u2f_key; 335 } 336 337 static const TypeInfo u2f_key_info = { 338 .name = TYPE_U2F_KEY, 339 .parent = TYPE_USB_DEVICE, 340 .instance_size = sizeof(U2FKeyState), 341 .abstract = true, 342 .class_size = sizeof(U2FKeyClass), 343 .class_init = u2f_key_class_init, 344 }; 345 346 static void u2f_key_register_types(void) 347 { 348 type_register_static(&u2f_key_info); 349 } 350 351 type_init(u2f_key_register_types)