// bad if this gets interrupted int8_t u2f_new_keypair(uint8_t * handle, uint8_t * pubkey) { struct atecc_response res; struct key_handle k; uint8_t keyslot = key_store.num_issued; if (keyslot > U2F_NUM_KEYS-1) { //app_wink(U2F_DEFAULT_COLOR_WINK_OUT_OF_SPACE); return -1; } //watchdog(); atecc_send_recv(ATECC_CMD_GENKEY, ATECC_GENKEY_PRIVATE, keyslot, NULL, 0, appdata.tmp, sizeof(appdata.tmp), &res); memmove(pubkey, res.buf, 64); eeprom_read(U2F_KEY_ADDR(keyslot), (uint8_t* )&k, U2F_KEY_HANDLE_SIZE); if (k.index-1 != keyslot) { k.index = keyslot; set_app_error(ERROR_BAD_KEY_STORE); } memmove(handle, &k, U2F_KEY_HANDLE_SIZE); key_store.num_issued++; flush_key_store(); return 0; }
static int buffer_request(struct u2f_hid_msg* req) { if (hid_layer.bytes_buffered + U2FHID_CONT_PAYLOAD_SIZE > BUFFER_SIZE) { set_app_error(ERROR_HID_BUFFER_FULL); stamp_error(req->cid, ERR_OTHER); return -1; } memmove(hid_layer.buffer + hid_layer.bytes_buffered, req->pkt.cont.payload, U2FHID_CONT_PAYLOAD_SIZE); hid_layer.bytes_buffered += U2FHID_CONT_PAYLOAD_SIZE; return 0; }
// Buffers data to a 64 byte buffer before writing it while // handling U2F HID sequencing void u2f_hid_writeback(uint8_t * payload, uint16_t len) { struct u2f_hid_msg * r = (struct u2f_hid_response *) _hid_pkt; _hid_in_session = 1; if (_hid_offset == 0) { r->cid = hid_layer.current_cid; if (!_hid_seq) { r->pkt.init.cmd = hid_layer.current_cmd; U2FHID_SET_LEN(r, hid_layer.res_len); _hid_offset = 7; } else { r->pkt.cont.seq = _hid_seq - 1; _hid_offset = 5; if (_hid_seq-1 > 127) { set_app_error(ERROR_SEQ_EXCEEDED); return; } } } while(len--) { _hid_pkt[_hid_offset++] = *payload++; hid_layer.bytes_written++; if (_hid_offset == HID_PACKET_SIZE) { _hid_offset = 0; _hid_seq++; usb_write(_hid_pkt, HID_PACKET_SIZE); memset(_hid_pkt, 0, HID_PACKET_SIZE); if (len) { u2f_hid_writeback(payload, len); return; } else break; } } }
static void hid_u2f_parse(struct u2f_hid_msg* req) { uint16_t len = 0; uint8_t secs; struct u2f_hid_init_response * init_res = appdata.tmp; switch(hid_layer.current_cmd) { case U2FHID_INIT: if (U2FHID_LEN(req) != 8) { stamp_error(hid_layer.current_cid, ERR_INVALID_LEN); goto fail; } u2f_hid_set_len(17); if (hid_layer.current_cid == 0) { u2f_prints("out of cid's\r\n"); set_app_error(ERROR_OUT_OF_CIDS); goto fail; } init_res->cid = get_new_cid(); init_res->version_id = 1; init_res->version_major = 1; init_res->version_minor = 0; init_res->version_build = 0; init_res->cflags = 0; // write back the same data nonce u2f_hid_writeback(req->pkt.init.payload, 8); u2f_hid_writeback((uint8_t *)init_res, 9); u2f_hid_flush(); hid_layer.current_cid = init_res->cid; break; case U2FHID_MSG: if (U2FHID_LEN(req) < 4) { stamp_error(hid_layer.current_cid, ERR_INVALID_LEN); u2f_prints("invalid len msg\r\n"); goto fail; } // buffer 2 payloads (120 bytes) to get full U2F message // assuming key handle is < 45 bytes // 7 bytes for apdu header // 7 + 66 bytes + key handle for authenticate message // 7 + 64 for register message if (hid_layer.bytes_buffered == 0) { start_buffering(req); if (hid_layer.bytes_buffered >= U2FHID_LEN(req)) { u2f_request((struct u2f_request_apdu *)hid_layer.buffer); } } else { buffer_request(req); if (hid_layer.bytes_buffered >= hid_layer.req_len) { u2f_request((struct u2f_request_apdu *)hid_layer.buffer); } } break; case U2FHID_PING: //u2f_prints("U2F PING\r\n"); if (!u2f_hid_busy()) { u2f_hid_set_len(U2FHID_LEN(req)); u2f_hid_writeback(req->pkt.init.payload, MIN(hid_layer.res_len, U2FHID_INIT_PAYLOAD_SIZE)); } else { u2f_hid_writeback(req->pkt.cont.payload, MIN(hid_layer.res_len - hid_layer.bytes_written, U2FHID_CONT_PAYLOAD_SIZE)); } if (hid_layer.res_len == hid_layer.bytes_written) u2f_hid_flush(); break; case U2FHID_WINK: if (U2FHID_LEN(req) != 0) { // this one is safe stamp_error(hid_layer.current_cid, ERR_INVALID_LEN); } u2f_hid_set_len(0); u2f_hid_writeback(NULL, 0); u2f_hid_flush(); app_wink(U2F_COLOR_WINK); break; case U2FHID_LOCK: secs = req->pkt.init.payload[0]; if (secs > 10) { stamp_error(hid_layer.current_cid, ERR_INVALID_PAR); } else { _hid_lock_cid = hid_layer.current_cid; _hid_lockt = get_ms() + 1000 * secs; u2f_hid_set_len(0); u2f_hid_writeback(NULL, 0); u2f_hid_flush(); } break; default: set_app_error(ERROR_HID_INVALID_CMD); stamp_error(hid_layer.current_cid, ERR_INVALID_CMD); } return; fail: u2f_prints("U2F HID FAIL\r\n"); return; }
// return 0 if finished // return 1 if expecting more cont packets static uint8_t hid_u2f_parse(struct u2f_hid_msg* req) { uint16_t len = 0; uint8_t secs; struct u2f_hid_init_response * init_res = appdata.tmp; switch(hid_layer.current_cmd) { case U2FHID_INIT: if (U2FHID_LEN(req) != 8) { stamp_error(hid_layer.current_cid, ERR_INVALID_LEN); goto fail; } u2f_hid_set_len(17); if (hid_layer.current_cid == U2FHID_BROADCAST) { if (hid_layer.current_cid == 0) { set_app_error(ERROR_OUT_OF_CIDS); goto fail; } init_res->cid = get_new_cid(); } else { init_res->cid = hid_layer.current_cid; } init_res->version_id = 2; init_res->version_major = 2; init_res->version_minor = 0; init_res->version_build = 0; #ifdef U2F_SUPPORT_WINK && CAPABILITY_LOCK init_res->cflags = CAPABILITY_WINK | CAPABILITY_LOCK; #elif U2F_SUPPORT_WINK init_res->cflags = CAPABILITY_WINK; #elif CAPABILITY_LOCK init_res->cflags = CAPABILITY_LOCK; #else init_res->cflags = 0; #endif // write back the same data nonce u2f_hid_writeback(req->pkt.init.payload, 8); u2f_hid_writeback((uint8_t *)init_res, 9); u2f_hid_flush(); hid_layer.current_cid = init_res->cid; break; case U2FHID_MSG: if (U2FHID_LEN(req) < 4) { stamp_error(hid_layer.current_cid, ERR_INVALID_LEN); goto fail; } // buffer 2 payloads (120 bytes) to get full U2F message // assuming key handle is < 45 bytes // 7 bytes for apdu header // 7 + 66 bytes + key handle for authenticate message // 7 + 64 for register message if (hid_layer.bytes_buffered == 0) { start_buffering(req); if (hid_layer.bytes_buffered >= U2FHID_LEN(req)) { u2f_request((struct u2f_request_apdu *)hid_layer.buffer); } } else { buffer_request(req); if (hid_layer.bytes_buffered >= hid_layer.req_len) { u2f_request((struct u2f_request_apdu *)hid_layer.buffer); } } break; case U2FHID_PING: if (hid_layer.bytes_buffered == 0) { start_buffering(req); u2f_hid_set_len(U2FHID_LEN(req)); if (hid_layer.bytes_buffered >= U2FHID_LEN(req)) { u2f_hid_writeback(hid_layer.buffer,hid_layer.bytes_buffered); u2f_hid_flush(); } else { return 1; } } else { if (hid_layer.bytes_buffered + U2FHID_CONT_PAYLOAD_SIZE > BUFFER_SIZE) { u2f_hid_writeback(hid_layer.buffer,hid_layer.bytes_buffered); hid_layer.bytes_buffered = 0; } buffer_request(req); if (hid_layer.bytes_buffered + hid_layer.bytes_written >= hid_layer.req_len) { u2f_hid_writeback(hid_layer.buffer,hid_layer.bytes_buffered); u2f_hid_flush(); } else { return 1; } } break; #ifdef U2F_SUPPORT_WINK case U2FHID_WINK: if (U2FHID_LEN(req) != 0) { // this one is safe stamp_error(hid_layer.current_cid, ERR_INVALID_LEN); } u2f_hid_set_len(0); u2f_hid_writeback(NULL, 0); u2f_hid_flush(); app_wink(U2F_COLOR_WINK); break; #endif #ifdef U2F_SUPPORT_HID_LOCK case U2FHID_LOCK: secs = req->pkt.init.payload[0]; if (secs > 10) { stamp_error(hid_layer.current_cid, ERR_INVALID_PAR); } else { if (secs) { _hid_lock_cid = hid_layer.current_cid; _hid_lockt = get_ms() + 1000 * secs; } else { _hid_lockt = get_ms(); _hid_lock_cid = 0; } hid_layer.current_cmd = U2FHID_LOCK; u2f_hid_set_len(0); u2f_hid_writeback(NULL, 0); u2f_hid_flush(); } break; #endif default: set_app_error(ERROR_HID_INVALID_CMD); stamp_error(hid_layer.current_cid, ERR_INVALID_CMD); u2f_printb("invalid cmd: ",1,hid_layer.current_cmd); } return u2f_hid_busy(); fail: u2f_prints("U2F HID FAIL\r\n"); return 0; }