| /* |
| * NDEF(NFC Data Exchange Format) routines for Wi-Fi Protected Setup |
| * Reference is "NFCForum-TS-NDEF_1.0 2006-07-24". |
| * Copyright (c) 2009-2012, Masashi Honma <masashi.honma@gmail.com> |
| * |
| * This software may be distributed under the terms of the BSD license. |
| * See README for more details. |
| */ |
| |
| #include "includes.h" |
| #include "common.h" |
| #include "wps/wps.h" |
| |
| #define FLAG_MESSAGE_BEGIN (1 << 7) |
| #define FLAG_MESSAGE_END (1 << 6) |
| #define FLAG_CHUNK (1 << 5) |
| #define FLAG_SHORT_RECORD (1 << 4) |
| #define FLAG_ID_LENGTH_PRESENT (1 << 3) |
| #define FLAG_TNF_NFC_FORUM (0x01) |
| #define FLAG_TNF_RFC2046 (0x02) |
| |
| struct ndef_record { |
| const u8 *type; |
| const u8 *id; |
| const u8 *payload; |
| u8 type_length; |
| u8 id_length; |
| u32 payload_length; |
| u32 total_length; |
| }; |
| |
| static char wifi_handover_type[] = "application/vnd.wfa.wsc"; |
| |
| static int ndef_parse_record(const u8 *data, u32 size, |
| struct ndef_record *record) |
| { |
| const u8 *pos = data + 1; |
| |
| if (size < 2) |
| return -1; |
| record->type_length = *pos++; |
| if (data[0] & FLAG_SHORT_RECORD) { |
| if (size < 3) |
| return -1; |
| record->payload_length = *pos++; |
| } else { |
| if (size < 6) |
| return -1; |
| record->payload_length = ntohl(*(u32 *)pos); |
| pos += sizeof(u32); |
| } |
| |
| if (data[0] & FLAG_ID_LENGTH_PRESENT) { |
| if ((int) size < pos - data + 1) |
| return -1; |
| record->id_length = *pos++; |
| } else |
| record->id_length = 0; |
| |
| record->type = record->type_length == 0 ? NULL : pos; |
| pos += record->type_length; |
| |
| record->id = record->id_length == 0 ? NULL : pos; |
| pos += record->id_length; |
| |
| record->payload = record->payload_length == 0 ? NULL : pos; |
| pos += record->payload_length; |
| |
| record->total_length = pos - data; |
| if (record->total_length > size) |
| return -1; |
| return 0; |
| } |
| |
| |
| static struct wpabuf * ndef_parse_records(const struct wpabuf *buf, |
| int (*filter)(struct ndef_record *)) |
| { |
| struct ndef_record record; |
| int len = wpabuf_len(buf); |
| const u8 *data = wpabuf_head(buf); |
| |
| while (len > 0) { |
| if (ndef_parse_record(data, len, &record) < 0) { |
| wpa_printf(MSG_ERROR, "NDEF : Failed to parse"); |
| return NULL; |
| } |
| if (filter == NULL || filter(&record)) |
| return wpabuf_alloc_copy(record.payload, |
| record.payload_length); |
| data += record.total_length; |
| len -= record.total_length; |
| } |
| wpa_printf(MSG_ERROR, "NDEF : Record not found"); |
| return NULL; |
| } |
| |
| |
| static struct wpabuf * ndef_build_record(u8 flags, void *type, |
| u8 type_length, void *id, |
| u8 id_length, |
| const struct wpabuf *payload) |
| { |
| struct wpabuf *record; |
| size_t total_len; |
| int short_record; |
| u8 local_flag; |
| size_t payload_length = wpabuf_len(payload); |
| |
| short_record = payload_length < 256 ? 1 : 0; |
| |
| total_len = 2; /* flag + type length */ |
| /* payload length */ |
| total_len += short_record ? sizeof(u8) : sizeof(u32); |
| if (id_length > 0) |
| total_len += 1; |
| total_len += type_length + id_length + payload_length; |
| record = wpabuf_alloc(total_len); |
| if (record == NULL) { |
| wpa_printf(MSG_ERROR, "NDEF : Failed to allocate " |
| "record for build"); |
| return NULL; |
| } |
| |
| local_flag = flags; |
| if (id_length > 0) |
| local_flag |= FLAG_ID_LENGTH_PRESENT; |
| if (short_record) |
| local_flag |= FLAG_SHORT_RECORD; |
| wpabuf_put_u8(record, local_flag); |
| |
| wpabuf_put_u8(record, type_length); |
| |
| if (short_record) |
| wpabuf_put_u8(record, payload_length); |
| else |
| wpabuf_put_be32(record, payload_length); |
| |
| if (id_length > 0) |
| wpabuf_put_u8(record, id_length); |
| wpabuf_put_data(record, type, type_length); |
| wpabuf_put_data(record, id, id_length); |
| wpabuf_put_buf(record, payload); |
| return record; |
| } |
| |
| |
| static int wifi_filter(struct ndef_record *record) |
| { |
| if (record->type_length != os_strlen(wifi_handover_type)) |
| return 0; |
| if (os_memcmp(record->type, wifi_handover_type, |
| os_strlen(wifi_handover_type)) != 0) |
| return 0; |
| return 1; |
| } |
| |
| |
| struct wpabuf * ndef_parse_wifi(const struct wpabuf *buf) |
| { |
| return ndef_parse_records(buf, wifi_filter); |
| } |
| |
| |
| struct wpabuf * ndef_build_wifi(const struct wpabuf *buf) |
| { |
| return ndef_build_record(FLAG_MESSAGE_BEGIN | FLAG_MESSAGE_END | |
| FLAG_TNF_RFC2046, wifi_handover_type, |
| os_strlen(wifi_handover_type), NULL, 0, buf); |
| } |
| |
| |
| struct wpabuf * ndef_build_wifi_hr(void) |
| { |
| struct wpabuf *rn, *cr, *ac_payload, *ac, *hr_payload, *hr; |
| struct wpabuf *carrier, *hc; |
| |
| rn = wpabuf_alloc(2); |
| if (rn == NULL) |
| return NULL; |
| wpabuf_put_be16(rn, os_random() & 0xffff); |
| |
| cr = ndef_build_record(FLAG_MESSAGE_BEGIN | FLAG_TNF_NFC_FORUM, "cr", 2, |
| NULL, 0, rn); |
| wpabuf_free(rn); |
| |
| if (cr == NULL) |
| return NULL; |
| |
| ac_payload = wpabuf_alloc(4); |
| if (ac_payload == NULL) { |
| wpabuf_free(cr); |
| return NULL; |
| } |
| wpabuf_put_u8(ac_payload, 0x01); /* Carrier Flags: CRS=1 "active" */ |
| wpabuf_put_u8(ac_payload, 0x01); /* Carrier Data Reference Length */ |
| wpabuf_put_u8(ac_payload, '0'); /* Carrier Data Reference: "0" */ |
| wpabuf_put_u8(ac_payload, 0); /* Aux Data Reference Count */ |
| |
| ac = ndef_build_record(FLAG_MESSAGE_END | FLAG_TNF_NFC_FORUM, "ac", 2, |
| NULL, 0, ac_payload); |
| wpabuf_free(ac_payload); |
| if (ac == NULL) { |
| wpabuf_free(cr); |
| return NULL; |
| } |
| |
| hr_payload = wpabuf_alloc(1 + wpabuf_len(cr) + wpabuf_len(ac)); |
| if (hr_payload == NULL) { |
| wpabuf_free(cr); |
| wpabuf_free(ac); |
| return NULL; |
| } |
| |
| wpabuf_put_u8(hr_payload, 0x12); /* Connection Handover Version 1.2 */ |
| wpabuf_put_buf(hr_payload, cr); |
| wpabuf_put_buf(hr_payload, ac); |
| wpabuf_free(cr); |
| wpabuf_free(ac); |
| |
| hr = ndef_build_record(FLAG_MESSAGE_BEGIN | FLAG_TNF_NFC_FORUM, "Hr", 2, |
| NULL, 0, hr_payload); |
| wpabuf_free(hr_payload); |
| if (hr == NULL) |
| return NULL; |
| |
| carrier = wpabuf_alloc(2 + os_strlen(wifi_handover_type)); |
| if (carrier == NULL) { |
| wpabuf_free(hr); |
| return NULL; |
| } |
| wpabuf_put_u8(carrier, 0x02); /* Carrier Type Format */ |
| wpabuf_put_u8(carrier, os_strlen(wifi_handover_type)); |
| wpabuf_put_str(carrier, wifi_handover_type); |
| |
| hc = ndef_build_record(FLAG_MESSAGE_END | FLAG_TNF_NFC_FORUM, "Hc", 2, |
| "0", 1, carrier); |
| wpabuf_free(carrier); |
| if (hc == NULL) { |
| wpabuf_free(hr); |
| return NULL; |
| } |
| |
| return wpabuf_concat(hr, hc); |
| } |