[LRFID] Add support for Nexkey/Nexwatch (#2680)

* [LRFID] Add support for Nexkey/Nexwatch
* Update protocol_nexwatch.c: Remove unnecessary check

Co-authored-by: SG <who.just.the.doctor@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>

lib/lfrfid/protocols/lfrfid_protocols.c

@@ -16,6 +16,7 @@
 #include "protocol_pac_stanley.h"
 #include "protocol_keri.h"
 #include "protocol_gallagher.h"
+#include "protocol_nexwatch.h"
 
 const ProtocolBase* lfrfid_protocols[] = {
     [LFRFIDProtocolEM4100] = &protocol_em4100,
@@ -35,4 +36,5 @@ const ProtocolBase* lfrfid_protocols[] = {
     [LFRFIDProtocolPACStanley] = &protocol_pac_stanley,
     [LFRFIDProtocolKeri] = &protocol_keri,
     [LFRFIDProtocolGallagher] = &protocol_gallagher,
+    [LFRFIDProtocolNexwatch] = &protocol_nexwatch,
 };

lib/lfrfid/protocols/lfrfid_protocols.h

@@ -25,6 +25,7 @@ typedef enum {
     LFRFIDProtocolPACStanley,
     LFRFIDProtocolKeri,
     LFRFIDProtocolGallagher,
+    LFRFIDProtocolNexwatch,
     LFRFIDProtocolMax,
 } LFRFIDProtocol;
 

lib/lfrfid/protocols/protocol_nexwatch.c

@@ -0,0 +1,323 @@
+#include <furi.h>
+#include <toolbox/protocols/protocol.h>
+#include <lfrfid/tools/bit_lib.h>
+#include "lfrfid_protocols.h"
+
+#define NEXWATCH_PREAMBLE_BIT_SIZE (8)
+#define NEXWATCH_PREAMBLE_DATA_SIZE (1)
+
+#define NEXWATCH_ENCODED_BIT_SIZE (96)
+#define NEXWATCH_ENCODED_DATA_SIZE ((NEXWATCH_ENCODED_BIT_SIZE) / 8)
+
+#define NEXWATCH_DECODED_BIT_SIZE (NEXWATCH_DECODED_DATA_SIZE * 8)
+#define NEXWATCH_DECODED_DATA_SIZE (8)
+
+#define NEXWATCH_US_PER_BIT (255)
+#define NEXWATCH_ENCODER_PULSES_PER_BIT (16)
+
+typedef struct {
+    uint8_t magic;
+    char desc[13];
+    uint8_t chk;
+} ProtocolNexwatchMagic;
+
+ProtocolNexwatchMagic magic_items[] = {
+    {0xBE, "Quadrakey", 0},
+    {0x88, "Nexkey", 0},
+    {0x86, "Honeywell", 0}};
+
+typedef struct {
+    uint8_t data_index;
+    uint8_t bit_clock_index;
+    bool last_bit;
+    bool current_polarity;
+    bool pulse_phase;
+} ProtocolNexwatchEncoder;
+
+typedef struct {
+    uint8_t encoded_data[NEXWATCH_ENCODED_DATA_SIZE];
+    uint8_t negative_encoded_data[NEXWATCH_ENCODED_DATA_SIZE];
+    uint8_t corrupted_encoded_data[NEXWATCH_ENCODED_DATA_SIZE];
+    uint8_t corrupted_negative_encoded_data[NEXWATCH_ENCODED_DATA_SIZE];
+
+    uint8_t data[NEXWATCH_DECODED_DATA_SIZE];
+    ProtocolNexwatchEncoder encoder;
+} ProtocolNexwatch;
+
+ProtocolNexwatch* protocol_nexwatch_alloc(void) {
+    ProtocolNexwatch* protocol = malloc(sizeof(ProtocolNexwatch));
+    return protocol;
+};
+
+void protocol_nexwatch_free(ProtocolNexwatch* protocol) {
+    free(protocol);
+};
+
+uint8_t* protocol_nexwatch_get_data(ProtocolNexwatch* protocol) {
+    return protocol->data;
+};
+
+void protocol_nexwatch_decoder_start(ProtocolNexwatch* protocol) {
+    memset(protocol->encoded_data, 0, NEXWATCH_ENCODED_DATA_SIZE);
+    memset(protocol->negative_encoded_data, 0, NEXWATCH_ENCODED_DATA_SIZE);
+    memset(protocol->corrupted_encoded_data, 0, NEXWATCH_ENCODED_DATA_SIZE);
+    memset(protocol->corrupted_negative_encoded_data, 0, NEXWATCH_ENCODED_DATA_SIZE);
+};
+
+static bool protocol_nexwatch_check_preamble(uint8_t* data, size_t bit_index) {
+    // 01010110
+    if(bit_lib_get_bits(data, bit_index, 8) != 0b01010110) return false;
+    return true;
+}
+
+static uint8_t protocol_nexwatch_parity_swap(uint8_t parity) {
+    uint8_t a = (((parity >> 3) & 1));
+    a |= (((parity >> 1) & 1) << 1);
+    a |= (((parity >> 2) & 1) << 2);
+    a |= ((parity & 1) << 3);
+    return a;
+}
+
+static uint8_t protocol_nexwatch_parity(const uint8_t hexid[5]) {
+    uint8_t p = 0;
+    for(uint8_t i = 0; i < 5; i++) {
+        p ^= ((hexid[i]) & 0xF0) >> 4;
+        p ^= ((hexid[i]) & 0x0F);
+    }
+    return protocol_nexwatch_parity_swap(p);
+}
+
+static uint8_t protocol_nexwatch_checksum(uint8_t magic, uint32_t id, uint8_t parity) {
+    uint8_t a = ((id >> 24) & 0xFF);
+    a -= ((id >> 16) & 0xFF);
+    a -= ((id >> 8) & 0xFF);
+    a -= (id & 0xFF);
+    a -= magic;
+    a -= (bit_lib_reverse_8_fast(parity) >> 4);
+    return bit_lib_reverse_8_fast(a);
+}
+
+static bool protocol_nexwatch_can_be_decoded(uint8_t* data) {
+    if(!protocol_nexwatch_check_preamble(data, 0)) return false;
+
+    // Check for reserved word (32-bit)
+    if(bit_lib_get_bits_32(data, 8, 32) != 0) {
+        return false;
+    }
+
+    uint8_t parity = bit_lib_get_bits(data, 76, 4);
+
+    // parity check
+    // from 32b hex id, 4b mode
+    uint8_t hex[5] = {0};
+    for(uint8_t i = 0; i < 5; i++) {
+        hex[i] = bit_lib_get_bits(data, 40 + (i * 8), 8);
+    }
+    //mode is only 4 bits.
+    hex[4] &= 0xf0;
+    uint8_t calc_parity = protocol_nexwatch_parity(hex);
+
+    if(calc_parity != parity) {
+        return false;
+    }
+
+    return true;
+}
+
+static bool protocol_nexwatch_decoder_feed_internal(bool polarity, uint32_t time, uint8_t* data) {
+    time += (NEXWATCH_US_PER_BIT / 2);
+
+    size_t bit_count = (time / NEXWATCH_US_PER_BIT);
+    bool result = false;
+
+    if(bit_count < NEXWATCH_ENCODED_BIT_SIZE) {
+        for(size_t i = 0; i < bit_count; i++) {
+            bit_lib_push_bit(data, NEXWATCH_ENCODED_DATA_SIZE, polarity);
+            if(protocol_nexwatch_can_be_decoded(data)) {
+                result = true;
+                break;
+            }
+        }
+    }
+
+    return result;
+}
+
+static void protocol_nexwatch_descramble(uint32_t* id, uint32_t* scrambled) {
+    // 255 = Not used/Unknown other values are the bit offset in the ID/FC values
+    const uint8_t hex_2_id[] = {31, 27, 23, 19, 15, 11, 7, 3, 30, 26, 22, 18, 14, 10, 6, 2,
+                                29, 25, 21, 17, 13, 9,  5, 1, 28, 24, 20, 16, 12, 8,  4, 0};
+
+    *id = 0;
+    for(uint8_t idx = 0; idx < 32; idx++) {
+        bool bit_state = (*scrambled >> hex_2_id[idx]) & 1;
+        *id |= (bit_state << (31 - idx));
+    }
+}
+
+static void protocol_nexwatch_decoder_save(uint8_t* data_to, const uint8_t* data_from) {
+    uint32_t id = bit_lib_get_bits_32(data_from, 40, 32);
+    data_to[4] = (uint8_t)id;
+    data_to[3] = (uint8_t)(id >>= 8);
+    data_to[2] = (uint8_t)(id >>= 8);
+    data_to[1] = (uint8_t)(id >>= 8);
+    data_to[0] = (uint8_t)(id >>= 8);
+    uint32_t check = bit_lib_get_bits_32(data_from, 72, 24);
+    data_to[7] = (uint8_t)check;
+    data_to[6] = (uint8_t)(check >>= 8);
+    data_to[5] = (uint8_t)(check >>= 8);
+}
+
+bool protocol_nexwatch_decoder_feed(ProtocolNexwatch* protocol, bool level, uint32_t duration) {
+    bool result = false;
+
+    if(duration > (NEXWATCH_US_PER_BIT / 2)) {
+        if(protocol_nexwatch_decoder_feed_internal(level, duration, protocol->encoded_data)) {
+            protocol_nexwatch_decoder_save(protocol->data, protocol->encoded_data);
+            result = true;
+            return result;
+        }
+
+        if(protocol_nexwatch_decoder_feed_internal(
+               !level, duration, protocol->negative_encoded_data)) {
+            protocol_nexwatch_decoder_save(protocol->data, protocol->negative_encoded_data);
+            result = true;
+            return result;
+        }
+    }
+
+    if(duration > (NEXWATCH_US_PER_BIT / 4)) {
+        // Try to decode wrong phase synced data
+        if(level) {
+            duration += 120;
+        } else {
+            if(duration > 120) {
+                duration -= 120;
+            }
+        }
+
+        if(protocol_nexwatch_decoder_feed_internal(
+               level, duration, protocol->corrupted_encoded_data)) {
+            protocol_nexwatch_decoder_save(protocol->data, protocol->corrupted_encoded_data);
+
+            result = true;
+            return result;
+        }
+
+        if(protocol_nexwatch_decoder_feed_internal(
+               !level, duration, protocol->corrupted_negative_encoded_data)) {
+            protocol_nexwatch_decoder_save(
+                protocol->data, protocol->corrupted_negative_encoded_data);
+
+            result = true;
+            return result;
+        }
+    }
+
+    return result;
+};
+
+bool protocol_nexwatch_encoder_start(ProtocolNexwatch* protocol) {
+    memset(protocol->encoded_data, 0, NEXWATCH_ENCODED_DATA_SIZE);
+    *(uint32_t*)&protocol->encoded_data[0] = 0b00000000000000000000000001010110;
+    bit_lib_copy_bits(protocol->encoded_data, 32, 32, protocol->data, 0);
+    bit_lib_copy_bits(protocol->encoded_data, 64, 32, protocol->data, 32);
+
+    protocol->encoder.last_bit =
+        bit_lib_get_bit(protocol->encoded_data, NEXWATCH_ENCODED_BIT_SIZE - 1);
+    protocol->encoder.data_index = 0;
+    protocol->encoder.current_polarity = true;
+    protocol->encoder.pulse_phase = true;
+    protocol->encoder.bit_clock_index = 0;
+
+    return true;
+};
+
+LevelDuration protocol_nexwatch_encoder_yield(ProtocolNexwatch* protocol) {
+    LevelDuration level_duration;
+    ProtocolNexwatchEncoder* encoder = &protocol->encoder;
+
+    if(encoder->pulse_phase) {
+        level_duration = level_duration_make(encoder->current_polarity, 1);
+        encoder->pulse_phase = false;
+    } else {
+        level_duration = level_duration_make(!encoder->current_polarity, 1);
+        encoder->pulse_phase = true;
+
+        encoder->bit_clock_index++;
+        if(encoder->bit_clock_index >= NEXWATCH_ENCODER_PULSES_PER_BIT) {
+            encoder->bit_clock_index = 0;
+
+            bool current_bit = bit_lib_get_bit(protocol->encoded_data, encoder->data_index);
+
+            if(current_bit != encoder->last_bit) {
+                encoder->current_polarity = !encoder->current_polarity;
+            }
+
+            encoder->last_bit = current_bit;
+
+            bit_lib_increment_index(encoder->data_index, NEXWATCH_ENCODED_BIT_SIZE);
+        }
+    }
+
+    return level_duration;
+};
+
+void protocol_nexwatch_render_data(ProtocolNexwatch* protocol, FuriString* result) {
+    uint32_t id = 0;
+    uint32_t scrambled = bit_lib_get_bits_32(protocol->data, 8, 32);
+    protocol_nexwatch_descramble(&id, &scrambled);
+
+    uint8_t m_idx;
+    uint8_t mode = bit_lib_get_bits(protocol->data, 40, 4);
+    uint8_t parity = bit_lib_get_bits(protocol->data, 44, 4);
+    uint8_t chk = bit_lib_get_bits(protocol->data, 48, 8);
+    for(m_idx = 0; m_idx < 3; m_idx++) {
+        magic_items[m_idx].chk = protocol_nexwatch_checksum(magic_items[m_idx].magic, id, parity);
+        if(magic_items[m_idx].chk == chk) {
+            break;
+        }
+    }
+    furi_string_printf(result, "ID: %lu, M:%u\r\nType: %s\r\n", id, mode, magic_items[m_idx].desc);
+}
+
+bool protocol_nexwatch_write_data(ProtocolNexwatch* protocol, void* data) {
+    LFRFIDWriteRequest* request = (LFRFIDWriteRequest*)data;
+    bool result = false;
+
+    protocol_nexwatch_encoder_start(protocol);
+    if(request->write_type == LFRFIDWriteTypeT5577) {
+        request->t5577.block[0] = LFRFID_T5577_MODULATION_PSK1 | LFRFID_T5577_BITRATE_RF_32 |
+                                  (3 << LFRFID_T5577_MAXBLOCK_SHIFT);
+        request->t5577.block[1] = bit_lib_get_bits_32(protocol->encoded_data, 0, 32);
+        request->t5577.block[2] = bit_lib_get_bits_32(protocol->encoded_data, 32, 32);
+        request->t5577.block[3] = bit_lib_get_bits_32(protocol->encoded_data, 64, 32);
+        request->t5577.blocks_to_write = 4;
+        result = true;
+    }
+    return result;
+};
+
+const ProtocolBase protocol_nexwatch = {
+    .name = "Nexwatch",
+    .manufacturer = "Honeywell",
+    .data_size = NEXWATCH_DECODED_DATA_SIZE,
+    .features = LFRFIDFeaturePSK,
+    .validate_count = 6,
+    .alloc = (ProtocolAlloc)protocol_nexwatch_alloc,
+    .free = (ProtocolFree)protocol_nexwatch_free,
+    .get_data = (ProtocolGetData)protocol_nexwatch_get_data,
+    .decoder =
+        {
+            .start = (ProtocolDecoderStart)protocol_nexwatch_decoder_start,
+            .feed = (ProtocolDecoderFeed)protocol_nexwatch_decoder_feed,
+        },
+    .encoder =
+        {
+            .start = (ProtocolEncoderStart)protocol_nexwatch_encoder_start,
+            .yield = (ProtocolEncoderYield)protocol_nexwatch_encoder_yield,
+        },
+    .render_data = (ProtocolRenderData)protocol_nexwatch_render_data,
+    .render_brief_data = (ProtocolRenderData)protocol_nexwatch_render_data,
+    .write_data = (ProtocolWriteData)protocol_nexwatch_write_data,
+};

lib/lfrfid/protocols/protocol_nexwatch.h

@@ -0,0 +1,4 @@
+#pragma once
+#include <toolbox/protocols/protocol.h>
+
+extern const ProtocolBase protocol_nexwatch;