Mifare dictionary attack performance improvements. (#2173)

* NFC dictionary attack performance improvements.
* Remove unnecessary assignment

firmware/targets/f7/api_symbols.csv

@@ -1854,6 +1854,7 @@ Function,+,menu_set_selected_item,void,"Menu*, uint32_t"
 Function,-,mf_classic_auth_attempt,_Bool,"FuriHalNfcTxRxContext*, MfClassicAuthContext*, uint64_t"
 Function,-,mf_classic_auth_init_context,void,"MfClassicAuthContext*, uint8_t"
 Function,-,mf_classic_authenticate,_Bool,"FuriHalNfcTxRxContext*, uint8_t, uint64_t, MfClassicKey"
+Function,-,mf_classic_authenticate_skip_activate,_Bool,"FuriHalNfcTxRxContext*, uint8_t, uint64_t, MfClassicKey, _Bool, uint32_t"
 Function,-,mf_classic_check_card_type,_Bool,"uint8_t, uint8_t, uint8_t"
 Function,-,mf_classic_dict_add_key,_Bool,"MfClassicDict*, uint8_t*"
 Function,-,mf_classic_dict_add_key_str,_Bool,"MfClassicDict*, FuriString*"

lib/nfc/nfc_worker.c

@@ -680,13 +680,15 @@ void nfc_worker_mf_classic_dict_attack(NfcWorker* nfc_worker) {
                 nfc_worker->callback(NfcWorkerEventNewDictKeyBatch, nfc_worker->context);
             }
             furi_hal_nfc_sleep();
-            if(furi_hal_nfc_activate_nfca(200, NULL)) {
-                furi_hal_nfc_sleep();
+            uint32_t cuid;
+            if(furi_hal_nfc_activate_nfca(200, &cuid)) {
+                bool deactivated = false;
                 if(!card_found_notified) {
                     nfc_worker->callback(NfcWorkerEventCardDetected, nfc_worker->context);
                     card_found_notified = true;
                     card_removed_notified = false;
                     nfc_worker_mf_classic_key_attack(nfc_worker, prev_key, &tx_rx, i);
+                    deactivated = true;
                 }
                 FURI_LOG_D(
                     TAG,
@@ -696,22 +698,26 @@ void nfc_worker_mf_classic_dict_attack(NfcWorker* nfc_worker) {
                     (uint32_t)key);
                 if(!is_key_a_found) {
                     is_key_a_found = mf_classic_is_key_found(data, i, MfClassicKeyA);
-                    if(mf_classic_authenticate(&tx_rx, block_num, key, MfClassicKeyA)) {
+                    if(mf_classic_authenticate_skip_activate(
+                           &tx_rx, block_num, key, MfClassicKeyA, !deactivated, cuid)) {
                         mf_classic_set_key_found(data, i, MfClassicKeyA, key);
                         FURI_LOG_D(TAG, "Key found");
                         nfc_worker->callback(NfcWorkerEventFoundKeyA, nfc_worker->context);
                         nfc_worker_mf_classic_key_attack(nfc_worker, key, &tx_rx, i + 1);
                     }
                     furi_hal_nfc_sleep();
+                    deactivated = true;
                 }
                 if(!is_key_b_found) {
                     is_key_b_found = mf_classic_is_key_found(data, i, MfClassicKeyB);
-                    if(mf_classic_authenticate(&tx_rx, block_num, key, MfClassicKeyB)) {
+                    if(mf_classic_authenticate_skip_activate(
+                           &tx_rx, block_num, key, MfClassicKeyB, !deactivated, cuid)) {
                         FURI_LOG_D(TAG, "Key found");
                         mf_classic_set_key_found(data, i, MfClassicKeyB, key);
                         nfc_worker->callback(NfcWorkerEventFoundKeyB, nfc_worker->context);
                         nfc_worker_mf_classic_key_attack(nfc_worker, key, &tx_rx, i + 1);
                     }
+                    deactivated = true;
                 }
                 if(is_key_a_found && is_key_b_found) break;
                 if(nfc_worker->state != NfcWorkerStateMfClassicDictAttack) break;

lib/nfc/protocols/mifare_classic.c

@@ -403,15 +403,16 @@ static bool mf_classic_auth(
     uint32_t block,
     uint64_t key,
     MfClassicKey key_type,
-    Crypto1* crypto) {
+    Crypto1* crypto,
+    bool skip_activate,
+    uint32_t cuid) {
     bool auth_success = false;
-    uint32_t cuid = 0;
     memset(tx_rx->tx_data, 0, sizeof(tx_rx->tx_data));
     memset(tx_rx->tx_parity, 0, sizeof(tx_rx->tx_parity));
     tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
 
     do {
-        if(!furi_hal_nfc_activate_nfca(200, &cuid)) break;
+        if(!skip_activate && !furi_hal_nfc_activate_nfca(200, &cuid)) break;
         if(key_type == MfClassicKeyA) {
             tx_rx->tx_data[0] = MF_CLASSIC_AUTH_KEY_A_CMD;
         } else {
@@ -460,7 +461,23 @@ bool mf_classic_authenticate(
     furi_assert(tx_rx);
 
     Crypto1 crypto = {};
-    bool key_found = mf_classic_auth(tx_rx, block_num, key, key_type, &crypto);
+    bool key_found = mf_classic_auth(tx_rx, block_num, key, key_type, &crypto, false, 0);
+    furi_hal_nfc_sleep();
+    return key_found;
+}
+
+bool mf_classic_authenticate_skip_activate(
+    FuriHalNfcTxRxContext* tx_rx,
+    uint8_t block_num,
+    uint64_t key,
+    MfClassicKey key_type,
+    bool skip_activate,
+    uint32_t cuid) {
+    furi_assert(tx_rx);
+
+    Crypto1 crypto = {};
+    bool key_found =
+        mf_classic_auth(tx_rx, block_num, key, key_type, &crypto, skip_activate, cuid);
     furi_hal_nfc_sleep();
     return key_found;
 }
@@ -483,7 +500,9 @@ bool mf_classic_auth_attempt(
                mf_classic_get_first_block_num_of_sector(auth_ctx->sector),
                key,
                MfClassicKeyA,
-               &crypto)) {
+               &crypto,
+               false,
+               0)) {
             auth_ctx->key_a = key;
             found_key = true;
         }
@@ -500,7 +519,9 @@ bool mf_classic_auth_attempt(
                mf_classic_get_first_block_num_of_sector(auth_ctx->sector),
                key,
                MfClassicKeyB,
-               &crypto)) {
+               &crypto,
+               false,
+               0)) {
             auth_ctx->key_b = key;
             found_key = true;
         }
@@ -568,7 +589,7 @@ void mf_classic_read_sector(FuriHalNfcTxRxContext* tx_rx, MfClassicData* data, u
         if(!key_a_found) break;
         FURI_LOG_D(TAG, "Try to read blocks with key A");
         key = nfc_util_bytes2num(sec_tr->key_a, sizeof(sec_tr->key_a));
-        if(!mf_classic_auth(tx_rx, start_block, key, MfClassicKeyA, &crypto)) break;
+        if(!mf_classic_auth(tx_rx, start_block, key, MfClassicKeyA, &crypto, false, 0)) break;
         for(size_t i = start_block; i < start_block + total_blocks; i++) {
             if(!mf_classic_is_block_read(data, i)) {
                 if(mf_classic_read_block(tx_rx, &crypto, i, &block_tmp)) {
@@ -587,7 +608,7 @@ void mf_classic_read_sector(FuriHalNfcTxRxContext* tx_rx, MfClassicData* data, u
         FURI_LOG_D(TAG, "Try to read blocks with key B");
         key = nfc_util_bytes2num(sec_tr->key_b, sizeof(sec_tr->key_b));
         furi_hal_nfc_sleep();
-        if(!mf_classic_auth(tx_rx, start_block, key, MfClassicKeyB, &crypto)) break;
+        if(!mf_classic_auth(tx_rx, start_block, key, MfClassicKeyB, &crypto, false, 0)) break;
         for(size_t i = start_block; i < start_block + total_blocks; i++) {
             if(!mf_classic_is_block_read(data, i)) {
                 if(mf_classic_read_block(tx_rx, &crypto, i, &block_tmp)) {
@@ -631,7 +652,7 @@ static bool mf_classic_read_sector_with_reader(
         }
 
         // Auth to first block in sector
-        if(!mf_classic_auth(tx_rx, first_block, key, key_type, crypto)) {
+        if(!mf_classic_auth(tx_rx, first_block, key, key_type, crypto, false, 0)) {
             // Set key to MF_CLASSIC_NO_KEY to prevent further attempts
             if(key_type == MfClassicKeyA) {
                 sector_reader->key_a = MF_CLASSIC_NO_KEY;
@@ -961,7 +982,7 @@ bool mf_classic_write_block(
 
     do {
         furi_hal_nfc_sleep();
-        if(!mf_classic_auth(tx_rx, block_num, key, key_type, &crypto)) {
+        if(!mf_classic_auth(tx_rx, block_num, key, key_type, &crypto, false, 0)) {
             FURI_LOG_D(TAG, "Auth fail");
             break;
         }

lib/nfc/protocols/mifare_classic.h

@@ -156,6 +156,14 @@ bool mf_classic_authenticate(
     uint64_t key,
     MfClassicKey key_type);
 
+bool mf_classic_authenticate_skip_activate(
+    FuriHalNfcTxRxContext* tx_rx,
+    uint8_t block_num,
+    uint64_t key,
+    MfClassicKey key_type,
+    bool skip_activate,
+    uint32_t cuid);
+
 bool mf_classic_auth_attempt(
     FuriHalNfcTxRxContext* tx_rx,
     MfClassicAuthContext* auth_ctx,