Merge pull request #2226 from nvx/bugfix/14a_apdu_ats_timeout

hf 14a apdu now uses the FWI and SGFI values from the ATS to determine an appropriate timeout.

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+ - Changed `hf 14a apdu` - It now uses the FWI and SGFI values from the ATS to determine an appropriate timeout (@nvx)
  - Added a thread to check when device comes online again. It will connect and update prompt (@iceman1001)
  - Changed CLI offline prompt - replaces the old prompt when offline is detected (@iceman100)
  - Changed `hf mf info` - it now uses found keys to try identify Gen2 cards (@iceman1001)

client/src/cmdhf14a.c

@@ -1006,6 +1006,11 @@ int SelectCard14443A_4_WithParameters(bool disconnect, bool verbose, iso14a_card
         return PM3_ECARDEXCHANGE;
     }
 
+    iso14a_card_select_t *vcard = (iso14a_card_select_t *) resp.data.asBytes;
+    if (card) {
+        memcpy(card, vcard, sizeof(iso14a_card_select_t));
+    }
+
     if (resp.oldarg[0] == 2) { // 0: couldn't read, 1: OK, with ATS, 2: OK, no ATS, 3: proprietary Anticollision
         // get ATS
         uint8_t rats[] = { 0xE0, 0x80 }; // FSDI=8 (FSD=256), CID=0
@@ -1029,19 +1034,19 @@ int SelectCard14443A_4_WithParameters(bool disconnect, bool verbose, iso14a_card
                 gs_frame_len = atsFSC[fsci];
             }
         }
+
+        if (card) {
+            card->ats_len = resp.oldarg[0];
+            memcpy(card->ats, resp.data.asBytes, card->ats_len);
+        }
     } else {
         // get frame length from ATS in card data structure
-        iso14a_card_select_t *vcard = (iso14a_card_select_t *) resp.data.asBytes;
         if (vcard->ats_len > 1) {
             uint8_t fsci = vcard->ats[1] & 0x0f;
             if (fsci < ARRAYLEN(atsFSC)) {
                 gs_frame_len = atsFSC[fsci];
             }
         }
-
-        if (card) {
-            memcpy(card, vcard, sizeof(iso14a_card_select_t));
-        }
     }
 
     SetISODEPState(ISODEP_NFCA);
@@ -1060,11 +1065,44 @@ int SelectCard14443A_4(bool disconnect, bool verbose, iso14a_card_select_t *card
 static int CmdExchangeAPDU(bool chainingin, uint8_t *datain, int datainlen, bool activateField, uint8_t *dataout, int maxdataoutlen, int *dataoutlen, bool *chainingout) {
     *chainingout = false;
 
+    size_t timeout = 1500;
     if (activateField) {
         // select with no disconnect and set gs_frame_len
-        int selres = SelectCard14443A_4(false, true, NULL);
+        iso14a_card_select_t card;
-        if (selres != PM3_SUCCESS)
+        int selres = SelectCard14443A_4(false, true, &card);
+        if (selres != PM3_SUCCESS) {
             return selres;
+        }
+
+        // Extract FWI and SFGI from ATS and increase timeout by the indicated values
+        // for most cards these values are trivially small so will make no practical
+        // difference but some "cards" like hf_cardhopper overwrite these to their
+        // maximum values resulting in ~5 seconds each which can cause timeouts if we
+        // just ignore it
+        if (((card.ats[1] & 0x20) == 0x20) && card.ats_len > 2) {
+            // TB is present in ATS
+
+            uint8_t tb;
+            if ((card.ats[1] & 0x10) == 0x10 && card.ats_len > 3) {
+                // TA is also present, so TB at ats[3]
+                tb = card.ats[3];
+            } else {
+                // TA is not present, so TB is at ats[2]
+                tb = card.ats[2];
+            }
+
+            uint8_t fwi = (tb & 0xF0) >> 4;
+            if (fwi != 0x0F) {
+                uint32_t fwt = 256 * 16 * (1 << fwi);
+                timeout += fwt;
+            }
+
+            uint8_t sfgi = tb & 0x0F;
+            if (sfgi != 0x0F) {
+                uint32_t sgft = 256 * 16 * (1 << sfgi);
+                timeout += sgft;
+            }
+        }
     }
 
     uint16_t cmdc = 0;
@@ -1082,7 +1120,7 @@ static int CmdExchangeAPDU(bool chainingin, uint8_t *datain, int datainlen, bool
 
     PacketResponseNG resp;
 
-    if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
+    if (WaitForResponseTimeout(CMD_ACK, &resp, timeout)) {
         uint8_t *recv = resp.data.asBytes;
         int iLen = resp.oldarg[0];
         uint8_t res = resp.oldarg[1];
@@ -2410,7 +2448,7 @@ int infoHF14A(bool verbose, bool do_nack_test, bool do_aid_search) {
 
     int isMagic = 0;
     if (isMifareClassic) {
-        isMagic = detect_mf_magic(true, MF_KEY_A, 0);
+        isMagic = detect_mf_magic(true, MF_KEY_B, 0xFFFFFFFFFFFF);
     }
     if (isMifareUltralight) {
         isMagic = (detect_mf_magic(false, MF_KEY_A, 0) == MAGIC_NTAG21X);