hf 14a: if the tag supports it, set default timeout according to ATS

[proxmark3-svn] / armsrc / iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index a7102168e09d75522e1e35ac02526136a464a57d..f2fa1ff29e3e766ad1581dfaca5304cecb088689 100644 (file)
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -141,16 +141,40 @@ const uint8_t OddByteParity[256] = {
   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
 };
 
+
 void iso14a_set_trigger(bool enable) {
        trigger = enable;
 }
 
 
-
 void iso14a_set_timeout(uint32_t timeout) {
        iso14a_timeout = timeout;
+       if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 }
 
+
+void iso14a_set_ATS_timeout(uint8_t *ats) {
+
+       uint8_t tb1;
+       uint8_t fwi; 
+       uint32_t fwt;
+       
+       if (ats[0] > 1) {                                                       // there is a format byte T0
+               if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
+                       if ((ats[1] & 0x10) == 0x10) {          // there is an interface byte TA(1) preceding TB(1)
+                               tb1 = ats[3];
+                       } else {
+                               tb1 = ats[2];
+                       }
+                       fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
+                       fwt = 256 * 16 * (1 << fwi);            // frame waiting time (FWT) in 1/fc
+                       
+                       iso14a_set_timeout(fwt/(8*16));
+               }
+       }
+}
+
+
 //-----------------------------------------------------------------------------
 // Generate the parity value for a byte sequence
 //
@@ -1600,7 +1624,7 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receive
                        if(ManchesterDecoding(b, offset, 0)) {
                                NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
                                return TRUE;
-                       } else if (c++ > iso14a_timeout) {
+                       } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
                                return FALSE; 
                        }
                }
@@ -1798,6 +1822,10 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u
 
        // reset the PCB block number
        iso14_pcb_blocknum = 0;
+
+       // set default timeout based on ATS
+       iso14a_set_ATS_timeout(resp);
+
        return 1;       
 }