Automatically send RATS to 14443-4a tags

RfidResearchGroup · Sep 18, 2023 · 09eb0d1 · 09eb0d1
1 parent 9497ff7
commit 09eb0d1
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Showing 7 changed files with 34 additions and 3 deletions.
diff --git a/firmware/application/src/app_cmd.c b/firmware/application/src/app_cmd.c
@@ -232,7 +232,9 @@ static data_frame_tx_t *cmd_processor_hf14a_scan(uint16_t cmd, uint16_t status,
     memcpy(&payload[offset], taginfo.atqa, sizeof(taginfo.atqa));
     offset += sizeof(taginfo.atqa);
     payload[offset++] = taginfo.sak;
-    payload[offset++] = 0; // TODO: no ATS support yet
+    payload[offset++] = taginfo.ats_len;
+    memcpy(&payload[offset], taginfo.ats, taginfo.ats_len);
+    offset += taginfo.ats_len;
     return data_frame_make(cmd, HF_TAG_OK, offset, payload);
 }
 

diff --git a/firmware/application/src/app_main.c b/firmware/application/src/app_main.c
@@ -648,11 +648,15 @@ static void btn_fn_copy_ic_uid(void) {
     status = pcd_14a_reader_scan_auto(&tag);
     if (status == HF_TAG_OK) {
         // copy uid
+        antres->size = tag.uid_len;
         memcpy(antres->uid, tag.uid, tag.uid_len);
         // copy atqa
         memcpy(antres->atqa, tag.atqa, 2);
         // copy sak
         antres->sak[0] = tag.sak;
+        // copy ats
+        antres->ats.length = tag.ats_len;
+        memcpy(antres->ats.data, tag.ats, tag.ats_len);
         NRF_LOG_INFO("Offline HF uid copied")
         offline_status_ok();
     } else {

diff --git a/firmware/application/src/app_status.h b/firmware/application/src/app_status.h
@@ -13,7 +13,7 @@
 #define     HF_ERR_BCC                              (0x05) // IC card BCC error
 #define     MF_ERR_AUTH                             (0x06) // MF card verification failed
 #define     HF_ERR_PARITY                           (0x07) // IC card parity error
-
+#define     HF_ERR_ATS                              (0x08) // ATS should be present but card NAKed
 
 /////////////////////////////////////////////////////////////////////
 // lf status

diff --git a/firmware/application/src/rfid/reader/hf/rc522.c b/firmware/application/src/rfid/reader/hf/rc522.c
@@ -491,6 +491,7 @@ uint8_t pcd_14a_reader_scan_once(picc_14a_tag_t *tag) {
     if (tag) {
         tag->uid_len = 0;
         memset(tag->uid, 0, 10);
+        tag->ats_len = 0;
     } else {
         return STATUS_PAR_ERR;  // Finding cards are not allowed to be transmitted to the label information structure
     }
@@ -578,6 +579,26 @@ uint8_t pcd_14a_reader_scan_once(picc_14a_tag_t *tag) {
         // Only 1 2 3 Three types, corresponding 4 7 10 Byte card number
         // Therefore + 1
         tag->cascade = cascade_level + 1;
+        if ((!do_cascade) && (tag->sak & 0x20)) {
+            // Tag supports 14443-4, sending RATS
+            uint16_t ats_size;
+            status = pcd_14a_reader_ats_request(tag->ats, &ats_size, 0xFF*8);
+            ats_size -= 2;  // size returned by pcd_14a_reader_ats_request includes CRC
+            if (ats_size > 254) {
+                NRF_LOG_INFO("Invalid ATS > 254!");
+                return HF_ERR_ATS;
+            }
+            tag->ats_len = ats_size;
+            // We do not validate ATS here as we want to report ATS as it is without breaking 14a scan
+            if (tag->ats[0] != ats_size - 1) {
+                NRF_LOG_INFO("Invalid ATS! First byte doesn't match received length");
+                // return HF_ERR_ATS;
+            }
+            if (status != HF_TAG_OK) {
+                NRF_LOG_INFO("Tag SAK claimed to support ATS but tag NAKd RATS");
+                // return HF_ERR_ATS;
+            }
+        }
     }
     return HF_TAG_OK;
 }
@@ -619,6 +640,7 @@ uint8_t pcd_14a_reader_ats_request(uint8_t *pAts, uint16_t *szAts, uint16_t szAt
     status = pcd_14a_reader_bytes_transfer(PCD_TRANSCEIVE, rats, sizeof(rats), pAts, szAts, szAtsBitMax);
 
     if (status != HF_TAG_OK) {
+        *szAts = 0;
         NRF_LOG_INFO("Err at ats receive.\n");
         return status;
     }

diff --git a/firmware/application/src/rfid/reader/hf/rc522.h b/firmware/application/src/rfid/reader/hf/rc522.h
@@ -159,6 +159,8 @@ typedef struct {
     uint8_t cascade;  // theAntiCollisionLevelValueIs1Representation 4Byte,2Represents7Byte,3Means10Byte
     uint8_t sak;      // chooseToConfirm
     uint8_t atqa[2];  // requestResponse
+    uint8_t ats[0xFF];// 14443-4 answer to select
+    uint8_t ats_len;  // 14443-4 answer to select size
 } PACKED picc_14a_tag_t;
 
 #ifdef __cplusplus

diff --git a/software/script/chameleon_cli_unit.py b/software/script/chameleon_cli_unit.py
@@ -335,7 +335,6 @@ def scan(self, deep=False):
                 print(f"- ATQA : {data_tag['atqa'].hex().upper()}")
                 print(f"- SAK  : {data_tag['sak'].hex().upper()}")
                 if len(data_tag['ats']) > 0:
-                    print(data_tag['ats'])
                     print(f"- ATS  : {data_tag['ats'].hex().upper()}")
                 if deep:
                     self.sak_info(data_tag)

diff --git a/software/script/chameleon_status.py b/software/script/chameleon_status.py
@@ -30,6 +30,7 @@ class Device(metaclass=MetaDevice):
     HF_ERR_BCC = 0x05     # IC card BCC error
     MF_ERR_AUTH = 0x06    # MF card verification failed
     HF_ERR_PARITY = 0x07  # IC card parity error
+    HF_ERR_ATS = 0x08     # ATS should be present but card NAKed, or ATS too large
 
     # Some operations with low frequency cards succeeded!
     LF_TAG_OK = 0x40
@@ -57,6 +58,7 @@ class Device(metaclass=MetaDevice):
     Device.HF_ERR_BCC: "HF tag uid bcc error",
     Device.MF_ERR_AUTH: "HF tag auth fail",
     Device.HF_ERR_PARITY: "HF tag data parity error",
+    Device.HF_ERR_ATS: "HF tag was supposed to send ATS but didn't",
 
     Device.LF_TAG_OK: "LF tag operation succeeded",
     Device.EM410X_TAG_NO_FOUND: "EM410x tag no found",