Fix cardversion format

.gitignore

@@ -175,3 +175,7 @@ cython_debug/
 
 # Docs site
 public/
+
+# MacOS
+.DS_Store
+**/.DS_Store

src/desfire/schemas/card_version.py

@@ -31,9 +31,36 @@ def __init__(self, data: list[int]):
 
     def __repr__(self) -> str:
         temp = "--- Desfire Card Details ---\r\n"
-        temp += f"Hardware Version: {self.hardware_minor_version}.{self.hardware_minor_version}\r\n"
+        temp += f"Hardware Version: {self.hardware_major_version}.{self.hardware_minor_version}\r\n"
         temp += f"Software Version: {self.software_major_version}.{self.software_minor_version}\r\n"
-        temp += f"EEPROM size:      {1 << (self.hardware_storage_size - 1)} bytes\r\n"
+
+        # EEPROM size calculation according to NXP documentation,
+        # see https://www.nxp.com/docs/en/application-note/AN10833.pdf
+        #     Formula is in Figure 1 on page 4, lower right corner of the table, but a bit unclear.
+        # .   Examples are in the table itself below some card types, e.g. MIFARE DESFire
+        # see also https://www.nxp.com/docs/en/data-sheet/NTAG213_215_216.pdf
+        #     on page 36, Table 28 and notes below
+        #
+        # Meaning and encoding of 'hardware_storage_size':
+        # Bit 0 (LSB) indicates the size encoding method
+        # Bit 1..7 are the 'size' value used in the formula below
+        #
+        # Formula:
+        #   if bit 0 = 1, then storageBytes = 2^(size // 2) up to storageBytes = 2^(size // 2 + 1)
+        #   if bit 0 = 0, then storageBytes = 2^(size // 2)
+        #
+        # Examples:
+        # Ultralight Family, e.g. Ultralight C has bit 0 = 1, e.g. 0x0B (for 48 Byte) or 0x0E (128 Byte)
+        # MIFARE DESFire Family has bit 0 = 0, e.g. 0x16: 2K, 0x18: 4K, 0x1A: 8K, 0x1C: 16K, 0x1E: 32K
+        #
+        # LSB indicates size encoding method
+        if (self.hardware_storage_size & 0x01) == 0x01:  # typical for Ultralight C, and EV1
+            temp += (
+                f"EEPROM size:      {1 << (self.hardware_storage_size >> 1)} up to "
+                f"{1 << ((self.hardware_storage_size >> 1) + 1)} bytes\r\n"
+            )
+        else:  # typical for DESFire EV1, EV2, and EV3
+            temp += f"EEPROM size:      {1 << (self.hardware_storage_size >> 1)} bytes\r\n"
         temp += f"Production:       week {self.production_date_cw:X}, year 20{self.production_date_year:02X}\r\n"
         temp += f"UID no:           {to_hex_string(self.uid)}\r\n"
         temp += f"Batch no:         {to_hex_string(self.batch_no)}\r\n"

tests/tests_test_card_version_repr.py

@@ -0,0 +1,61 @@
+from desfire.schemas.card_version import CardVersion
+
+
+def test_card_version_repr_hardware_major_minor():
+    # Prepare data for real MIFARE DESFire EV1 card with 4K from 2013
+    data = [
+        0x04,  # first block, hardware vendor id
+        0x01,
+        0x01,
+        0x01,
+        0x00,
+        0x18,
+        0x05,
+        0x04,  # second block, software vendor id
+        0x01,
+        0x01,
+        0x01,
+        0x04,
+        0x18,
+        0x05,
+        0x04,  # third block, starts with UID
+        0x4D,
+        0x70,
+        0xBA,
+        0x5F,
+        0x35,
+        0x80,
+        0xBA,
+        0x44,
+        0x97,
+        0xD6,
+        0x70,
+        0x28,
+        0x13,
+    ]
+    cv = CardVersion(data)
+    s = repr(cv)
+    assert "Hardware Version: 1.0" in s
+    assert "Software Version: 1.4" in s
+    print(s)
+
+
+"""
+output with current code was:
+--- Desfire Card Details ---
+Hardware Version: 0.0
+Software Version: 1.4
+EEPROM size:      8388608 bytes
+Production:       week 28, year 2013
+UID no:           04 4D 70 BA 5F 35 80
+Batch no:         BA 44 97 D6
+
+new code produces following output:
+--- Desfire Card Details ---
+Hardware Version: 1.0
+Software Version: 1.4
+EEPROM size:      4096 bytes
+Production:       week 28, year 2013
+UID no:           04 4D 70 BA 5F 35 80
+Batch no:         BA 44 97 D6
+"""