Add CLI view commands to display memory content (#208)

* Add utility to print memory dump (xxd like)

* Add CLI eview. Dump emulation memory data

* Add CLI view. Display content from tag memory or dump file

---------

Co-authored-by: marfo <marfo@localhost.localdomain>

software/script/chameleon_cli_unit.py

@@ -21,6 +21,7 @@ import chameleon_cmd
 from chameleon_utils import ArgumentParserNoExit, ArgsParserError, UnexpectedResponseError
 from chameleon_utils import CLITree
 from chameleon_utils import CR, CG, CB, CC, CY, C0
+from chameleon_utils import print_mem_dump
 from chameleon_enum import Command, Status, SlotNumber, TagSenseType, TagSpecificType
 from chameleon_enum import MifareClassicWriteMode, MifareClassicPrngType, MifareClassicDarksideStatus, MfcKeyType
 from chameleon_enum import AnimationMode, ButtonPressFunction, ButtonType, MfcValueBlockOperator
@@ -1011,6 +1012,52 @@ class HFMFWRBL(MF1AuthArgsUnit):
         else:
             print(f" - {CR}Write fail.{C0}")
 
+@hf_mf.command('view')
+class HFMFView(MF1AuthArgsUnit):
+    def args_parser(self) -> ArgumentParserNoExit:
+        parser = ArgumentParserNoExit()
+        parser.description = 'Display content from tag memory or dump file'
+        mifare_type_group = parser.add_mutually_exclusive_group()
+        mifare_type_group.add_argument('--mini', help='MIFARE Classic Mini / S20', action='store_const', dest='maxSectors', const=5)
+        mifare_type_group.add_argument('--1k', help='MIFARE Classic 1k / S50 (default)', action='store_const', dest='maxSectors', const=16)
+        mifare_type_group.add_argument('--2k', help='MIFARE Classic/Plus 2k', action='store_const', dest='maxSectors', const=32)
+        mifare_type_group.add_argument('--4k', help='MIFARE Classic 4k / S70', action='store_const', dest='maxSectors', const=40)
+        parser.add_argument('-d', '--dump-file', required=False, type=argparse.FileType("rb"), help="Dump file to read")
+        parser.add_argument('-k', '--key-file', required=False, type=argparse.FileType("r"), help="File containing keys of tag to write (exported with fchk --export)")
+        parser.set_defaults(maxSectors=16)
+        return parser
+
+    def on_exec(self, args: argparse.Namespace):
+        data = bytearray(0)
+        if args.dump_file is not None:
+            print("Reading dump file")
+            data = args.dump_file.read()
+        elif args.key_file is not None:
+            print("Reading tag memory")
+            # read keys from file
+            keys = list()
+            for line in args.key_file.readlines():
+                a, b = [bytes.fromhex(h) for h in line[:-1].split(":")]
+                keys.append((a, b))
+            if len(keys) != args.maxSectors:
+                raise ArgsParserError(f"Invalid key file. Found {len(keys)}, expected {args.maxSectors}")
+            # iterate over blocks
+            for blk in range(0, args.maxSectors * 4):
+                resp = None
+                try:
+                    # first try with key B
+                    resp = self.cmd.mf1_read_one_block(blk, MfcKeyType.B, keys[blk//4][1])
+                except UnexpectedResponseError:
+                    # ignore read errors at this stage as we want to try key A
+                    pass
+                if not resp:
+                    # try with key A if B was unsuccessful
+                    # this will raise an exception if key A fails too
+                    resp = self.cmd.mf1_read_one_block(blk, MfcKeyType.A, keys[blk//4][0])
+                data.extend(resp)
+        else:
+            raise ArgsParserError("Missing args. Specify --dump-file (-d) or --key-file (-k)")
+        print_mem_dump(data,16)
 
 @hf_mf.command('value')
 class HFMFVALUE(ReaderRequiredUnit):
@@ -1420,6 +1467,39 @@ class HFMFESave(SlotIndexArgsAndGoUnit, DeviceRequiredUnit):
                 fd.write(data)
         print("\n - Read success")
 
+@hf_mf.command('eview')
+class HFMFEView(SlotIndexArgsAndGoUnit, DeviceRequiredUnit):
+    def args_parser(self) -> ArgumentParserNoExit:
+        parser = ArgumentParserNoExit()
+        parser.description = 'View data from emulator memory'
+        self.add_slot_args(parser)
+        return parser
+    
+    def on_exec(self, args: argparse.Namespace):
+        selected_slot = self.cmd.get_active_slot()
+        slot_info = self.cmd.get_slot_info()
+        tag_type = TagSpecificType(slot_info[selected_slot]['hf'])      
+        
+        if tag_type == TagSpecificType.MIFARE_Mini:
+            block_count = 20
+        elif tag_type == TagSpecificType.MIFARE_1024:
+            block_count = 64
+        elif tag_type == TagSpecificType.MIFARE_2048:
+            block_count = 128
+        elif tag_type == TagSpecificType.MIFARE_4096:
+            block_count = 256
+        else:
+            raise Exception("Card in current slot is not Mifare Classic/Plus in SL1 mode")
+        index = 0
+        data = bytearray(0)
+        max_blocks = self.device_com.data_max_length // 16
+        while block_count > 0:
+            # read all the blocks
+            chunk_count = min(block_count, max_blocks)
+            data.extend(self.cmd.mf1_read_emu_block_data(index, chunk_count))
+            index += chunk_count
+            block_count -= chunk_count
+        print_mem_dump(data,16)
 
 @hf_mf.command('econfig')
 class HFMFEConfig(SlotIndexArgsAndGoUnit, HF14AAntiCollArgsUnit, DeviceRequiredUnit):

software/script/chameleon_utils.py

@@ -102,6 +102,21 @@ class ArgumentParserNoExit(argparse.ArgumentParser):
         print('')
         self.help_requested = True
 
+def print_mem_dump(bindata, blocksize):
+
+    hexadecimal_len = blocksize*3+1
+    ascii_len = blocksize+1
+    print(f"[=] ----+{hexadecimal_len*'-'}+{ascii_len*'-'}")
+    print(f"[=] blk | data{(hexadecimal_len-5)*' '}| ascii")
+    print(f"[=] ----+{hexadecimal_len*'-'}+{ascii_len*'-'}")
+
+    blocks = [bindata[i:i+blocksize] for i in range(0, len(bindata), blocksize)]
+    blk_index = 1
+    for b in blocks:
+        hexstr = ' '.join(b.hex()[i:i+2] for i in range(0, len(b.hex()), 2))
+        asciistr = ''.join([chr(b[i]) if (b[i] > 31 and b[i] < 127) else '.' for i in range(0,len(b),1)])
+        print(f"[=] {blk_index:3} | {hexstr.upper()} | {asciistr} ")
+        blk_index += 1
 
 def expect_response(accepted_responses: Union[int, list[int]]) -> Callable[..., Any]:
     """