From a4010900eaa29fd86c114af869594b81bf8a6e14 Mon Sep 17 00:00:00 2001
From: Uli Heilmeier <uh@heilmeier.eu>
Date: Sun, 18 Aug 2019 20:06:15 +0200
Subject: [PATCH] Doc: Add notes about trace to Wireshark export

Adding some notes how to bring trace output into Wireshark.
---
 doc/trace_wireshark_notes.md | 60 ++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 doc/trace_wireshark_notes.md

diff --git a/doc/trace_wireshark_notes.md b/doc/trace_wireshark_notes.md
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+# Trace command notes
+
+The `trace` command lists the data exchange by the proxmark3 and a tag or a reader in human readable form.
+
+With `trace list` a table is shown which gives timing information, the src of the data bytes, the transmitted/received bytes itself, a check if the CRC was correct and some decoding of the command.
+
+To get a more detailed explanation of the transmitted data for ISO14443A traces the output can be converted to a pcapng file to read it with [Wireshark](https://www.wireshark.org/).
+
+To do so
+
+* use `trace list 14a x`
+* copy the output (starting with the timestamp) into a textfile
+* run `text2pcap -t "%S." -l 264 -n <input-text-file> <output-pcapng-file>`
+* now open your pcapng file in Wireshark or read it with the CLI version `tshark`
+
+An example frame
+
+with `trace list 14a`:
+
+```
+19072 |      29536 | Rdr |93  70  88  04  cf  ff  bc  7f  bb  |  ok | SELECT_UID
+```
+
+the same data with `tshark -r foo.pcapng -V -x`:
+
+```
+Frame 5: 13 bytes on wire (104 bits), 13 bytes captured (104 bits) on interface 0
+    Interface id: 0 (unknown)
+        Interface name: unknown
+    Encapsulation type: ISO 14443 contactless smartcard standards (177)
+    Arrival Time: Aug 17, 2019 23:17:00.000002606 CEST
+    [Time shift for this packet: 0.000000000 seconds]
+    Epoch Time: 1566076620.000002606 seconds
+    [Time delta from previous captured frame: 0.000000840 seconds]
+    [Time delta from previous displayed frame: 0.000000840 seconds]
+    [Time since reference or first frame: 0.000001907 seconds]
+    Frame Number: 5
+    Frame Length: 13 bytes (104 bits)
+    Capture Length: 13 bytes (104 bits)
+    [Frame is marked: False]
+    [Frame is ignored: False]
+    [Protocols in frame: iso14443]
+ISO 14443
+    Pseudo header
+        Version: 0x00
+        Event: Data transfer PCD -> PICC (0xfe)
+        Length field: 9
+    Message: Select
+        SEL: 0x93
+        NVB: 0x70
+        CT: 0x88
+        UID_CLn: 04cfff
+        BCC: 0xbc
+        CRC: 0xbb7f [correct]
+        [CRC Status: Good]
+
+0000  00 fe 00 09 93 70 88 04 cf ff bc 7f bb            .....p.......
+```
+
+If the Wireshark ISO14443a dissector is missing some commands or needs some other rework please [file a bug](https://bugs.wireshark.org/bugzilla/).