KDE PIM/KItinerary/MAV Barcode: Difference between revisions

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== Payload Structure ==
== Payload Structure ==
Note: this is based on very few samples so far and thus isn't very reliable yet!


* Seems byte- rather than bit-aligned.
* Seems byte- rather than bit-aligned.
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* Content has a high amount of null bytes.
* Content has a high amount of null bytes.
* Date/time values are encoded as seconds since Jan 1st 2017. Times are local but do not account for DST. (Exception: traveler birth date).
* Date/time values are encoded as seconds since Jan 1st 2017. Times are local but do not account for DST. (Exception: traveler birth date).
* At least three observed variants, so maybe some kind of (fixed-length?) block structure (<s>but no signs of TLV</s> byte 24/25/(26) might suggest some kind of TLV?):
* Consists of a variable set of blocks.
** 217 bytes, personalized train ticket without seat reservation
* Block layout is defined by information in the header block, there does not seem to be a TLV-like structure.
** 274 bytes, personalized train ticket with seat reservation
* Observed block layouts:
** 153 bytes, bike addon ticket
** Header block.
** 331 bytes, personailed train ticket with seat reservation and "Pótjegy"
** Either passenger or bike addon block.
** seems to correlate to the type of light blue boxes on the PDF, but so far it's unclear how to determine which blocks are present
** Trip block.
** 0-2 reservation/surcharge blocks.


=== Header Block ===
=== Header Block ===

Revision as of 15:36, 24 August 2021

Current Version (>= 2020?)

General Observation

  • Uses PDF417 barcode format, same content on PDF and in the official app.
  • Variable length.
  • For domestic tickets only.
  • No similarities with a known ERA format.

Outer Structure

  • Two byte header, fixed 0x0403.
  • Gzip-compressed payload using deflate compression, starting with the standard Gzip header 0x1f8b0800000000000000.
  • 256 remaining bytes, high entropy and length suggest a cryptographic signature.

Payload Structure

  • Seems byte- rather than bit-aligned.
  • String encoding is UTF-8.
  • Number encoding seems big endian.
  • Content has a high amount of null bytes.
  • Date/time values are encoded as seconds since Jan 1st 2017. Times are local but do not account for DST. (Exception: traveler birth date).
  • Consists of a variable set of blocks.
  • Block layout is defined by information in the header block, there does not seem to be a TLV-like structure.
  • Observed block layouts:
    • Header block.
    • Either passenger or bike addon block.
    • Trip block.
    • 0-2 reservation/surcharge blocks.

Header Block

  • Always present.
  • Always at offset 0.
  • 39 bytes long.
Offset Size Data Type Meaning Notes
0 17 string ticket number printed as "CIV" in the PDF
17 1 null ? null in all samples
18 2 uint16 UIC company code issuer?, 0x0483 (1155) for MAV
20 4 time issuing time
24 1 ? ticket type?? 'C' for bike addon tickets, 'B' or 'D' for regular tickets (with or without seat reservation, 'E' for tickets with surcharge (and with or without seat reservation), null for "connecting ticket to season ticket"
25 2 ? ?
27 1 null ? null in all samples
28 1 ? ticket type?? 0x01 for bike addon block, 0x81 for passenger block
29 1 null ? null in all samples
30 1 uint8 number of reservation/surcharge blocks
31 4 null ? null in all samples
35 4 ? ?

Passenger Block

  • Present when header block byte 28 is 0x81.
  • When present, located right after the header block.
  • 68 bytes long.
Offset Size Data Type Meaning Notes
39 45 string passenger name null terminated
84 4 uint32 passenger birth date year * 10000 + month * 100 + day
88 15 null ? null in all samples
103 4 ? ?

Bike Addon Block

  • Present when header block byte 28 is 0x01.
  • When present, located right after the header block.
  • 4 bytes long.
Offset Size Data Type Meaning Notes
0 4 ? ? values seem fixed in all samples?

Trip Block

  • Always present.
  • Follows the passenger or bike addon block.
  • 102 bytes long.
Offset Size Data Type Meaning Notes
107 3 uint24 UIC departure station code including the national prefix ('55' for HU)
110 3 uint24 UIC arrival station code
113 90 null ? null in all samples
203 1 text class "1" or "2"
204 1 ? ? 0x01 in all samples
205 4 time time of validity/travel
209 8 ? ?

Seat Reservation Block

  • 57 bytes long.
  • Also used for surcharge ("Pótjegy") blocks, in which case the fields for coach and seat numbers are all null.
  • Order of surcharge and reservation blocks seems undefined if both are present.
  • Follow all other blocks, number of blocks determined by header block byte 30.
Offset Size Data Type Meaning Notes
0 3 uint24 UIC departure station code
3 3 uint24 UIC arrival station code
6 4 ? ?
10 4 time time of validity/travel
14 2 uint16 UIC company code operator?, 0x0483 (1155) for MAV
16 5 string train number null-terminated
21 1 ? ? 0x01 in all samples
22 3 string coach number null terminated
25 2 uint16 seat number
27 2 uint16 seat number repeated from byte 25/26?
29 28 null ? null bytes in all samples

Missing/Suspected Information

  • Station names are not included, but station codes might be. UIC station numbers (possibly without the country prefix) would be the obvious suspect, given the MÁV website uses those as well.
  • If the train number is included, one would expect at least the day of travel to be included as well.
  • Class: several candidate locations exist, but given it's small footprint we need a lot more samples to confirm one of those.

Old Format (<2020?)

General Structure

  • QR code containing a hex string
  • content of the hex string is zlib-compressed, no header bytes
  • result of decompression is a UTF-8 encoded string
    • the first 512 bytes appear to be a hex string again, length and entropy suggest a cryptographic signature
    • the second part looks like a '!' delimited list

Content

Index Format Meaning Notes
0 ~<number> ticket number printed as "CIV" in the PDF
1 passenger name
2 yyyy.MM.dd passenger birth date
3 total price in HUF
4 ? ? "P05"
5 yyyy.MM.dd hh:mm begin of validity
6 yyyy.MM.dd hh:mm~v end of validity no idea what the literal '~v' means there
7 MÁV <number> travel distance
8 '-' separated string vias
9 departure station name
10 arrival station name
11 empty?
12 empty?
13 empty?
14 empty?
15 train number number only, not product/category prefix
16 class
17 yyyy.MM.dd~m day of travel?
18 string discount_type e.g. "Teljesárú" (full price)
19 <number>~h ticket price in HUF
20 departure station name possibly for the seat reservation
21 arrival station name possibly for the seat reservation
22 yyyy.DD.mm day of travel?
23 hh:mm time of departure
24 empty?
25 empty?
26 train number incl. product/category prefix
27 coach number
28 seat number
29 number price of reservation in HUF
30 extension-ticket "Helyjegy", "Pót- és helyjegy"
31 MÁV <number> ? same as entry 7, not always present