KDE PIM/KItinerary/vr.fi Barcode: Difference between revisions

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* there's a 13 digit order number and optionally a 15 digit reference number on each ticket, sequential and covering multiple sections/travelers
* there's a 13 digit order number and optionally a 15 digit reference number on each ticket, sequential and covering multiple sections/travelers
* one barcode seems to be exactly for one journey section
* one barcode seems to be exactly for one journey section
* all available samples are for a single adult traveler
* all available samples are for a single adult traveler, and for second class


= Bit Layout =
= Bit Layout =
Line 25: Line 25:
| 4:7 - 5:7 || 9 bit uint ||  day of travel || counted from Jan 1
| 4:7 - 5:7 || 9 bit uint ||  day of travel || counted from Jan 1
|-
|-
| 6 - 13:3 || 0x00 0x49 0x24 0x92 0x49 0x24 0x92 0x1 || || fixed in all samples, patterns repeats below
| 6 - 13:1 || 0x00 0x49 0x24 0x92 0x49 0x24 0x92 0b00 || || fixed in all samples, patterns repeats below
|-
|-
| 13:4 - 15:3 || todo || todo || correlation between samples suggests departure location
| 13:2 - 16:7 || 5 x 6bit || departure station || see below
|-
|-
| 15:4 - 17:2 || 0b1001 0b0010 0100 0b001 || || fixed in all samples
| 17:0 || null || ||
|-
|-
| 17:3 - 21:7 || todo || todo || correlation between samples suggests arrival location
| 17:1 - 20:6 || 5 x 6bit || arrival station || see below
|-
| 20:7 - 21:7 || todo || todo ||
|-
|-
| 22:0 - 23:5 || 14 bit uint || train number || might be including too many/few leading 0 bits, 0 for buses
| 22:0 - 23:5 || 14 bit uint || train number || might be including too many/few leading 0 bits, 0 for buses
|-  
|-  
| 23:6 - 28 || todo || todo ||
| 23:6 - 25:3 || null || ||
|-
| 25:4 - 28:7 || todo || todo ||
|-  
|-  
| 29 || 0b0010 0000 || || fixed in all samples
| 29 || 0b0010 0000 || || fixed in all samples
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| 42:1 - 106:0 || 64 byte varying || || high entropy in all samples, signature?
| 42:1 - 106:0 || 64 byte varying || || high entropy in all samples, signature?
|-
|-
| 106:1 - 106:7 || null || ||
| 106:1 - 106:7 || 0x00 or 0x80 || ||
|-
|-
|}
|}
= Station Codes =
* Using 2-4 characters long alphabetical codes from https://rata.digitraffic.fi/api/v1/metadata/stations, Wikidata has those codes as untyped P296 properties
* Values are encoded as a six bit number per character. Adding 55 to that number results in the corresponding ASCII code, which would suggest values 0-9 are reserved for digits. The value 36 (']' by that rule) is used to mark an unset character (for codes shorter than 5 characters).
* The official table also uses the 'Ä' and 'Ö' characters, it's unclear how those would be encoded here though.

Revision as of 14:47, 1 April 2020

General Observations

  • always exactly 107 byte
  • all binary, there are no recognizable ASCII strings in this
  • the last ~64 byte have very high entropy, suggesting a signature or a compressed section
  • there's a base64 encoded sequential number printed below the Aztec code on the ticket, containing 24bit.
  • there's a 13 digit order number and optionally a 15 digit reference number on each ticket, sequential and covering multiple sections/travelers
  • one barcode seems to be exactly for one journey section
  • all available samples are for a single adult traveler, and for second class

Bit Layout

Byte[:Bit] (MSB) Content Meaning Notes
0 - 1 0b0001 0000 0b0000 0010 unknown fixed in all samples
2 0b1010 0000 or 0b1000 0000 unknown
3 0b0000 0001 unknown fixed in all samples
4:0 4:6 null
4:7 - 5:7 9 bit uint day of travel counted from Jan 1
6 - 13:1 0x00 0x49 0x24 0x92 0x49 0x24 0x92 0b00 fixed in all samples, patterns repeats below
13:2 - 16:7 5 x 6bit departure station see below
17:0 null
17:1 - 20:6 5 x 6bit arrival station see below
20:7 - 21:7 todo todo
22:0 - 23:5 14 bit uint train number might be including too many/few leading 0 bits, 0 for buses
23:6 - 25:3 null
25:4 - 28:7 todo todo
29 0b0010 0000 fixed in all samples
30:0 - 30:5 6 bit uint coach number leading 0 bits uncertain
30:6 - 31:4 7 bit uint seat number 0 if no seat reserved
31:5 - 31:7 0b100 fixed in all samples
32 - 40 0x89 0x24 0x92 0x49 0x24 0x90 0x60 0x00 0x01 fixed in all samples, repeats a pattern from 6-12
41:0 - 42:0 todo todo varies slightly between samples
42:1 - 106:0 64 byte varying high entropy in all samples, signature?
106:1 - 106:7 0x00 or 0x80

Station Codes

  • Using 2-4 characters long alphabetical codes from https://rata.digitraffic.fi/api/v1/metadata/stations, Wikidata has those codes as untyped P296 properties
  • Values are encoded as a six bit number per character. Adding 55 to that number results in the corresponding ASCII code, which would suggest values 0-9 are reserved for digits. The value 36 (']' by that rule) is used to mark an unset character (for codes shorter than 5 characters).
  • The official table also uses the 'Ä' and 'Ö' characters, it's unclear how those would be encoded here though.