KDE PIM/KItinerary/vr.fi Barcode: Difference between revisions
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| 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: | | 6 - 13:1 || 0x00 0x49 0x24 0x92 0x49 0x24 0x92 0b00 || || fixed in all samples, patterns repeats below | ||
|- | |- | ||
| 13: | | 13:2 - 15:3 || 3 x 6bit || departure station || see below | ||
|- | |- | ||
| 15:4 - 17: | | 15:4 - 17:0 || 0b1001 0b0010 0100 0b0 || || fixed in all samples | ||
|- | |- | ||
| 17:3 - 21:7 || todo || todo || | | 17:1 - 19:2 || 3 x 6bit || arrival station || see below | ||
|- | |||
| 19:3 - 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 | ||
| Line 53: | Line 55: | ||
| 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 || | | 106:1 - 106:7 || 0x00 or 0x80 || || | ||
|- | |- | ||
|} | |} | ||
= Station Codes = | |||
* Using 2-3 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 in case of two letter station codes. | |||
Revision as of 15:16, 30 March 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 - 15:3 | 3 x 6bit | departure station | see below |
| 15:4 - 17:0 | 0b1001 0b0010 0100 0b0 | fixed in all samples | |
| 17:1 - 19:2 | 3 x 6bit | arrival station | see below |
| 19:3 - 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 2-3 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 in case of two letter station codes.