Latest revision as of 08:58, 15 May 2021

Format

This is an ERA SSB version 1 code as described in "ERA TAP TSI Annex B.6 - Appendix C.1", with the following details/deviations:

the issuer code is "0010" (UIC company code of VR).
always exactly 107 byte
barcodes on (newer? vending machine bought?) tickets have a "2" in the version field, they are nevertheless in the ERA SSB v1 format.
arrival and destination are using alpha-numerical encoding and VR station codes.
the customer number field contains a static value? (20105355479332)

Other Observations

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

Obsolete (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.

@@ Line 1: / Line 1: @@
-= General Observations =
+= Format =
+This is an ERA SSB version 1 code as described in "ERA TAP TSI Annex B.6 - Appendix C.1", with the following details/deviations:
+* the issuer code is "0010" (UIC company code of VR).
 * always exactly 107 byte
-* all binary, there are no recognizable ASCII strings in this
+* barcodes on (newer? vending machine bought?) tickets have a "2" in the version field, they are nevertheless in the ERA SSB v1 format.
-* the last ~64 byte have very high entropy, suggesting a signature or a compressed section
+* arrival and destination are using alpha-numerical encoding and VR station codes.
+* the customer number field contains a static value? (20105355479332)
+= Other Observations =
 * 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
-= Bit Layout =
+= Obsolete (Bit Layout) =
 {| class="wikitable"
@@ Line 25: / Line 29: @@
 | 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
+|-
+| 13:2 - 16:7 || 5 x 6bit || departure station || see below
 |-
-| 13:4 - 15:3 || todo || todo ||
+| 17:0 || null || ||
 |-
-| 15:4 - 17:2 || 0b1001 0b0010 0100 0b001 || || fixed in all samples
+| 17:1 - 20:6 || 5 x 6bit || arrival station || see below
 |-
-| 17:3 - 21:7 || todo || todo ||
+| 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 - 28 || todo || todo ||
+| 23:6 - 25:3 || null || ||
+|-
+| 25:4 - 28:7 || todo || todo ||
 |-
 | 29 || 0b0010 0000 || || fixed in all samples
 |-
-| 30:0 - 30:5 || 5 bit uint || coach number || leading 0 bits uncertain
+| 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
@@ Line 51: / Line 59: @@
 | 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.