Difference between revisions of "KDE PIM/KItinerary/Thalys Barcode"

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(General Observations)
(General Observations)
(2 intermediate revisions by the same user not shown)
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* always exactly 114 byte
 
* always exactly 114 byte
* all binary, there are no recognizable ASCII strings in this
 
 
* there's two 14-15 byte variable lengths blocks towards the end with very high entropy, possibly some kind of signature
 
* there's two 14-15 byte variable lengths blocks towards the end with very high entropy, possibly some kind of signature
 
* based on currently only 4 samples, so there's limited confidence in this
 
* based on currently only 4 samples, so there's limited confidence in this
 
* 0:4 - 2:1 (14 bit) is "3018", which is the UIC operator code of Thalys. This matches Appendix C of ANNEX B.6 of TAP TSI, but unfortunately only for the first 18 bit it seems. Might still mean a similar encoding is used, but in a different layout.
 
* 0:4 - 2:1 (14 bit) is "3018", which is the UIC operator code of Thalys. This matches Appendix C of ANNEX B.6 of TAP TSI, but unfortunately only for the first 18 bit it seems. Might still mean a similar encoding is used, but in a different layout.
 +
* all expected data has been located, but not the date/time?
  
 
= Bit Layout =
 
= Bit Layout =
Line 16: Line 16:
 
| 5:0 - 5:7 || 0x01 or 0x02 || class ||
 
| 5:0 - 5:7 || 0x01 or 0x02 || class ||
 
|-
 
|-
| 6:0 - 8:7 || null || ||
+
| 6:0 - 9:5 || null || ||
 
|-
 
|-
| 9:0 - 9:7 || 0x01 || || ticket/traveler count, or traveler type?
+
| 9:6 - 16:3 || 9 x 6bit string || ticket number ||
 
|-
 
|-
| 10:0 - 18:3 || TODO || ||
+
| 16:4 - 18:3 || TODO || ||
 
|-
 
|-
| 18:4 - 22:1 || 5 x 6bit || departure station || see below
+
| 18:4 - 22:1 || 5 x 6bit string || departure station || see below
 
|-
 
|-
| 22:2 - 25:7 || 5 x 6bit || arrival station || see below
+
| 22:2 - 25:7 || 5 x 6bit string || arrival station || see below
 
|-  
 
|-  
| 26:1 - 35:7 || TODO || ||
+
| 26:0 - 27:7 || TODO || ||
 
|-
 
|-
| 36:0 - 42:7 || null || ||
+
| 28:0 - 29:1 || null || ||
 +
|-
 +
| 29:2 - 32:1 || 4 x 6bit string || train number || preceding bits might be a 5th character for this
 +
|-
 +
| 32:2 - 33:3 || 9bit uint || coach number || field seems a bit large for this?
 +
|-
 +
| 33:4 - 35:5 || 3 x 6bit string || seat number ||
 +
|-
 +
| 35:6 - 42:7 || null || ||
 
|-
 
|-
 
| 43:0 - 49:7 || 0x9a 0c 28 82 c8 22 b2 || || fixed in all samples
 
| 43:0 - 49:7 || 0x9a 0c 28 82 c8 22 b2 || || fixed in all samples
Line 54: Line 62:
  
 
Remaining bytes are filled by null until reaching 114 bytes.
 
Remaining bytes are filled by null until reaching 114 bytes.
 +
 +
Strings:
 +
* encoded as 6bit per character
 +
* a character can be converted to the corresponding ASCII value by adding 32
  
 
Station identifiers:
 
Station identifiers:
 
* using Benerail identifiers, which consists of 5 upper-case letters, the first two being the ISO 3166-1 alpha 2 code
 
* using Benerail identifiers, which consists of 5 upper-case letters, the first two being the ISO 3166-1 alpha 2 code
* each letter is encoded as a 5 bit value that can be converted to the corresponding ASCII value by adding 32.
+
* very similar to SNCF identifiers, but there are slight differences e.g. for Amsterdam Central (NLASC vs NLAMA).

Revision as of 16:23, 14 February 2020

General Observations

  • always exactly 114 byte
  • there's two 14-15 byte variable lengths blocks towards the end with very high entropy, possibly some kind of signature
  • based on currently only 4 samples, so there's limited confidence in this
  • 0:4 - 2:1 (14 bit) is "3018", which is the UIC operator code of Thalys. This matches Appendix C of ANNEX B.6 of TAP TSI, but unfortunately only for the first 18 bit it seems. Might still mean a similar encoding is used, but in a different layout.
  • all expected data has been located, but not the date/time?

Bit Layout

Byte[:Bit] (MSB) Content Meaning Notes
0:0 - 4:7 0x32 F2 84 20 40 fixed in all samples
5:0 - 5:7 0x01 or 0x02 class
6:0 - 9:5 null
9:6 - 16:3 9 x 6bit string ticket number
16:4 - 18:3 TODO
18:4 - 22:1 5 x 6bit string departure station see below
22:2 - 25:7 5 x 6bit string arrival station see below
26:0 - 27:7 TODO
28:0 - 29:1 null
29:2 - 32:1 4 x 6bit string train number preceding bits might be a 5th character for this
32:2 - 33:3 9bit uint coach number field seems a bit large for this?
33:4 - 35:5 3 x 6bit string seat number
35:6 - 42:7 null
43:0 - 49:7 0x9a 0c 28 82 c8 22 b2 fixed in all samples
50:0 - 55:7 TODO
56:0 - 58:7 0x0a 80 30 fixed in all samples
59:0 - 59:7 0x2C or 0x2E

After this there follow two blocks with the following variable length layout:

Byte[:Bit] (MSB) Content Meaning Notes
0:0 - 0:7 0x02 fixed
1:0 - 1:7 8bit uint length
N bytes high entropy content

Remaining bytes are filled by null until reaching 114 bytes.

Strings:

  • encoded as 6bit per character
  • a character can be converted to the corresponding ASCII value by adding 32

Station identifiers:

  • using Benerail identifiers, which consists of 5 upper-case letters, the first two being the ISO 3166-1 alpha 2 code
  • very similar to SNCF identifiers, but there are slight differences e.g. for Amsterdam Central (NLASC vs NLAMA).

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