< KDE PIM | KItineraryRevision as of 18:59, 25 February 2020 by Vkrause (talk | contribs) (→Record Sequence)(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff) General Observations QR code, content has variable length at around 330 bytes. Contains readable strings as well as binary parts. Strings seem to be UTF-8 encoded. Seems to be a sequence of variable length records, rather than a fixed binary layout, could be some form of TLV encoding (there are some similarities to ASN.1 BER/DER for example). Records consist of a 1 byte type field, a 1 byte length field and N content bytes. For strings, the length is the amount of bytes needed to represent the UTF-8 string, not the amount of characters. The type field however does not seem to describe semantics, as values repeat for different values (rather than a data type of some form?). This could suggest that the record order defines their semantics? The presence of null records suggests that too, as well as the same record sequence in all samples. It is possible that there is a multi-byte length encoding comparable to BER/DER. The first 10 bytes don't seem to match the pattern yet, but that might be due to unknown multi-byte length encoding (could be a record containing the entire ticket). Record Sequence starting at offset 10: Nesting Depth Type Id Content Type Meaning Notes 1 0x12 nested record 2 0x0A 2bytes followed by nested records ? 0x08 04 3 0x12 string ticket type? "Point-to-point Ticket", "Supersaver Ticket" 2 0x12 string Departure station 2 0x1A string Arrival station 2 0x20 2 byte ? 0x2801 in all samples 2 0x32 string Via 2 0x38 1 byte ? 0x42 in all samples 2 0x42 7 byte ? date/time? 2 0x4A 7 byte ? date/time? 2 0x60 variable, null terminated ? 2-3 bytes in all samples 2 0x7A string ticket type or tariff parenthesis enclosed abbreviations, string is also printed on the ticket 2 0x88 1 byte ? null 2 0x98 1 byte ? 0x02 2 0xA0 1 byte ? null 1 0x1A nested record ? 2 0x0A string ? 8 digit number 2 0x12 string ? 36 char uuid 2 0x1A string family name 2 0x22 string given name 2 0x2A 7 byte ? date/time? 2 0x3A string tariff information? "HALBTAX" 1 0x2A nested record ? 2 0x0A 7 byte ? date/time? 2 0x10 4 byte ? followed by 0x200B outside of TLV structures? 1 0x32 nested record price information? 2 0x0A string ? "PCD" 2 0x12 string currency "CHF" 2 0x1A string ticket price 1 0x3A null ? 1 0x42 nested record train information not present in unbound tickets 2 0x5A string train number 2 0x70 null 2 0x78 null 1 0x48 7byte, no length byte!?! ? breaks the overall TLV structure?? almost fixed value in all samples 1 0x0A string ? 4 digit number (3342 in all samples) 1 0x12 string ? 5 digit number (00001 in all samples) 1 0x2A nested record 2 0x30 nested record 3 0x02 20-21 byte ? signature? this is somewhat similar to Thalys 3 0x02 20-21 byte ? Retrieved from "https://community.kde.org/index.php?title=KDE_PIM/KItinerary/SBB_Barcode&oldid=87754" Content is available under Creative Commons License SA 4.0 unless otherwise noted.