Specification: nfc

When a passenger intends to use the service, they present their travel card, which may have a token referencing an account with corresponding travel rights. In cases where there is no token present, the serial number of the travel card will be used. If there is a customer account associated with that serial number, a potential token will be generated and written back to the travel card. See diagram for total flow.

Token should be transmitted as base64 encoded URL string without padding.

• Topic: validators/nfc
• Direction: Publish (Inbound to client)
• JSON Schema: nfc.schema.json
• MQTT QoS: 0 (at most once)
• Trigger: Once every time a passenger presents a travel card to the barcode reader.

Card content dump

If the device is configured accordingly, the complete content of the card can be transferred from the device, as depicted in the flow chart. This simplifies the client’s perspective as it enables direct access to the card’s content. Please refer to the validators/configure topic for the configuration flag that determines whether cardContent is set. Below are examples demonstrating the scenarios when cardContent is enabled.

This concept is applicable in situations where the smart card holds various types of travel rights and there is a requirement to prioritize among them. Examples of such types include NOD (Nasjonal OrdreDatabase), account-based, and others.

Only supported type for now is nsd and that needs to be set as type, for future proofing when new types are added.

• nsd: Nasjonal Standard Desfire. Data format for ticketing using Mifare Desfire cards. In Norway described by “Håndbok V821 del 18”.

Examples

{
  "traceId": "543070fe-ef32-11ed-a05b-0242ac120003",
  "deviceId": "flv202400004",
  "eventTimestamp": "2023-04-22T10:28:37.337Z",
  "travelCardNumber": "323116753",
  "token": "CtYBCtMBCtN...VDRFNBKgsIpdicoAYQ4NeUdzAB"
}

Example with card content

{
  "traceId": "543070fe-ef32-11ed-a05b-0242ac120003",
  "deviceId": "flv202400004",
  "eventTimestamp": "2023-04-22T10:28:37.337Z",
  "travelCardNumber": "323116753",
  "cardContent": [
    {
      "appId": "<ID>",
      "type": "nsd",
      "files": [{ "fileNumber": "<FileNumber>", "content": "0x0032" }]
    }
  ]
}

Flow

  flowchart TD
      A[Customer shows card] --> B(NFC device\nreads card)
  
      B --> B1{Is supported card?}
      B1 -->|no| ResponseInvalid_0[Built in response:\n Not valid]
  
  
      B1 -->|Yes| C{Device contains\naccess keys}
  
      C -->|Yes| AC1_Dump{Is dump card content\nconfig active?}
      AC1_Dump -->|Yes| AC1_Dump_1(Read entire\ncard content)
  
      AC1_Dump_1 -->|/validators/nfc|AC4
  
      AC1_Dump -->|No| AC1(Read card,\nfetch NSD serial number and\npotential token)
      AC1 --> AC2{Is token\non card?}
      AC2 -->|Yes| AC3(Read token)
  
      AC3 -->|/validators/nfc| AC4{Does token\nexists at Provider?}
      AC4 -->|Yes| AC5(Validate Token)
      AC5 -->|"/validators/[deviceId]/response"| AC6[Show response\nto customer]
      AC4 -->|Blocked/removed| AC7(APDU Subprocess\nRemove token from card)
      AC7 -->|"/validators/[deviceId]/response"| ResponseInvalid
  
  
      C -->|No| NAC1(Fetch NSD serial number)
      NAC1 -->|/validators/nfc| NAC2(APDU Subprocess\nFetch token)
      NAC2 --> NAC3{Is token\non card?}
  
  
      AC2 -->|No| AC2_Get(Send only serial number)
      AC2_Get -->|/validators/nfc| NoToken(Get token from\nserial number)
  
      NAC3 -->|No| NoToken
      NAC3 -->|Yes| NACToken1{Does token\nexists at Provider?}
  
      NACToken1 -->|Blocked/removed| NACToken1No(APDU Subprocess\nRemove token from card)
      NACToken1No  -->|"/validators/[deviceId]/response"| NACToken1NoResponse[Show response\nto customer]
  
      NoToken --> FetchTokenStatus{Does token\nexists at Provider?}
      FetchTokenStatus-->|Blocked/removed| FetchTokenInvalid(No valid travel right)
      FetchTokenStatus-->|Not found| FetchTokenInvalid
      FetchTokenInvalid -->|"/validators/[deviceId]/response"| ResponseInvalid[Show response:\n Not valid]
  
      FetchTokenStatus-->|Found| FetchTokenFound(APDU Subprocess:\nWrite token to card)
  
      FetchTokenFound -->|Yes| FetchTokenFoundValidate(Validate Token)
      FetchTokenFoundValidate -->|"/validators/[deviceId]/response"| FetchTokenResponse[Show response\nto customer]
  
      NACToken1 -->|Found| FetchTokenFoundValidate
  

• The APDU sub-processes are custom command transceive processes that utilize the apdu topics for communication and data exchange.
• In the flow chart, the “Provider” refers to the Account Based Ticketing (ABT) provider. This provider handles tasks such as customer data management and ticket purchases within the ABT system.