FD1 Session

Functions relating to a connection Session. These calls are primarily intended for WebSockets; if you are using HTTP GET/POST/PUT interfaces then session information is passed with HTTP headers.

fd1.session.login

Transmits your login credentials to the server, typically authorising your data access. If you are using a websocket, then your first "send" should be a fd1.session.login packet. This also applies if you reconnect due to network drop out - another session login is required as you may connect to a different server.

You MUST send a valid fd1.session.login before FD1 will allow any other endpoints to be activated.

You MAY send multiple session.login commands, these are added to the scope you are allowed

There are several methods of authentication available. The server may enable/disable/enforce your selection.

Example

A normal login using an ApiKey

{
  a: "fd1.session.login",
  v: {
    apikey: "ABAabfjhfh40584g5hfgge5756"
  }
}

A login using a QR code. A QR code login may be used by customers directly to access a very specific subset of data, such as a receipt or product information

{
  a: "fd1.session.login",
  v: {
    qr: "https://mycoolwebsite.xyz/welcome.htm?fd1=akajsh59585h5gfiu4b5utg568rg5h65g6h5"
  }
}

A username/password login where the password is not transmitted over the network

Step 1. Request a server supplied nonce/token

{
  a: "fd1.session.login",
  v: {
    method: "user/pass",
    user: "bob@example.com"
  }
}

Wait for server response containing the nonce and salt

{
  r: "fd1.session.login",
  data: {
    nonce: "abcdef12345",
    salt1: "na8f9$9hb",
    salt2: "9gb76"
  }
}

Combine the nonce with sha-256 of (salt + password) and transmit the result, using the logic

1. Combine salts and password, then calculate the SHA-256 of that
   set temp = String(salt1) + String(password) + String(salt2)
   set encoded = crypto.subtle.digest("SHA-256", temp)
   set b64 = MakeBase64(encoded)
2. Combine nonce and sha-256 base64 value
   let combined = String(nonce) + String(b64)
3. Calculate SHA-256 of that value
   let sha256 = crypto.subtle.digest("SHA-256", combined)
   NB. The actual required steps are more complex. See https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest for worked examples
4. Convert the SHA-256 result to base64, and transmit that.

{
  a: "fd1.session.login",
  v: {
    method: "user/pass",
    sha256: "28fe9283ba09c7e"
  }
}

A Proof of key exchange. Each end must have been initialised with a unique key. ie both ends have the same key. These keys are typically 1Mb or more in size.

Step 1. Request a server supplied nonce

{
  a: "fd1.session.login",
  v: {
    method: "proofofkey",
    dateutc: "2024-05-02 06:07:08"
  }
}

Wait for server response containing the nonce

{
  r: "fd1.session.login",
  data: {
    nonce: "abcdef12345"
  }
}

Calculate an offset into the preshared key

{
  a: "fd1.session.login",
  v: {
    method: "user/pass",
    sha256: "28fe9283ba09c7e"
  }
}

fd1.session.set_option

Change individual options on the session.

let myDate = new Date();
let localtime = myDate.getFullYear() + "-"
    + (myDate.getMonth() + 1) + "-" 
    + myDate.getDate() + " " 
    + myDate.getHours() + ":" 
    + myDate.getMinutes() + ":" 
    + myDate.getSeconds() + "." 
    + myDate.getMilliseconds()
                                    

Example

When using SalesBuilder, reply with partial sale details

{
  a: "fd1.session.set_option",
  k: "jafj459385hggdg39vgcg53038qQQ8",
  v: {
    salesbuilder: "reply-brief-sale"
  }
}