tlv-to-json

TLV string to JSON object

This library provides a simple way to convert TLV string to a JSON object.

The type and length are fixed in size, and the value field is of variable size.

More information here: https://en.wikipedia.org/wiki/Type–length–value

Examples

Simple example

Input string:

0105HELLO0205WORLD0304A943

Implementation:

import { TLV } from 'tlv-to-json';

const output = TLV.toJSON('/* PUT HERE THE INPUT STRING */');

console.log(JSON.stringify(output, null, 2));

Output JSON:

{
  "T01": "HELLO",
  "T02": "WORLD",
  "T03": "A943"
}

Please note types are prefixed with the letter T.

Advanced example

Input string:

00020101021226430012com.facebook011259703395303802079990997520400005303152540410.05802US5907SHOPIFY6008Beaumont80540024com.facebook.pay.options0108B08262600203002030300281730029com.facebook.pay.options.uuid013628c729bb-0b23-4014-9974-da73573cbc8463040989

Implementation:

import { TLV } from 'tlv-to-json';

const output = TLV.toJSON('/* PUT HERE THE INPUT STRING */');

console.log(JSON.stringify(output, null, 2));

Output JSON:

{
  "T00": "01",
  "T01": "12",
  "T26": {
    "T00": "com.facebook",
    "T01": "597033953038",
    "T02": "9990997"
  },
  "T52": "0000",
  "T53": "152",
  "T54": "10.0",
  "T58": "US",
  "T59": "SHOPIFY",
  "T60": "Beaumont",
  "T80": {
    "T00": "com.facebook.pay.options",
    "T01": "B0826260",
    "T02": "002",
    "T03": "002"
  },
  "T81": {
    "T00": "com.facebook.pay.options.uuid",
    "T01": "28c729bb-0b23-4014-9974-da73573cbc84"
  },
  "T63": "0989"
}

Please note types are prefixed with the letter T.

Recursive example

Input string:

0105HELLO0229012501210117011301090105WORLD03044369

Implementation:

import { TLV } from 'tlv-to-json';

const output = TLV.toJSON('/* PUT HERE THE INPUT STRING */');

console.log(JSON.stringify(output, null, 2));

Output JSON:

{
  "T01": "HELLO",
  "T02": {
    "T01": {
      "T01": {
        "T01": {
          "T01": {
            "T01": {
              "T01": "WORLD"
            }
          }
        }
      }
    }
  },
  "T03": "4369"
}

Please note types are prefixed with the letter T.

CRC Check

By default, the toJSON function assume the input string's last 4 digits are a CRC16 Checksum Hexadecimal.

To disable the checksum verificación you can pass false to the second parameter:

const json = TLV.toJSON('/* THE INPUT STRING */', false);

In case of checksum error, this message will be displayed:

Checksum failed (Calculated: AAE6, Expected: 0989)