Chilkat Online Tools

VB.NET / New FreshBooks / Verify Webhook Callback

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' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim http As New Chilkat.Http
Dim success As Boolean

' Use this online tool to generate code from sample JSON: Generate Code to Create JSON

' The following JSON is sent in the request body.

' {
'   "callback": {
'     "callback_id": 123,
'     "verifier": "{{verifier}}"
'   }
' }

Dim json As New Chilkat.JsonObject
json.UpdateInt("callback.callback_id",123)
json.UpdateString("callback.verifier","{{verifier}}")

' Adds the "Authorization: Bearer <access_token>" header.
http.AuthToken = "<access_token>"
http.SetRequestHeader("Content-Type","application/json")

Dim sbRequestBody As New Chilkat.StringBuilder
json.EmitSb(sbRequestBody)

Dim resp As Chilkat.HttpResponse = http.PTextSb("PUT","https://api.freshbooks.com/events/account/{{accountId}}/events/callbacks/{{callbackId}}",sbRequestBody,"utf-8","application/json",False,False)
If (http.LastMethodSuccess = False) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


Debug.WriteLine(resp.StatusCode)
Debug.WriteLine(resp.BodyStr)

Curl Command

curl -X PUT
	-H "Authorization: Bearer <access_token>"
	-H "Content-Type: application/json"
	-d '{
    "callback": {
        "callback_id": {{callbackId}},
        "verifier": "{{verifier}}"
    }
}'
https://api.freshbooks.com/events/account/{{accountId}}/events/callbacks/{{callbackId}}

Postman Collection Item JSON

{
  "name": "Verify Webhook Callback",
  "request": {
    "method": "PUT",
    "header": [
      {
        "key": "Content-Type",
        "name": "Content-Type",
        "value": "application/json",
        "type": "text"
      }
    ],
    "body": {
      "mode": "raw",
      "raw": "{\n    \"callback\": {\n        \"callback_id\": {{callbackId}},\n        \"verifier\": \"{{verifier}}\"\n    }\n}"
    },
    "url": {
      "raw": "https://api.freshbooks.com/events/account/{{accountId}}/events/callbacks/{{callbackId}}",
      "protocol": "https",
      "host": [
        "api",
        "freshbooks",
        "com"
      ],
      "path": [
        "events",
        "account",
        "{{accountId}}",
        "events",
        "callbacks",
        "{{callbackId}}"
      ]
    },
    "description": "## Verifying Webhooks\n\nEach Webhook sent by FreshBooks includes a header, X-FreshBooks-Hmac-SHA256, with a base64-encoded signature generated using with the data sent in the request and token originally sent in the web hook verification process as a secret.\n\nWhen you receive the webhook, you can verify that it came from FreshBooks by computing the signature and comparing it against the header.\n\nWhen generating your cryptographic hash function, you will have two inputs. \n\n1. Your string input will be the response parameters which you will need to enter as a JSON String. \n\ni.e. `message = '{\"name\": \"client.update\", \"object_id\": \"177864\", \"user_id\": \"1\", \"account_id\": \"K1pdgJ\"}'` \n\n2. Your verifier (or 'secret') is sent as a response from your initial webhook registration. \n\nIt is also important that you maintain spaces between all colons and commas.  \n\nYou will also need to make sure that your verifier is a base64 encoded string. \n\nHere is an example script in Python: \n\n\n```\nimport base64\nimport hmac\nimport hashlib\n\nverifier = \"UWQfd9zCzxmVwFZWKqqKwLxqz8gvzGdAn\"\nmessage = '{\"name\": \"client.update\", \"object_id\": \"177864\", \"user_id\": \"1\", \"account_id\": \"FrEsHb\"}'\ndig = hmac.new(\n    verifier,\n    msg=message,\n    digestmod=hashlib.sha256\n).digest()\nprint(base64.b64encode(dig).decode())\n``` \nand an example in Node.js:\n\n\n```\nconst crypto = require('crypto')\nconst utf8 = require('utf8');\n\nconst hmac = hmac256(utf8.encode('{\"name\": \"client.update\", \"object_id\": \"177864\", \"user_id\": \"1\", \"account_id\": \"FrEsHb\"}'),\n\n  Buffer.from(utf8.encode('UWQfd9zCzxmVwFZWKqqKwLxqz8gvzGdAn')),\n\n  'base64')\n\nconsole.log(hmac)\n\n\n\nfunction hmac256(data, authKey, encoding) {\n\n  const x = crypto.createHmac('sha256', authKey)\n  x.update(data)\n  return x.digest(encoding)\n}\n```\n"
  },
  "response": [
  ]
}