- Introduction to Video
- Stream video files
- Start live streaming
- Make API requests
- Play your videos
- Enable static MP4 renditions
- Download for offline editing
- Embed videos for social media
- Listen for webhooks
- Secure video playback
- Create clips from your videos
- Get images from a video
- Create timeline hover previews
- Adjust audio levels
- Add watermarks to your videos
- Add subtitles to your videos
- Minimize processing time
- Upload files directly
- Autoplay your videos
- Stream an audio-only version of your video
- Synchronize video playback
- Integrate with your CMS
Verify webhook signatures
You have the option to verify webhook requests that Mux sends to your endpoints. Mux will include a signature in the request's header. You can use this signature in your code to make sure the request was sent by Mux and not a third party.
In this guide:
Before you get started, you will need your webhook's signing secret. You can find that where you configure webhooks on the webhooks settings page. Please note that the signing secret is different for each webhook endpoint that we notify.
Webhooks contain a header called mux-signature
with the timestamp and a signature. The timestamp is prefixed by t=
and the signature is prefixed by a scheme. Schemes start with v
, followed by an integer. Currently, the only valid signature scheme is v1
. Mux generates signatures using HMAC with SHA2-256.
Mux-Signature: t=1565220904,v1=20c75c1180c701ee8a796e81507cfd5c932fc17cf63a4a55566fd38da3a2d3d2`
Split the header at the ,
character and get the values for t
(timestamp) and v1
(the signature)
You will need:
- the timestamp from Step 1 as a string (for example: "1565220904")
- the dot character
.
- the raw request body (this will be JSON in a string format)
Use the 3 components from Step 2 to compute an HMAC with the SHA256 hash function. Depending on the language that you are using this will look something like the following:
secret = 'my secret' // your signing secret payload = timestamp + "." + request_body expected_signature = createHmacSha256(payload, secret)
Compare the signature in the header to the expected signature. If the signature matches, compute the difference between the current timestamp and the received timestamp, then check to make sure that the timestamp is within our tolerance. By default, our SDKs allow a tolerance of 5 minutes.
Our official SDKs for Node and Elixir contain helper methods for verifying Mux webhooks. If you're using one of these languages it's best to use our available helper methods. Note that the helper methods use the raw request body instead of a payload including the timestamp. A full Express example is available in the Node SDK.
# check the mux-elixr docs for details and a full example using Phoenix
# https://github.com/muxinc/mux-elixir#verifying-webhook-signatures-in-phoenix
Mux.Webhooks.verify_header(raw_body, signature_header, secret)