You have the option to verify webhook requests that Mux sends to your endpoints. Mux will include a signature in the request's
mux-signature header. You can use this signature in your code to make sure the request was sent by Mux and not a third party.
First, you will need your webhook's signing secret. You can find that where you configure webhooks on the webhooks settings page. Note that the signing secret is different for each url we notify.
You can also verify the signature manually, if you do not use one of the above SDKs. The
mux-signature header contains 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 SHA-256
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:
- 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 = // 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, and decide if the difference is within our tolerance. By default our SDKs allow a tolerance of 5 minutes.