Secure URLs prevent others from generating LibPixel image URLs on your behalf, which would count toward your usage limits.
Secure URLs contain an additional
signature parameter at the end of the query string. Signatures are generated using your private Auth Secret.
By default, signatures are only required when using the
src parameter. To enable it for all requests, visit the Settings page and enable Require Authenticated Requests.
The easiest way to generate Secure URLs is by using a LibPixel Client Library. However, if one doesn't exist for the programming language you're using, you can generate the signatures yourself.
Steps for generating a signature:
Generate an image URL as normal.
Extract the path and query string from the URL. This is the data you'll be signing. The path must begin with a
/, and must at least contain 1 character.
Generate an HMAC-SHA1 in hexadecimal format using your Auth Secret. This is your signature value.
Append a query string parameter
signature with the signature value to the end of the original query string.
? character between the path and query string components, but only if there is a query string.
If you signed a URL without a query string, then you must add a query string to the resulting URL which contains only the signature.
For the example
https://yourdomain.libpx.com/?src=https://abcd.somewhere.com/images/header.png&width=200, you would sign the string