Replace sha256sum command with openssl command.

Author: msporny

index.html

@@ -4866,12 +4866,13 @@ <h3>Base Context</h3>
           <p>
 The base context, located at <code>https://www.w3.org/ns/credentials/v2</code>
 with a SHA-256 digest of
-<strong><code>944167aaabd904ea9e35c98fd7e8794eb6dd42ae4666b036b171e87fc34cc7cc</code></strong>,
+<strong><code>ff1fdfa8d3f07547ec149b6652fe3f5a4276b9f0c48344dc29400763ba7b44fa</code></strong>,
 can be used to implement a local cached copy. It is possible to confirm the
 SHA-256 digest by running the following command from a modern Unix command
-interface line: `curl -s https://www.w3.org/ns/credentials/v2 | sha256sum`. It
-is strongly advised that all JSON-LD Contexts used in an application utilize a
-similar mechanism to ensure end-to-end security.
+interface line:
+`curl -s https://www.w3.org/ns/credentials/v2 | openssl dgst -sha256 -hex -r`.
+It is strongly advised that all JSON-LD Contexts used in an application utilize
+a similar mechanism to ensure end-to-end security.
           </p>
           <p>
 This section serves as a reminder of the importance of ensuring that, when