admin: SSP SP-metadata doesn't contain 'entityid' key

[tvdijen]

Describe the bug
The SP-metadata (SSP-array style) does not contain the 'entityid' key.
This is problematic, because some code depends on it (i.e. https://github.com/simplesamlphp/simplesamlphp/blob/master/src/SimpleSAML/Metadata/MetaDataStorageHandler.php#L377), effectively breaking HTTP-Artifact binding and possibly more.

To Reproduce
Steps to reproduce the behavior:

1. Set up SSP as a service provider
2. Go to admin Federation page and pull down the SSP metadata
3. See no 'entityid' key

Expected behavior
An 'entityid' key

Additional context

• The hosted IDP metadata does have this key and is not affected.

[thijskh]

The question this raises with me is why it needs the extra key in the first place. Since the entityID is already in the array index, so why does it need to be duplicated.

[tvdijen]

Agreed, we should be able to get rid of the key everywhere and just use the array index.