Describes how messages requesting operation on a collection is are checked against the permission model.
The permissions are defined on a pr. user/role based for each operation or set of operations. See Collection settings for detailes model.
All messages in the system must be signed to ensure that the senders of the messages are who they claim they are and that the messages have not been tampered with.
Because messages are exchanged encapsulated in XML, there are two well defined ways to handle signing of the messages. One is XML Signatures, the other - and somewhat simpler - is Cryptographic Message Syntax - also known as PKCS#7. As one of the objectives is to prevent message tampering, there is no need for the granularity of XML Signatures. Therefore Cryptographic Message Syntax - or CMS for short - is chosen for signing and optionally encrypting messages. The identity of the signer is embedded in the public certificate
The hash algorithm for the generation of the message hash is SHA512.
The message signature is calculated on the message xml interpreted as a utf-8-encoded byte stream and transmitted, base 64-encoded, in the message header org.bitrepository.messages.signature