Filename extension .rpmsg | Internet media type unknown | |
Magic number 76 E8 04 60 C4 11 E3 86 [1] | ||
Usage
An rpmsg file is a restricted-permission message with an extension of rpmsg [2]. It is used to implement IRM for Outlook messages with the aim of restricting certain actions such as the ability to forwarded or copy [3][4].
Contents
Implementation
The rpmsg file is created by writing body, attachments and images to a compound file and then compressing and encrypting it to create a BLOB: the rpmsg file [5]. This resulting file is named message.rpmsg and is included as an attachment to a normal Outlook message.
Rights Control
When a rights managed mail is created the author specifies what rights they wish to grant to the recipient and these rights are specified in the form of an XrML file called a 'Publishing License'. This file is included within the encrypted rpmsg file. When the rpmsg attachment is decrypted the enclosed 'Publishing License' is referenced by Outlook to determine what the recipient can and cannot do with the message (rights to forward, copy etc.).[6][7]