Hi, > An encryption header MUST only be used for one session. However when > doing a rangend tranfer on a previously aborted file the key/IV pair > MUST be reused and packed into a new header to keep the integrity of > the file.
This is a nice catch. But I have two issues with it. Once jingle session is closed, all state is disposed. It is not practical to maintain all the keys being used during all sessions in some upper layer in case of a ranged transfer appears. The second issue: it seems to me not to work at all in practice: - Sender initiates a session, sends a file offer and transmits the file. - Transmission is aborted. It can be that "100% sent" is reported to the sender due to quick proxy, but slow receiver. Thus the sender cannot know how much data the receiver actually have got successfully. - Sender is going to transmit the file again and initiates a new session. The session has a new key/iv. - Receiver approves the file offer adding a ranged element. - Now the sender sees a ranged element but it is too late: session is already initiated with a new key/iv. And it continues to transmit the file. - Receiver gets the rest of the file encrypted with different key/iv and cannot decrypt it. Thanks, Andrey _______________________________________________ Standards mailing list Info: https://mail.jabber.org/mailman/listinfo/standards Unsubscribe: standards-unsubscr...@xmpp.org _______________________________________________
