From b201ce9c7cc008399bb7cc8bfc2c0b149ee5bb45 Mon Sep 17 00:00:00 2001 From: Paul Schaub Date: Fri, 29 Dec 2017 16:11:46 +0100 Subject: [PATCH] Fix typos in XEP-0396 --- xep-0396.xml | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/xep-0396.xml b/xep-0396.xml index 013e3b3a..5e1405f8 100644 --- a/xep-0396.xml +++ b/xep-0396.xml @@ -51,9 +51,9 @@

&xep0391; can be used to utilize different end-to-end encryption methods to secure Jingle Transports, eg. in the context of &xep0234;. This document aims to extend &xep0391; to allow the use of OMEMO encryption with Jingle transports. To achieve this goal, this protocol extension makes use of OMEMOs KeyTransportElements.

-

Conveniently the OMEMO protocol already provides a way to transport key material to another entity. So called KeyTransportElements are basically normal OMEMO MessageElements, but without a payload, so the contained key can be used for something else (See Section 4.6 of XEP-0384). This extension uses the key encrypted in the KeyTransportMessages <key> attribute and initialization vector from the <iv> attribute to secure Jingle Transports. The key corresponds to the Transport Key of XEP-0391, while the iv corresponds to the Initialization Vector. The KeyTransportMessage is the equivalent to the Envelope Element. Note that within the Envelope Element, the Transport Key is encrypted with the OMEMO ratchet.

+

Conveniently the OMEMO protocol already provides a way to transport key material to another entity. So called KeyTransportElements are basically normal OMEMO MessageElements, but without a payload, so the contained key can be used for something else (see Section 4.6 of XEP-0384). This extension uses the key encrypted in the KeyTransportMessages <key> attribute and initialization vector from the <iv> attribute to secure Jingle Transports. The key corresponds to the Transport Key of XEP-0391, while the iv corresponds to the Initialization Vector. The KeyTransportMessage is the equivalent to the Envelope Element. Note that within the Envelope Element, the Transport Key is encrypted with the OMEMO ratchet.

- +

Unfortunately &xep0384; determines the type of the transported key to be AES-128-GCM-NoPadding, so no other configuration can be used in the context of this extension.

Since OMEMO deviceIds are not bound to XMPP resources, the initiator MUST encrypt the Transport Key for every device of the recipient.