WARNING: This document has not yet been accepted for consideration or approved in any official manner by the XMPP Standards Foundation, and this document is not yet an XMPP Extension Protocol (XEP). If this document is accepted as a XEP by the XMPP Council, it will be published at <http://xmpp.org/extensions/> and announced on the <firstname.lastname@example.org> mailing list.
When an XMPP client is negotiating a stream with an XMPP server, it typically needs to perform authentication and authorization. Typically stream negotiation requires providing a password on each connection attempt. Naturally this means that an XMPP client needs to store password: reconnections are very frequent on some types of clients, asking a user to provide a password on each reconnect would result in a very bad user experience.
This results in increased security threats associated with storing account password on physical device: password can be extracted from this device by whoever gains access to it. Also, a user can't revoke access to clients without changing password. More, password change won't help to immediately revoke access from a device with established connection.
This document describes a method address mentioned issues and provide more security for users. The idea is to use XMPP-based tokens, which allow to control client sessions.
The content in the auth element should be base64 encoding of a string containing a null byte, followed by username, another null byte and the string representation of the user authentication token. This is similar to authentication with a password using the PLAIN mechanism, except the token is added instead of password.
During authentication process the client can revoke all tokens before bind. This might be necessary if someone has gained access to a client device and revokes all tokens immediately after connection, not giving a chance to account owner to revoke access.
After passing all the authentication steps, the client makes a request to delete all tokens
The server is recording IP addresses used by user. While this enforces privacy during regular usage, making user aware of a malicious attempts to access his data, it also creates a privacy risk for a user if this data is leaked: it might help to determine user identity and location. Server operators should be warned about this risk and take measures against it.
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Disclaimer of Warranty
## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##
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In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall the XMPP Standards Foundation or any author of this Specification be liable for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if the XMPP Standards Foundation or such author has been advised of the possibility of such damages.
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The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 6120) and XMPP IM (RFC 6121) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.
The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".
1. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.
2. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <https://xmpp.org/registrar/>.