Used Data Forms for extension of In-Band Registration as required by XEP-0077 § 4.
Added "defined condition" elements in error stanzas as required by RFC 6120 § 8.3.2.
Changed type of "invalid-token" error to "modify".
Fix namespacing of Ad-Hoc commands
Bump namespace to invite:1
First submission.
Romeo is an active XMPP IM (Instant Messaging) user or the operator of an XMPP server. He convinces Juliet (who may not have an XMPP account yet) to install a client but she may still need to choose an XMPP server, create an account, and add Romeo as a contact. This specification defines two ways for Romeo to simplify this process for Juliet:
If Romeo is an XMPP user, he can create an out-of-band link (URI) which allows Juliet to:
The process is designed to automatically skip steps that Juliet already completed, to make the overall experience as smooth as possible.
If Romeo is an administrator of an XMPP server, he can create an out-of-band link (URI) which allows Juliet to:
This specification makes use of XMPP URIs. The basic URI scheme for XMPP
is defined in RFC 5122
To create out-of-band invitation links, Romeo's server needs to implement
the Ad-Hoc Commands (XEP-0050)
Furthermore, Romeo's server SHOULD provide a HTTPS service hosting the landing page.
Romeo's server MUST support at least one Pre-Authenticated In-Band Registration mechanism.
Romeo can query his server for the availability of "User Invitation" and "Account Creation" commands:
This XEP defines the following ad-hoc commands:
A user can execute the 'urn:xmpp:invite#invite' command to immediately obtain a new invitation link with a unique invitation token.
The server SHOULD immediately provide a command result, with no further intreaction with the user. The result can have the following fields:
The mandatory uri field MUST contain an XMPP URI. That URI SHOULD have the following format:
xmpp:inviter@example.com?roster;preauth=TOKEN;ibr=y
The preauth value SHOULD be a securely generated random alpha-numeric string used to automatically authenticate a roster subscription.
The optional ibr=y query component in the XMPP URI indicates that
the invitee is allowed to create an account on Romeo's server, using the
'preauth' token as described in Pre-Authenticated In-Band Registration (XEP-0445)
If the server does not support or allow in-band registration for invited users, the server MUST omit the ibr=y query component.
Additionally, the server SHOULD provide the landing-url
field which contains an HTTPS URL of a web-based landing page as described
in Pre-Authenticated Roster Subscription (XEP-0379)
If the server omits the landing-page field, Romeo's client SHOULD generate an appropriate landing page URL hosted by the client developer or a trusted third party.
A server MAY provide a field which provides the expiration date of the
generated token. The expiration date MUST conform to the DateTime profile
specified in XMPP Date and Time Profiles (XEP-0082)
Romeo's client should provide adequate means to export the landing-page URL, possibly accompanied with a short description and the expire information, so that Romeo can share it with Juliet by other means than XMPP, like e-mail or a QR code.
The landing page that the generated URL points to should correspond to
the format described in Pre-Authenticated Roster Subscription (XEP-0379)
If the landing page is hosted by Romeo's server, the server MAY display additional information based on the supplied TOKEN value, like the name of the inviter or validity information.
If Juliet does not have an XMPP client installed, she will not be able to open the xmpp: link from the invitation page. For this case, the landing page needs to indicate that a client must be installed first, and that the link will not work as intended without. The automatic installation of an appropriate IM client when a user clicks on an xmpp: is outside of the scope of this document.
With an XMPP client installed, Juliet can open the xmpp: link and have the client process it appropriately, as follows:
If Juliet's client is already configured with an account, the default
action for the presented
xmpp:inviter@example.com?roster;... URI is to add the
inviter to Juliet's roster. This should be performed as described in
§3.4 of Pre-Authenticated Roster Subscription (XEP-0379)
If Juliet already has Romeo in her roster, her client should open the appropriate chat interface instead.
If Juliet's client does not have an XMPP account configured, she needs to login or register an account first. Therefore, the client should provide an interface with the following options:
If the xmpp: URI provided by Romeo contains the ibr=y parameter, it indicates that the server supports the Pre-Authenticated In-Band Registration defined in this document. If Juliet chooses this approach, the server will ensure that after the registration, Romeo is added to her roster with a full presence subscription.
If
Juliet chooses to login or register with a different server, her
client must complete the respective process and issue a subscription
request as described in §3.4 of Pre-Authenticated Roster Subscription (XEP-0379)
If Romeo is the administrator of an XMPP server, he might want to ensure that Juliet obtains an account on this server, with a username defined either by Romeo or by Juliet, and in a way that does not require the out-of-band communication of user passwords.
To create an account invitation, the server administrator (or a user
authorized to create accounts) can use the urn:xmpp:invite#create-account
command. The goal of this command is to allow an experienced user to ease
the onboarding process for a friend. Therefore, it is using a data form to
customize the parameters accordingly. A server implementation may extend
the data form as appropriate. The only mandatory field is
username (text-single; localpart as defined in RFC 6122
A boolean roster-subscription field MAY be used to define whether the new account should be automatically subscribed to the inviter.
A server MAY require a username to be specified for account creation.
In this case, the server MUST add the <required/> element to the
username field.
The username MUST be a valid localpart as defined in RFC 6122
The format of the server response for account creation is the same as for user invitations. The uri field SHOULD contain an XMPP URI of the following format:
xmpp:juliet@example.com?register;preauth=TOKEN
If no username was specified during the account creation process, the local part of the JID in the XMPP URI is omitted by the server which results in the following format:
xmpp:example.com?register;preauth=TOKEN
The preauth value SHOULD be a securely generated random alpha-numeric string used to automatically authenticate the account creation.
In order to allow invited users to register on a server, the server must support pre-authenticated in-band registration based on one of the following specifications:
The invited user's client needs to connect to the server, check which of the above mechanisms are supported, and continue as specified in the respective document.
After the invitee has successfully registered on the inviter's server
and roster subscription is enabled for account creation, the server MUST
use roster pushes as defined in RFC 6121
If the inviter's server does not support user invitation, the client
application SHOULD silently fall back to Pre-Authenticated Roster Subscription (XEP-0379)
If a username was specified during the account creation process, the server SHOULD NOT create an account on the server until the invitee actually registers it with the corresponding token. The server MUST reserve the username at least until the corresponding token expires.
If the invitee opens an invitation URI with ibr=y and chooses to create a new account, the client SHOULD pre-fill the inviter JID's domain part as the new account's domain. The client MAY provide a mechanism to enter or choose a different server, though.
OPTIONAL.
OPTIONAL.
See security considerations in Pre-Authenticated Roster Subscription (XEP-0379)
This document requires no interaction with the Internet Assigned Numbers Authority (IANA)
As authorized by XMPP URI Query Components (XEP-0147)
The key-value parameter preauth is added to the
register query action as defined in In-Band Registration (XEP-0077)
register
...
preauth
the token used to allow one-time in-band registration on the inviter's server
]]>
In addition to the preauth key-value parameter defined
in Pre-Authenticated Roster Subscription (XEP-0379)
roster
...
ibr
y
the parameter to indicate that the token allows the invitee to create an account on the inviter's server via in-band registration
]]>
Field Standardization for Data Forms (XEP-0068)
urn:xmpp:invite#invitation
XEP-0401
A data form containing an invitation to add a contact or to register an account.
REQUIRED for protocol specifications.