[Uri-review] Registration request for smtp:// and submit:// URI schemes (draft-melnikov-smime-msa-to-mda-04)

[Alexey Melnikov <[e-mail]>]

Hi,
I wanted to use smtp:// URIs in X.509 URI subjectAltName values. My use 
case is returning such URIs in S/MIME certificates of S/MIME capable 
Mail Transfer Agents (MTAs). My colleague pointed out that smtp:// URIs 
are not registered with IANA (despite being used by several products, 
including at least one open source), so here is my attempt to register 
it. I am also registering submit:// URI scheme, which is a similar URI 
schemes, but for designating Mail Submission Agents.

SMTP URI registration

       URI scheme name: smtp

       Status: permanent

       URI scheme syntax:
       smtpuri = "smtp://" authority ["/" [ "?" query ]]
       authority = <defined in RFC 3986>
       query = <defined in RFC 3986>
       If :<port> is omitted from authority, the port defaults to 25.
       The query component is reserved for future extensions.

       URI scheme semantics:
       The smtp: URI scheme is used to designate SMTP servers (e.g.
       listener endpoints, S/MIME agents performing Domain signing), SMTP
       accounts.
       There is no MIME type associated with this URI.

       Encoding considerations:

       SMTP user names are UTF-8 strings and MUST be percent-encoded as
       required by the URI specification [RFC3986], Section 2.1.

       Applications/protocols that use this URI scheme name:
       The smtp: URI is intended to be used by applications that might
       need access to an SMTP server (for example email clients or MTAs
       can use smtp: URIs in configuration files)
       or for SMTP servers to describe their listener endpoints.
       A web browser can launch an email client application that can use
       the specified smtp: URI for account configuration or for showing
       SMTP server capabilities.
       These URIs can also be used in LDAP data stores for storing server or
       account configuration, as well as in X.509 certificates 
containing URIs.

       Interoperability considerations:
       Several implementations are already using smtp: URIs for server
       configuration in configuration files or APIs.

       Security considerations: Clients resolving smtp: URIs that wish to
       achieve data confidentiality and/or integrity SHOULD use the
       STARTTLS command (if supported by the server) before starting
       authentication, or use a SASL mechanism, such as GSSAPI, that
       provides a confidentiality security layer.

       Contact: Alexey Melnikov <[e-mail]>

       Author/Change controller: IESG

       References: [[draft-melnikov-smime-msa-to-mda-04]] and [RFC5321].

SUBMIT URI registration

       URI scheme name: submit

       Status: permanent

       URI scheme syntax:
       submituri = "submit://" authority ["/" [ "?" query ]]
       authority = <defined in RFC 3986>
       query = <defined in RFC 3986>
       If :<port> is omitted from authority, the port defaults to 587.
       The query component is reserved for future extensions.

       URI scheme semantics:
       The submit: URI scheme is used to designate SMTP Submission
       servers (e.g. listener endpoints, S/MIME agents performing Domain
       signing), SMTP accounts.
       There is no MIME type associated with this URI.

       Encoding considerations:
       SMTP user names are UTF-8 strings and MUST be percent-encoded as
       required by the URI specification [RFC3986], Section 2.1.

       Applications/protocols that use this URI scheme name:
       The submit: URI scheme is intended to be used by applications 
that might
       need access to an SMTP Submission server (for example email
       clients) or for SMTP Submission servers to describe their listener
       endpoints.
       The submit: URI scheme is intended to be used by applications 
that might
       need access to an SMTP Submission server (for example email clients)
       or for SMTP Submission servers to describe their listener endpoints.
       A web browser can launch an email client application that can use
       the specified submit: URI for account configuration or for showing
       SMTP server capabilities.
       These URIs can also be used in LDAP data stores for storing server or
       account configuration, as well as in X.509 certificates 
containing URIs.

       Interoperability considerations:
       None.

       Security considerations: Clients resolving submit: URIs that wish
       to achieve data confidentiality and/or integrity SHOULD use the
       STARTTLS command (if supported by the server) before starting
       authentication, or use a SASL mechanism, such as GSSAPI, that
       provides a confidentiality security layer.

       Contact: Alexey Melnikov <[e-mail]>

       Author/Change controller: IESG

       References: [draft-melnikov-smime-msa-to-mda-04]] and [RFC6409].