Many thanks for the work to unentangle the document!
Please see our initial responses:
Authors,
While reviewing this document during AUTH48, please resolve (as necessary)
the following questions, which are also in the source file.
1) <!-- [rfced] May we update this text for readability?
Original:
While the content of the protocol is highly sensitive, TACACS+ lacks
effective confidentiality, integrity, and authentication of the
connection and network traffic between the TACACS+ server and client,
requiring secure transport to safeguard a deployment. The security
mechanisms as described in Section 10 of [RFC8907] are extremely
weak.
Suggested:
The content of the protocol is highly sensitive and requires
secure transport to safeguard a deployment. However, TACACS+ lacks
effective confidentiality, integrity, and authentication of the
connection and network traffic between the TACACS+ server and client.
The security mechanisms as described in Section 10 of [RFC8907] are
extremely weak.
-->
<Authors>Thanks, that makes sense</Authors>
2) <!-- [rfced] Should "for test" be "for testing"?
Original:
It is a connection without TLS, using the unsecure
TACACS+ authentication and obfuscation (or the unobfuscated option
for test).
-->
<Authors>Thanks, that makes sense</Authors>
3) <!-- [rfced] We recommend simplifying this sentence for clarity. Does
the connection persist until either a) the TLS TACACS+ peer closes it or b)
an inactivity timeout occurs? Please consider how the text may be updated.
Original:
The connection persists until the TLS TACACS+ peer closes it, either
due to an error, or at the conclusion of the TACACS+ session, or, if
Single Connection Mode (Section 4.3 of [RFC8907]) has been
negotiated, when an inactivity timeout occurs.
Perhaps:
The connection persists until the TLS TACACS+ peer closes it or
until an inactivity timeout occurs when Single Connection Mode
(Section 4.3 of [RFC8907]) is used. The TLS TACACS+ peer may close
the connection due to an error or because the TACACS+ session has
concluded.
-->
<Authors>Having reviewed this change, and the relation to next paragraph, we’d
like to propose the following which replaces the Original quoted above, and the
next paragraph in the document:
TLS TACACS+ connections are generally not long-lived. The connection will
be closed by either TLS+ TACACS Peer if it encounters an error or
inactivity timeout.
For connections not operating in Single Connection Mode (as defined in
Section 4.3 of [RFC8907]) the TCP session SHALL be closed upon
completion of the associated TACACS+ session. Connections operating in Single
Connection Mode MAY persist for a longer duration but are typically
subject to timeout and closure after a brief period of inactivity.
Consequently, support for transport-layer keepalive mechanisms is not
required.
Why a connection is closed has no bearing on TLS resumption, unless
closed by a TLS error, in which case it is possible that the ticket has been
invalidated.
</Authors>
4) <!-- [rfced] "verification" does not appear in Section 6 of RFC 5280.
Would it be helpful to the reader to use "validation" for consistency with
the reference?
Original:
The implementation of certificate-based mutual authentication MUST
support certificate path verification as described in Section 6 of
[RFC5280].
-->
<Authors>Thanks, that makes sense</Authors>
5) <!-- [rfced] Is it correct to refer to the "TLS Resumption protocol"?
Original:
The TLS Resumption protocol, detailed in [RFC8446], can minimize the
number of round trips required during the handshake process.
Perhaps:
TLS Resumption [RFC8446] can minimize the
number of round trips required during the handshake process.
-->
<Authors>Thanks, that makes sense</Authors>
6) <!-- [rfced] Section 5.2 of [RFC5425] is titled "Subject Name
Authorization" and doesn't appear to mention any kind of obfuscation
mechanism. Also, is the obfuscation mechanism described in both RFC 8907
and 5425 (or other)? Please review and let us know how/if the text may be
clarified.
Original:
[RFC8907] describes the obfuscation mechanism, documented in Section
5.2 of [RFC5425]. Such a method is weak.
-->
<Authors>
We propose:
The obfuscation mechanism documented in [RFC8907] section 4.5. Data Obfuscation
is weak
</Authors>
7) <!-- [rfced] We are having trouble parsing "for implementing protocols
that use TLS and their deployment."
Original:
[BCP195] offers substantial guidance for implementing protocols that
use TLS and their deployment.
Perhaps:
[BCP195] offers substantial guidance for implementing and deploying
protocols that use TLS.
-->
<Authors>Thanks, that makes sense</Authors>
8) <!-- [rfced] The use of "MUST" twice in this sentence reads oddly.
Please review.
Original:
Further, operators MUST ensure that the TLS TACACS+ servers covered
by a wildcard certificate MUST be impervious to redirection of
traffic to a different server (for example, due to on-path attacks or
DNS cache poisoning).
Perhaps A:
Further, operators MUST ensure that the TLS TACACS+ servers covered
by a wildcard certificate are impervious to redirection of
traffic to a different server (for example, due to on-path attacks or
DNS cache poisoning).
Perhaps B:
Further, operators MUST ensure that the TLS TACACS+ servers are covered
by a wildcard certificate and MUST be impervious to redirection of
traffic to a different server (for example, due to on-path attacks or
DNS cache poisoning).
-->
<Authors>Thanks, Authors have voted for option A</Authors>
9) <!-- [rfced] Does the operator need to consider the impact of supporting
both TLS and non-TLS connections?
Original:
* The operator must consider the impact of mixed TLS and Non-TLS on
security, as mentioned above.
Perhaps:
* The operator must consider the security impact of supporting both TLS
and non-TLS connections, as mentioned above.
-->
<Authors>Thanks, that makes sense</Authors>
10) <!-- [rfced] The description of the service name in the first paragraph
differs from the what appears in the registration template below it and
what appears on the IANA site. Is the intent to relay that the service
name "tacacss" is commonly referred to as "TACACS+ over TLS" rather than
the description in the template? Or, should the descriptions be the same?
Original:
IANA has allocated a new well-known system TCP/IP port number (300)
for the service name "tacacss", described as "TACACS+ over TLS". The
service name "tacacss" follows the common practice of appending an
"s" to the name given to the Non-TLS well- known port name. This
allocation is justified in Section 5.3.
IANA has added tacacss as a new entry to the "Service name and
Transport Protocol Port Number Registry" available at
<https://www.iana.org/assignments/service-names-port-numbers>.
Description in the template and the IANA registry:
TLS Secure Login Host Protocol (TACACSS)
See
<https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?=&skey=2&page=6>.
If the text should be the same, perhaps the paragraphs could be combined as
follows:
IANA has allocated the following new well-known system in the
"Service Name and Transport Protocol Port Number Registry" (see
<https://www.iana.org/assignments/service-names-port-numbers/>). The
service name "tacacss" follows the common practice of appending an
"s" to the name given to the non-TLS well-known port name. See the
justification for the allocation in Section 5.3.
Related:
Original in Section 3.1:
Given the prevalence of default port usage in existing TACACS+ client
implementations, this specification assigns a well-known TCP port
number for TACACS+ over TLS: [TBD] (Section 7), with the associated
service name "tacacss" Section 7.
Perhaps:
Given the prevalence of default port usage in existing TACACS+ client
implementations, this specification assigns well-known TCP port
300 for TACACS+ over TLS (see Section 7).
Original in Section 3.1 - We believe this is intentional to align with the
line prior:
* for Non-TLS connection TACACS+: Port number 49.
* for TLS connection TACACS+: (TBD).
-->
<Authors>Thanks, that makes sense</Authors>
11) <!-- [rfced] This document used both "non-TLS" and "Non-TLS". We have
lowercased instances of "Non-TLS" for consistency and because
overcapitalization can detract from readability.
-->
<Authors>Thanks, that makes sense</Authors>
Thank you.
Sandy Ginoza
RFC Production Center
Cisco Confidential
On Oct 24, 2025, at 5:59 PM,
[email protected]<mailto:[email protected]> wrote:
*****IMPORTANT*****
Updated 2025/10/24
RFC Author(s):
--------------
Instructions for Completing AUTH48
Your document has now entered AUTH48. Once it has been reviewed and
approved by you and all coauthors, it will be published as an RFC.
If an author is no longer available, there are several remedies
available as listed in the FAQ (https://www.rfc-editor.org/faq/).
You and you coauthors are responsible for engaging other parties
(e.g., Contributors or Working Group) as necessary before providing
your approval.
Planning your review
---------------------
Please review the following aspects of your document:
* RFC Editor questions
Please review and resolve any questions raised by the RFC Editor
that have been included in the XML file as comments marked as
follows:
<!-- [rfced] ... -->
These questions will also be sent in a subsequent email.
* Changes submitted by coauthors
Please ensure that you review any changes submitted by your
coauthors. We assume that if you do not speak up that you
agree to changes submitted by your coauthors.
* Content
Please review the full content of the document, as this cannot
change once the RFC is published. Please pay particular attention to:
- IANA considerations updates (if applicable)
- contact information
- references
* Copyright notices and legends
Please review the copyright notice and legends as defined in
RFC 5378 and the Trust Legal Provisions
(TLP – https://trustee.ietf.org/license-info).
* Semantic markup
Please review the markup in the XML file to ensure that elements of
content are correctly tagged. For example, ensure that <sourcecode>
and <artwork> are set correctly. See details at
<https://authors.ietf.org/rfcxml-vocabulary>.
* Formatted output
Please review the PDF, HTML, and TXT files to ensure that the
formatted output, as generated from the markup in the XML file, is
reasonable. Please note that the TXT will have formatting
limitations compared to the PDF and HTML.
Submitting changes
------------------
To submit changes, please reply to this email using ‘REPLY ALL’ as all
the parties CCed on this message need to see your changes. The parties
include:
* your coauthors
* [email protected]<mailto:[email protected]> (the RPC team)
* other document participants, depending on the stream (e.g.,
IETF Stream participants are your working group chairs, the
responsible ADs, and the document shepherd).
* [email protected]<mailto:[email protected]>, which
is a new archival mailing list
to preserve AUTH48 conversations; it is not an active discussion
list:
* More info:
https://mailarchive.ietf.org/arch/msg/ietf-announce/yb6lpIGh-4Q9l2USxIAe6P8O4Zc
* The archive itself:
https://mailarchive.ietf.org/arch/browse/auth48archive/
* Note: If only absolutely necessary, you may temporarily opt out
of the archiving of messages (e.g., to discuss a sensitive matter).
If needed, please add a note at the top of the message that you
have dropped the address. When the discussion is concluded,
[email protected]<mailto:[email protected]> will
be re-added to the CC list and
its addition will be noted at the top of the message.
You may submit your changes in one of two ways:
An update to the provided XML file
— OR —
An explicit list of changes in this format
Section # (or indicate Global)
OLD:
old text
NEW:
new text
You do not need to reply with both an updated XML file and an explicit
list of changes, as either form is sufficient.
We will ask a stream manager to review and approve any changes that seem
beyond editorial in nature, e.g., addition of new text, deletion of text,
and technical changes. Information about stream managers can be found in
the FAQ. Editorial changes do not require approval from a stream manager.
Approving for publication
--------------------------
To approve your RFC for publication, please reply to this email stating
that you approve this RFC for publication. Please use ‘REPLY ALL’,
as all the parties CCed on this message need to see your approval.
Files
-----
The files are available here:
https://www.rfc-editor.org/authors/rfc9887.xml
https://www.rfc-editor.org/authors/rfc9887.html
https://www.rfc-editor.org/authors/rfc9887.pdf
https://www.rfc-editor.org/authors/rfc9887.txt
Diff file of the text:
https://www.rfc-editor.org/authors/rfc9887-diff.html
https://www.rfc-editor.org/authors/rfc9887-rfcdiff.html (side by side)
Diff of the XML:
https://www.rfc-editor.org/authors/rfc9887-xmldiff1.html
Tracking progress
-----------------
The details of the AUTH48 status of your document are here:
https://www.rfc-editor.org/auth48/rfc9887
Please let us know if you have any questions.
Thank you for your cooperation,
RFC Editor
--------------------------------------
RFC9887 (draft-ietf-opsawg-tacacs-tls13-24)
Title : Terminal Access Controller Access-Control System Plus over
TLS 1.3 (TACACS+ over TLS)
Author(s) : T. Dahm, J. Heasley, D. C. Medway Gash, A. Ota
WG Chair(s) : Joe Clarke, Benoît Claise
Area Director(s) : Mohamed Boucadair, Mahesh Jethanandani
--
Gruß,
Thorsten Dahm
--
auth48archive mailing list -- [email protected]
To unsubscribe send an email to [email protected]
