Re: [regext] Comments to the feedback about epp-over-http

[Mario Loffredo <[e-mail]>]

Hi James,

For what I have understood, your implementation is based on the 
assumption that once the HTTP Connection is established, it is used for 
the transit of all the HTTP requests of an EPP session, starting from 
the Login and ending with the Logout.

Consequently, you rely on keeping the HTTP connection alive as long as 
the EPP session works. Correct?

If so, in my opinion, that is a wrong assumption.

Clients should not be forced to keep alive the HTTP connections if HTTP 
allows to maintain HTTP sessions alive across a sequence of HTTP  
connections.

There are other implications connected with the Keep-Alive Timeout value.

Don't know how did you set the Keep-Alive Timeout: the default value is 
60 secs.

As a consequence, the EPP session timeout value in your implementation 
cannot be higher than the Keep-Alive timeout value, othewise you might 
have the case that an EPP session is still alive but the underlying HTTP 
conection isn't.

Another consequence of binding EPP session to HTTP connections is that, 
when a server is stopped, not only the ongoing EPP requests get lost, 
but also all the corresponding EPP sessions.

Finally, another factor to consider is that there could be some 
intermediaries (proxies) in the middle. Each of them can set their own 
Keep-Alive Timeout you can't control.


On the other hand, following the commonly used approach to make the EPP 
session completely independent on the HTTP conections would contribute 
to make an HTTP-based EPP server more manageable, efficient, flexible 
and fault tollerant.

In my previous mail, I wrote that your implementation seems to me 
impractical because currently no HTTP programmer on both client and 
server side is accostumed to deal directly with HTTP connections because 
that job is done by  the application server (or similar) on top of which 
you deploy (or built) your application based on a high-level protocol 
such as EPP and RDAP. Following this apporach, the implementation of 
EPP-over-HTTP would not be affected by the possible change of the HTTP 
version supported.

Surely, one can tune the performance of the entire server by setting 
some parameters regarding HTTP connections but basically the main job 
consists in processing the requests to return the responses, That's it. 
On client side, you can configure a connection pool instead of 
starting-ending an HTTP connection every time an HTTP request is sent 
but even client libraries allows for creating an HTTP client instance 
and using it to send HTTP requests and process the related responses.

We cannot use HTTP as it was TCP. There are three layers in the middle 
that save HTTP programmers from being involved in low-level details 
(luckily).


With regard to the compliance with RFC5730, the proposed approach 
interprets the specification on the basis that HTTP is neither 
connectionless nor connection-oriented.

It still runs on top of a connection-oriented transport (typically TCP), 
but it does not assign any state to that particular connection. The 
client is free to re-use the same connection for multiple requests (as 
many HTTP/1.1 clients do), or to create a brand new connection for each 
request (as HTTP/1.0 clients used to do).


Best,

Mario


Il 30/03/2022 15:59, Gould, James ha scritto:
>
> Mario,
>
> I include my feedback embedded below.
>
> -- 
>
> JG
>
>
>
>
> *James Gould
> *Fellow Engineer
> [e-mail] 
> <applewebdata://13890C55-AAE8-4BF3-A6CE-B4BA42740803/[e-mail]>
>
> 703-948-3271
> 12061 Bluemont Way
> Reston, VA 20190
>
> Verisign.com <http://verisigninc.com/>
>
> *From: *Mario Loffredo <[e-mail]>
> *Date: *Wednesday, March 30, 2022 at 8:28 AM
> *To: *James Gould <[e-mail]>om>, "[e-mail]" 
> <[e-mail]>
> *Subject: *[EXTERNAL] Re: [regext] Comments to the feedback about 
> epp-over-http
>
> Hi James,
>
> my comments are embedded below.
>
> Il 29/03/2022 17:50, Gould, James ha scritto:
>
>     Mario,
>
>     My responses are embedded below.
>
>     -- 
>
>     JG
>
>
>
>
>     *James Gould
>     *Fellow Engineer
>     [e-mail]
>     <applewebdata://13890C55-AAE8-4BF3-A6CE-B4BA42740803/[e-mail]>
>
>     703-948-3271
>     12061 Bluemont Way
>     Reston, VA 20190
>
>     Verisign.com
>     <http://secure-web.cisco.com/1fmebMbwOUgdo-WyMaIsLZ1SH_XvKhWjFsvhnqk29yAQF2aCDU1bQl0rsVTtHPLG2BkDpIZ4MRjQsieE6r3TIX1L0ZZ7ekjXpaFeAZJDrC_Po6vguQRG0GQxM_3QyDX71rQvTjctNCis34Eb3FlrargkQgR5XO62fk7y3kgDfQM3nIcfYBm16faG667F4c9QVNETKgFbhSeqgY14mUJuMb_4AAv736hwPtIFaeVSRpYMMCGp1ZN1ut0cVsLLpuUa2/http%3A%2F%2Fverisigninc.com%2F>
>
>     *From: *Mario Loffredo <[e-mail]>
>     <mailto:[e-mail]>
>     *Date: *Tuesday, March 29, 2022 at 11:00 AM
>     *To: *James Gould <[e-mail]>
>     <mailto:[e-mail]>, "[e-mail]"
>     <mailto:[e-mail]> <[e-mail]> <mailto:[e-mail]>
>     *Subject: *[EXTERNAL] Re: [regext] Comments to the feedback about
>     epp-over-http
>
>     Hi James,
>
>     Il 29/03/2022 13:41, Gould, James ha scritto:
>
>         Mario,
>
>         My feedback is embedded below.
>
>         -- 
>
>         JG
>
>
>
>
>         *James Gould
>         *Fellow Engineer
>         [e-mail]
>         <applewebdata://13890C55-AAE8-4BF3-A6CE-B4BA42740803/[e-mail]>
>
>         703-948-3271
>         12061 Bluemont Way
>         Reston, VA 20190
>
>         Verisign.com
>         <http://secure-web.cisco.com/1EaISbPmlOZzCKgUuIbmDA4rr-y-fT4gnfY0xiPotQBQC-vNT5PBKwJ1STPDcTK6y65BpvZgT5XqntG_ZysxPVZX8XjGyZXOW-P8nL-bdEwKNOkYvtyGhf1-PjTUP3gKykqkaX6QProvtyfCBkgC_m9J8xcE7yHeQ2_JycG85cc1JtO74KeQ6D9bsl9tHxNpgzRFA-IE_CZkI01GCY0-9LRrY2Tdd3mwPuBMAXYl7okYjJdszZFa2vwEdisCoAWAN/http%3A%2F%2Fverisigninc.com%2F>
>
>         *From: *Mario Loffredo <[e-mail]>
>         <mailto:[e-mail]>
>         *Date: *Monday, March 28, 2022 at 6:59 AM
>         *To: *James Gould <[e-mail]>
>         <mailto:[e-mail]>, "[e-mail]"
>         <mailto:[e-mail]> <[e-mail]>
>         <mailto:[e-mail]>
>         *Subject: *[EXTERNAL] Re: [regext] Comments to the feedback
>         about epp-over-http
>
>         Hi James,
>
>         thanks for ypur quick reply.
>
>         Please find my comments below.
>
>         Il 25/03/2022 16:45, Gould, James ha scritto:
>
>             Mario,
>
>             For #4 “Cookie vs. HTTP Connection”, you asked the
>             question “can you further clarify why we should opt for
>             establishing the cookie at setup of the connection and how
>             should it be possible? For example, what kind of request
>             should be used to start the HTTP connection?”.
>
>             I implemented pluggable transports in the Verisign EPP
>             SDK, which included HTTP, HTTPS, TCP, and TLS.  The
>             Verisign EPP SDK does include a client interface as well
>             as a server stub implementation, so I was able to see the
>             transports from both sides.  Support for HTTP and HTTPS
>             was removed once we stopped supporting EPP over HTTP.  The
>             cookie is setup at the time of the HTTP or HTTPS
>             connection.  There is no “request” that is used to start
>             the HTTP connection, just like the case for TCP and TLS. 
>             A network connection is made, which includes the
>             underlying TLS handshake in the case of HTTPS and TLS and
>             the cookie is setup for HTTP and HTTPS, and then the EPP
>             application protocol rides on top of it.
>
>         It seems to me a very low-level implementation.
>
>         Sorry but I stiil don't understand how cookies are returned.
>         They should be returned in an HTTP response that doesn't
>         correspond to an HTTP request. Correct?
>
>         JG: HTTP is being defined as a transport for EPP, so it should
>         be treated as such.  The setup and tear-down of the HTTP
>         connection, includes the setup of the cookies that is used for
>         HTTP session tracking. When a connection is made to the EPP /
>         HTTPS server, the TLS connection is first established via the
>         TLS-handshake and the HTTP session is established via setup of
>         the session cookie (e.g., JSESSIONID), which then enables the
>         server to maintain state.  State such as tracking failed login
>         attempts and timeouts (idle / command / absolute), which will
>         result in a drop in the HTTP session / connection when the
>         login attempt threshold is exceeded.  At the application
>         layer, a HTTPS connection is treated in the same way as a TLS
>         connection, where the transport handles the framing and the
>         connection state, and the application layer returns the EPP
>         Greeting when the connection is setup and drops the connection
>         with a EPP logout occurs or other EPP session conditions
>         (e.g., exceeding timeouts).  The HTTP session cookie is
>         returned in all the HTTP responses. There is absolutely no
>         intermingling of the transport layer (HTTP) with the
>         application layer (EPP) other than making a connection
>         available to read and write framed packets and the ability to
>         close the connection when needed.
>
>         If so, it seems to me uncompliant with what is stated in the
>         first paragraph of Section 2.1 of RFC7230:
>
>             HTTP is a stateless request/response protocol that operates by
>
>             exchanging messages (Section 3  <https://secure-web.cisco.com/1HLyHB_XdFEjfXQwGFkG0LZSLLnG4WFNvmZ-TNjfY6OfIaLTmL1biILbx72S_U5GmIiJtbpg0x39TJ52od6XvJJ-XGkebzBiEggAwQ42v85iZAXdc75eWbMUFwdy__GSQvGqoc_3jBcXvzaJksIZ9kIaGCObuN4sNz3NQqB4Gsr44Gdw9c4U6nDx9j_3kyp9hk3Za8zxK-CiPfgUAyNLhZ53ksc5Ae9PHvSSpW9kjbB9txLir0tvwL_pUPzDpJS2Y/https%3A%2F%2Fwww.rfc-editor.org%2Frfc%2Frfc7230%23section-3>) across a reliable transport- or
>
>             session-layer "connection" (Section 6  <https://secure-web.cisco.com/1vvJc-KSBR_KweDtRuo-dlLx6E_Z9fnj9TRqKJPKmI-z_MzpIyDJWDzfwvS180O64nU4M_K-HwHtvVlPkTyfnMVQ8I50S_dOCSrwzrW9QXz8ckfa9Yj0UZmgPk4aOBSCgpizCtKhPiufait2c-bik8SwDi5FGriXh2QetIDOP_N5qvkVGUCrJ7Agu0Kz55-5IRTrJpPK2rtdg6AYpfgj-5oaNCOjZ9kZcI233HN_HumLXDVcKmYklOTTqh_7mGPwt/https%3A%2F%2Fwww.rfc-editor.org%2Frfc%2Frfc7230%23section-6>).*An HTTP "client" is a*
>
>         *   program that establishes a connection to a server for the
>         purpose of*
>
>         *   sending one or more HTTP requests.*   *An HTTP "server" is a program*
>
>         *   that accepts connections in order to service HTTP requests
>         by sending*
>
>         *   HTTP responses.*
>
>         JG: I don’t see how using HTTP as a EPP transport would be
>         considered uncompliant with RFC7230.  Below is the flow of
>         using HTTP as an EPP transport:
>
>         1.Establish TCP connection
>
>         2.Establish TLS session via TLS-handshake
>
>         3.Establish HTTP session via setup of the HTTP session cookie
>         (e.g., JSESSIONID)
>
>         4.Return EPP Greeting in framed HTTP response with the session
>         cookie (e.g., JSESSIONID)
>
>         5.Support HTTP requests in the form of framed EPP commands
>         that are returned in HTTP responses in the form of framed EPP
>         responses.
>
>         6.EPP session ends that drops the connection (HTTP / TLS / TCP)
>
>     [ML] I apologize James but I still don't understand how it would
>     be possible to return an HTTP response including the EPP Greeting
>     and establish a session cookie without having previously received
>     an HTTP request or, to say it better, how it would be possible at
>     the abstraction level provided by all the libraries and frameworks
>     supporting HTTP communication on both client and server side.
>
>     Being HTTP used as a purely transport (L4) protocol but not as a
>     request/response (L7) protocol,  the implementation wouldn't be
>     compliant with RFC7230.
>
>     The same concept is also repeated in Section 2.1 of RFC 2818 "HTTP
>     over TLS":
>
>         The agent acting as the HTTP client should also act as the TLS
>
>         client.  It should initiate a connection to the server on the
>
>         appropriate port and then send the TLS ClientHello to begin the TLS
>
>         handshake.*When the TLS handshake has finished. The client may then*
>
>     *   initiate the first HTTP request.*   All HTTP data MUST be sent as TLS
>
>         "application data".  Normal HTTP behavior, including retained
>
>         connections should be followed.
>
>     JG: The first step is a HTTP GET request that establishes the HTTP
>     session and receives the EPP Greeting in the HTTP GET response,
>     which includes the HTTP session cookie.  Subsequent requests can
>     use a HTTP POST for the EPP command and receive the HTTPS POST
>     response for the EPP response.  The EPP SDK Stub Server supported
>     use of either the HTTP GET or POST and if a HTTP session did not
>     exist, it returned the EPP Greeting in the HTTP response with the
>     HTTP session cookie.  After the HTTP session was established, the
>     responsibility of the HTTP layer was strictly to accept HTTP
>     requests, which works as the packet framing of TCP, and places the
>     EPP responses in the HTTP responses.  The HTTP request and
>     response is fully compliance with the RFCs, since the connection
>     is a request with a greeting response, and subsequent EPP command
>     and responses are handled in HTTP requests and responses. 
>     Connection state is maintained in the HTTP session, which would
>     deal with issues like a failed login threshold and timeouts (idle
>     and command).  The Verisign EPP SDK includes an packet assembler
>     class, which is configurable, which deals with the marshaling and
>     unmarshaling of the commands and responses of the underlying EPP
>     transport, which included assemblers for TCP, TLS, HTTP, and
>     HTTPS.  You could even setup client session pools using the
>     assembler of your choice, where a single client could interface
>     with an EPP/TLS server and an EPP/HTTPS server, all by specifying
>     the desired EPP transport.  If you are to mix the EPP protocol
>     with the underlying transport layer, then it would remove the
>     ability to plug in the desired transport.
>
> [ML] Now everything is clear to me. I didn't udenstrand your previous 
> message because you omitted that a client starts the HTTP session via 
> HTTP GET :-)
>
> Both .it and .pl  implement only the POST method. HTTP and EPP 
> sessions are started together and linked each other after a Login 
> command due to the following reasons:
>
>  1. The session ID is the unique key to retrieve EPP session information
>
> JG: That intermingles the application layer with the transport.  Do 
> you support EPP / TLS in parallel with EPP / HTTPS?  If so, this 
> intermingling would pose an issue.  The EPP session id should be 
> independent of the HTTPS session id.
>
> 2) Except for the client IP address, the information that a server 
> must maintain as long as an EPP session lives is included in the Login 
> request (i.e. the registrar name and the XML namespaces)
>
> 3) It's very unlikely that an EPP client doesn't know the services 
> provided by a given EPP server
>
> JG: Does this mean that .it and .pl doesn’t provide the EPP Greeting 
> when the connection is established?  Returning the EPP Greeting at the 
> time of connection is a requirement in RFC 5730 “An EPP server MUST 
> respond to client-initiated communication (which can be either a 
> lower-layer connection request or an EPP service discovery message) by 
> returning a greeting to a client.”.
>
> 4) As a consequence of point 2 and 3, why should a client submit a 
> meaningless HTTP request to the server before submitting the Login 
> command  to start an EPP session?
>
> JG: The EPP transport needs to support what is defined in RFC 5730.  
> The connection is established and the server returns an EPP Greeting.
>
> 5) RFC5730 states that an EPP session starts with a <Login> command 
> and RFC6265 states that servers maintain stateful sessions over HTTP 
> by setting the session cookie. Hence, It seems natural to me that 
> servers start an HTTP session  and set the session ID after a 
> successful Login command.
>
> JG: The EPP session may start with the login command, but the 
> transport session is established ahead of the EPP session being 
> established.
>
> 6) Application protocol sessions on server side normally start after 
> authenticating the client (please note that this is exactly what we 
> are pursuing in RDAP)
>
> JG: You really need to follow the flow defined in RFC 5730 for an EPP 
> transport.  My recommendation again is to set the HTTP session id at 
> the time of the connection and have the server return the EPP 
> Greeting, just like what occurs with EPP over TLS.  The transport 
> should not intermingle with the application protocol, which enables 
> the pluggable of transports on the client-side and the server-side.
>
> 7) It seems inefficient to release an HTTP session from an EPP session 
> because it can result in wasting resources to maintain possible 
> useless HTTP sessions.
>
> JG: I don’t see the wasting resource use case here. When a client 
> makes an EPP over HTTPS connection to the server, the HTTP session is 
> established and EPP rides on top of it.  The first EPP packet sent is 
> the EPP Greeting by the server.  The server can establish policies 
> such as maximum failed login attempts to drop the connection.
>
> 8) If an HTTP session is not established after an authentication, IP 
> whitelisting is a must instead of a recommendation. Even if in general 
> registries require registrars to declare their own clients' IP 
> addresses out-of-band, this is not an absolute constraint and the same 
> IP address might be used by multiple registrars. For the same reason, 
> you cannot limit the number of HTTP sessions per registrar thus 
> mitigating the risks pointed out in point 7.
>
> JG: IP whilelisting can be aggregated in the ACL and then checked 
> during the login command.
>
> Regarding to the EPP commands, other than Hello and Login, that don't 
> include a valid session ID,  think it's better the server returns an 
> EPP error ("Command use error") instead of a Greeting response 
> including a new session ID.
>
> JG: If you’re not returning the EPP Greeting at the time of the 
> connection, you’re not implementing EPP.  The definition of an EPP 
> transport needs to fully support the EPP protocol defined in RFC 5730.
>
> Have a question: how do you figure out the case where a client issues 
> two Login commands with the same valid session ID previously received 
> via the GET response? I imagine that only one would be accepted.
>
> If so, the mapping between an HTTP session and EPP session exists also 
> in your implementation. It occurs when the EPP session is created 
> instead of when the HTTP session is created.
>
> JG: The HTTP session maps to the state held on the server-side, which 
> would include items like the client IP address, client certificate, 
> and other attributes that can be used along with the passed user name 
> and password in the login command.  The EPP HTTP transport should 
> handle the same features as EPP TCP in RFC 5734, which includes the 
> connection requirements (e.g., TLS) and the method of packet framing.  
> In the case of HTTP, there is the need for establishing the HTTP 
> Session Id and using the HTTP request and response packets for 
> containing / framing the EPP packets.
>
> Best,
>
> Mario
>
>         7.
>
>         Anyway, the approach normally followed by every HTTP
>         implementer leverages the services provided by an application
>         server that incorporates an HTTP server.
>
>         You don't need to manage HTTP connections, HTTP
>         resquest/response marhsalling/unmarshalling and other
>         low-level details. You just need to focus on the core of your
>         server.
>
>         Similarly, on the other side side, after having configured an
>         HTTP client instance, a client simply builds and sends an HTTP
>         request, and  then receives and processes an HTTP response.
>
>         JG: An EPP client or server should be capable of reusing all
>         the same command and response processing without dealing with
>         transport specific logic.  The transport layer can be built as
>         a layer that is pluggable.  A client can configure the
>         transport to use on a per-server basis, and the server can
>         reuse the same command processing logic whether running on top
>         of TLS or HTTPS, since TLS and HTTPS are purely transports.
>
>     [ML] It's unclear to me how two communications working at
>     different layers could be handled in the same way. As I wrote in
>     my previous reply to Matthias, the approach proposed aims to
>     preserve EPP commands semantics so that the EPP server core should
>     be the same regardless the fact that it is supported by HTTP or TCP.
>
>     JG: It's very straight forward to make the EPP transport pluggable
>     if you treat the EPP transport as purely a transport.  The
>     application layer does need to go through a pluggable transport
>     layer to enable the transport layer to frame, and
>     marshal/unmarshal the commands and responses.  In the case of the
>     Verisign EPP SDK, that assembler layer took care of it for TCP,
>     TLS, HTTP, and HTTPS.  The EPP command processing is not dependent
>     on the transport layer, meaning the EPP command processing layer
>     doesn’t need to be concerned with setting a HTTP session cookie
>     upon a successful EPP Login or handling the EPP Hello in any
>     special way as it relates to HTTP cookies.  EPP is a stateful
>     protocol, where the underlying transport needs to support being
>     stateful.  If the desire was to move towards stateless, then
>     you’re not defining an EPP transport but a new EPP protocol.  My
>     recommendation is to keep the EPP over HTTP simple and establish
>     the HTTP cookie at the setup of the HTTP connection and separate
>     the EPP sessions from the HTTP session.
>
>     Mario
>
>             If there is a HTTP transport for EPP, then it should be
>             purely a transport and not intermingle with the
>             application protocol.  There is no need to directly tie a
>             HTTP session with the established EPP session.  By keeping
>             them separate, it makes it much easier for the client and
>             the server to have pluggable transports, where the
>             processing of the EPP commands including the hello, login,
>             and logout treat the transport as simply a connection with
>             no intermingling of session management.
>
>         If it means that you have to reimplement what has commonly
>         been used for years, it isn't clear to me how it could be much
>         easier. On the contrary, it seems to me much trickier,
>         especially if you implement EPP-over-HTTP from scratch.
>
>         If the goal is using the same approach for mapping every
>         transport layer without considering the peculiarites of each
>         transport protocol and the technology the implementers are
>         accostumed to use to deal with them, it doesn't make sense to me.
>
>         For example, I cannot figure out how HTTP load balancing could
>         support your solution.
>
>         JG: The HTTP transport for EPP can easily be defined as a pure
>         transport, which provides a connection for the application
>         layer to leverage in the same fashion as TLS.  The load
>         balancer can leverage the TLS session id to route to the EPP
>         gateway and in the case of HTTP, the HTTP session can be used
>         to route the request to the appropriate application server
>         that contains the connection state.  Some HTTP application
>         server proxies leverage the HTTP session to route the requests
>         to the application server that contains the HTTP session and
>         state.  You need to establish the HTTP session when the
>         connection is established to support the needed routing. 
>         There are other load balancing options, but by simplifying EPP
>         over HTTP to have HTTP as purely a transport, it provides
>         maximum flexibility in routing and maximum pluggability of
>         transports (TCP, TLS, HTTP, HTTPS).
>
>         Best,
>
>         Mario
>
>             -- 
>
>             JG
>
>
>
>
>             *James Gould
>             *Fellow Engineer
>             [e-mail]
>             <applewebdata://13890C55-AAE8-4BF3-A6CE-B4BA42740803/[e-mail]>
>
>             703-948-3271
>             12061 Bluemont Way
>             Reston, VA 20190
>
>             Verisign.com
>             <http://secure-web.cisco.com/1ojxKstUEceETR7pe4khQ2dcwgGUwoOuZu4vhcT-TZcTCCpM93jXl6eq5i46tfTPt6lE9M6FO7hPqFZQVgxN5su1ozpEIXrOmp6SzB5kEB5SXCcRaJIg-vRb2B_SxGeDcgjxTqmZNEVO_Z0LtwZEFTLbzsLhmMMT-MlZ9pX7rpBY6Q8K0RxXyklhUEXCOqlJ0RMcZX2tEZNHp0Pr6XFhgw4X7OA0XCs0tk_jqiJbYMrkAFF0PXiAItfCmm_MR8whC/http%3A%2F%2Fverisigninc.com%2F>
>
>             *From: *regext <[e-mail]>
>             <mailto:[e-mail]> on behalf of Mario
>             Loffredo <[e-mail]>
>             <mailto:[e-mail]>
>             *Date: *Friday, March 25, 2022 at 11:01 AM
>             *To: *"[e-mail]" <mailto:[e-mail]>
>             <[e-mail]> <mailto:[e-mail]>
>             *Subject: *[EXTERNAL] [regext] Comments to the feedback
>             about epp-over-http
>
>             Hi folks,
>
>             here are in the following some comments grouped by subject
>             to last meeting's feedback about EPP-over-HTTP:
>
>             *1) Draft title*
>
>             Ulrich suggested to call the document EPP-over-HTTPS.
>
>             I replied that the name was assigned to be consistent with
>             RFC5734, i.e. EPP-over-TCP.
>
>             SImilarly to RFC5734, the draft states, first in the
>             abstract and then in the security considerations, that TLS
>             is required.
>
>             That being said, the authors don't object to renaming the
>             dcocument EPP-over-HTTPS if the WG agrees.
>
>             *2)  Cookies*
>
>             Jim (Reed) asked why cookies should be used in this case.
>
>             The reasons why we have used session cookiea are that they
>             represent a standard method (RFC6265), well known to the
>             community of REST service implementers, largely used and
>             natively supported by libraries and frameworks on both
>             client and server side. For example, it is the same method
>             used by rdap-openid to map an RDAP session and tie it to
>             an access token :-)
>
>             .it and .pl have been using this method since the
>             beginning and the registrars, after being informed that
>             they had to enable cookies in their HTTP clients, have no
>             longer complained about cookie management.
>
>             In addition, the implementation of such a method doesn't 
>             introduce any change to the EPP core spec. Indeed, it
>             preserves EPP comands semantics and doesn't mix the
>             application layer with the transport layer.
>
>             I would like to say that, regarding the clear distinction
>             between those layers, this proposal is even better than
>             RFC5734 as every EPP response is returned by the server as
>             a consequence of receiving an EPP request.
>
>             On the contrary, in RFC5734, an EPP <greeting> is returned
>             to the client after the TCP connection has been
>             established so, at least in this case, the**two layers get
>             mixed.
>
>             Which method other than session cookie shoud be used instead ?
>
>             *3)   Security Considerations*
>
>             Ulirch recommended to review the security considerations
>             by inheriting those from TLS WG about which versions and
>             ciphers of TLS to use.
>
>             Thanks a lot for the heads up, Ulrich. Surely, we'll do.
>
>             Gavin noted that, unlike EPP-over-TCP, this draft states
>             that client IP address check is optional.
>
>             As a matter of fact, it is stated as recommended.
>
>             Anyway, the authors don't object to changing it into an
>             absolute rquirement if the WG agrees.
>
>             *4)  Cookie vs. HTTP Connection*
>
>             One comment from James in the chat is about establishing
>             the cookie at setup of the connection and not linking it
>             to the EPP Login command.
>
>             James, can you further clarify why we should opt for
>             establishing the cookie at setup of the connection and how
>             shoudl it be possible? For example, what kind of request
>             should be used to start the HTTP connection?
>
>             IMO, an HTTP session is something that is inherently
>             unlinked to the HTTP connections.
>
>             HTTP connections can be broken but sessions don't get lost.
>
>             Programmatically, REST implementers are in charge of
>             processing HTTP requests and building responses rather
>             than managing HTTP connections, which is instead delegated
>             to the application servers.
>
>             Finally, I would like to outline that Section 2.9.1 of
>             RFC5730 states that an EPP session starts with a Login
>             command and the mechanism described by RFC6265 lets (I'm
>             quoting here) "the servers maintain a stateful session
>             over the mostly stateless HTTP protocol". As a
>             consequence, it seems much more practical to start the
>             EPP/HTTP session as a result of a Login command.
>
>             *5) EPP/HTTP Sessions vs. HTTP3 Connections*
>
>             Ulrich remarked that, in HTTP3, it is possible to have
>             multiple sessions on an HTTP connection.
>
>             This is valid also for the other HTTP versions.
>
>             In fact, an HTTP connection can be kept alive and, over
>             it, a client could submit multiple login-commands-logout
>             sequences.
>
>             This is quite usual for a smart client managing a pool of
>             HTTP connections.
>
>             Instead, It is unlikely but not impossible to come across
>             HTTP connections supporting multiple concurrent sessions.
>
>             What should be the possible drawbacks for a server in
>             allowing the scenarios above?
>
>             *6) Client authentication in HTTP3*
>
>             Another note pointed out that HTTP3 client authentication
>             requirements are different from this draft and they need
>             to be reconciled.
>
>             Think that it could be sufficient to add to the security
>             considerations some text similar to what is included in
>             section 4.4 "Peer authentication" of RFC 9001 "Using TLS
>             to secure QUIC":
>
>                 A client MUST authenticate the identity of the server.  This
>
>                 typically involves verification that the identity of the server is
>
>                 included in a certificate and that the certificate is issued by a
>
>                 trusted entity (see for example [RFC2818  <https://secure-web.cisco.com/1tkPqD6aAMfTp6t6KppHDGdn0xpgOWSMeCqwZR-hs9Duph9SiceA0vCbaJJVqywNzcZscc6vUZkCPH9lCdtXq_nVJ3OfnNMz-XTQvhBuSBLsXa0VfO5ZNrGo47fSin8GRaQOWRSvSQP_7vRecBdddhF6L0Yqx3KcxAGpvdxpFCsPhLcd5bm-aVy3vTko6TfGBlohe2XEw3bwUmH-u56ZuZz50CUXUqA3YDFgBENAwPrLBjwdDxwgG1JFVGPZF_LEQ/https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Frfc2818>]).
>
>               
>
>             The draft has only considered the optional use of a
>             certificate on server side (not on client side). In doing
>             that, the draft is consistent with another sentence in the
>             same paragraph of RFC9001:
>
>                 A server MAY request that the client authenticate during the
>
>                 handshake.  A server MAY refuse a connection if the client is unable
>
>                 to authenticate when requested.
>
>               
>
>               
>
>             Would it address the feedback?
>
>             That's all for now.
>
>             Hope I did not miss anything.
>
>             Thanks a lot for your interest and feedback.
>
>             Looking forward to your further comments.
>
>             Best,
>
>             Mario
>
>             -- 
>
>             Dr. Mario Loffredo
>
>             Technological Unit “Digital Innovation”
>
>             Institute of Informatics and Telematics (IIT)
>
>             National Research Council (CNR)
>
>             via G. Moruzzi 1, I-56124 PISA, Italy
>
>             Phone: [phone]
>
>             Web:http://www.iit.cnr.it/mario.loffredo  <http://secure-web.cisco.com/1Af0lIvD4wj2TkngfEVwrFVEVRozLiVIU2m1Gi1AH1GN4-eWP-IREXsOLCh8OJ03YAxRNYqVCPHQSwgj-tMCyzvN3jokOBTIBx4-5n1pJdiRXxl-ShJCaHkCjGNPa8EA5qw4kPjkxIrFAy1qOTcPFhieqdc_xyu8yisYoXzily9ozVw3GZaUtkKrLnmnDJhlFv2LRTCTnw913LzH8bX-hB6FpPlyFi_0v2_H1NFCgZYjuu4pgUeOeIqQJRQwtzNLS/http%3A%2F%2Fwww.iit.cnr.it%2Fmario.loffredo>
>
>         -- 
>
>         Dr. Mario Loffredo
>
>         Technological Unit “Digital Innovation”
>
>         Institute of Informatics and Telematics (IIT)
>
>         National Research Council (CNR)
>
>         via G. Moruzzi 1, I-56124 PISA, Italy
>
>         Phone: [phone]
>
>         Web:http://www.iit.cnr.it/mario.loffredo  <http://secure-web.cisco.com/1OpUT5efcRPCKu9ZmpfyFmbeoIexTqMIlduFKl7VTUSeET1W3oogufCAfJPPw-WSQ0iyo_wkztY_7M69qw0yf13C4w7OWB_Zk5w2FsV-GGCSLot8lFQdslU0DvCpCTw9FjZr0AsFsubGH-kToYrLxzzEj7vGDKuxIFxPK92P5bu2CDOE4UFtRPRGvu9rzX83rks8X2le_j1uSS1SD5B8CyvSp0tsne0HWMS5luho_DIhdOil7-0a_7ZX6CQA08GQq/http%3A%2F%2Fwww.iit.cnr.it%2Fmario.loffredo>
>
>
>
>
>         _______________________________________________
>
>         regext mailing list
>
>         [e-mail]
>
>         https://www.ietf.org/mailman/listinfo/regext  <https://secure-web.cisco.com/16jl36WEWq0s-czRNUY5mezogTB1s8eM6-POsf3osvBxTtShse2Gx3vayC92AUxQ8ebDwE9Ob8SzhMcrkTCHnZy_RbpQlkSPKyyG9v1LOvWmmr2bX-q2Kwz-52tKvzlBlfgMU_rKnCsIFS9e53n9Fl1sqideuhzE2Qvq05_MQ6tGzuKP1z0P4vYyDR8QmVl4xwlz-BKFhZLijpQYz9CLe61qg3JAC0a2ldUiZMLUwjnSSssMNXvvVibSRdv-9l9yg/https%3A%2F%2Fwww.ietf.org%2Fmailman%2Flistinfo%2Fregext>
>
>     -- 
>
>     Dr. Mario Loffredo
>
>     Technological Unit “Digital Innovation”
>
>     Institute of Informatics and Telematics (IIT)
>
>     National Research Council (CNR)
>
>     via G. Moruzzi 1, I-56124 PISA, Italy
>
>     Phone: [phone]
>
>     Web:http://www.iit.cnr.it/mario.loffredo  <http://secure-web.cisco.com/1yKvefSSzzB1xtPf0Zt9UvXnOkA28n5LvF1HkMnNZqV6Dwz7x7ZD06GbmS94ZAQwsmSA6iszQPAkGi5fNCSMjCHwEbful0vNQc0bfu7a2ydpIkKyqCYgjHlBp7I_-3eCZXAtMTjU_xfTEae9EnXNbksctYNkGyOsHDR02jSoOeVLa3lgW8hWUZ20zgxxFQlt_HdsERDtOQY4EoiE3orLFHDV3wtSA-ChHIYVp1pfMvU2aCEBQ3tWEhFOLp740jUPP/http%3A%2F%2Fwww.iit.cnr.it%2Fmario.loffredo>
>
> -- 
> Dr. Mario Loffredo
> Technological Unit “Digital Innovation”
> Institute of Informatics and Telematics (IIT)
> National Research Council (CNR)
> via G. Moruzzi 1, I-56124 PISA, Italy
> Phone: [phone]
> Web:http://www.iit.cnr.it/mario.loffredo  <http://secure-web.cisco.com/1pp2UVbYq0m0PdgNAIf-MFBBPlI6rgwJb-nl0OyxKTaZvJklLUlXEVPn3qvn6ziLbUr86nSYHSn9PLRlT1wKKUgtGjJOdnJ8Ghkk3hlYjxMa4J4AaIOBZ7WvzWPIEvoHPBVb2TdHFIKvtiJkT5ev0nRTy-ErBgM9XRxiNe_p-wkwdeLKKqJWcyzpKSrlr3WZKQaTzmyHAwtIPMymiYesdU2YUhfSeGkOO4qysnLCFQpp6nqMFwr28xmvjE8p7Rz8v/http%3A%2F%2Fwww.iit.cnr.it%2Fmario.loffredo>
>
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-- 
Dr. Mario Loffredo
Technological Unit “Digital Innovation”
Institute of Informatics and Telematics (IIT)
National Research Council (CNR)
via G. Moruzzi 1, I-56124 PISA, Italy
Phone: [phone]
Web:http://www.iit.cnr.it/mario.loffredo