Re: [netconf] [Technical Errata Reported] RFC8040 (7866)

[Andy Bierman <[e-mail]>]

On Thu, Apr 4, 2024 at 6:16 AM Jernej Tuljak <[e-mail]>
wrote:

> On 03/04/2024 18:55, Andy Bierman wrote:
>
>
>
> On Wed, Apr 3, 2024 at 6:16 AM Jernej Tuljak <[e-mail]>
> wrote:
>
>> On 29/03/2024 17:09, Andy Bierman wrote:
>>
>>
>>
>> On Fri, Mar 29, 2024 at 12:46 AM Jernej Tuljak <[e-mail]>
>> wrote:
>>
>>> On 28/03/2024 17:25, Andy Bierman wrote:
>>>
>>>
>>>
>>> On Thu, Mar 28, 2024 at 2:41 AM Jernej Tuljak <[e-mail]>
>>> wrote:
>>>
>>>> And I'm still not sure why RFC8040 refers to "reserved characters" as
>>>> the only characters that need to be percent-encoded.
>>>>
>>>> Section 2.1 of RFC3986 that describes percent encoding says:
>>>>
>>>>     A percent-encoding mechanism is used to represent a data octet in a
>>>>     component when that octet's corresponding character is outside the
>>>>     allowed set or is being used as a delimiter of, or within, the
>>>>     component.
>>>>
>>>> Then in 2.2 it says:
>>>>
>>>>     URIs include components and subcomponents that are delimited by
>>>>     characters in the "reserved" set.  These characters are called
>>>>     "reserved" because they may (or may not) be defined as delimiters by
>>>>     the generic syntax, by each scheme-specific syntax, or by the
>>>>     implementation-specific syntax of a URI's dereferencing algorithm.
>>>>
>>>> To me this means there's more than just what RFC3986 considers to be a
>>>> "reserved character" that should to be percent-encoded. The "more" in
>>>> this case being characters "outside the allowed set". Characters like
>>>> the double-quote, which I've brought up before, but never got a
>>>> response:
>>>>
>>>>
>>>
>>> The part of sec. 2.2 that was left out lists the chars:
>>>
>>>       reserved    = gen-delims / sub-delims
>>>
>>>       gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"
>>>
>>>       sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
>>>                   / "*" / "+" / "," / ";" / "="
>>>
>>>
>>> IMO these chars need to be percent-encoded in RESTCONF URIs
>>>
>>>
>>>>
>>>> https://mailarchive.ietf.org/arch/msg/netconf/I8kXANHiqeV2JsCWmtTE2fGjYd8/
>>>
>>>
>>>
>>> Perhaps there are some details that are not spelled out.
>>> Double-quote and space are not special in RESTCONF.
>>>
>>>
>>> Are you saying that valid RESTCONF URIs are not required to be valid
>>> RFC3986 URIs?
>>>
>>>
>> No, I am saying that if restconf-next ever happens, then the document can
>> clarify any additional
>> reserved characters.
>>
>>
>> You said that double-quote and space are not special in RESTCONF, but how
>> can that be true, when they are special in RFC3986? What makes them special
>> is that they are not allowed at all. Anywhere. No production of RFC3986
>> ABNF grammar [1] can match them. So they need to be percent-encoded. They
>> do not represent reserved characters but at the same time cannot be
>> recognized as unreserved characters.
>>
>>
>
> I meant no special meaning in RESTCONF.
> RFC 3986 defines the URI encoding.
> There is no intent for RESTCONF to change anything or cherry-pick certain
> requirements and ignore others.
>
> I am not sure what document changes are needed. Perhaps none.
>
>
> I have a specific change in mind.
>
>
You should file a new errata.
This is a separate bug.
It seems OK to me to make this correction.
(I checked our code and it follows NEW, not OLD)


Andy

RFC8040, Section 3.5.3.:
>
> OLD:
>
>    The following example shows how reserved characters are
>    percent-encoded within a key value.  The value of "key1" contains
>    a comma, single-quote, double-quote, colon, double-quote, space,
>    and forward slash (,'":" /).  Note that double-quote is not a
>    reserved character and does not need to be percent-encoded.  The
>    value of "key2" is the empty string, and the value of "key3" is the
>    string "foo".
>
>    Example URL:
>
>       /restconf/data/example-top:top/list1=%2C%27"%3A"%20%2F,,foo
>
> NEW:
>
>    The following example shows how specific characters are
>    percent-encoded within a key value.  The value of "key1" contains
>    a comma, single-quote, double-quote, colon, double-quote, space,
>    and forward slash (,'":" /).  Note that double-quote and space are
>    not reserved characters but also do not correspond to characters in
>    the unreserved set and therefore need to be percent-encoded.  The
>    value of "key2" is the empty string, and the value of "key3" is the
>    string "foo".
>
>    Example URL:
>
>       /restconf/data/example-top:top/list1=%2C%27%22%3A%22%20%2F,,foo
>
>
> Or something along those lines. It seemed related to this errata (7866),
> which is why I brought it up again.
>
> Jernej
>
> Perhaps hold for document update.
>
> [1] - https://datatracker.ietf.org/doc/html/rfc3986#appendix-A
>>
>> Jernej
>>
>
>
> Andy
>
>
>>
>>
>>
>>
>>> Jernej
>>>
>>
>> Andy
>>
>>
>>>
>>> One thing that is clear:
>>> Any user of a RESTCONF URI MUST be capable of converting percent-encoded
>>> chars,
>>> no matter what they are.
>>>
>>>
>>>
>>>>
>>>> Jernej
>>>>
>>>
>>> Andy
>>>
>>>
>>>>
>>>> On 27/03/2024 16:54, Kent Watsen wrote:
>>>> > This errata is incomplete.
>>>> > The issue occurs three times.
>>>> > The occurrence in Section 5.1 is missing.
>>>> >
>>>> > K.
>>>> >
>>>> >
>>>> >> On Mar 23, 2024, at 1:38 PM, RFC Errata System <
>>>> [e-mail]> wrote:
>>>> >>
>>>> >> The following errata report has been submitted for RFC8040,
>>>> >> "RESTCONF Protocol".
>>>> >>
>>>> >> --------------------------------------
>>>> >> You may review the report below and at:
>>>> >> https://www.rfc-editor.org/errata/eid7866
>>>> >>
>>>> >> --------------------------------------
>>>> >> Type: Technical
>>>> >> Reported by: Andy Bierman <[e-mail]>
>>>> >>
>>>> >> Section: 3.5.3
>>>> >>
>>>> >> Original Text
>>>> >> -------------
>>>> >> Text occurs in two places
>>>> >>
>>>> >> 1)
>>>> >>
>>>> >>       The leaf-list value is specified as a string, using the
>>>> canonical
>>>> >>       representation for the YANG data type.  Any reserved characters
>>>> >>       MUST be percent-encoded, according to Sections 2.1 and 2.5 of
>>>> >>       [RFC3986].
>>>> >>
>>>> >>
>>>> >> 2)
>>>> >>
>>>> >>       The key value is specified as a string, using the canonical
>>>> >>       representation for the YANG data type.  Any reserved characters
>>>> >>       MUST be percent-encoded, according to Sections 2.1 and 2.5 of
>>>> >>       [RFC3986].
>>>> >>
>>>> >>
>>>> >> Corrected Text
>>>> >> --------------
>>>> >>
>>>> >> 1)
>>>> >>
>>>> >>       The leaf-list value is specified as a string, using the
>>>> canonical
>>>> >>       representation for the YANG data type.  Any reserved characters
>>>> >>       MUST be percent-encoded, according to Sections 2.1, 2.2, and
>>>> 2.5 of
>>>> >>       [RFC3986].
>>>> >>
>>>> >> 2)
>>>> >>
>>>> >>       The key value is specified as a string, using the canonical
>>>> >>       representation for the YANG data type.  Any reserved characters
>>>> >>       MUST be percent-encoded, according to Sections 2.1, 2.2, and
>>>> 2.5 of
>>>> >>       [RFC3986].
>>>> >>
>>>> >>
>>>> >> Notes
>>>> >> -----
>>>> >> The reserved character list is defined in section 2.2 of RFC 3986
>>>> >>
>>>> >> Instructions:
>>>> >> -------------
>>>> >> This erratum is currently posted as "Reported". (If it is spam, it
>>>> >> will be removed shortly by the RFC Production Center.) Please
>>>> >> use "Reply All" to discuss whether it should be verified or
>>>> >> rejected. When a decision is reached, the verifying party
>>>> >> will log in to change the status and edit the report, if necessary.
>>>> >>
>>>> >> --------------------------------------
>>>> >> RFC8040 (draft-ietf-netconf-restconf-18)
>>>> >> --------------------------------------
>>>> >> Title               : RESTCONF Protocol
>>>> >> Publication Date    : January 2017
>>>> >> Author(s)           : A. Bierman, M. Bjorklund, K. Watsen
>>>> >> Category            : PROPOSED STANDARD
>>>> >> Source              : Network Configuration
>>>> >> Stream              : IETF
>>>> >> Verifying Party     : IESG
>>>> > _______________________________________________
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>>>>
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>>>>
>>>
>>>
>>
>