Network Working Group M. Nottingham
Internet-Draft Fastly
Intended status: Standards Track November 1, 2019
Expires: May 4, 2020
Binary Structured HTTP Headers
draft-nottingham-binary-structured-headers-00
Abstract
This specification defines a binary serialisation of Structured
Headers for HTTP, along with a negotiation mechanism for its use in
HTTP/2. It also defines how to use Structured Headers for many
existing headers - thereby "backporting" them - when supported by two
peers.
Note to Readers
_RFC EDITOR: please remove this section before publication_
The issues list for this draft can be found at
https://github.com/mnot/I-D/labels/binary-structured-headers [1].
The most recent (often, unpublished) draft is at
https://mnot.github.io/I-D/binary-structured-headers/ [2].
Recent changes are listed at https://github.com/mnot/I-D/commits/gh-
pages/binary-structured-headers [3].
See also the draft's current status in the IETF datatracker, at
https://datatracker.ietf.org/doc/draft-nottingham-binary-structured-
headers/ [4].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on May 4, 2020.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3
2. Binary Structured Headers . . . . . . . . . . . . . . . . . . 3
2.1. The Binary Literal Representation . . . . . . . . . . . . 4
2.1.1. Lists . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.2. Dictionaries . . . . . . . . . . . . . . . . . . . . 4
2.1.3. Items . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.4. String Literals . . . . . . . . . . . . . . . . . . . 5
2.2. Binary Structured Types . . . . . . . . . . . . . . . . . 5
2.2.1. Inner Lists . . . . . . . . . . . . . . . . . . . . . 6
2.2.2. Parameters . . . . . . . . . . . . . . . . . . . . . 6
2.2.3. Item Payload Types . . . . . . . . . . . . . . . . . 7
3. Using Binary Structured Headers in HTTP/2 . . . . . . . . . . 10
3.1. Binary Structured Headers Setting . . . . . . . . . . . . 11
3.2. The BINHEADERS Frame . . . . . . . . . . . . . . . . . . 11
4. Using Binary Structured Headers with Existing Fields . . . . 12
4.1. Directly Represented Fields . . . . . . . . . . . . . . . 12
4.2. Aliased Fields . . . . . . . . . . . . . . . . . . . . . 14
4.2.1. URLs . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2.2. Dates . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2.3. ETags . . . . . . . . . . . . . . . . . . . . . . . . 16
4.2.4. Links . . . . . . . . . . . . . . . . . . . . . . . . 16
4.2.5. Cookies . . . . . . . . . . . . . . . . . . . . . . . 17
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
6. Security Considerations . . . . . . . . . . . . . . . . . . . 17
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1. Normative References . . . . . . . . . . . . . . . . . . 17
7.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 19
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1. Introduction
HTTP messages often pass through several systems - clients,
intermediaries, servers, and subsystems of each - that parse and
process their header and trailer fields. This repeated parsing (and
often re-serialisation) adds latency and consumes CPU, energy, and
other resources.
Structured Headers for HTTP [I-D.ietf-httpbis-header-structure]
offers a set of data types that new headers can combine to express
their semantics. This specification defines a binary serialisation
of those structures in Section 2, and specifies its use in HTTP/2 -
specifically, as part of HPACK Literal Header Field Representations
([RFC7541]) - in Section 3.
Section 4 defines how to use Structured Headers for many existing
headers when supported by two peers.
The primary goal of this specification are to reduce parsing overhead
and associated costs, as compared to the textual representation of
Structured Headers. A secondary goal is a more compact wire format
in common situations. An additional goal is to enable future work on
more granular header compression mechanisms.
1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Binary Structured Headers
This section defines a binary serialisation for the Structured Header
Types defined in [I-D.ietf-httpbis-header-structure].
The types permissable as the top-level of Structured Header field
values - Dictionary, List, and Item - are defined in terms of a
Binary Literal Representation (Section 2.1), which is a replacement
for the String Literal Representation in [RFC7541].
Binary representations of the remaining types are defined in
Section 2.2.
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2.1. The Binary Literal Representation
The Binary Literal Representation is a replacement for the String
Literal Representation defined in [RFC7541], Section 5.2, for use in
BINHEADERS frames (Section 3.2).
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| Type (4) | PLength (4+) |
+---+---------------------------+
| Payload Data (Length octets) |
+-------------------------------+
A binary literal representation contains the following fields:
o Type: Four bits indicating the type of the payload.
o PLength: The number of octets used to represent the payload,
encoded as per [RFC7541], Section 5.1, with a 4-bit prefix.
o Payload Data: The payload, as per below.
The following payload types are defined:
2.1.1. Lists
List values (type=0x1) have a payload consisting of a stream of
Binary Structured Types representing the members of the list.
Members that are Items are represented as per Section 2.2.3; members
that are inner-lists are represented as per Section 2.2.1.
If any member cannot be represented, the entire field value MUST be
serialised as a String Literal (Section 2.1.4).
2.1.2. Dictionaries
Dictionary values (type=0x2) have a payload consisting of a stream of
members.
Each member is represented by a key length, followed by that many
bytes of the member-name, followed by Binary Structured Types
representing the member-value.
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0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
| KL (8+) | member-name (KL octets)
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---
| member-value
+---+---+---+---+---+---+---+---
A parameter's fields are:
o KL: The number of octets used to represent the member-name,
encoded as per [RFC7541], Section 5.1, with a 8-bit prefix
o member-name: KL octets of the member-name
o member-value: One or more Binary Structure Types
member-values that are Items are represented as per Section 2.2.3;
member-values that are inner-lists are represented as per
Section 2.2.1.
If any member cannot be represented, the entire field value MUST be
serialised as a String Literal (Section 2.1.4).
2.1.3. Items
Item values (type=0x3) have a payload consisting of Binary Structured
Types, as described in Section 2.2.3.
2.1.4. String Literals
String Literals (type=0x4) are the string value of a header field;
they are used to carry header field values that are not Binary
Structured Headers, and may not be Structured Headers at all. As
such, their semantics are that of String Literal Representations in
[RFC7541], Section 5.2.
Their payload is the octets of the field value.
ISSUE: use Huffman coding? https://github.com/mnot/I-D/issues/305 [5]
2.2. Binary Structured Types
Every Binary Structured Type starts with a 5-bit type field that
identifies the format of its payload:
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0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
Type (5) | Payload...
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
Some Binary Structured Types contain padding bits; senders MUST set
padding bits to 0; recipients MUST ignore their values.
2.2.1. Inner Lists
The Inner List data type (type=0x1) has a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
L(3+) | Members (L octets)
+---+---+---+---+---+---+---+---+---+---+---
Its fields are:
o L: The number of octets used to represent the members, encoded as
per [RFC7541], Section 5.1, with a 3-bit prefix
o Members: L octets
Each member of the list will be represented as an Item
(Section 2.2.3); if any member cannot, the entire field value will be
serialised as a String Literal (Section 2.1.4).
The inner list's parameters, if present, are serialised in a
following Parameter type (Section 2.2.2); they do not form part of
the payload of the inner list.
2.2.2. Parameters
The Parameters data type (type=0x2) has a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
L(3+) | Parameters (L octets)
+---+---+---+---+---+---+---+---+---+---+---
Its fields are:
o L: The number of octets used to represent the token, encoded as
per [RFC7541], Section 5.1, with a 3-bit prefix
o Parameters: L octets
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Each parameter is represented by key length, followed by that many
bytes of the parameter-name, followed by a Binary Structured Type
representing the parameter-value.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
| KL (8+) | parameter-name (KL octets)
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---
| parameter-value (VL octets)
+---+---+---+---+---+---+---+---
A parameter's fields are:
o KL: The number of octets used to represent the parameter-name,
encoded as per [RFC7541], Section 5.1, with a 8-bit prefix
o parameter-name: KL octets of the parameter-name
o parameter-value: A Binary Structured type representing a bare item
(Section 2.2.3)
Parameter-values are bare items; that is, they MUST NOT have
parameters themselves.
If the parameters cannot be represented, the entire field value will
be serialised as a String Literal (Section 2.1.4).
Parameters are always associated with the Binary Structured Type that
immediately preceded them. If parameters are not explicitly allowed
on the preceding type, or there is no preceding type, it is an error.
ISSUE: use Huffman coding for parameter-name?
https://github.com/mnot/I-D/issues/305 [6]
2.2.3. Item Payload Types
Individual Structured Header Items can be represented using the
Binary Payload Types defined below.
The item's parameters, if present, are serialised in a following
Parameter type (Section 2.2.2); they do not form part of the payload
of the item.
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2.2.3.1. Integers
The Integer data type (type=0x3) has a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
S | X | Length (8+)
+---+---+---+---+---+---+---+---+---+---+---
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---
| Integer (Length octets)
+---+---+---+---+---+---+---+---
Its fields are:
o S: sign bit; 0 is negative, 1 is positive
o X: 2 bits of padding
o Length: The number of octets used to represent the integer,
encoded as per [RFC7541], Section 5.1, with a 2-bit prefix
o Integer: Length octets
2.2.3.2. Floats
The Float data type (type=0x4) have a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
S | X | ILength (8+)
+---+---+---+---+---+---+---+---+---+---+---
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---
| Integer (ILength octets)
+---+---+---+---+---+---+---+---
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---
| FLength (8+)
+---+---+---+---+---+---+---+---
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---
| Fractional (FLength octets)
+---+---+---+---+---+---+---+---
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Its fields are:
o S: sign bit; 0 is negative, 1 is positive
o X: 2 bits of padding
o ILength: The number of octets used to represent the integer
component, encoded as per [RFC7541], Section 5.1, with a 2-bit
prefix.
o Integer - ILength octets
o FLength: The number of octets used to represent the fractional
component, encoded as per [RFC7541], Section 5.1, with a 2-bit
prefix.
o Fractional: FLength octets
2.2.3.3. Strings
The String data type (type=0x5) has a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
L(3+) | String (L octets)
+---+---+---+---+---+---+---+---+---+---+---
Its fields are:
o L: The number of octets used to represent the string, encoded as
per [RFC7541], Section 5.1, with a 3-bit prefix.
o String: L octets.
ISSUE: use Huffman coding? https://github.com/mnot/I-D/issues/305 [7]
2.2.3.4. Tokens
The Token data type (type=0x6) has a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
L(3+) | Token (L octets)
+---+---+---+---+---+---+---+---+---+---+---
Its fields are:
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o L: The number of octets used to represent the token, encoded as
per [RFC7541], Section 5.1, with a 3-bit prefix.
o Token: L octets.
ISSUE: use Huffman coding? https://github.com/mnot/I-D/issues/305 [8]
2.2.3.5. Byte Sequences
The Byte Sequence data type (type=0x7) has a payload in the format:
5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+---+---+---
L(3+) | Byte Sequence (L octets)
+---+---+---+---+---+---+---+---+---+---+---
Its fields are:
o L: The number of octets used to represent the byte sequence,
encoded as per [RFC7541], Section 5.1, with a 3-bit prefix.
o Byte Sequence: L octets.
2.2.3.6. Booleans
The Boolean data type (type=0x8) has a payload of two bits:
5 6 7
+---+---+---+
B | X |
+---+---+---+
If B is 0, the value is False; if B is 1, the value is True. X is
padding.
3. Using Binary Structured Headers in HTTP/2
When both peers on a connection support this specification, they can
take advantage of that knowledge to serialise headers that they know
to be Structured Headers (or compatible with them; see Section 4).
Peers advertise and discover this support using a HTTP/2 setting
defined in Section 3.1, and convey Binary Structured Headers in a
frame type defined in Section 3.2.
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3.1. Binary Structured Headers Setting
Advertising support for Binary Structured Headers is accomplished
using a HTTP/2 setting, SETTINGS_BINARY_STRUCTURED_HEADERS (0xTODO).
Receiving SETTINGS_BINARY_STRUCTURED_HEADERS from a peer indicates
that:
1. The peer supports the Binary Structured Types defined in
Section 2.
2. The peer will process the BINHEADERS frames as defined in
Section 3.2.
3. When a downstream consumer does not likewise support that
encoding, the peer will transform them into HEADERS frames (if
the peer is HTTP/2) or a form it will understand (e.g., the
textual representation of Structured Headers data types defined
in [I-D.ietf-httpbis-header-structure]).
4. The peer will likewise transform all fields defined as Aliased
Fields (Section 4.2) into their non-aliased forms as necessary.
The default value of SETTINGS_BINARY_STRUCTURED_HEADERS is 0. Future
extensions to Structured Headers might use it to indicate support for
new types.
3.2. The BINHEADERS Frame
When a peer has indicated that it supports this specification
{#setting}, a sender can send the BINHEADERS Frame Type (0xTODO).
The BINHEADERS Frame Type behaves and is represented exactly as a
HEADERS Frame type ([RFC7540], Section 6.2), with one exception;
instead of using the String Literal Representation defined in
[RFC7541], Section 5.2, it uses the Binary Literal Representation
defined in Section 2.1.
Fields that are Structured Headers can have their values represented
using the Binary Literal Representation corresponding to that
header's top-level type - List, Dictionary, or Item; their values
will then be serialised as a stream of Binary Structured Types.
Additionally, any field (including those defined as Structured
Headers) can be serialised as a String Literal (Section 2.1.4), which
accommodates headers that are not defined as Structured Headers, not
valid Structured Headers, or that the sending implementation does not
wish to send as Binary Structured Types for some other reason.
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Note that Field Names are always serialised as String Literals
(Section 2.1.4).
This means that a BINHEADERS frame can be converted to a HEADERS
frame by converting the field values to the string representations of
the various Structured Headers Types, and String Literals
(Section 2.1.4) to their string counterparts.
Conversely, a HEADERS frame can be converted to a BINHEADERS frame by
encoding all of the Literal field values as Binary Structured Types.
In this case, the header types used are informed by the
implementations knowledge of the individual header field semantics;
see Section 4. Those which it cannot (do to either lack of knowledge
or an error) or does not wish to convert into Structured Headers are
conveyed in BINHEADERS as String Literals (Section 2.1.4).
Field values are stored in the HPACK [RFC7541] dynamic table without
Huffman encoding, although specific Binary Structured Types might
specify the use of such encodings.
Note that BINHEADERS and HEADERS frames MAY be mixed on the same
connection, depending on the requirements of the sender. Also, note
that only the field values are encoded as Binary Structured Types;
field names are encoded as they are in HPACK.
4. Using Binary Structured Headers with Existing Fields
Any header field can potentially be parsed as a Structured Header
according to the algorithms in [I-D.ietf-httpbis-header-structure]
and serialised as a Binary Structured Header. However, many cannot,
so optimistically parsing them can be expensive.
This section identifies fields that will usually succeed in
Section 4.1, and those that can be mapped into Structured Headers by
using an alias field name in Section 4.2.
4.1. Directly Represented Fields
The following HTTP field names can have their values parsed as
Structured Headers according to the algorithms in
[I-D.ietf-httpbis-header-structure], and thus can usually be
serialised using the corresponding Binary Structured Types.
When one of these fields' values cannot be represented using
Structured Types, its value can instead be represented as a String
Literal (Section 2.1.4).
o Accept - List
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o Accept-Encoding - List
o Accept-Language - List
o Accept-Patch - List
o Accept-Ranges - List
o Access-Control-Allow-Credentials - Item
o Access-Control-Allow-Headers - List
o Access-Control-Allow-Methods - List
o Access-Control-Allow-Origin - Item
o Access-Control-Max-Age - Item
o Access-Control-Request-Headers - List
o Access-Control-Request-Method - Item
o Age - Item
o Allow - List
o ALPN - List
o Alt-Svc - List
o Alt-Used - Item
o Cache-Control - Dictionary
o Content-Encoding - Item
o Content-Language - List
o Content-Length - Item
o Content-Type - Item
o Expect - Item
o Forwarded - List
o Host - Item
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o Origin - Item
o Pragma - Dictionary
o Prefer - Dictionary
o Preference-Applied - Dictionary
o Retry-After - Item (see caveat below)
o Surrogate-Control - Dictionary
o TE - List
o Trailer - List
o Transfer-Encoding - List
o Vary - List
o X-Content-Type-Options - Item
Note that only the delta-seconds form of Retry-After is supported; a
Retry-After value containing a http-date will need to be either
converted into delta-seconds or serialised as a String Literal
(Section 2.1.4).
4.2. Aliased Fields
The following HTTP field names can have their values represented in
Structured headers by mapping them into its data types and then
serialising the resulting Structured Header using an alternative
field name.
For example, the Date HTTP header field carries a http-date, which is
a string representing a date:
Date: Sun, 06 Nov 1994 08:49:37 GMT
Its value is more efficiently represented as an integer number of
delta seconds from the Unix epoch (00:00:00 UTC on 1 January 1970,
minus leap seconds). Thus, the example above would be represented in
(non-binary) Structured headers as:
SH-Date: 784072177
As with directly represented fields, if the intended value of an
aliased field cannot be represented using Structured Types
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successfully, its value can instead be represented as a String
Literal (Section 2.1.4).
Note that senders MUST know that the next-hop recipient understands
these fields (typically, using the negotiation mechanism defined in
Section 3) before using them. Likewise, recipients MUST transform
them back to their unaliased form before forwarding the message to a
peer or other consuming components that do not have this capability.
Each field name listed below indicates a replacement field name and a
way to map its value to Structured Headers.
ISSUE: using separate names assures that the different syntax doesn't
"leak" into normal headers, but it isn't strictly necessary if
implementations always convert back to the correct form when giving
it to peers or consuming software that doesn't understand this.
https://github.com/mnot/I-D/issues/307 [9]
4.2.1. URLs
The following field names (paired with their replacement field names)
have values that can be represented in Binary Structured Headers by
considering their payload a string.
o Content-Location - SH-Content-Location
o Location - SH-Location
o Referer - SH-Referer
For example, a (non-binary) Location:
SH-Location: "https://example.com/foo"
TOOD: list of strings, one for each path segment, to allow better
compression in the future?
4.2.2. Dates
The following field names (paired with their replacement field names)
have values that can be represented in Binary Structured Headers by
parsing their payload according to [RFC7230], Section 7.1.1.1, and
representing the result as an integer number of seconds delta from
the Unix Epoch (00:00:00 UTC on 1 January 1970, minus leap seconds).
o Date - SH-Date
o Expires - SH-Expires
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o If-Modified-Since - SH-IMS
o If-Unmodified-Since - SH-IUS
o Last-Modified - SH-LM
For example, a (non-binary) Expires:
SH-Expires: 1571965240
4.2.3. ETags
The following field names (paired with their replacement field names)
have values that can be represented in Binary Structured Headers by
representing the entity-tag as a string, and the weakness flag as a
boolean "w" parameter on it, where true indicates that the entity-tag
is weak; if 0 or unset, the entity-tag is strong.
o ETag - SH-ETag
For example, a (non-Binary) ETag:
SH-ETag: "abcdef"; w=?1
If-None-Match is a list of the structure described above.
o If-None-Match - SH-INM
For example, a (non-binary) If-None-Match:
SH-INM: "abcdef"; w=?1, "ghijkl"
4.2.4. Links
The field-value of the Link header field [RFC8288] can be represented
in Binary Structured Headers by representing the URI-Reference as a
string, and link-param as parameters.
o Link: SH-Link
For example, a (non-binary) Link:
SH-Link: "/terms"; rel="copyright"; anchor="#foo"
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4.2.5. Cookies
The field-value of the Cookie and Set-Cookie fields [RFC6265] can be
represented in Binary Structured Headers as a List with parameters
and a Dictionary, respectively. The serialisation is almost
identical, except that the Expires parameter is always a string (as
it can contain a comma), multiple cookie-strings can appear in Set-
Cookie, and cookie-pairs are delimited in Cookie by a comma, rather
than a semicolon.
Set-Cookie: SH-Set-Cookie Cookie: SH-Cookie
SH-Set-Cookie: lang=en-US, Expires="Wed, 09 Jun 2021 10:18:14 GMT"
SH-Cookie: SID=31d4d96e407aad42, lang=en-US
ISSUE: explicitly convert Expires to an integer?
https://github.com/mnot/I-D/issues/308 [10]
5. IANA Considerations
ISSUE: todo
6. Security Considerations
As is so often the case, having alternative representations of data
brings the potential for security weaknesses, when attackers exploit
the differences between those representations and their handling.
One mitigation to this risk is the strictness of parsing for both
non-binary and binary Structured Headers data types, along with the
"escape valve" of String Literals (Section 2.1.4). Therefore,
implementation divergence from this strictness can have security
impact.
7. References
7.1. Normative References
[]
Nottingham, M. and P. Kamp, "Structured Headers for HTTP",
draft-ietf-httpbis-header-structure-14 (work in progress),
October 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
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[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,
DOI 10.17487/RFC6265, April 2011,
<https://www.rfc-editor.org/info/rfc6265>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<https://www.rfc-editor.org/info/rfc7230>.
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015,
<https://www.rfc-editor.org/info/rfc7540>.
[RFC7541] Peon, R. and H. Ruellan, "HPACK: Header Compression for
HTTP/2", RFC 7541, DOI 10.17487/RFC7541, May 2015,
<https://www.rfc-editor.org/info/rfc7541>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8288] Nottingham, M., "Web Linking", RFC 8288,
DOI 10.17487/RFC8288, October 2017,
<https://www.rfc-editor.org/info/rfc8288>.
7.2. URIs
[1] https://github.com/mnot/I-D/labels/binary-structured-headers
[2] https://mnot.github.io/I-D/binary-structured-headers/
[3] https://github.com/mnot/I-D/commits/gh-pages/binary-structured-
headers
[4] https://datatracker.ietf.org/doc/draft-nottingham-binary-
structured-headers/
[5] https://github.com/mnot/I-D/issues/305
[6] https://github.com/mnot/I-D/issues/305
[7] https://github.com/mnot/I-D/issues/305
[8] https://github.com/mnot/I-D/issues/305
[9] https://github.com/mnot/I-D/issues/307
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[10] https://github.com/mnot/I-D/issues/308
Author's Address
Mark Nottingham
Fastly
Email: mnot@mnot.net
URI: https://www.mnot.net/
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