draft-ietf-httpbis-message-signatures-01.txt   draft-ietf-httpbis-message-signatures-02.txt 
HTTP A. Backman, Ed. HTTP A. Backman, Ed.
Internet-Draft Amazon Internet-Draft Amazon
Intended status: Standards Track J. Richer Intended status: Standards Track J. Richer
Expires: 21 May 2021 Bespoke Engineering Expires: 16 September 2021 Bespoke Engineering
M. Sporny M. Sporny
Digital Bazaar Digital Bazaar
17 November 2020 15 March 2021
Signing HTTP Messages Signing HTTP Messages
draft-ietf-httpbis-message-signatures-01 draft-ietf-httpbis-message-signatures-02
Abstract Abstract
This document describes a mechanism for creating, encoding, and This document describes a mechanism for creating, encoding, and
verifying digital signatures or message authentication codes over verifying digital signatures or message authentication codes over
content within an HTTP message. This mechanism supports use cases content within an HTTP message. This mechanism supports use cases
where the full HTTP message may not be known to the signer, and where where the full HTTP message may not be known to the signer, and where
the message may be transformed (e.g., by intermediaries) before the message may be transformed (e.g., by intermediaries) before
reaching the verifier. reaching the verifier.
Note to Readers Note to Readers
_RFC EDITOR: please remove this section before publication_ _RFC EDITOR: please remove this section before publication_
This work was originally based on draft-cavage-http-signatures-12, Discussion of this draft takes place on the HTTP working group
but has since diverged from it, to reflect discussion since adoption mailing list (ietf-http-wg@w3.org), which is archived at
by the HTTP Working Group. In particular, it addresses issues that https://lists.w3.org/Archives/Public/ietf-http-wg/
have been identified, and adds features to support new use cases. It (https://lists.w3.org/Archives/Public/ietf-http-wg/).
is a work-in-progress and not yet suitable for deployment.
Working Group information can be found at https://httpwg.org/
(https://httpwg.org/); source code and issues list for this draft can
be found at https://github.com/httpwg/http-extensions/labels/
signatures (https://github.com/httpwg/http-extensions/labels/
signatures).
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 21 May 2021. This Internet-Draft will expire on 16 September 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/ Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document. license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License. provided without warranty as described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Discussion . . . . . . . . . . . . . . . . . 5 1.1. Requirements Discussion . . . . . . . . . . . . . . . . . 4
1.2. HTTP Message Transformations . . . . . . . . . . . . . . 5 1.2. HTTP Message Transformations . . . . . . . . . . . . . . 5
1.3. Safe Transformations . . . . . . . . . . . . . . . . . . 6 1.3. Safe Transformations . . . . . . . . . . . . . . . . . . 5
1.4. Conventions and Terminology . . . . . . . . . . . . . . . 7 1.4. Conventions and Terminology . . . . . . . . . . . . . . . 6
1.5. Application of HTTP Message Signatures . . . . . . . . . 7
2. Identifying and Canonicalizing Content . . . . . . . . . . . 8 2. Identifying and Canonicalizing Content . . . . . . . . . . . 8
2.1. HTTP Header Fields . . . . . . . . . . . . . . . . . . . 8 2.1. HTTP Headers . . . . . . . . . . . . . . . . . . . . . . 8
2.1.1. Canonicalization Examples . . . . . . . . . . . . . . 9 2.1.1. Canonicalized Structured HTTP Headers . . . . . . . . 9
2.2. Dictionary Structured Field Members . . . . . . . . . . . 9 2.1.2. Canonicalization Examples . . . . . . . . . . . . . . 9
2.2. Dictionary Structured Field Members . . . . . . . . . . . 10
2.2.1. Canonicalization Examples . . . . . . . . . . . . . . 10 2.2.1. Canonicalization Examples . . . . . . . . . . . . . . 10
2.3. List Prefixes . . . . . . . . . . . . . . . . . . . . . . 10 2.3. List Prefixes . . . . . . . . . . . . . . . . . . . . . . 11
2.3.1. Canonicalization Examples . . . . . . . . . . . . . . 10 2.3.1. Canonicalization Examples . . . . . . . . . . . . . . 11
2.4. Signature Creation Time . . . . . . . . . . . . . . . . . 11 2.4. Specialty Content Fields . . . . . . . . . . . . . . . . 12
2.5. Signature Expiration Time . . . . . . . . . . . . . . . . 11 2.4.1. Request Target . . . . . . . . . . . . . . . . . . . 12
2.6. Target Endpoint . . . . . . . . . . . . . . . . . . . . . 11 2.4.2. Signature Parameters . . . . . . . . . . . . . . . . 13
2.6.1. Canonicalization Examples . . . . . . . . . . . . . . 12 3. HTTP Message Signatures . . . . . . . . . . . . . . . . . . . 14
3. HTTP Message Signatures . . . . . . . . . . . . . . . . . . . 12 3.1. Signature Metadata . . . . . . . . . . . . . . . . . . . 14
3.1. Signature Metadata . . . . . . . . . . . . . . . . . . . 13 3.2. Creating a Signature . . . . . . . . . . . . . . . . . . 16
3.2. Creating a Signature . . . . . . . . . . . . . . . . . . 13 3.2.1. Choose and Set Signature Metadata Properties . . . . 16
3.2.1. Choose and Set Signature Metadata Properties . . . . 14 3.2.2. Create the Signature Input . . . . . . . . . . . . . 18
3.2.2. Create the Signature Input . . . . . . . . . . . . . 16 3.2.3. Sign the Signature Input . . . . . . . . . . . . . . 19
3.2.3. Sign the Signature Input . . . . . . . . . . . . . . 17 3.3. Verifying a Signature . . . . . . . . . . . . . . . . . . 19
3.3. Verifying a Signature . . . . . . . . . . . . . . . . . . 17 3.3.1. Enforcing Application Requirements . . . . . . . . . 20
3.3.1. Enforcing Application Requirements . . . . . . . . . 18
4. Including a Message Signature in a Message . . . . . . . . . 19
4.1. The 'Signature-Input' HTTP Header . . . . . . . . . . . . 19
4.1.1. Metadata Parameters . . . . . . . . . . . . . . . . . 19
4.2. The 'Signature' HTTP Header . . . . . . . . . . . . . . . 20
4.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . 20
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
5.1. HTTP Signature Algorithms Registry . . . . . . . . . . . 21
5.1.1. Registration Template . . . . . . . . . . . . . . . . 21
5.1.2. Initial Contents . . . . . . . . . . . . . . . . . . 22
5.2. HTTP Signature Metadata Parameters Registry . . . . . . . 24
5.2.1. Registration Template . . . . . . . . . . . . . . . . 24
5.2.2. Initial Contents . . . . . . . . . . . . . . . . . . 24
6. Security Considerations . . . . . . . . . . . . . . . . . . . 25
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.1. Normative References . . . . . . . . . . . . . . . . . . 25
7.2. Informative References . . . . . . . . . . . . . . . . . 26
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 27
A.1. Example Keys . . . . . . . . . . . . . . . . . . . . . . 27
A.1.1. Example Key RSA test . . . . . . . . . . . . . . . . 27
A.2. Example keyId Values . . . . . . . . . . . . . . . . . . 28
A.3. Test Cases . . . . . . . . . . . . . . . . . . . . . . . 29
A.3.1. Signature Generation . . . . . . . . . . . . . . . . 29
A.3.2. Signature Verification . . . . . . . . . . . . . . . 32
Appendix B. Topics for Working Group Discussion . . . . . . . . 34
B.1. Issues . . . . . . . . . . . . . . . . . . . . . . . . . 34
B.1.1. Confusing guidance on algorithm and key
identification . . . . . . . . . . . . . . . . . . . 35
B.1.2. Lack of definition of keyId hurts interoperability . 35
B.1.3. Algorithm Registry duplicates work of JWA . . . . . . 35
B.1.4. Algorithm Registry should not be initialized with
deprecated entries . . . . . . . . . . . . . . . . . 36
B.1.5. No percent-encoding normalization of path/query . . . 36
B.1.6. Misleading name for headers parameter . . . . . . . . 36
B.1.7. Changes to whitespace in header field values break
verification . . . . . . . . . . . . . . . . . . . . 36
B.1.8. Multiple Set-Cookie headers are not well supported . 36
B.1.9. Covered Content list is not signed . . . . . . . . . 37
B.1.10. Algorithm is not signed . . . . . . . . . . . . . . . 37
B.1.11. Verification key identifier is not signed . . . . . . 37
B.1.12. Max values, precision for Integer String and Decimal
String not defined . . . . . . . . . . . . . . . . . 37
B.1.13. keyId parameter value could break list syntax . . . . 37
B.1.14. Creation Time and Expiration Time do not allow for
clock skew . . . . . . . . . . . . . . . . . . . . . 37
B.1.15. Should require lowercased header field names as
identifiers . . . . . . . . . . . . . . . . . . . . . 37
B.1.16. Reconcile Date header and Creation Time . . . . . . . 38
B.1.17. Remove algorithm-specific rules for content
identifiers . . . . . . . . . . . . . . . . . . . . . 38
B.1.18. Add guidance for signing compressed headers . . . . . 38
B.1.19. Transformations to Via header field value break
verification . . . . . . . . . . . . . . . . . . . . 38
B.1.20. Case changes to case-insensitive header field values
break verification . . . . . . . . . . . . . . . . . 38
B.1.21. Need more examples for Signature header . . . . . . . 38
B.1.22. Expiration not needed . . . . . . . . . . . . . . . . 39
B.2. Features . . . . . . . . . . . . . . . . . . . . . . . . 39 4. Including a Message Signature in a Message . . . . . . . . . 21
B.2.1. Define more content identifiers . . . . . . . . . . . 39 4.1. The 'Signature-Input' HTTP Header . . . . . . . . . . . . 21
B.2.2. Multiple signature support . . . . . . . . . . . . . 39 4.2. The 'Signature' HTTP Header . . . . . . . . . . . . . . . 21
B.2.3. Support for incremental signing of header field value 4.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . 22
list items . . . . . . . . . . . . . . . . . . . . . 40 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
B.2.4. Support expected authority changes . . . . . . . . . 40 5.1. HTTP Signature Algorithms Registry . . . . . . . . . . . 23
B.2.5. Support for signing specific cookies . . . . . . . . 40 5.1.1. Registration Template . . . . . . . . . . . . . . . . 23
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1.2. Initial Contents . . . . . . . . . . . . . . . . . . 24
Document History . . . . . . . . . . . . . . . . . . . . . . . . 41 5.2. HTTP Signature Metadata Parameters Registry . . . . . . . 25
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 43 5.2.1. Registration Template . . . . . . . . . . . . . . . . 25
5.2.2. Initial Contents . . . . . . . . . . . . . . . . . . 25
5.3. HTTP Signature Specialty Content Identifiers Registry . . 26
5.3.1. Registration Template . . . . . . . . . . . . . . . . 26
5.3.2. Initial Contents . . . . . . . . . . . . . . . . . . 26
6. Security Considerations . . . . . . . . . . . . . . . . . . . 27
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.1. Normative References . . . . . . . . . . . . . . . . . . 27
7.2. Informative References . . . . . . . . . . . . . . . . . 28
Appendix A. Detecting HTTP Message Signatures . . . . . . . . . 29
Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 29
B.1. Example Keys . . . . . . . . . . . . . . . . . . . . . . 29
B.1.1. Example Key RSA test . . . . . . . . . . . . . . . . 29
B.2. Example keyid Values . . . . . . . . . . . . . . . . . . 30
B.3. Test Cases . . . . . . . . . . . . . . . . . . . . . . . 31
B.3.1. Signature Generation . . . . . . . . . . . . . . . . 31
B.3.2. Signature Verification . . . . . . . . . . . . . . . 34
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 36
Document History . . . . . . . . . . . . . . . . . . . . . . . . 37
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39
1. Introduction 1. Introduction
Message integrity and authenticity are important security properties Message integrity and authenticity are important security properties
that are critical to the secure operation of many HTTP applications. that are critical to the secure operation of many HTTP applications.
Application developers typically rely on the transport layer to Application developers typically rely on the transport layer to
provide these properties, by operating their application over [TLS]. provide these properties, by operating their application over [TLS].
However, TLS only guarantees these properties over a single TLS However, TLS only guarantees these properties over a single TLS
connection, and the path between client and application may be connection, and the path between client and application may be
composed of multiple independent TLS connections (for example, if the composed of multiple independent TLS connections (for example, if the
skipping to change at page 7, line 31 skipping to change at page 6, line 50
For brevity, the term "signature" on its own is used in this document For brevity, the term "signature" on its own is used in this document
to refer to both digital signatures and keyed MACs. Similarly, the to refer to both digital signatures and keyed MACs. Similarly, the
verb "sign" refers to the generation of either a digital signature or verb "sign" refers to the generation of either a digital signature or
keyed MAC over a given input string. The qualified term "digital keyed MAC over a given input string. The qualified term "digital
signature" refers specifically to the output of an asymmetric signature" refers specifically to the output of an asymmetric
cryptographic signing operation. cryptographic signing operation.
In addition to those listed above, this document uses the following In addition to those listed above, this document uses the following
terms: terms:
Decimal String Signer:
An Integer String optionally concatenated with a period "."
followed by a second Integer String, representing a positive real
number expressed in base 10. The first Integer String represents
the integral portion of the number, while the optional second
Integer String represents the fractional portion of the number.
(( Editor's note: There's got to be a definition for this that we
can reference. ))
Integer String
A US-ASCII string of one or more digits "0-9", representing a
positive integer in base 10. (( Editor's note: There's got to be a
definition for this that we can reference. ))
Signer
The entity that is generating or has generated an HTTP Message The entity that is generating or has generated an HTTP Message
Signature. Signature.
Verifier Verifier:
An entity that is verifying or has verified an HTTP Message An entity that is verifying or has verified an HTTP Message
Signature against an HTTP Message. Note that an HTTP Message Signature against an HTTP Message. Note that an HTTP Message
Signature may be verified multiple times, potentially by different Signature may be verified multiple times, potentially by different
entities. entities.
The term "Unix time" is defined by [POSIX.1] section 4.16
(http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/
V1_chap04.html#tag_04_16).
This document contains non-normative examples of partial and complete This document contains non-normative examples of partial and complete
HTTP messages. To improve readability, header fields may be split HTTP messages. To improve readability, header fields may be split
into multiple lines, using the "obs-fold" syntax. This syntax is into multiple lines, using the "obs-fold" syntax. This syntax is
deprecated in [MESSAGING], and senders MUST NOT generate messages deprecated in [MESSAGING], and senders MUST NOT generate messages
that include it. that include it.
Additionally, some examples use '\' line wrapping for long values
that contain no whitespace, as per [RFC8792].
1.5. Application of HTTP Message Signatures
HTTP Message Signatures are designed to be a general-purpose security
mechanism applicable in a wide variety of circumstances and
applications. In order to properly and safely apply HTTP Message
Signatures, an application or profile of this specification MUST
specify all of the following items:
* The set of content identifiers (Section 2) that are expected and
required. For example, an authorization protocol would mandate
that the "Authorization" header be covered to protect the
authorization credentials, as well as a "*created" field to allow
replay detection.
* A means of retrieving the key material used to verify the
signature. An application will usually use the "keyid" field of
the "Signature-Input" header value and define rules for resolving
a key from there.
* A means of determining the signature algorithm used to verify the
signature content is appropriate for the key material.
* A means of determining that a given key and algorithm presented in
the request are appropriate for the request being made. For
example, a server expecting only ECDSA signatures should know to
reject any RSA signatures; or a server expecting asymmetric
cryptography should know to reject any symmetric cryptography.
The details of this kind of profiling are the purview of the
application and outside the scope of this specification.
2. Identifying and Canonicalizing Content 2. Identifying and Canonicalizing Content
In order to allow signers and verifiers to establish which content is In order to allow signers and verifiers to establish which content is
covered by a signature, this document defines content identifiers for covered by a signature, this document defines content identifiers for
signature metadata and discrete pieces of message content that may be data items covered by an HTTP Message Signature.
covered by an HTTP Message Signature.
Some content within HTTP messages may undergo transformations that Some content within HTTP messages can undergo transformations that
change the bitwise value without altering meaning of the content (for change the bitwise value without altering meaning of the content (for
example, the merging together of header fields with the same name). example, the merging together of header fields with the same name).
Message content must therefore be canonicalized before it is signed, Message content must therefore be canonicalized before it is signed,
to ensure that a signature can be verified despite such innocuous to ensure that a signature can be verified despite such intermediary
transformations. This document defines rules for each content transformations. This document defines rules for each content
identifier that transform the identifier's associated content into identifier that transform the identifier's associated content into
such a canonical form. such a canonical form.
The following sections define content identifiers, their associated Content identifiers are defined using production grammar defined by
content, and their canonicalization rules. [RFC8941] section 4. The content identifier is an "sf-string" value.
The content identifier type MAY define parameters which are included
using the "parameters" rule.
2.1. HTTP Header Fields content-identifier = sf-string parameters
An HTTP header field is identified by its header field name. While Note that this means the value of the identifier itself is encased in
HTTP header field names are case-insensitive, implementations MUST double quotes, with parameters following as a semicolon-separated
use lowercased field names (e.g., "content-type", "date", "etag") list, such as ""cache-control"", ""date"", or ""@signature-params"".
when using them as content identifiers.
An HTTP header field value is canonicalized as follows: The following sections define content identifier types, their
parameters, their associated content, and their canonicalization
rules.
2.1. HTTP Headers
The content identifier for an HTTP header is the lowercased form of
its header field name. While HTTP header field names are case-
insensitive, implementations MUST use lowercased field names (e.g.,
"content-type", "date", "etag") when using them as content
identifiers.
Unless overridden by additional parameters and rules, the HTTP header
field value MUST be canonicalized with the following steps:
1. Create an ordered list of the field values of each instance of 1. Create an ordered list of the field values of each instance of
the header field in the message, in the order that they occur (or the header field in the message, in the order that they occur (or
will occur) in the message. will occur) in the message.
2. Strip leading and trailing whitespace from each item in the list. 2. Strip leading and trailing whitespace from each item in the list.
3. Concatenate the list items together, with a comma "," and space " 3. Concatenate the list items together, with a comma "," and space "
" between each item. The resulting string is the canonicalized " between each item.
value.
2.1.1. Canonicalization Examples The resulting string is the canonicalized value.
2.1.1. Canonicalized Structured HTTP Headers
If value of the the HTTP header in question is a structured field
[RFC8941], the content identifier MAY include the "sf" parameter. If
this parameter is included, the HTTP header value MUST be
canonicalized using the rules specified in [RFC8941] section 4. Note
that this process will replace any optional whitespace with a single
space.
The resulting string is used as the field value input in Section 2.1.
2.1.2. Canonicalization Examples
This section contains non-normative examples of canonicalized values This section contains non-normative examples of canonicalized values
for header fields, given the following example HTTP message: for header fields, given the following example HTTP message:
HTTP/1.1 200 OK HTTP/1.1 200 OK
Server: www.example.com Server: www.example.com
Date: Tue, 07 Jun 2014 20:51:35 GMT Date: Tue, 07 Jun 2014 20:51:35 GMT
X-OWS-Header: Leading and trailing whitespace. X-OWS-Header: Leading and trailing whitespace.
X-Obs-Fold-Header: Obsolete X-Obs-Fold-Header: Obsolete
line folding. line folding.
X-Empty-Header: X-Empty-Header:
Cache-Control: max-age=60 Cache-Control: max-age=60
Cache-Control: must-revalidate Cache-Control: must-revalidate
The following table shows example canonicalized values for header The following table shows example canonicalized values for header
fields, given that message: fields, given that message:
+===================+==================================+ +=====================+==================================+
| Header Field | Canonicalized Value | | Header Field | Canonicalized Value |
+===================+==================================+ +=====================+==================================+
| cache-control | max-age=60, must-revalidate | | "cache-control" | max-age=60, must-revalidate |
+-------------------+----------------------------------+ +---------------------+----------------------------------+
| date | Tue, 07 Jun 2014 20:51:35 GMT | | "date" | Tue, 07 Jun 2014 20:51:35 GMT |
+-------------------+----------------------------------+ +---------------------+----------------------------------+
| server | www.example.com | | "server" | www.example.com |
+-------------------+----------------------------------+ +---------------------+----------------------------------+
| x-empty-header | | | "x-empty-header" | |
+-------------------+----------------------------------+ +---------------------+----------------------------------+
| x-obs-fold-header | Obsolete line folding. | | "x-obs-fold-header" | Obsolete line folding. |
+-------------------+----------------------------------+ +---------------------+----------------------------------+
| x-ows-header | Leading and trailing whitespace. | | "x-ows-header" | Leading and trailing whitespace. |
+-------------------+----------------------------------+ +---------------------+----------------------------------+
Table 1: Non-normative examples of header field Table 1: Non-normative examples of header field
canonicalization. canonicalization.
2.2. Dictionary Structured Field Members 2.2. Dictionary Structured Field Members
An individual member in the value of a Dictionary Structured Field is An individual member in the value of a Dictionary Structured Field is
identified by the lowercased field name, followed by a semicolon identified by using the parameter "key" on the content identifier for
"":"", followed by the member name. An individual member in the the header. The value of this parameter is a the key being
value of a Dictionary Structured Field is canonicalized by applying identified, without any parameters present on that key in the
the serialization algorithm described in Section 4.1.2 of original dictionary.
[StructuredFields] on a Dictionary containing only that member.
An individual member in the value of a Dictionary Structured Field is
canonicalized by applying the serialization algorithm described in
Section 4.1.2 of [RFC8941] on a Dictionary containing only that
member.
2.2.1. Canonicalization Examples 2.2.1. Canonicalization Examples
This section contains non-normative examples of canonicalized values This section contains non-normative examples of canonicalized values
for Dictionary Structured Field Members given the following example for Dictionary Structured Field Members given the following example
header field, whose value is assumed to be a Dictionary: header field, whose value is assumed to be a Dictionary:
X-Dictionary: a=1, b=2;x=1;y=2, c=(a, b, c) X-Dictionary: a=1, b=2;x=1;y=2, c=(a b c)
The following table shows example canonicalized values for different The following table shows example canonicalized values for different
content identifiers, given that field: content identifiers, given that field:
+====================+=====================+ +======================+=====================+
| Content Identifier | Canonicalized Value | | Content Identifier | Canonicalized Value |
+====================+=====================+ +======================+=====================+
| x-dictionary:a | 1 | | "x-dictionary";key=a | 1 |
+--------------------+---------------------+ +----------------------+---------------------+
| x-dictionary:b | 2;x=1;y=2 | | "x-dictionary";key=b | 2;x=1;y=2 |
+--------------------+---------------------+ +----------------------+---------------------+
| x-dictionary:c | (a, b, c) | | "x-dictionary";key=c | (a, b, c) |
+--------------------+---------------------+ +----------------------+---------------------+
Table 2: Non-normative examples of Table 2: Non-normative examples of
Dictionary member canonicalization. Dictionary member canonicalization.
2.3. List Prefixes 2.3. List Prefixes
A prefix of a List Structured Field consisting of the first N members A prefix of a List Structured Field consisting of the first N members
in the field's value (where N is an integer greater than 0 and less in the field's value (where N is an integer greater than 0 and less
than or equal to the number of members in the List) is identified by than or equal to the number of members in the List) is identified by
the lowercased field name, followed by a semicolon "":"", followed by the parameter "prefix" with the value of N as an integer.
N expressed as an Integer String. A list prefix is canonicalized by
applying the serialization algorithm described in Section 4.1.1 of A list prefix value is canonicalized by applying the serialization
[StructuredFields] on a List containing only the first N members as algorithm described in Section 4.1.1 of [RFC8941] on a List
specified in the list prefix, in the order they appear in the containing only the first N members as specified in the list prefix,
original List. in the order they appear in the original List.
2.3.1. Canonicalization Examples 2.3.1. Canonicalization Examples
This section contains non-normative examples of canonicalized values This section contains non-normative examples of canonicalized values
for list prefixes given the following example header fields, whose for list prefixes given the following example header fields, whose
values are assumed to be Dictionaries: values are assumed to be Dictionaries:
X-List-A: (a, b, c, d, e, f) X-List-A: (a b c d e f)
X-List-B: () X-List-B: ()
The following table shows example canonicalized values for different The following table shows example canonicalized values for different
content identifiers, given those fields: content identifiers, given those fields:
+====================+=====================+ +=====================+=====================+
| Content Identifier | Canonicalized Value | | Content Identifier | Canonicalized Value |
+====================+=====================+ +=====================+=====================+
| x-list-a:0 | () | | "x-list-a";prefix=0 | () |
+--------------------+---------------------+ +---------------------+---------------------+
| x-list-a:1 | (a) | | "x-list-a";prefix=1 | (a) |
+--------------------+---------------------+ +---------------------+---------------------+
| x-list-a:3 | (a, b, c) | | "x-list-a";prefix=3 | (a, b, c) |
+--------------------+---------------------+ +---------------------+---------------------+
| x-list-a:6 | (a, b, c, d, e, f) | | "x-list-a";prefix=6 | (a, b, c, d, e, f) |
+--------------------+---------------------+ +---------------------+---------------------+
| x-list-b:0 | () | | "x-list-b";prefix=0 | () |
+--------------------+---------------------+ +---------------------+---------------------+
Table 3: Non-normative examples of list
prefix canonicalization.
2.4. Signature Creation Time Table 3: Non-normative examples of list
prefix canonicalization.
The signature's Creation Time (Section 3.1) is identified by the 2.4. Specialty Content Fields
"*created" identifier.
Its canonicalized value is an Integer String containing the Content not found in an HTTP header can be included in the signature
signature's Creation Time expressed as the number of seconds since base string by defining a content identifier and the canonicalization
the Epoch, as defined in Section 4.16 method for its content.
(https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/
V1_chap04.html#tag_04_16) of [POSIX.1].
The use of seconds since the Epoch to canonicalize a timestamp To differentiate speciality content identifiers from HTTP headers,
simplifies processing and avoids timezone management required by specialty content identifiers MUST start with the "at" "@" character.
specifications such as [RFC3339]. This specification defines the following specialty content
identifiers:
2.5. Signature Expiration Time @request-target The target request endpoint. Section 2.4.1
The signature's Expiration Time (Section 3.1) is identified by the @signature-params The signature metadata parameters for this
"*expires" identifier. signature. Section 2.4.2
Its canonicalized value is a Decimal String containing the Additional specialty content identifiers MAY be defined and
signature's Expiration Time expressed as the number of seconds since registered in the HTTP Signatures Specialty Content Identifier
the Epoch, as defined in Section 4.16 Registry. Section 5.3
(https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/
V1_chap04.html#tag_04_16) of [POSIX.1].
2.6. Target Endpoint 2.4.1. Request Target
The request target endpoint, consisting of the request method and the The request target endpoint, consisting of the request method and the
path and query of the effective request URI, is identified by the path and query of the effective request URI, is identified by the
"*request-target" identifier. "@request-target" identifier.
Its value is canonicalized as follows: Its value is canonicalized as follows:
1. Take the lowercased HTTP method of the message. 1. Take the lowercased HTTP method of the message.
2. Append a space " ". 2. Append a space " ".
3. Append the path and query of the request target of the message, 3. Append the path and query of the request target of the message,
formatted according to the rules defined for the :path pseudo- formatted according to the rules defined for the :path pseudo-
header in [HTTP2], Section 8.1.2.3. The resulting string is the header in [HTTP2], Section 8.1.2.3. The resulting string is the
canonicalized value. canonicalized value.
2.6.1. Canonicalization Examples 2.4.1.1. Canonicalization Examples
The following table contains non-normative example HTTP messages and The following table contains non-normative example HTTP messages and
their canonicalized "*request-target" values. their canonicalized "@request-target" values.
+=========================+=================+ +=========================+=================+
|HTTP Message | *request-target | |HTTP Message | @request-target |
+=========================+=================+ +=========================+=================+
| POST /?param=value HTTP/1.1| post | | POST /?param=value HTTP/1.1| post |
| Host: www.example.com | /?param=value | | Host: www.example.com | /?param=value |
+-------------------------+-----------------+ +-------------------------+-----------------+
| POST /a/b HTTP/1.1 | post /a/b | | POST /a/b HTTP/1.1 | post /a/b |
| Host: www.example.com | | | Host: www.example.com | |
+-------------------------+-----------------+ +-------------------------+-----------------+
| GET http://www.example.com/a/ HTTP/1.1| get /a/ | | GET http://www.example.com/a/ HTTP/1.1| get /a/ |
+-------------------------+-----------------+ +-------------------------+-----------------+
| GET http://www.example.com HTTP/1.1| get / | | GET http://www.example.com HTTP/1.1| get / |
+-------------------------+-----------------+ +-------------------------+-----------------+
| CONNECT server.example.com:80 HTTP/1.1| connect / | | CONNECT server.example.com:80 HTTP/1.1| connect / |
| Host: server.example.com| | | Host: server.example.com| |
+-------------------------+-----------------+ +-------------------------+-----------------+
| OPTIONS * HTTP/1.1 | options * | | OPTIONS * HTTP/1.1 | options * |
| Host: server.example.com| | | Host: server.example.com| |
+-------------------------+-----------------+ +-------------------------+-----------------+
Table 4: Non-normative examples of "*request-target" Table 4: Non-normative examples of "@request-target"
canonicalization. canonicalization.
2.4.2. Signature Parameters
The signature parameters special content is identified by the
"@signature-params" identifier.
Its canonicalized value is the serialization of the signature
parameters for this signature, including the covered content list
with all associated parameters. Section 3.1
Note that an HTTP message could contain multiple signatures, but only
the signature parameters used for the current signature are included.
2.4.2.1. Canonicalization Examples
Given the following signature parameters:
+==============+=========================================+
| Property | Value |
+==============+=========================================+
| Algorithm | hs2019 |
+--------------+-----------------------------------------+
| Covered | "@request-target", "host", "date", |
| Content | "cache-control", "x-emptyheader", |
| | "x-example", "x-dictionary;key=b", |
| | "x-dictionary;key=a", "x-list;prefix=3" |
+--------------+-----------------------------------------+
| Creation | 1402174295 |
| Time | |
+--------------+-----------------------------------------+
| Expiration | 1402174595 |
| Time | |
+--------------+-----------------------------------------+
| Verification | The public key provided in |
| Key Material | Appendix B.1.1 and identified by the |
| | "keyid" value "test-key-a". |
+--------------+-----------------------------------------+
Table 5
The signature parameter value is defined as:
"@signature-params": ("@request-target" "host" "date" "cache-control" "x-empty-header" "x-example" "x-dictionary";key=b "x-dictionary";key=a "x-list";prefix=3); keyid="test-key-a"; alg="hs2019"; created=1402170695; expires=1402170995
3. HTTP Message Signatures 3. HTTP Message Signatures
An HTTP Message Signature is a signature over a string generated from An HTTP Message Signature is a signature over a string generated from
a subset of the content in an HTTP message and metadata about the a subset of the content in an HTTP message and metadata about the
signature itself. When successfully verified against an HTTP signature itself. When successfully verified against an HTTP
message, it provides cryptographic proof that with respect to the message, it provides cryptographic proof that with respect to the
subset of content that was signed, the message is semantically subset of content that was signed, the message is semantically
equivalent to the message for which the signature was generated. equivalent to the message for which the signature was generated.
3.1. Signature Metadata 3.1. Signature Metadata
HTTP Message Signatures have metadata properties that provide HTTP Message Signatures have metadata properties that provide
information regarding the signature's generation and/or verification. information regarding the signature's generation and/or verification.
The following metadata properties are defined: The following metadata properties are defined:
Algorithm Algorithm:
An HTTP Signature Algorithm defined in the HTTP Signature An HTTP Signature Algorithm defined in the HTTP Signature
Algorithms Registry defined in this document. It describes the Algorithms Registry defined in this document, represented as a
signing and verification algorithms for the signature. string. It describes the signing and verification algorithms for
the signature.
Creation Time
Creation Time:
A timestamp representing the point in time that the signature was A timestamp representing the point in time that the signature was
generated. Sub-second precision is not supported. A signature's generated, represented as an integer. Sub-second precision is not
Creation Time MAY be undefined, indicating that it is unknown. supported. A signature's Creation Time MAY be undefined,
indicating that it is unknown.
Covered Content Expiration Time:
A timestamp representing the point in time at which the signature
expires, represented as an integer. An expired signature always
fails verification. A signature's Expiration Time MAY be
undefined, indicating that the signature does not expire.
Verification Key Material:
The key material required to verify the signature.
Covered Content:
An ordered list of content identifiers (Section 2) that indicates An ordered list of content identifiers (Section 2) that indicates
the metadata and message content that is covered by the signature. the metadata and message content that is covered by the signature.
The order of identifiers in this list affects signature generation This list MUST NOT include the "@signature-params" content
and verification, and therefore MUST be preserved. identifier.
Expiration Time The signature metadata is serialized using the rules in [RFC8941]
section 4 as follows:
A timestamp representing the point in time at which the signature 1. Let the output be an empty string.
expires. An expired signature always fails verification. A
signature's Expiration Time MAY be undefined, indicating that the
signature does not expire.
Verification Key Material 2. Serialize the content identifiers as an ordered "inner-list"
according to [RFC8941] section 4.1.1.1 and append this to the
output.
The key material required to verify the signature. 3. Append the signature metadata as parameters according to
[RFC8941] section 4.1.1.2 in the any order, skipping fields that
are not available:
* "alg": Algorithm as an "sf-string" value.
* "keyid": Verification Key Material as an "sf-string" value.
* "created": Creation Time as an "sf-integer" timestamp value.
* "expires": Expiration Time as an "sf-integer" timestamp value.
Note that the "inner-list" serialization is used instead of the "sf-
list" serialization in order to facilitate this value's inclusion in
the "Signature-Input" header's dictionary, as discussed in
Section 4.1.
The Table 6 values would be serialized as follows:
("@request-target" "host" "date" "cache-control" "x-empty-header" "x-example"); keyid="test-key-a"; alg="hs2019"; created=1402170695; expires=1402170995
3.2. Creating a Signature 3.2. Creating a Signature
In order to create a signature, a signer completes the following In order to create a signature, a signer completes the following
process: process:
1. Choose key material and algorithm, and set metadata properties 1. Choose key material and algorithm, and set metadata properties
Section 3.2.1 Section 3.2.1
2. Create the Signature Input Section 3.2.2 2. Create the Signature Input Section 3.2.2
skipping to change at page 14, line 41 skipping to change at page 17, line 15
5. The signer creates an ordered list of content identifiers 5. The signer creates an ordered list of content identifiers
representing the message content and signature metadata to be representing the message content and signature metadata to be
covered by the signature, and assigns this list as the covered by the signature, and assigns this list as the
signature's Covered Content. signature's Covered Content.
* Each identifier MUST be one of those defined in Section 2. * Each identifier MUST be one of those defined in Section 2.
* This list MUST NOT be empty, as this would result in creating * This list MUST NOT be empty, as this would result in creating
a signature over the empty string. a signature over the empty string.
* If the signature's Algorithm name does not start with rsa, * Signers SHOULD include "@request-target" in the list.
hmac, or ecdsa, signers SHOULD include "*created" and
"*request-target" in the list.
* If the signature's Algorithm starts with rsa, hmac, or ecdsa, * Signers SHOULD include a date stamp, such as the "date"
signers SHOULD include "date" and "*request-target" in the header. Alternatively, the "created" signature metadata
list. parameter can fulfil this role.
* Further guidance on what to include in this list and in what * Further guidance on what to include in this list and in what
order is out of scope for this document. However, the list order is out of scope for this document. However, the list
order is significant and once established for a given order is significant and once established for a given
signature it MUST be preserved for that signature. signature it MUST be preserved for that signature.
* Note that the signature metadata is not included in the
explicit list of covered content identifiers since its value
is always covered.
For example, given the following HTTP message: For example, given the following HTTP message:
GET /foo HTTP/1.1 GET /foo HTTP/1.1
Host: example.org Host: example.org
Date: Sat, 07 Jun 2014 20:51:35 GMT Date: Sat, 07 Jun 2014 20:51:35 GMT
X-Example: Example header X-Example: Example header
with some whitespace. with some whitespace.
X-EmptyHeader: X-EmptyHeader:
X-Dictionary: a=1, b=2 X-Dictionary: a=1, b=2
X-List: (a, b, c, d) X-List: (a b c d)
Cache-Control: max-age=60 Cache-Control: max-age=60
Cache-Control: must-revalidate Cache-Control: must-revalidate
The following table presents a non-normative example of metadata The following table presents a non-normative example of metadata
values that a signer may choose: values that a signer may choose:
+==============+================================================+ +==============+=========================================+
| Property | Value | | Property | Value |
+==============+================================================+ +==============+=========================================+
| Algorithm | hs2019 | | Algorithm | hs2019 |
+--------------+------------------------------------------------+ +--------------+-----------------------------------------+
| Covered | "*request-target", "*created", "host", "date", | | Covered | "@request-target", "host", "date", |
| Content | "cache-contol", "x-emptyheader", "x-example", | | Content | "cache-control", "x-emptyheader", |
| | "x-dictionary:b", "x-dictionary:a", "x-list:3" | | | "x-example", "x-dictionary;key=b", |
+--------------+------------------------------------------------+ | | "x-dictionary;key=a", "x-list;prefix=3" |
| Creation | 1402174295 | +--------------+-----------------------------------------+
| Time | | | Creation | 1402174295 |
+--------------+------------------------------------------------+ | Time | |
| Expiration | 1402174595 | +--------------+-----------------------------------------+
| Time | | | Expiration | 1402174595 |
+--------------+------------------------------------------------+ | Time | |
| Verification | The public key provided in Appendix A.1.1 and | +--------------+-----------------------------------------+
| Key Material | identified by the "keyId" value "test-key-a". | | Verification | The public key provided in |
+--------------+------------------------------------------------+ | Key Material | Appendix B.1.1 and identified by the |
| | "keyid" value "test-key-a". |
+--------------+-----------------------------------------+
Table 5: Non-normative example metadata values Table 6: Non-normative example metadata values
3.2.2. Create the Signature Input 3.2.2. Create the Signature Input
The Signature Input is a US-ASCII string containing the content that The Signature Input is a US-ASCII string containing the content that
will be signed. To create it, the signer concatenates together will be signed. To create it, the signer or verifier concatenates
entries for each identifier in the signature's Covered Content in the together entries for each identifier in the signature's Covered
order it occurs in the list, with each entry separated by a newline Content in the order it occurs in the list, with each entry separated
""\n"". An identifier's entry is a US-ASCII string consisting of the by a newline ""\n"". An identifier's entry is a "sf-string" followed
lowercased identifier followed with a colon "":"", a space "" "", and with a colon "":"", a space "" "", and the identifier's canonicalized
the identifier's canonicalized value (described below). value.
If Covered Content contains "*created" and the signature's Creation
Time is undefined or the signature's Algorithm name starts with
"rsa", "hmac", or "ecdsa" an implementation MUST produce an error.
If Covered Content contains "*expires" and the signature does not The signer or verifier then includes the signature metadata specialty
have an Expiration Time or the signature's Algorithm name starts with field "@signature-params" as the last entry in the covered content,
"rsa", "hmac", or "ecdsa" an implementation MUST produce an error. separated by a newline ""\n"". Section 2.4.2
If Covered Content contains an identifier for a header field that is If Covered Content contains an identifier for a header field that is
not present or malformed in the message, the implementation MUST malformed or is not present in the message, the implementation MUST
produce an error. produce an error.
If Covered Content contains an identifier for a Dictionary member If Covered Content contains an identifier for a Dictionary member
that references a header field that is not present, is malformed in that references a header field using the "key" parameter that is not
the message, or is not a Dictionary Structured Field, the present, is malformed in the message, or is not a Dictionary
implementation MUST produce an error. If the header field value does Structured Field, the implementation MUST produce an error. If the
not contain the specified member, the implementation MUST produce an header field value does not contain the specified member, the
error. implementation MUST produce an error.
If Covered Content contains an identifier for a List Prefix that If Covered Content contains an identifier for a List Prefix that
references a header field that is not present, is malformed in the references a header field using the "prefix" parameter that is not
message, or is not a List Structured Field, the implementation MUST present, is malformed in the message, or is not a List Structured
produce an error. If the header field value contains fewer than the Field, the implementation MUST produce an error. If the header field
specified number of members, the implementation MUST produce an value contains fewer than the specified number of members, the
error. implementation MUST produce an error.
For the non-normative example Signature metadata in Table 5, the For the non-normative example Signature metadata in Table 6, the
corresponding Signature Input is: corresponding Signature Input is:
*request-target: get /foo "@request-target": get /foo
*created: 1402170695 "host": example.org
host: example.org "date": Tue, 07 Jun 2014 20:51:35 GMT
date: Tue, 07 Jun 2014 20:51:35 GMT "cache-control": max-age=60, must-revalidate
cache-control: max-age=60, must-revalidate "x-emptyheader":
x-emptyheader: "x-example": Example header with some whitespace.
x-example: Example header with some whitespace. "x-dictionary";key=b: 2
x-dictionary: b=2 "x-dictionary";key=a: 1
x-dictionary: a=1 "x-list";prefix=3: (a, b, c)
x-list: (a, b, c) "@signature-params": ("@request-target" "host" "date" "cache-control" "x-empty-header" "x-example" "x-dictionary";key=b "x-dictionary";key=b "x-list";prefix=3); keyid="test-key-a"; alg="hs2019"; created=1402170695; expires=1402170995
Figure 1: Non-normative example Signature Input Figure 1: Non-normative example Signature Input
3.2.3. Sign the Signature Input 3.2.3. Sign the Signature Input
The signer signs the Signature Input using the signing algorithm The signer signs the Signature Input using the signing algorithm
described by the signature's Algorithm property, and the key material described by the signature's Algorithm property, and the key material
chosen by the signer. The signer then encodes the result of that chosen by the signer. The signer then encodes the result of that
operation as a base 64-encoded string [RFC4648]. This string is the operation as a base 64-encoded string [RFC4648]. This string is the
signature value. signature value.
For the non-normative example Signature metadata in Section 3.2.1 and For the non-normative example Signature metadata in Section 3.2.1 and
skipping to change at page 17, line 49 skipping to change at page 20, line 13
In order to verify a signature, a verifier MUST: In order to verify a signature, a verifier MUST:
1. Examine the signature's metadata to confirm that the signature 1. Examine the signature's metadata to confirm that the signature
meets the requirements described in this document, as well as any meets the requirements described in this document, as well as any
additional requirements defined by the application such as which additional requirements defined by the application such as which
header fields or other content are required to be covered by the header fields or other content are required to be covered by the
signature. signature.
2. Use the received HTTP message and the signature's metadata to 2. Use the received HTTP message and the signature's metadata to
recreate the Signature Input, using the process described in recreate the Signature Input, using the process described in
Section 3.2.2. Section 3.2.2. The value of the "@signature-params" input is the
value of the signature input header field for this signature, not
including the signature's label.
3. Use the signature's Algorithm and Verification Key Material with 3. Use the signature's Algorithm and Verification Key Material with
the recreated Signing Input to verify the signature value. the recreated Signing Input to verify the signature value.
A signature with a Creation Time that is in the future or an A signature with a Creation Time that is in the future or an
Expiration Time that is in the past MUST NOT be processed. Expiration Time that is in the past MUST NOT be processed.
The verifier MUST ensure that a signature's Algorithm is appropriate The verifier MUST ensure that a signature's Algorithm is appropriate
for the key material the verifier will use to verify the signature. for the key material the verifier will use to verify the signature.
If the Algorithm is not appropriate for the key material (for If the Algorithm is not appropriate for the key material (for
skipping to change at page 19, line 17 skipping to change at page 21, line 27
Message signatures can be included within an HTTP message via the Message signatures can be included within an HTTP message via the
"Signature-Input" and "Signature" HTTP header fields, both defined "Signature-Input" and "Signature" HTTP header fields, both defined
within this specification. The "Signature" HTTP header field within this specification. The "Signature" HTTP header field
contains signature values, while the "Signature-Input" HTTP header contains signature values, while the "Signature-Input" HTTP header
field identifies the Covered Content and metadata that describe how field identifies the Covered Content and metadata that describe how
each signature was generated. each signature was generated.
4.1. The 'Signature-Input' HTTP Header 4.1. The 'Signature-Input' HTTP Header
The "Signature-Input" HTTP header field is a Dictionary Structured The "Signature-Input" HTTP header field is a Dictionary Structured
Header [StructuredFields] containing the metadata for zero or more Header [RFC8941] containing the metadata for zero or more message
message signatures generated from content within the HTTP message. signatures generated from content within the HTTP message. Each
Each member describes a single message signature. The member's name member describes a single message signature. The member's name is an
is an identifier that uniquely identifies the message signature identifier that uniquely identifies the message signature within the
within the context of the HTTP message. The member's value is the context of the HTTP message. The member's value is the serialization
message signature's Covered Content, expressed as a List of Tokens. of the covered content including all signature metadata parameters,
Further signature metadata is expressed in parameters on the member described in Section 3.1.
value, as described below.
4.1.1. Metadata Parameters
The parameters on each "Signature-Input" member value contain
metadata about the signature. Each parameter name MUST be a
parameter name registered in the IANA HTTP Signatures Metadata
Parameters Registry defined in Section 5.2 of this document. This
document defines the following parameters, and registers them as the
initial contents of the registry:
alg
RECOMMENDED. The "alg" parameter is a Token containing the name
of the signature's Algorithm, as registered in the HTTP Signature
Algorithms Registry defined by this document. Verifiers MUST
determine the signature's Algorithm from the "keyId" parameter
rather than from "alg". If "alg" is provided and differs from or
is incompatible with the algorithm or key material identified by
"keyId" (for example, "alg" has a value of "rsa-sha256" but
"keyId" identifies an EdDSA key), then implementations MUST
produce an error.
created
RECOMMENDED. The "created" parameter is a Decimal containing the
signature's Creation Time, expressed as the canonicalized value of
the "*created" content identifier, as defined in Section 2. If
not specified, the signature's Creation Time is undefined. This
parameter is useful when signers are not capable of controlling
the Date HTTP Header such as when operating in certain web browser
environments.
expires
OPTIONAL. The "expires" parameter is a Decimal containing the
signature's Expiration Time, expressed as the canonicalized value
of the "*expires" content identifier, as defined in Section 2. If
the signature does not have an Expiration Time, this parameter
MUST be omitted. If not specified, the signature's Expiration
Time is undefined.
keyId Signature-Input: sig1=("@request-target" "host" "date"
"cache-control" "x-empty-header" "x-example"); keyid="test-key-a";
alg="hs2019"; created=1402170695; expires=1402170995
REQUIRED. The "keyId" parameter is a String whose value can be To facilitate signature validation, the "Signature-Input" header MUST
used by a verifier to identify and/or obtain the signature's contain the same serialization value used in generating the signature
Verification Key Material. Further format and semantics of this input.
value are out of scope for this document.
4.2. The 'Signature' HTTP Header 4.2. The 'Signature' HTTP Header
The "Signature" HTTP header field is a Dictionary Structured Header The "Signature" HTTP header field is a Dictionary Structured Header
[StructuredFields] containing zero or more message signatures [RFC8941] containing zero or more message signatures generated from
generated from content within the HTTP message. Each member's name content within the HTTP message. Each member's name is a signature
is a signature identifier that is present as a member name in the identifier that is present as a member name in the "Signature-Input"
"Signature-Input" Structured Header within the HTTP message. Each Structured Header within the HTTP message. Each member's value is a
member's value is a Byte Sequence containing the signature value for Byte Sequence containing the signature value for the message
the message signature identified by the member name. Any member in signature identified by the member name. Any member in the
the "Signature" HTTP header field that does not have a corresponding "Signature" HTTP header field that does not have a corresponding
member in the HTTP message's "Signature-Input" HTTP header field MUST member in the HTTP message's "Signature-Input" HTTP header field MUST
be ignored. be ignored.
Signature: sig1=:K2qGT5srn2OGbOIDzQ6kYT+ruaycnDAAUpKv+ePFfD0RAxn/1BUe\
Zx/Kdrq32DrfakQ6bPsvB9aqZqognNT6be4olHROIkeV879RrsrObury8L9SCEibe\
oHyqU/yCjphSmEdd7WD+zrchK57quskKwRefy2iEC5S2uAH0EPyOZKWlvbKmKu5q4\
CaB8X/I5/+HLZLGvDiezqi6/7p2Gngf5hwZ0lSdy39vyNMaaAT0tKo6nuVw0S1MVg\
1Q7MpWYZs0soHjttq0uLIA3DIbQfLiIvK6/l0BdWTU7+2uQj7lBkQAsFZHoA96ZZg\
FquQrXRlmYOh+Hx5D9fJkXcXe5tmAg==:
4.3. Examples 4.3. Examples
The following is a non-normative example of "Signature-Input" and The following is a non-normative example of "Signature-Input" and
"Signature" HTTP header fields representing the signature in "Signature" HTTP header fields representing the signature in
Figure 2: Figure 2:
Signature-Input: sig1=(*request-target, *created, host, date, # NOTE: '\' line wrapping per RFC 8792
cache-control, x-empty-header, x-example); keyId="test-key-a";
alg=hs2019; created=1402170695; expires=1402170995 Signature-Input: sig1=("@request-target" "host" "date"
Signature: sig1=:K2qGT5srn2OGbOIDzQ6kYT+ruaycnDAAUpKv+ePFfD0RAxn/1BUe "cache-control" "x-empty-header" "x-example"); keyid="test-key-a";
Zx/Kdrq32DrfakQ6bPsvB9aqZqognNT6be4olHROIkeV879RrsrObury8L9SCEibe alg="hs2019"; created=1402170695; expires=1402170995
oHyqU/yCjphSmEdd7WD+zrchK57quskKwRefy2iEC5S2uAH0EPyOZKWlvbKmKu5q4 Signature: sig1=:K2qGT5srn2OGbOIDzQ6kYT+ruaycnDAAUpKv+ePFfD0RAxn/1BUe\
CaB8X/I5/+HLZLGvDiezqi6/7p2Gngf5hwZ0lSdy39vyNMaaAT0tKo6nuVw0S1MVg Zx/Kdrq32DrfakQ6bPsvB9aqZqognNT6be4olHROIkeV879RrsrObury8L9SCEibe\
1Q7MpWYZs0soHjttq0uLIA3DIbQfLiIvK6/l0BdWTU7+2uQj7lBkQAsFZHoA96ZZg oHyqU/yCjphSmEdd7WD+zrchK57quskKwRefy2iEC5S2uAH0EPyOZKWlvbKmKu5q4\
CaB8X/I5/+HLZLGvDiezqi6/7p2Gngf5hwZ0lSdy39vyNMaaAT0tKo6nuVw0S1MVg\
1Q7MpWYZs0soHjttq0uLIA3DIbQfLiIvK6/l0BdWTU7+2uQj7lBkQAsFZHoA96ZZg\
FquQrXRlmYOh+Hx5D9fJkXcXe5tmAg==: FquQrXRlmYOh+Hx5D9fJkXcXe5tmAg==:
Since "Signature-Input" and "Signature" are both defined as Since "Signature-Input" and "Signature" are both defined as
Dictionary Structured Headers, they can be used to easily include Dictionary Structured Headers, they can be used to easily include
multiple signatures within the same HTTP message. For example, a multiple signatures within the same HTTP message. For example, a
signer may include multiple signatures signing the same content with signer may include multiple signatures signing the same content with
different keys and/or algorithms to support verifiers with different different keys and/or algorithms to support verifiers with different
capabilities, or a reverse proxy may include information about the capabilities, or a reverse proxy may include information about the
client in header fields when forwarding the request to a service client in header fields when forwarding the request to a service
host, and may also include a signature over those fields and the host, and may also include a signature over those fields and the
client's signature. The following is a non-normative example of client's signature. The following is a non-normative example of
header fields a reverse proxy might add to a forwarded request that header fields a reverse proxy might add to a forwarded request that
contains the signature in the above example: contains the signature in the above example:
# NOTE: '\' line wrapping per RFC 8792
X-Forwarded-For: 192.0.2.123 X-Forwarded-For: 192.0.2.123
Signature-Input: reverse_proxy_sig=(*created, host, date, Signature-Input: reverse_proxy_sig=("host" "date"
signature:sig1, x-forwarded-for); keyId="test-key-a"; "signature";key=sig1 "x-forwarded-for"); keyid="test-key-a";
alg=hs2019; created=1402170695; expires=1402170695.25 alg="hs2019"; created=1402170695; expires=1402170695
Signature: reverse_proxy_sig=:ON3HsnvuoTlX41xfcGWaOEVo1M3bJDRBOp0Pc/O Signature: reverse_proxy_sig=:ON3HsnvuoTlX41xfcGWaOEVo1M3bJDRBOp0Pc/O\
jAOWKQn0VMY0SvMMWXS7xG+xYVa152rRVAo6nMV7FS3rv0rR5MzXL8FCQ2A35DCEN jAOWKQn0VMY0SvMMWXS7xG+xYVa152rRVAo6nMV7FS3rv0rR5MzXL8FCQ2A35DCEN\
LOhEgj/S1IstEAEFsKmE9Bs7McBsCtJwQ3hMqdtFenkDffSoHOZOInkTYGafkoy78 LOhEgj/S1IstEAEFsKmE9Bs7McBsCtJwQ3hMqdtFenkDffSoHOZOInkTYGafkoy78\
l1VZvmb3Y4yf7McJwAvk2R3gwKRWiiRCw448Nt7JTWzhvEwbh7bN2swc/v3NJbg/w l1VZvmb3Y4yf7McJwAvk2R3gwKRWiiRCw448Nt7JTWzhvEwbh7bN2swc/v3NJbg/w\
JYyYVbelZx4IywuZnYFxgPl/qvqbAjeEVvaLKLgSMr11y+uzxCHoMnDUnTYhMrmOT JYyYVbelZx4IywuZnYFxgPl/qvqbAjeEVvaLKLgSMr11y+uzxCHoMnDUnTYhMrmOT\
4O8lBLfRFOcoJPKBdoKg9U0a96U2mUug1bFOozEVYFg==: 4O8lBLfRFOcoJPKBdoKg9U0a96U2mUug1bFOozEVYFg==:
5. IANA Considerations 5. IANA Considerations
5.1. HTTP Signature Algorithms Registry 5.1. HTTP Signature Algorithms Registry
This document defines HTTP Signature Algorithms, for which IANA is This document defines HTTP Signature Algorithms, for which IANA is
asked to create and maintain a new registry titled "HTTP Signature asked to create and maintain a new registry titled "HTTP Signature
Algorithms". Initial values for this registry are given in Algorithms". Initial values for this registry are given in
Section 5.1.2. Future assignments and modifications to existing Section 5.1.2. Future assignments and modifications to existing
assignment are to be made through the Expert Review registration assignment are to be made through the Expert Review registration
policy [RFC8126] and shall follow the template presented in policy [RFC8126] and shall follow the template presented in
Section 5.1.1. Section 5.1.1.
5.1.1. Registration Template 5.1.1. Registration Template
Algorithm Name Algorithm Name:
An identifier for the HTTP Signature Algorithm. The name MUST be An identifier for the HTTP Signature Algorithm. The name MUST be
an ASCII string consisting only of lower-case characters (""a"" - an ASCII string consisting only of lower-case characters (""a"" -
""z""), digits (""0"" - ""9""), and hyphens (""-""), and SHOULD ""z""), digits (""0"" - ""9""), and hyphens (""-""), and SHOULD
NOT exceed 20 characters in length. The identifier MUST be unique NOT exceed 20 characters in length. The identifier MUST be unique
within the context of the registry. within the context of the registry.
Status Status:
A brief text description of the status of the algorithm. The A brief text description of the status of the algorithm. The
description MUST begin with one of "Active" or "Deprecated", and description MUST begin with one of "Active" or "Deprecated", and
MAY provide further context or explanation as to the reason for MAY provide further context or explanation as to the reason for
the status. the status.
Description Description:
A description of the algorithm used to sign the signing string A description of the algorithm used to sign the signing string
when generating an HTTP Message Signature, or instructions on how when generating an HTTP Message Signature, or instructions on how
to determine that algorithm. When the description specifies an to determine that algorithm. When the description specifies an
algorithm, it MUST include a reference to the document or algorithm, it MUST include a reference to the document or
documents that define the algorithm. documents that define the algorithm.
5.1.2. Initial Contents 5.1.2. Initial Contents
(( MS: The references in this section are problematic as many of the (( MS: The references in this section are problematic as many of the
specifications that they refer to are too implementation specific, specifications that they refer to are too implementation specific,
rather than just pointing to the proper signature and hashing rather than just pointing to the proper signature and hashing
specifications. A better approach might be just specifying the specifications. A better approach might be just specifying the
signature and hashing function specifications, leaving implementers signature and hashing function specifications, leaving implementers
to connect the dots (which are not that hard to connect). )) to connect the dots (which are not that hard to connect). ))
5.1.2.1. hs2019 5.1.2.1. hs2019
Algorithm Name Algorithm Name:
"hs2019" "hs2019"
Status Status:
active active
Description Description:
Derived from metadata associated with keyid. Recommend support
Derived from metadata associated with keyId. Recommend support
for: for:
* RSASSA-PSS [RFC8017] using SHA-512 [RFC6234] * RSASSA-PSS [RFC8017] using SHA-512 [RFC6234]
* HMAC [RFC2104] using SHA-512 [RFC6234] * HMAC [RFC2104] using SHA-512 [RFC6234]
* ECDSA using curve P-256 DSS [FIPS186-4] and SHA-512 [RFC6234] * ECDSA using curve P-256 DSS [FIPS186-4] and SHA-512 [RFC6234]
* Ed25519ph, Ed25519ctx, and Ed25519 [RFC8032] * Ed25519ph, Ed25519ctx, and Ed25519 [RFC8032]
5.1.2.2. rsa-sha1 5.1.2.2. rsa-sha1
Algorithm Name Algorithm Name:
"rsa-sha1" "rsa-sha1"
Status Status:
Deprecated; SHA-1 not secure. Deprecated; SHA-1 not secure.
Description Description:
RSASSA-PKCS1-v1_5 [RFC8017] using SHA-1 [RFC6234] RSASSA-PKCS1-v1_5 [RFC8017] using SHA-1 [RFC6234]
5.1.2.3. rsa-sha256 5.1.2.3. rsa-sha256
Algorithm Name Algorithm Name:
"rsa-sha256" "rsa-sha256"
Status Status:
Deprecated; specifying signature algorithm enables attack vector. Deprecated; specifying signature algorithm enables attack vector.
Description Description:
RSASSA-PKCS1-v1_5 [RFC8017] using SHA-256 [RFC6234] RSASSA-PKCS1-v1_5 [RFC8017] using SHA-256 [RFC6234]
5.1.2.4. hmac-sha256 5.1.2.4. hmac-sha256
Algorithm Name Algorithm Name:
"hmac-sha256" "hmac-sha256"
Status Status:
Deprecated; specifying signature algorithm enables attack vector. Deprecated; specifying signature algorithm enables attack vector.
Description Description:
HMAC [RFC2104] using SHA-256 [RFC6234] HMAC [RFC2104] using SHA-256 [RFC6234]
5.1.2.5. ecdsa-sha256 5.1.2.5. ecdsa-sha256
Algorithm Name Algorithm Name:
"ecdsa-sha256" "ecdsa-sha256"
Status Status:
Deprecated; specifying signature algorithm enables attack vector. Deprecated; specifying signature algorithm enables attack vector.
Description Description:
ECDSA using curve P-256 DSS [FIPS186-4] and SHA-256 [RFC6234] ECDSA using curve P-256 DSS [FIPS186-4] and SHA-256 [RFC6234]
5.2. HTTP Signature Metadata Parameters Registry 5.2. HTTP Signature Metadata Parameters Registry
This document defines the "Signature-Input" Structured Header, whose This document defines the "Signature-Input" Structured Header, whose
member values may have parameters containing metadata about a message member values may have parameters containing metadata about a message
signature. IANA is asked to create and maintain a new registry signature. IANA is asked to create and maintain a new registry
titled "HTTP Signature Metadata Parameters" to record and maintain titled "HTTP Signature Metadata Parameters" to record and maintain
the set of parameters defined for use with member values in the the set of parameters defined for use with member values in the
"Signature-Input" Structured Header. Initial values for this "Signature-Input" Structured Header. Initial values for this
skipping to change at page 24, line 34 skipping to change at page 26, line 5
template presented in Section 5.2.1. template presented in Section 5.2.1.
5.2.1. Registration Template 5.2.1. Registration Template
5.2.2. Initial Contents 5.2.2. Initial Contents
The table below contains the initial contents of the HTTP Signature The table below contains the initial contents of the HTTP Signature
Metadata Parameters Registry. Each row in the table represents a Metadata Parameters Registry. Each row in the table represents a
distinct entry in the registry. distinct entry in the registry.
+=========+========+================================+ +=========+========+==============================+
| Name | Status | Reference(s) | | Name | Status | Reference(s) |
+=========+========+================================+ +=========+========+==============================+
| alg | Active | Section 4.1.1 of this document | | alg | Active | Section 3.1 of this document |
+---------+--------+--------------------------------+ +---------+--------+------------------------------+
| created | Active | Section 4.1.1 of this document | | created | Active | Section 3.1 of this document |
+---------+--------+--------------------------------+ +---------+--------+------------------------------+
| expires | Active | Section 4.1.1 of this document | | expires | Active | Section 3.1 of this document |
+---------+--------+--------------------------------+ +---------+--------+------------------------------+
| keyId | Active | Section 4.1.1 of this document | | keyid | Active | Section 3.1 of this document |
+---------+--------+--------------------------------+ +---------+--------+------------------------------+
Table 6: Initial contents of the HTTP Signature Table 7: Initial contents of the HTTP Signature
Metadata Parameters Registry. Metadata Parameters Registry.
5.3. HTTP Signature Specialty Content Identifiers Registry
This document defines a method for canonicalizing HTTP message
content, including content that can be generated from the context of
the HTTP message outside of the HTTP headers. This content is
identified by a unique key. IANA is asked to create and maintain a
new registry typed "HTTP Signature Specialty Content Identifiers" to
record and maintain the set of non-header content identifiers and
their canonicalization method. Initial values for this registry are
given in Section 5.3.2. Future assignments and modifications to
existing assignments are to be made through the Expert Review
registration policy [RFC8126] and shall follow the template presented
in Section 5.3.1.
5.3.1. Registration Template
5.3.2. Initial Contents
The table below contains the initial contents of the HTTP Signature
Specialty Content Identifiers Registry.
+===================+========+================================+
| Name | Status | Reference(s) |
+===================+========+================================+
| @request-target | Active | Section 2.4.1 of this document |
+-------------------+--------+--------------------------------+
| @signature-params | Active | Section 2.4.2 of this document |
+-------------------+--------+--------------------------------+
Table 8: Initial contents of the HTTP Signature Specialty
Content Identifiers Registry.
6. Security Considerations 6. Security Considerations
(( TODO: need to dive deeper on this section; not sure how much of (( TODO: need to dive deeper on this section; not sure how much of
what's referenced below is actually applicable, or if it covers what's referenced below is actually applicable, or if it covers
everything we need to worry about. )) everything we need to worry about. ))
(( TODO: Should provide some recommendations on how to determine what (( TODO: Should provide some recommendations on how to determine what
content needs to be signed for a given use case. )) content needs to be signed for a given use case. ))
There are a number of security considerations to take into account There are a number of security considerations to take into account
skipping to change at page 25, line 31 skipping to change at page 27, line 31
7.1. Normative References 7.1. Normative References
[FIPS186-4] [FIPS186-4]
"Digital Signature Standard (DSS)", 2013, "Digital Signature Standard (DSS)", 2013,
<https://csrc.nist.gov/publications/detail/fips/186/4/ <https://csrc.nist.gov/publications/detail/fips/186/4/
final>. final>.
[HTTP2] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext [HTTP2] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540, Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015, DOI 10.17487/RFC7540, May 2015,
<https://www.rfc-editor.org/info/rfc7540>. <https://www.rfc-editor.org/rfc/rfc7540>.
[MESSAGING] [MESSAGING]
Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing", Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014, RFC 7230, DOI 10.17487/RFC7230, June 2014,
<https://www.rfc-editor.org/info/rfc7230>. <https://www.rfc-editor.org/rfc/rfc7230>.
[POSIX.1] "The Open Group Base Specifications Issue 7, 2018 [POSIX.1] "The Open Group Base Specifications Issue 7, 2018
edition", 2018, edition", 2018,
<https://pubs.opengroup.org/onlinepubs/9699919799/>. <https://pubs.opengroup.org/onlinepubs/9699919799/>.
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104, Hashing for Message Authentication", RFC 2104,
DOI 10.17487/RFC2104, February 1997, DOI 10.17487/RFC2104, February 1997,
<https://www.rfc-editor.org/info/rfc2104>. <https://www.rfc-editor.org/rfc/rfc2104>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu,
"Handling Long Lines in Content of Internet-Drafts and
RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020,
<https://www.rfc-editor.org/rfc/rfc8792>.
[RFC8941] Nottingham, M. and P-H. Kamp, "Structured Field Values for
HTTP", RFC 8941, DOI 10.17487/RFC8941, February 2021,
<https://www.rfc-editor.org/rfc/rfc8941>.
[SEMANTICS] [SEMANTICS]
Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231, Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014, DOI 10.17487/RFC7231, June 2014,
<https://www.rfc-editor.org/info/rfc7231>. <https://www.rfc-editor.org/rfc/rfc7231>.
[StructuredFields]
"Structured Field Vaues for HTTP", 2020,
<https://datatracker.ietf.org/doc/draft-ietf-httpbis-
header-structure>.
7.2. Informative References 7.2. Informative References
[RFC3230] Mogul, J. and A. Van Hoff, "Instance Digests in HTTP",
RFC 3230, DOI 10.17487/RFC3230, January 2002,
<https://www.rfc-editor.org/info/rfc3230>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<https://www.rfc-editor.org/info/rfc3339>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/info/rfc4648>. <https://www.rfc-editor.org/rfc/rfc4648>.
[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
(SHA and SHA-based HMAC and HKDF)", RFC 6234, (SHA and SHA-based HMAC and HKDF)", RFC 6234,
DOI 10.17487/RFC6234, May 2011, DOI 10.17487/RFC6234, May 2011,
<https://www.rfc-editor.org/info/rfc6234>. <https://www.rfc-editor.org/rfc/rfc6234>.
[RFC7239] Petersson, A. and M. Nilsson, "Forwarded HTTP Extension", [RFC7239] Petersson, A. and M. Nilsson, "Forwarded HTTP Extension",
RFC 7239, DOI 10.17487/RFC7239, June 2014, RFC 7239, DOI 10.17487/RFC7239, June 2014,
<https://www.rfc-editor.org/info/rfc7239>. <https://www.rfc-editor.org/rfc/rfc7239>.
[RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
DOI 10.17487/RFC7518, May 2015,
<https://www.rfc-editor.org/info/rfc7518>.
[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>.
[RFC8017] Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch, [RFC8017] Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
"PKCS #1: RSA Cryptography Specifications Version 2.2", "PKCS #1: RSA Cryptography Specifications Version 2.2",
RFC 8017, DOI 10.17487/RFC8017, November 2016, RFC 8017, DOI 10.17487/RFC8017, November 2016,
<https://www.rfc-editor.org/info/rfc8017>. <https://www.rfc-editor.org/rfc/rfc8017>.
[RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital [RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
Signature Algorithm (EdDSA)", RFC 8032, Signature Algorithm (EdDSA)", RFC 8032,
DOI 10.17487/RFC8032, January 2017, DOI 10.17487/RFC8032, January 2017,
<https://www.rfc-editor.org/info/rfc8032>. <https://www.rfc-editor.org/rfc/rfc8032>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/rfc/rfc8126>.
[TLS] Rescorla, E., "The Transport Layer Security (TLS) Protocol [TLS] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>. <https://www.rfc-editor.org/rfc/rfc8446>.
[WP-HTTP-Sig-Audit] [WP-HTTP-Sig-Audit]
"Security Considerations for HTTP Signatures", 2013, "Security Considerations for HTTP Signatures", 2013,
<https://web-payments.org/specs/source/http-signatures- <https://web-payments.org/specs/source/http-signatures-
audit/>. audit/>.
Appendix A. Examples Appendix A. Detecting HTTP Message Signatures
A.1. Example Keys There have been many attempts to create signed HTTP messages in the
past, including other non-standard definitions of the "Signature"
header used within this specification. It is recommended that
developers wishing to support both this specification and other
historial drafts do so carefully and deliberately, as
incompatibilities between this specification and various versions of
other drafts could lead to problems.
It is recommended that implementers first detect and validate the
"Signature-Input" header defined in this specification to detect that
this standard is in use and not an alternative. If the "Signature-
Input" header is present, all "Signature" headers can be parsed and
interpreted in the context of this draft.
Appendix B. Examples
B.1. Example Keys
This section provides cryptographic keys that are referenced in This section provides cryptographic keys that are referenced in
example signatures throughout this document. These keys MUST NOT be example signatures throughout this document. These keys MUST NOT be
used for any purpose other than testing. used for any purpose other than testing.
A.1.1. Example Key RSA test B.1.1. Example Key RSA test
The following key is a 2048-bit RSA public and private key pair: The following key is a 2048-bit RSA public and private key pair:
-----BEGIN RSA PUBLIC KEY----- -----BEGIN RSA PUBLIC KEY-----
MIIBCgKCAQEAhAKYdtoeoy8zcAcR874L8cnZxKzAGwd7v36APp7Pv6Q2jdsPBRrw MIIBCgKCAQEAhAKYdtoeoy8zcAcR874L8cnZxKzAGwd7v36APp7Pv6Q2jdsPBRrw
WEBnez6d0UDKDwGbc6nxfEXAy5mbhgajzrw3MOEt8uA5txSKobBpKDeBLOsdJKFq WEBnez6d0UDKDwGbc6nxfEXAy5mbhgajzrw3MOEt8uA5txSKobBpKDeBLOsdJKFq
MGmXCQvEG7YemcxDTRPxAleIAgYYRjTSd/QBwVW9OwNFhekro3RtlinV0a75jfZg MGmXCQvEG7YemcxDTRPxAleIAgYYRjTSd/QBwVW9OwNFhekro3RtlinV0a75jfZg
kne/YiktSvLG34lw2zqXBDTC5NHROUqGTlML4PlNZS5Ri2U4aCNx2rUPRcKIlE0P kne/YiktSvLG34lw2zqXBDTC5NHROUqGTlML4PlNZS5Ri2U4aCNx2rUPRcKIlE0P
uKxI4T+HIaFpv8+rdV6eUgOrB2xeI1dSFFn/nnv5OoZJEIB+VmuKn3DCUcCZSFlQ uKxI4T+HIaFpv8+rdV6eUgOrB2xeI1dSFFn/nnv5OoZJEIB+VmuKn3DCUcCZSFlQ
PSXSfBDiUGhwOw76WuSSsf1D4b/vLoJ10wIDAQAB PSXSfBDiUGhwOw76WuSSsf1D4b/vLoJ10wIDAQAB
skipping to change at page 28, line 42 skipping to change at page 30, line 42
9C+celgZd2PW7aGYLCHq7nPbmfDV0yHcWjOhXZ8jRMjmANVR/eLQ2EfsRLdW69bn 9C+celgZd2PW7aGYLCHq7nPbmfDV0yHcWjOhXZ8jRMjmANVR/eLQ2EfsRLdW69bn
f3ZD7JS1fwGnO3exGmHO3HZG+6AvberKYVYNHahNFEw5TsAcQWDLRpkGybBcxqZo f3ZD7JS1fwGnO3exGmHO3HZG+6AvberKYVYNHahNFEw5TsAcQWDLRpkGybBcxqZo
81YCqlqidwfeO5YtlO7etx1xLyqa2NsCeG9A86UjG+aeNnXEIDk1PDK+EuiThIUa 81YCqlqidwfeO5YtlO7etx1xLyqa2NsCeG9A86UjG+aeNnXEIDk1PDK+EuiThIUa
/2IxKzJKWl1BKr2d4xAfR0ZnEYuRrbeDQYgTImOlfW6/GuYIxKYgEKCFHFqJATAG /2IxKzJKWl1BKr2d4xAfR0ZnEYuRrbeDQYgTImOlfW6/GuYIxKYgEKCFHFqJATAG
IxHrq1PDOiSwXd2GmVVYyEmhZnbcp8CxaEMQoevxAta0ssMK3w6UsDtvUvYvF22m IxHrq1PDOiSwXd2GmVVYyEmhZnbcp8CxaEMQoevxAta0ssMK3w6UsDtvUvYvF22m
qQKBiD5GwESzsFPy3Ga0MvZpn3D6EJQLgsnrtUPZx+z2Ep2x0xc5orneB5fGyF1P qQKBiD5GwESzsFPy3Ga0MvZpn3D6EJQLgsnrtUPZx+z2Ep2x0xc5orneB5fGyF1P
WtP+fG5Q6Dpdz3LRfm+KwBCWFKQjg7uTxcjerhBWEYPmEMKYwTJF5PBG9/ddvHLQ WtP+fG5Q6Dpdz3LRfm+KwBCWFKQjg7uTxcjerhBWEYPmEMKYwTJF5PBG9/ddvHLQ
EQeNC8fHGg4UXU8mhHnSBt3EA10qQJfRDs15M38eG2cYwB1PZpDHScDnDA0= EQeNC8fHGg4UXU8mhHnSBt3EA10qQJfRDs15M38eG2cYwB1PZpDHScDnDA0=
-----END RSA PRIVATE KEY----- -----END RSA PRIVATE KEY-----
A.2. Example keyId Values B.2. Example keyid Values
The table below maps example "keyId" values to associated algorithms The table below maps example "keyid" values to associated algorithms
and/or keys. These are example mappings that are valid only within and/or keys. These are example mappings that are valid only within
the context of examples in examples within this and future documents the context of examples in examples within this and future documents
that reference this section. Unless otherwise specified, within the that reference this section. Unless otherwise specified, within the
context of examples it should be assumed that the signer and verifier context of examples it should be assumed that the signer and verifier
understand these "keyId" mappings. These "keyId" values are not understand these "keyid" mappings. These "keyid" values are not
reserved, and deployments are free to use them, with these reserved, and deployments are free to use them, with these
associations or others. associations or others.
+============+=================================+================+ +============+=================================+================+
| keyId | Algorithm | Verification | | keyid | Algorithm | Verification |
| | | Key | | | | Key |
+============+=================================+================+ +============+=================================+================+
| test-key-a | "hs2019", using RSASSA-PSS | The public key | | test-key-a | "hs2019", using RSASSA-PSS | The public key |
| | [RFC8017] and SHA-512 [RFC6234] | specified in | | | [RFC8017] and SHA-512 [RFC6234] | specified in |
| | | Appendix A.1.1 | | | | Appendix B.1.1 |
+------------+---------------------------------+----------------+ +------------+---------------------------------+----------------+
| test-key-b | rsa-sha256 | The public key | | test-key-b | rsa-sha256 | The public key |
| | | specified in | | | | specified in |
| | | Appendix A.1.1 | | | | Appendix B.1.1 |
+------------+---------------------------------+----------------+ +------------+---------------------------------+----------------+
Table 7 Table 9
A.3. Test Cases B.3. Test Cases
This section provides non-normative examples that may be used as test This section provides non-normative examples that may be used as test
cases to validate implementation correctness. These examples are cases to validate implementation correctness. These examples are
based on the following HTTP message: based on the following HTTP message:
POST /foo?param=value&pet=dog HTTP/1.1 POST /foo?param=value&pet=dog HTTP/1.1
Host: example.com Host: example.com
Date: Tue, 07 Jun 2014 20:51:35 GMT Date: Tue, 07 Jun 2014 20:51:35 GMT
Content-Type: application/json Content-Type: application/json
Digest: SHA-256=X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE= Digest: SHA-256=X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=
Content-Length: 18 Content-Length: 18
{"hello": "world"} {"hello": "world"}
A.3.1. Signature Generation B.3.1. Signature Generation
A.3.1.1. hs2019 signature over minimal recommended content B.3.1.1. hs2019 signature over minimal recommended content
This presents metadata for a Signature using "hs2019", over minimum This presents metadata for a Signature using "hs2019", over minimum
recommended data to sign: recommended data to sign:
+==============+===================================+ +==============+===================================+
| Property | Value | | Property | Value |
+==============+===================================+ +==============+===================================+
| Algorithm | "hs2019", using RSASSA-PSS | | Algorithm | "hs2019", using RSASSA-PSS |
| | [RFC8017] using SHA-512 [RFC6234] | | | [RFC8017] using SHA-512 [RFC6234] |
+--------------+-----------------------------------+ +--------------+-----------------------------------+
| Covered | *created, *request-target | | Covered | @request-target |
| Content | | | Content | |
+--------------+-----------------------------------+ +--------------+-----------------------------------+
| Creation | 8:51:35 PM GMT, June 7th, 2014 | | Creation | 8:51:35 PM GMT, June 7th, 2014 |
| Time | | | Time | |
+--------------+-----------------------------------+ +--------------+-----------------------------------+
| Expiration | Undefined | | Expiration | Undefined |
| Time | | | Time | |
+--------------+-----------------------------------+ +--------------+-----------------------------------+
| Verification | The public key specified in | | Verification | The public key specified in |
| Key Material | Appendix A.1.1. | | Key Material | Appendix B.1.1. |
+--------------+-----------------------------------+ +--------------+-----------------------------------+
Table 8 Table 10
The Signature Input is: The Signature Input is:
*created: 1402170695 "@request-target": post /foo?param=value&pet=dog
*request-target: post /foo?param=value&pet=dog "@signature-params": ("@request-target"); keyid="test-key-a"; created=1402170695
The signature value is: The signature value is:
QaVaWYfF2da6tG66Xtd0GrVFChJ0fOWUe/C6kaYESPiYYwnMH9egOgyKqgLLY9NQJFk7b QaVaWYfF2da6tG66Xtd0GrVFChJ0fOWUe/C6kaYESPiYYwnMH9egOgyKqgLLY9NQJFk7b
QY834sHEUwjS5ByEBaO3QNwIvqEY1qAAU/2MX14tc9Yn7ELBnaaNHaHkV3xVO9KIuLT7V QY834sHEUwjS5ByEBaO3QNwIvqEY1qAAU/2MX14tc9Yn7ELBnaaNHaHkV3xVO9KIuLT7V
6e4OUuGb1axfbXpMgPEql6CEFrn6K95CLuuKP5/gOEcBtmJp5L58gN4VvZrk2OVA6U971 6e4OUuGb1axfbXpMgPEql6CEFrn6K95CLuuKP5/gOEcBtmJp5L58gN4VvZrk2OVA6U971
YiEDNuDa4CwMcQMvcGssbc/L3OULTUffD/1VcPtdGImP2uvVQntpT8b2lBeBpfh8MuaV2 YiEDNuDa4CwMcQMvcGssbc/L3OULTUffD/1VcPtdGImP2uvVQntpT8b2lBeBpfh8MuaV2
vtzidyBYFtAUoYhRWO8+ntqA1q2OK4LMjM2XgDScSVWvGdVd459A0wI9lRlnPap3zg== vtzidyBYFtAUoYhRWO8+ntqA1q2OK4LMjM2XgDScSVWvGdVd459A0wI9lRlnPap3zg==
A possible "Signature-Input" and "Signature" header containing this A possible "Signature-Input" and "Signature" header containing this
signature is: signature is:
Signature-Input: sig1=(*created, *request-target); # NOTE: '\' line wrapping per RFC 8792
keyId="test-key-a"; created=1402170695
Signature: sig1=:QaVaWYfF2da6tG66Xtd0GrVFChJ0fOWUe/C6kaYESPiYYwnMH9eg Signature-Input: sig1=("@request-target");
OgyKqgLLY9NQJFk7bQY834sHEUwjS5ByEBaO3QNwIvqEY1qAAU/2MX14tc9Yn7ELB keyid="test-key-a"; created=1402170695
naaNHaHkV3xVO9KIuLT7V6e4OUuGb1axfbXpMgPEql6CEFrn6K95CLuuKP5/gOEcB Signature: sig1=:QaVaWYfF2da6tG66Xtd0GrVFChJ0fOWUe/C6kaYESPiYYwnMH9eg\
tmJp5L58gN4VvZrk2OVA6U971YiEDNuDa4CwMcQMvcGssbc/L3OULTUffD/1VcPtd OgyKqgLLY9NQJFk7bQY834sHEUwjS5ByEBaO3QNwIvqEY1qAAU/2MX14tc9Yn7ELB\
GImP2uvVQntpT8b2lBeBpfh8MuaV2vtzidyBYFtAUoYhRWO8+ntqA1q2OK4LMjM2X naaNHaHkV3xVO9KIuLT7V6e4OUuGb1axfbXpMgPEql6CEFrn6K95CLuuKP5/gOEcB\
tmJp5L58gN4VvZrk2OVA6U971YiEDNuDa4CwMcQMvcGssbc/L3OULTUffD/1VcPtd\
GImP2uvVQntpT8b2lBeBpfh8MuaV2vtzidyBYFtAUoYhRWO8+ntqA1q2OK4LMjM2X\
gDScSVWvGdVd459A0wI9lRlnPap3zg==: gDScSVWvGdVd459A0wI9lRlnPap3zg==:
A.3.1.2. hs2019 signature covering all header fields B.3.1.2. hs2019 signature covering all header fields
This presents metadata for a Signature using "hs2019" that covers all This presents metadata for a Signature using "hs2019" that covers all
header fields in the request: header fields in the request:
+==============+========================================+ +==============+============================================+
| Property | Value | | Property | Value |
+==============+========================================+ +==============+============================================+
| Algorithm | "hs2019", using RSASSA-PSS [RFC8017] | | Algorithm | "hs2019", using RSASSA-PSS [RFC8017] using |
| | using SHA-512 [RFC6234] | | | SHA-512 [RFC6234] |
+--------------+----------------------------------------+ +--------------+--------------------------------------------+
| Covered | *created, *request-target, host, date, | | Covered | "@request-target", "host", "date", |
| Content | content-type, digest, content-length | | Content | "content-type", "digest", "content-length" |
+--------------+----------------------------------------+ +--------------+--------------------------------------------+
| Creation | 8:51:35 PM GMT, June 7th, 2014 | | Creation | 8:51:35 PM GMT, June 7th, 2014 |
| Time | | | Time | |
+--------------+----------------------------------------+ +--------------+--------------------------------------------+
| Expiration | Undefined | | Expiration | Undefined |
| Time | | | Time | |
+--------------+----------------------------------------+ +--------------+--------------------------------------------+
| Verification | The public key specified in | | Verification | The public key specified in |
| Key Material | Appendix A.1.1. | | Key Material | Appendix B.1.1. |
+--------------+----------------------------------------+ +--------------+--------------------------------------------+
Table 9 Table 11
The Signature Input is: The Signature Input is:
*created: 1402170695 "@request-target": post /foo?param=value&pet=dog
*request-target: post /foo?param=value&pet=dog "host": example.com
host: example.com "date": Tue, 07 Jun 2014 20:51:35 GMT
date: Tue, 07 Jun 2014 20:51:35 GMT "content-type": application/json
content-type: application/json "digest": SHA-256=X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=
digest: SHA-256=X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE= "content-length": 18
content-length: 18 "@signature-params": ("@request-target" "host" "date" "content-type" "digest" "content-length"); keyid="test-key-a"; alg="hs2019"; created=1402170695
The signature value is: The signature value is:
B24UG4FaiE2kSXBNKV4DA91J+mElAhS3mncrgyteAye1GKMpmzt8jkHNjoudtqw3GngGY B24UG4FaiE2kSXBNKV4DA91J+mElAhS3mncrgyteAye1GKMpmzt8jkHNjoudtqw3GngGY
3n0mmwjdfn1eA6nAjgeHwl0WXced5tONcCPNzLswqPOiobGeA5y4WE8iBveel30OKYVel 3n0mmwjdfn1eA6nAjgeHwl0WXced5tONcCPNzLswqPOiobGeA5y4WE8iBveel30OKYVel
0lZ1OnXOmN5TIEIIPo9LrE+LzZis6A0HA1FRMtKgKGhT3N965pkqfhKbq/V48kpJKT8+c 0lZ1OnXOmN5TIEIIPo9LrE+LzZis6A0HA1FRMtKgKGhT3N965pkqfhKbq/V48kpJKT8+c
Zs0TOn4HFMG+OIy6c9ofSBrXD68yxP6QYTz6xH0GMWawLyPLYR52j3I05fK1ylAb6K0ox Zs0TOn4HFMG+OIy6c9ofSBrXD68yxP6QYTz6xH0GMWawLyPLYR52j3I05fK1ylAb6K0ox
PxzQ5nwrLD+mUVPZ9rDs1En6fmOX9xfkZTblG/5D+s1fHHs9dDXCOVkT5dLS8DjdIA== PxzQ5nwrLD+mUVPZ9rDs1En6fmOX9xfkZTblG/5D+s1fHHs9dDXCOVkT5dLS8DjdIA==
A possible "Signature-Input" and "Signature" header containing this A possible "Signature-Input" and "Signature" header containing this
signature is: signature is:
Signature-Input: sig1=(*request-target, *created, host, date, # NOTE: '\' line wrapping per RFC 8792
content-type, digest, content-length); keyId="test-key-a";
alg=hs2019; created=1402170695 Signature-Input: sig1=("@request-target" "host" "date"
Signature: sig1=:B24UG4FaiE2kSXBNKV4DA91J+mElAhS3mncrgyteAye1GKMpmzt8 "content-type" "digest" "content-length"); keyid="test-key-a";
jkHNjoudtqw3GngGY3n0mmwjdfn1eA6nAjgeHwl0WXced5tONcCPNzLswqPOiobGe alg="hs2019"; created=1402170695
A5y4WE8iBveel30OKYVel0lZ1OnXOmN5TIEIIPo9LrE+LzZis6A0HA1FRMtKgKGhT Signature: sig1=:B24UG4FaiE2kSXBNKV4DA91J+mElAhS3mncrgyteAye1GKMpmzt8\
3N965pkqfhKbq/V48kpJKT8+cZs0TOn4HFMG+OIy6c9ofSBrXD68yxP6QYTz6xH0G jkHNjoudtqw3GngGY3n0mmwjdfn1eA6nAjgeHwl0WXced5tONcCPNzLswqPOiobGe\
MWawLyPLYR52j3I05fK1ylAb6K0oxPxzQ5nwrLD+mUVPZ9rDs1En6fmOX9xfkZTbl A5y4WE8iBveel30OKYVel0lZ1OnXOmN5TIEIIPo9LrE+LzZis6A0HA1FRMtKgKGhT\
3N965pkqfhKbq/V48kpJKT8+cZs0TOn4HFMG+OIy6c9ofSBrXD68yxP6QYTz6xH0G\
MWawLyPLYR52j3I05fK1ylAb6K0oxPxzQ5nwrLD+mUVPZ9rDs1En6fmOX9xfkZTbl\
G/5D+s1fHHs9dDXCOVkT5dLS8DjdIA==: G/5D+s1fHHs9dDXCOVkT5dLS8DjdIA==:
A.3.2. Signature Verification B.3.2. Signature Verification
A.3.2.1. Minimal Required Signature Header B.3.2.1. Minimal Required Signature Header
This presents a "Signature-Input" and "Signature" header containing This presents a "Signature-Input" and "Signature" header containing
only the minimal required parameters: only the minimal required parameters:
Signature-Input: sig1=(); keyId="test-key-a"; created=1402170695 # NOTE: '\' line wrapping per RFC 8792
Signature: sig1=:cxieW5ZKV9R9A70+Ua1A/1FCvVayuE6Z77wDGNVFSiluSzR9TYFV
vwUjeU6CTYUdbOByGMCee5q1eWWUOM8BIH04Si6VndEHjQVdHqshAtNJk2Quzs6WC Signature-Input: sig1=(); keyid="test-key-a"; created=1402170695
2DkV0vysOhBSvFZuLZvtCmXRQfYGTGhZqGwq/AAmFbt5WNLQtDrEe0ErveEKBfaz+ Signature: sig1=:cxieW5ZKV9R9A70+Ua1A/1FCvVayuE6Z77wDGNVFSiluSzR9TYFV\
IJ35zhaj+dun71YZ82b/CRfO6fSSt8VXeJuvdqUuVPWqjgJD4n9mgZpZFGBaDdPiw vwUjeU6CTYUdbOByGMCee5q1eWWUOM8BIH04Si6VndEHjQVdHqshAtNJk2Quzs6WC\
pfbVZHzcHrumFJeFHWXH64a+c5GN+TWlP8NPg2zFdEc/joMymBiRelq236WGm5VvV 2DkV0vysOhBSvFZuLZvtCmXRQfYGTGhZqGwq/AAmFbt5WNLQtDrEe0ErveEKBfaz+\
IJ35zhaj+dun71YZ82b/CRfO6fSSt8VXeJuvdqUuVPWqjgJD4n9mgZpZFGBaDdPiw\
pfbVZHzcHrumFJeFHWXH64a+c5GN+TWlP8NPg2zFdEc/joMymBiRelq236WGm5VvV\
9a22RW2/yLmaU/uwf9v40yGR/I1NRA==: 9a22RW2/yLmaU/uwf9v40yGR/I1NRA==:
The corresponding signature metadata derived from this header field The corresponding signature metadata derived from this header field
is: is:
+=================+==========================================+ +=================+==========================================+
| Property | Value | | Property | Value |
+=================+==========================================+ +=================+==========================================+
| Algorithm | "hs2019", using RSASSA-PSS using SHA-256 | | Algorithm | "hs2019", using RSASSA-PSS using SHA-256 |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Covered Content | *created | | Covered Content | `` |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Creation Time | 8:51:35 PM GMT, June 7th, 2014 | | Creation Time | 8:51:35 PM GMT, June 7th, 2014 |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Expiration Time | Undefined | | Expiration Time | Undefined |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Verification | The public key specified in | | Verification | The public key specified in |
| Key Material | Appendix A.1.1. | | Key Material | Appendix B.1.1. |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
Table 10 Table 12
The corresponding Signature Input is: The corresponding Signature Input is:
*created: 1402170695 "@signature-params": sig1=(); alg="hs2019"; keyid="test-key-a"; created=1402170695
A.3.2.2. Minimal Recommended Signature Header B.3.2.2. Minimal Recommended Signature Header
This presents a "Signature-Input" and "Signature" header containing This presents a "Signature-Input" and "Signature" header containing
only the minimal required and recommended parameters: only the minimal required and recommended parameters:
Signature-Input: sig1=(); alg=hs2019; keyId="test-key-a"; # NOTE: '\' line wrapping per RFC 8792
Signature-Input: sig1=(); alg="hs2019"; keyid="test-key-a";
created=1402170695 created=1402170695
Signature: sig1=:cxieW5ZKV9R9A70+Ua1A/1FCvVayuE6Z77wDGNVFSiluSzR9TYFV Signature: sig1=:cxieW5ZKV9R9A70+Ua1A/1FCvVayuE6Z77wDGNVFSiluSzR9TYFV\
vwUjeU6CTYUdbOByGMCee5q1eWWUOM8BIH04Si6VndEHjQVdHqshAtNJk2Quzs6WC vwUjeU6CTYUdbOByGMCee5q1eWWUOM8BIH04Si6VndEHjQVdHqshAtNJk2Quzs6WC\
2DkV0vysOhBSvFZuLZvtCmXRQfYGTGhZqGwq/AAmFbt5WNLQtDrEe0ErveEKBfaz+ 2DkV0vysOhBSvFZuLZvtCmXRQfYGTGhZqGwq/AAmFbt5WNLQtDrEe0ErveEKBfaz+\
IJ35zhaj+dun71YZ82b/CRfO6fSSt8VXeJuvdqUuVPWqjgJD4n9mgZpZFGBaDdPiw IJ35zhaj+dun71YZ82b/CRfO6fSSt8VXeJuvdqUuVPWqjgJD4n9mgZpZFGBaDdPiw\
pfbVZHzcHrumFJeFHWXH64a+c5GN+TWlP8NPg2zFdEc/joMymBiRelq236WGm5VvV pfbVZHzcHrumFJeFHWXH64a+c5GN+TWlP8NPg2zFdEc/joMymBiRelq236WGm5VvV\
9a22RW2/yLmaU/uwf9v40yGR/I1NRA==: 9a22RW2/yLmaU/uwf9v40yGR/I1NRA==:
The corresponding signature metadata derived from this header field The corresponding signature metadata derived from this header field
is: is:
+=================+==========================================+ +=================+==========================================+
| Property | Value | | Property | Value |
+=================+==========================================+ +=================+==========================================+
| Algorithm | "hs2019", using RSASSA-PSS using SHA-512 | | Algorithm | "hs2019", using RSASSA-PSS using SHA-512 |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Covered Content | *created | | Covered Content | `` |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Creation Time | 8:51:35 PM GMT, June 7th, 2014 | | Creation Time | 8:51:35 PM GMT, June 7th, 2014 |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Expiration Time | Undefined | | Expiration Time | Undefined |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
| Verification | The public key specified in | | Verification | The public key specified in |
| Key Material | Appendix A.1.1. | | Key Material | Appendix B.1.1. |
+-----------------+------------------------------------------+ +-----------------+------------------------------------------+
Table 11 Table 13
The corresponding Signature Input is: The corresponding Signature Input is:
*created: 1402170695 "@signature-params": sig1=(); alg="rsa-sha256"; keyid="test-key-b"
A.3.2.3. Minimal Signature Header using rsa-sha256 B.3.2.3. Minimal Signature Header using rsa-sha256
This presents a minimal "Signature-Input" and "Signature" header for This presents a minimal "Signature-Input" and "Signature" header for
a signature using the "rsa-sha256" algorithm: a signature using the "rsa-sha256" algorithm:
Signature: sig1=(date); alg=rsa-sha256; keyId="test-key-b" # NOTE: '\' line wrapping per RFC 8792
Signature: sig1=:HtXycCl97RBVkZi66ADKnC9c5eSSlb57GnQ4KFqNZplOpNfxqk62
JzZ484jXgLvoOTRaKfR4hwyxlcyb+BWkVasApQovBSdit9Ml/YmN2IvJDPncrlhPD Signature: sig1=("date"); alg=rsa-sha256; keyid="test-key-b"
VDv36Z9/DiSO+RNHD7iLXugdXo1+MGRimW1RmYdenl/ITeb7rjfLZ4b9VNnLFtVWw Signature: sig1=:HtXycCl97RBVkZi66ADKnC9c5eSSlb57GnQ4KFqNZplOpNfxqk62\
rjhAiwIqeLjodVImzVc5srrk19HMZNuUejK6I3/MyN3+3U8tIRW4LWzx6ZgGZUaEE JzZ484jXgLvoOTRaKfR4hwyxlcyb+BWkVasApQovBSdit9Ml/YmN2IvJDPncrlhPD\
P0aBlBkt7Fj0Tt5/P5HNW/Sa/m8smxbOHnwzAJDa10PyjzdIbywlnWIIWtZKPPsoV VDv36Z9/DiSO+RNHD7iLXugdXo1+MGRimW1RmYdenl/ITeb7rjfLZ4b9VNnLFtVWw\
rjhAiwIqeLjodVImzVc5srrk19HMZNuUejK6I3/MyN3+3U8tIRW4LWzx6ZgGZUaEE\
P0aBlBkt7Fj0Tt5/P5HNW/Sa/m8smxbOHnwzAJDa10PyjzdIbywlnWIIWtZKPPsoV\
oKVopUWEU3TNhpWmaVhFrUL/O6SN3w==: oKVopUWEU3TNhpWmaVhFrUL/O6SN3w==:
The corresponding signature metadata derived from this header field The corresponding signature metadata derived from this header field
is: is:
+===========================+==========================+ +===========================+==========================+
| Property | Value | | Property | Value |
+===========================+==========================+ +===========================+==========================+
| Algorithm | rsa-sha256 | | Algorithm | rsa-sha256 |
+---------------------------+--------------------------+ +---------------------------+--------------------------+
| Covered Content | date | | Covered Content | date |
+---------------------------+--------------------------+ +---------------------------+--------------------------+
| Creation Time | Undefined | | Creation Time | Undefined |
+---------------------------+--------------------------+ +---------------------------+--------------------------+
| Expiration Time | Undefined | | Expiration Time | Undefined |
+---------------------------+--------------------------+ +---------------------------+--------------------------+
| Verification Key Material | The public key specified | | Verification Key Material | The public key specified |
| | in Appendix A.1.1. | | | in Appendix B.1.1. |
+---------------------------+--------------------------+ +---------------------------+--------------------------+
Table 12 Table 14
The corresponding Signature Input is: The corresponding Signature Input is:
date: Tue, 07 Jun 2014 20:51:35 GMT "date": Tue, 07 Jun 2014 20:51:35 GMT
"@signature-params": ("date"); alg=rsa-sha256; keyid="test-key-b"
Appendix B. Topics for Working Group Discussion
_RFC EDITOR: please remove this section before publication_
The draft has known issues that will need to be addressed during
development, and these issues have been enumerated but not addressed
in this version. Topics are not listed in any particular order.
B.1. Issues
B.1.1. Confusing guidance on algorithm and key identification
The current draft encourages determining the Algorithm metadata
property from the "keyId" field, both in the guidance for the use of
"algorithm" and "keyId", and the definition for the "hs2019"
algorithm and deprecation of the other algorithms in the registry.
The current state arose from concern that a malicious party could
change the value of the "algorithm" parameter, potentially tricking
the verifier into accepting a signature that would not have been
verified under the actual parameter.
Punting algorithm identification into "keyId" hurts interoperability,
since we aren't defining the syntax or semantics of "keyId". It
actually goes against that claim, as we are dictating that the
signing algorithm must be specified by "keyId" or derivable from it.
It also renders the algorithm registry essentially useless. Instead
of this approach, we can protect against manipulation of the
Signature header field by adding support for (and possibly mandating)
including Signature metadata within the Signature Input.
B.1.2. Lack of definition of keyId hurts interoperability
The current text leaves the format and semantics of "keyId"
completely up to the implementation. This is primarily due to the
fact that most implementers of Cavage have extensive investment in
key distribution and management, and just need to plug an identifier
into the header. We should support those cases, but we also need to
provide guidance for the developer that doesn't have that and just
wants to know how to identify a key. It may be enough to punt this
to profiling specs, but this needs to be explored more.
B.1.3. Algorithm Registry duplicates work of JWA
[RFC7518] already defines an IANA registry for cryptographic
algorithms. This wasn't used by Cavage out of concerns about
complexity of JOSE, and issues with JWE and JWS being too flexible,
leading to insecure combinations of options. Using JWA's definitions
does not need to mean we're using JOSE, however. We should look at
if/how we can leverage JWA's work without introducing too many sharp
edges for implementers.
In any use of JWS algorithms, this spec would define a way to create
the JWS Signing Input string to be applied to the algorithm. It
should be noted that this is incompatible with JWS itself, which
requires the inclusion of a structured header in the signature input.
A possible approach is to incorporate all elements of the JWA
signature algorithm registry into this spec using a prefix or other
marker, such as "jws-RS256" for the RSA 256 JSON Web Signature
algorithm.
B.1.4. Algorithm Registry should not be initialized with deprecated
entries
The initial entries in this document reflect those in Cavage. The
ones that are marked deprecated were done so because of the issue
explained in Appendix B.1.1, with the possible exception of "rsa-
sha1". We should probably just remove that one.
B.1.5. No percent-encoding normalization of path/query
See: issue #26 (https://github.com/w3c-dvcg/http-signatures/
issues/26)
The canonicalization rules for "*request-target" do not perform
handle minor, semantically meaningless differences in percent-
encoding, such that verification could fail if an intermediary
normalizes the effective request URI prior to forwarding the message.
At a minimum, they should be case and percent-encoding normalized as
described in sections 6.2.2.1 and 6.2.2.2 of [RFC3986].
B.1.6. Misleading name for headers parameter
The Covered Content list contains identifiers for more than just
headers, so the "header" parameter name is no longer appropriate.
Some alternatives: "content", "signed-content", "covered-content".
B.1.7. Changes to whitespace in header field values break verification
Some header field values contain RWS, OWS, and/or BWS. Since the
header field value canonicalization rules do not address whitespace,
changes to it (e.g., removing OWS or BWS or replacing strings of RWS
with a single space) can cause verification to fail.
B.1.8. Multiple Set-Cookie headers are not well supported
The Set-Cookie header can occur multiple times but does not adhere to
the list syntax, and thus is not well supported by the header field
value concatenation rules.
B.1.9. Covered Content list is not signed
The Covered Content list should be part of the Signature Input, to
protect against malicious changes.
B.1.10. Algorithm is not signed
The Algorithm should be part of the Signature Input, to protect
against malicious changes.
B.1.11. Verification key identifier is not signed
The Verification key identifier (e.g., the value used for the "keyId"
parameter) should be part of the Signature Input, to protect against
malicious changes.
B.1.12. Max values, precision for Integer String and Decimal String not
defined
The definitions for Integer String and Decimal String do not specify
a maximum value. The definition for Decimal String (used to provide
sub-second precision for Expiration Time) does not define minimum or
maximum precision requirements. It should set a sane requirement
here (e.g., MUST support up to 3 decimal places and no more).
B.1.13. keyId parameter value could break list syntax
The "keyId" parameter value needs to be constrained so as to not
break list syntax (e.g., by containing a comma).
B.1.14. Creation Time and Expiration Time do not allow for clock skew
The processing instructions for Creation Time and Expiration Time
imply that verifiers are not permitted to account for clock skew
during signature verification.
B.1.15. Should require lowercased header field names as identifiers
The current text allows mixed-case header field names when they are
being used as content identifiers. This is unnecessary, as header
field names are case-insensitive, and creates opportunity for
incompatibility. Instead, content identifiers should always be
lowercase.
B.1.16. Reconcile Date header and Creation Time
The draft is missing guidance on if/how the Date header relates to
signature Creation Time. There are cases where they may be
different, such as if a signature was pre-created. Should Creation
Time default to the value in the Date header if the "created"
parameter is not specified?
B.1.17. Remove algorithm-specific rules for content identifiers
The rules that restrict when the signer can or must include certain
identifiers appear to be related to the pseudo-revving of the Cavage
draft that happened when the "hs2019" algorithm was introduced. We
should drop these rules, as it can be expected that anyone
implementing this draft will support all content identifiers.
B.1.18. Add guidance for signing compressed headers
The draft should provide guidance on how to sign headers when
[RFC7541] is used. This guidance might be as simple as "sign the
uncompressed header field value."
B.1.19. Transformations to Via header field value break verification
Intermediaries are permitted to strip comments from the "Via" header
field value, and consolidate related sequences of entries. The
canonicalization rules do not account for these changes, and thus
they cause signature verification to fail if the "Via" header is
signed. At the very least, guidance on signing or not signing "Via"
headers needs to be included.
B.1.20. Case changes to case-insensitive header field values break
verification
Some header field values are case-insensitive, in whole or in part.
The canonicalization rules do not account for this, thus a case
change to a covered header field value causes verification to fail.
B.1.21. Need more examples for Signature header
Add more examples showing different cases e.g, where "created" or
"expires" are not present.
B.1.22. Expiration not needed
In many cases, putting the expiration of the signature into the hands
of the signer opens up more options for failures than necessary.
Instead of the "expires", any verifier can use the "created" field
and an internal lifetime or offset to calculate expiration. We
should consider dropping the "expires" field.
B.2. Features
B.2.1. Define more content identifiers
It should be possible to independently include the following content
and metadata properties in Covered Content:
* The signature's Algorithm
* The signature's Covered Content
* The value used for the "keyId" parameter
* Request method
* Individual components of the effective request URI: scheme,
authority, path, query
* Status code
* Request body (currently supported via Digest header [RFC3230] )
B.2.2. Multiple signature support
(( Editor's note: I believe this use case is theoretical. Please let
me know if this is a use case you have. ))
There may be scenarios where attaching multiple signatures to a
single message is useful:
* A gateway attaches a signature over headers it adds (e.g.,
"Forwarded") to messages already signed by the user agent.
* A signer attaches two signatures signed by different keys, to be
verified by different entities.
This could be addressed by changing the Signature header syntax to
accept a list of parameter sets for a single signature, e.g., by
separating parameters with "";"" instead of "","". It may also be
necessary to include a signature identifier parameter.
B.2.3. Support for incremental signing of header field value list items
(( Editor's note: I believe this use case is theoretical. Please let
me know if this is a use case you have. ))
Currently, signing a header field value is all-or-nothing: either the
entire value is signed, or none of it is. For header fields that use
list syntax, it would be useful to be able to specify which items in
the list are signed.
A simple approach that allowed the signer to indicate the list size
at signing time would allow a signer to sign header fields that are
may be appended to by intermediaries as the message makes its way to
the recipient. Specifying list size in terms of number of items
could introduce risks of list syntax is not strictly adhered to
(e.g., a malicious party crafts a value that gets parsed by the
application as 5 items, but by the verifier as 4). Specifying list
size in number of octets might address this, but more exploration is
required.
B.2.4. Support expected authority changes
In some cases, the authority of the effective request URI may be
expected to change, for example from "public-service-
name.example.com" to "service-host-1.public-service-
name.example.com". This is commonly the case for services that are
hosted behind a load-balancing gateway, where the client sends
requests to a publicly known domain name for the service, and these
requests are transformed by the gateway into requests to specific
hosts in the service fleet.
One possible way to handle this would be to special-case the Host
header field to allow verifier to substitute a known expected value,
or a value provided in another header field (e.g., "Via") when
generating the Signature Input, provided that the verifier also
recognizes the real value in the "Host" header. Alternatively, this
logic could apply to an "(audience)" content identifier.
B.2.5. Support for signing specific cookies
A signer may only wish to sign one or a few cookies, for example if
the website requires its authentication state cookie to be signed,
but also sets other cookies (e.g., for analytics, ad tracking, etc.)
Acknowledgements Acknowledgements
This specification is based on the draft-cavage-http-signatures This specification was initially based on the draft-cavage-http-
draft. The editor would like to thank the authors of that draft, signatures internet draft. The editors would like to thank the
Mark Cavage and Manu Sporny, for their work on that draft and their authors of that draft, Mark Cavage and Manu Sporny, for their work on
continuing contributions. that draft and their continuing contributions.
The editor would also like to thank the following individuals for The editor would also like to thank the following individuals for
feedback on and implementations of the draft-cavage-http-signatures feedback on and implementations of the draft-cavage-http-signatures
draft (in alphabetical order): Mark Adamcin, Mark Allen, Paul draft (in alphabetical order): Mark Adamcin, Mark Allen, Paul
Annesley, Karl Boehlmark, Stephane Bortzmeyer, Sarven Capadisli, Liam Annesley, Karl Boehlmark, Stephane Bortzmeyer, Sarven Capadisli, Liam
Dennehy, ductm54, Stephen Farrell, Phillip Hallam-Baker, Eric Holmes, Dennehy, ductm54, Stephen Farrell, Phillip Hallam-Baker, Eric Holmes,
Andrey Kislyuk, Adam Knight, Dave Lehn, Dave Longley, James H. Andrey Kislyuk, Adam Knight, Dave Lehn, Dave Longley, James H.
Manger, Ilari Liusvaara, Mark Nottingham, Yoav Nir, Adrian Palmer, Manger, Ilari Liusvaara, Mark Nottingham, Yoav Nir, Adrian Palmer,
Lucas Pardue, Roberto Polli, Julian Reschke, Michael Richardson, Lucas Pardue, Roberto Polli, Julian Reschke, Michael Richardson,
Wojciech Rygielski, Adam Scarr, Cory J. Slep, Dirk Stein, Henry Wojciech Rygielski, Adam Scarr, Cory J. Slep, Dirk Stein, Henry
Story, Lukasz Szewc, Chris Webber, and Jeffrey Yasskin Story, Lukasz Szewc, Chris Webber, and Jeffrey Yasskin
Document History Document History
_RFC EDITOR: please remove this section before publication_ _RFC EDITOR: please remove this section before publication_
* draft-ietf-httpbis-message-signatures * draft-ietf-httpbis-message-signatures
skipping to change at page 41, line 29 skipping to change at page 37, line 16
Lucas Pardue, Roberto Polli, Julian Reschke, Michael Richardson, Lucas Pardue, Roberto Polli, Julian Reschke, Michael Richardson,
Wojciech Rygielski, Adam Scarr, Cory J. Slep, Dirk Stein, Henry Wojciech Rygielski, Adam Scarr, Cory J. Slep, Dirk Stein, Henry
Story, Lukasz Szewc, Chris Webber, and Jeffrey Yasskin Story, Lukasz Szewc, Chris Webber, and Jeffrey Yasskin
Document History Document History
_RFC EDITOR: please remove this section before publication_ _RFC EDITOR: please remove this section before publication_
* draft-ietf-httpbis-message-signatures * draft-ietf-httpbis-message-signatures
- Since -01 - Since -02
- -02
o Removed editorial comments on document sources.
o Removed in-document issues list in favor of tracked issues.
o Replaced unstructured "Signature" header with "Signature- o Replaced unstructured "Signature" header with "Signature-
Input" and "Signature" Dictionary Structured Header Fields. Input" and "Signature" Dictionary Structured Header Fields.
o Defined content identifiers for individual Dictionary o Defined content identifiers for individual Dictionary
members, e.g., "x-dictionary-field:member-name". members, e.g., ""x-dictionary-field";key=member-name".
o Defined content identifiers for first N members of a List, o Defined content identifiers for first N members of a List,
e.g., "x-list-field:4". e.g., ""x-list-field":prefix=4".
o Fixed up examples. o Fixed up examples.
o Updated introduction now that it's adopted. o Updated introduction now that it's adopted.
o Defined specialty content identifiers and a means to extend
them.
o Required signature parameters to be included in signature.
o Added guidance on backwards compatibility, detection, and
use of signature methods.
- -01 - -01
o Strengthened requirement for content identifiers for header o Strengthened requirement for content identifiers for header
fields to be lower-case (changed from SHOULD to MUST). fields to be lower-case (changed from SHOULD to MUST).
o Added real example values for Creation Time and Expiration o Added real example values for Creation Time and Expiration
Time. Time.
o Minor editorial corrections and readability improvements. o Minor editorial corrections and readability improvements.
 End of changes. 162 change blocks. 
833 lines changed or deleted 649 lines changed or added

This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/