Internet DRAFT - draft-ietf-jose-jwk-thumbprint
draft-ietf-jose-jwk-thumbprint
JOSE Working Group M. Jones
Internet-Draft Microsoft
Intended status: Standards Track N. Sakimura
Expires: January 10, 2016 NRI
July 9, 2015
JSON Web Key (JWK) Thumbprint
draft-ietf-jose-jwk-thumbprint-08
Abstract
This specification defines a method for computing a hash value over a
JSON Web Key (JWK). It defines which fields in a JWK are used in the
hash computation, the method of creating a canonical form for those
fields, and how to convert the resulting Unicode string into a byte
sequence to be hashed. The resulting hash value can be used for
identifying or selecting the key represented by the JWK that is the
subject of the thumbprint.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 10, 2016.
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
Jones & Sakimura Expires January 10, 2016 [Page 1]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. JSON Web Key (JWK) Thumbprint . . . . . . . . . . . . . . . . 3
3.1. Example JWK Thumbprint Computation . . . . . . . . . . . . 4
3.2. JWK Members Used in the Thumbprint Computation . . . . . . 5
3.2.1. JWK Thumbprint of a Private Key . . . . . . . . . . . 6
3.2.2. Why Not Include Optional Members? . . . . . . . . . . 6
3.3. Order and Representation of Members in Hash Input . . . . 7
3.4. Selection of Hash Function . . . . . . . . . . . . . . . . 8
3.5. JWK Thumbprints of Keys Not in JWK Format . . . . . . . . 8
4. Practical JSON and Unicode Considerations . . . . . . . . . . 8
5. Relationship to Digests of X.509 Values . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Normative References . . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . . 12
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 12
Appendix B. Document History . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
Jones & Sakimura Expires January 10, 2016 [Page 2]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
1. Introduction
This specification defines a method for computing a hash value
(a.k.a. digest) over a JSON Web Key (JWK) [JWK]. It defines which
fields in a JWK are used in the hash computation, the method of
creating a canonical form for those fields, and how to convert the
resulting Unicode string into a byte sequence to be hashed. The
resulting hash value can be used for identifying or selecting the key
represented by the JWK that is the subject of the thumbprint, for
instance, by using the base64url-encoded JWK Thumbprint value as a
"kid" (key ID) value.
1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
"Key words for use in RFCs to Indicate Requirement Levels" [RFC2119].
The interpretation should only be applied when the terms appear in
all capital letters.
2. Terminology
This specification uses the same terminology as the "JSON Web Key
(JWK)" [JWK], "JSON Web Signature (JWS)" [JWS], and "JSON Web
Algorithms (JWA)" [JWA] specifications.
This term is defined by this specification:
JWK Thumbprint
The digest value for a JWK.
3. JSON Web Key (JWK) Thumbprint
The thumbprint of a JSON Web Key (JWK) is computed as follows:
1. Construct a JSON object [RFC7159] containing only the required
members of a JWK representing the key and with no whitespace or
line breaks before or after any syntactic elements and with the
required members ordered lexicographically by the Unicode
[UNICODE] code points of the member names. (This JSON object is
itself a legal JWK representation of the key.)
2. Hash the octets of the UTF-8 representation of this JSON object
with a cryptographic hash function H. For example, SHA-256 [SHS]
might be used as H. See Section 3.4 for a discussion on the
Jones & Sakimura Expires January 10, 2016 [Page 3]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
choice of hash function.
The resulting value is the JWK Thumbprint with H of the JWK. The
details of this computation are further described in subsequent
sections.
3.1. Example JWK Thumbprint Computation
This section demonstrates the JWK Thumbprint computation for the JWK
below (with long lines broken for display purposes only):
{
"kty": "RSA",
"n": "0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAt
VT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn6
4tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FD
W2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n9
1CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINH
aQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
"e": "AQAB",
"alg": "RS256",
"kid": "2011-04-29"
}
As defined in "JSON Web Key (JWK)" [JWK] and "JSON Web Algorithms
(JWA)" [JWA], the required members for an RSA public key are:
o "kty"
o "n"
o "e"
Therefore, these are the members used in the thumbprint computation.
Their lexicographic order, per Section 3.3, is:
o "e"
o "kty"
o "n"
Therefore the JSON object constructed as an intermediate step in the
computation is as follows (with long lines broken for display
purposes only):
{"e":"AQAB","kty":"RSA","n":"0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2
aiAFbWhM78LhWx4cbbfAAtVT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCi
FV4n3oknjhMstn64tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65Y
GjQR0_FDW2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n
91CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINHaQ-G_x
Jones & Sakimura Expires January 10, 2016 [Page 4]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
BniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw"}
The octets of the UTF-8 representation of this JSON object are:
[123, 34, 101, 34, 58, 34, 65, 81, 65, 66, 34, 44, 34, 107, 116, 121,
34, 58, 34, 82, 83, 65, 34, 44, 34, 110, 34, 58, 34, 48, 118, 120,
55, 97, 103, 111, 101, 98, 71, 99, 81, 83, 117, 117, 80, 105, 76, 74,
88, 90, 112, 116, 78, 57, 110, 110, 100, 114, 81, 109, 98, 88, 69,
112, 115, 50, 97, 105, 65, 70, 98, 87, 104, 77, 55, 56, 76, 104, 87,
120, 52, 99, 98, 98, 102, 65, 65, 116, 86, 84, 56, 54, 122, 119, 117,
49, 82, 75, 55, 97, 80, 70, 70, 120, 117, 104, 68, 82, 49, 76, 54,
116, 83, 111, 99, 95, 66, 74, 69, 67, 80, 101, 98, 87, 75, 82, 88,
106, 66, 90, 67, 105, 70, 86, 52, 110, 51, 111, 107, 110, 106, 104,
77, 115, 116, 110, 54, 52, 116, 90, 95, 50, 87, 45, 53, 74, 115, 71,
89, 52, 72, 99, 53, 110, 57, 121, 66, 88, 65, 114, 119, 108, 57, 51,
108, 113, 116, 55, 95, 82, 78, 53, 119, 54, 67, 102, 48, 104, 52, 81,
121, 81, 53, 118, 45, 54, 53, 89, 71, 106, 81, 82, 48, 95, 70, 68,
87, 50, 81, 118, 122, 113, 89, 51, 54, 56, 81, 81, 77, 105, 99, 65,
116, 97, 83, 113, 122, 115, 56, 75, 74, 90, 103, 110, 89, 98, 57, 99,
55, 100, 48, 122, 103, 100, 65, 90, 72, 122, 117, 54, 113, 77, 81,
118, 82, 76, 53, 104, 97, 106, 114, 110, 49, 110, 57, 49, 67, 98, 79,
112, 98, 73, 83, 68, 48, 56, 113, 78, 76, 121, 114, 100, 107, 116,
45, 98, 70, 84, 87, 104, 65, 73, 52, 118, 77, 81, 70, 104, 54, 87,
101, 90, 117, 48, 102, 77, 52, 108, 70, 100, 50, 78, 99, 82, 119,
114, 51, 88, 80, 107, 115, 73, 78, 72, 97, 81, 45, 71, 95, 120, 66,
110, 105, 73, 113, 98, 119, 48, 76, 115, 49, 106, 70, 52, 52, 45, 99,
115, 70, 67, 117, 114, 45, 107, 69, 103, 85, 56, 97, 119, 97, 112,
74, 122, 75, 110, 113, 68, 75, 103, 119, 34, 125]
Using SHA-256 [SHS] as the hash function H, the JWK SHA-256
Thumbprint value is the SHA-256 hash of these octets, specifically:
[55, 54, 203, 177, 120, 124, 184, 48, 156, 119, 238, 140, 55, 5, 197,
225, 111, 251, 158, 133, 151, 21, 144, 31, 30, 76, 89, 177, 17, 130,
245, 123]
The base64url encoding [JWS] of this JWK SHA-256 Thumbprint value
(which might, for instance, be used as a "kid" (key ID) value) is:
NzbLsXh8uDCcd-6MNwXF4W_7noWXFZAfHkxZsRGC9Xs
3.2. JWK Members Used in the Thumbprint Computation
Only the required members of a key's representation are used when
computing its JWK Thumbprint value. As defined in "JSON Web Key
(JWK)" [JWK] and "JSON Web Algorithms (JWA)" [JWA], the required
members for an elliptic curve public key for the curves specified in
Section 6.2.1.1 of [JWK], in lexicographic order, are:
Jones & Sakimura Expires January 10, 2016 [Page 5]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
o "crv"
o "kty"
o "x"
o "y"
the required members for an RSA public key, in lexicographic order,
are:
o "e"
o "kty"
o "n"
and the required members for a symmetric key, in lexicographic order,
are:
o "k"
o "kty"
As other "kty" (key type) values are defined, the specifications
defining them should be similarly consulted to determine which
members, in addition to "kty", are required.
3.2.1. JWK Thumbprint of a Private Key
The JWK Thumbprint of a JWK representing a private key is computed as
the JWK Thumbprint of a JWK representing the corresponding public
key. This has the intentional benefit that the same JWK Thumbprint
value can be computed both by parties using either the public or
private key. The JWK Thumbprint can then be used to refer to both
keys of the key pair. Application context can be used to determine
whether the public or the private key is the one being referred to by
the JWK Thumbprint.
This specification defines the method of computing JWK Thumbprints of
JWKs representing private keys for interoperability reasons -- so
that different implementations computing JWK Thumbprints of private
keys will produce the same result.
3.2.2. Why Not Include Optional Members?
Optional members of JWKs are intentionally not included in the JWK
Thumbprint computation so that their absence or presence in the JWK
does not alter the resulting value. The JWK Thumbprint value is a
digest of the members required to represent the key as a JWK -- not
of additional data that may also accompany the key.
Optional members are not included so that the JWK Thumbprint refers
to a key -- not a key with an associated set of key attributes. This
Jones & Sakimura Expires January 10, 2016 [Page 6]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
has the benefit that while in different application contexts
different subsets of attributes about the key might or might not be
included in the JWK, the JWK Thumbprint of any JWK representing the
key remains the same regardless of which optional attributes are
present. Different kinds of thumbprints could be defined by other
specifications that might include some or all additional JWK members,
should use cases arise where such different kinds of thumbprints
would be useful. See Section 9.1 of [JWK] for notes on some ways to
cryptographically bind attributes to a key.
3.3. Order and Representation of Members in Hash Input
The required members in the input to the hash function are ordered
lexicographically by the Unicode code points of the member names.
Characters in member names and member values MUST be represented
without being escaped. This means that thumbprints of JWKs that
require such characters are not defined by this specification. (This
is not expected to limit the applicability of this specification, in
practice, as the members of JWK representations are not expected to
use any of these characters.) The characters specified as requiring
escaping by Section 7 of [RFC7159] are quotation mark, reverse
solidus (a.k.a. backslash), and the control characters U+0000 through
U+001F.
If the JWK key type uses members whose values are themselves JSON
objects, the members of those objects MUST likewise be
lexicographically ordered. (As of the time of this writing, none are
defined that do.)
If the JWK key type uses members whose values are JSON numbers, if
the numbers are integers, they MUST be represented as a JSON number
as defined in Section 6 of [RFC7159] without including a fraction
part or exponent part. For instance, the value "1.024e3" MUST be
represented as "1024". This means that thumbprints of JWKs that use
numbers that are not integers are not defined by this specification.
Also, as noted in "The I-JSON Message Format" [RFC7493],
implementations cannot expect an integer whose absolute value is
greater than 9007199254740991 (i.e., that is outside the range
[-(2**53)+1, (2**53)-1]) to be treated as an exact value. (As of the
time of this writing, none are defined that use JSON numbers.)
See Section 4 for a discussion of further practical considerations
pertaining to the representation of the hash input.
Jones & Sakimura Expires January 10, 2016 [Page 7]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
3.4. Selection of Hash Function
A specific hash function must be chosen by an application to compute
the hash value of the hash input. For example, SHA-256 [SHS] might
be used as the hash function by the application. While SHA-256 is a
good default choice at the time of this writing, the hash function of
choice can be expected to change over time as the cryptographic
landscape evolves.
Note that in many cases, only the party that creates a key will need
to know the hash function used. A typical usage is for the producer
of the key to use the base64url-encoded JWK Thumbprint value as a
"kid" (key ID) value. In this case, the consumer of the "kid" treats
it as an opaque value that it uses to select the key.
However, in some cases, multiple parties will be reproducing the JWK
Thumbprint calculation and comparing the results. In these cases,
the parties will need to know which hash function was used and use
the same one.
3.5. JWK Thumbprints of Keys Not in JWK Format
Note that a key need not be in JWK format to create a JWK Thumbprint
of it. The only prerequisites are that the JWK representation of the
key be defined and the party creating the JWK Thumbprint is in
possession of the necessary key material. These are sufficient to
create the hash input from the JWK representation of the key, as
described in Section 3.3.
4. Practical JSON and Unicode Considerations
Implementations will almost certainly use functionality provided by
the platform's JSON support when parsing the JWK and emitting the
JSON object used as the hash input. As a practical consideration,
future JWK member names and values should be avoided for which
different platforms or libraries might emit different
representations. As of the time of this writing, currently all
defined JWK member names and values use only printable ASCII
characters, which should not exhibit this problem. Note however,
that JSON.stringify() cannot be counted on to lexicographically sort
the members of JSON objects, so while it may be able to be used to
emit some kinds of member values, different code is likely to be
needed to perform the sorting.
In particular, while the operation of lexicographically ordering
member names by their Unicode code points is well defined, different
platform sort functions may produce different results for non-ASCII
Jones & Sakimura Expires January 10, 2016 [Page 8]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
characters, in ways that may not be obvious to developers. If
writers of future specifications defining new JWK key type values
choose to restrict themselves to printable ASCII member names and
values (which are for machine and not human consumption anyway), some
future interoperability problems might be avoided.
However, if new JWK members are defined that use non-ASCII member
names or values, their definitions should specify the exact Unicode
code point sequences used to represent them. This is particularly
important in cases in which Unicode normalization could result in the
transformation of one set of code points into another under any
circumstances.
Use of escaped characters in JWKs for which JWK Thumbprints will be
computed should be avoided. Use of escaped characters in the hash
input JWKs derived from these original JWKs is prohibited.
There is a natural representation to use for numeric values that are
integers. However, this specification does not attempt to define a
standard representation for numbers that are not integers or that
contain an exponent component. This is not expected to be a problem
in practice, as the required members of JWK representations are
expected to use only numbers that are integers.
Use of number representations containing fraction or exponent parts
in JWKs for which JWK Thumbprints will be computed should be avoided.
All of these practical considerations are really an instance of Jon
Postel's principle: "Be liberal in what you accept, and conservative
in what you send."
5. Relationship to Digests of X.509 Values
JWK Thumbprint values are computed on the JWK members required to
represent a key, rather than all members of a JWK that the key is
represented in. Thus, they are more analogous to applications that
use digests of X.509 Subject Public Key Info (SPKI) values, which are
defined in Section 4.1.2.7 of [RFC5280], than to applications that
use digests of complete certificate values, as the "x5t" (X.509
certificate SHA-1 thumbprint) [JWS] value defined for X.509
certificate objects does. While logically equivalent to a digest of
the SPKI representation of the key, a JWK Thumbprint is computed over
a JSON representation of that key, rather than over an ASN.1
representation of it.
Jones & Sakimura Expires January 10, 2016 [Page 9]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
6. IANA Considerations
This specification adds to the instructions to the Designated Experts
for the following IANA registries, all of which are in the JSON
Object Signing and Encryption (JOSE) protocol category [IANA.JOSE]:
o JSON Web Key Types
o JSON Web Key Elliptic Curve
o JSON Web Key Parameters
IANA, please add a link to this specification in the Reference
sections of these registries after the existing links to RFC 7518 for
the first two and the link to RFC 7517 for the last.
Because of the practical JSON and Unicode considerations described in
Section 4, for these registries, the Designated Experts must either
require that JWK member names and values being registered use only
printable ASCII characters excluding double quote ('"') and
backslash ('\') (the Unicode characters with code points U+0021,
U+0023 through U+005B, and U+005D through U+007E) or if new JWK
members or values are defined that use other code points, require
that their definitions specify the exact Unicode code point sequences
used to represent them. Furthermore, proposed registrations must not
be accepted that use Unicode code points that can only be represented
in JSON strings as escaped characters.
7. Security Considerations
The JSON Security Considerations and Unicode Comparison Security
Considerations described in Sections 10.2 and 10.3 of "JSON Web
Signature (JWS)" [JWS] also apply to this specification.
Also, as described in Section 4, some implementations may produce
incorrect results if esoteric or escaped characters are used in the
member names. The security implications of this appear to be limited
for JWK Thumbprints of public keys, since while it may result in
implementations failing to identify the intended key, it should not
leak information, since the information in a public key is already
public in nature, by definition.
A hash of a symmetric key has the potential to leak information about
the key value. Thus, the JWK Thumbprint of a symmetric key should be
typically be concealed from parties not in possession of the
symmetric key, unless in the application context, the cryptographic
hash used, such as SHA-256, is known to provide sufficient protection
against disclosure of the key value.
A JWK Thumbprint will only uniquely identify a particular key if a
Jones & Sakimura Expires January 10, 2016 [Page 10]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
single unambiguous JWK representation for that key is defined and
used when computing the JWK Thumbprint. (Such representations are
defined for all the key types defined in "JSON Web Algorithms (JWA)"
[JWA].) For example, if an RSA key were to use "e":"AAEAAQ"
(representing [0, 1, 0, 1]) rather than the specified correct
representation of "e":"AQAB" (representing [1, 0, 1]), a different
thumbprint value would be produced for what could be effectively the
same key, at least for implementations that are lax in validating the
JWK values that they accept. Thus, JWK Thumbprint values can only be
relied upon to be unique for a given key if the implementation also
validates that the correct representation of the key is used.
Even more insidious is that an attacker may supply a key that is a
transformation of a legal key in order to have it appear to be a
different key. For instance, if a legitimate RSA key uses a modulus
value N and an attacker supplies a key with modulus 3*N, the modified
key would still work about 1/3 of the time, but would appear to be a
different key. Thus, while thumbprint values are valuable for
identifying legitimate keys, comparing thumbprint values is not a
reliable means of excluding (blacklisting) the use of particular keys
(or transformations thereof).
8. References
8.1. Normative References
[IANA.JOSE]
IANA, "JSON Object Signing and Encryption (JOSE)",
<http://www.iana.org/assignments/jose>.
[JWA] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
May 2015, <http://www.rfc-editor.org/info/rfc7518>.
[JWK] Jones, M., "JSON Web Key (JWK)", RFC 7517, May 2015,
<http://www.rfc-editor.org/info/rfc7517>.
[JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, May 2015,
<http://www.rfc-editor.org/info/rfc7515>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7159, March 2014.
[SHS] National Institute of Standards and Technology, "Secure
Jones & Sakimura Expires January 10, 2016 [Page 11]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
Hash Standard (SHS)", FIPS PUB 180-4, March 2012, <http://
csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf>.
[UNICODE] The Unicode Consortium, "The Unicode Standard",
<http://www.unicode.org/versions/latest/>.
8.2. Informative References
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC7493] Bray, T., "The I-JSON Message Format", RFC 7493,
March 2015.
Appendix A. Acknowledgements
James Manger and John Bradley participated in discussions that led to
the creation of this specification. Thanks also to Joel Halpern,
Barry Leiba, Adam Montville, Kathleen Moriarty, and Jim Schaad for
their reviews of this specification.
Appendix B. Document History
[[ to be removed by the RFC editor before publication as an RFC ]]
-08
o Added IANA instructions in response to a comment by Barry Leiba.
-07
o Addressed Gen-ART review comment by Joel Halpern.
-06
o Addressed comments in SecDir review by Adam Montville.
-05
o Addressed comments in Kathleen Moriarty's AD review.
-04
Jones & Sakimura Expires January 10, 2016 [Page 12]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
o Addressed additional review comments by Jim Schaad, which resulted
in several clarifications and some corrections to the case of RFC
2119 keywords.
-03
o Addressed review comments by James Manger and Jim Schaad,
including adding a section on the relationship to digests of X.509
values.
-02
o No longer register the new JSON Web Signature (JWS) and JSON Web
Encryption (JWE) Header Parameters and the new JSON Web Key (JWK)
member name "jkt" (JWK SHA-256 Thumbprint) for holding these
values.
o Added security considerations about the measures needed to ensure
that a unique JWK Thumbprint value is produced for a key.
o Added text saying that the base64url encoded JWK Thumbprint value
could be used as a "kid" (key ID) value.
o Broke a sentence up that used to be way too long.
-01
o Addressed issues pointed out by Jim Schaad, including defining the
JWK Thumbprint computation in a manner that allows different hash
functions to be used over time.
o Added Nat Sakimura as an editor.
-00
o Created draft-ietf-jose-jwk-thumbprint-00 from
draft-jones-jose-jwk-thumbprint-01 with no normative changes.
Authors' Addresses
Michael B. Jones
Microsoft
Email: mbj@microsoft.com
URI: http://self-issued.info/
Jones & Sakimura Expires January 10, 2016 [Page 13]
Internet-Draft JSON Web Key (JWK) Thumbprint July 2015
Nat Sakimura
Nomura Research Institute
Email: n-sakimura@nri.co.jp
URI: http://nat.sakimura.org/
Jones & Sakimura Expires January 10, 2016 [Page 14]
