Internet DRAFT - draft-ietf-oauth-jwt-bcp
draft-ietf-oauth-jwt-bcp
OAuth Working Group Y. Sheffer
Internet-Draft Intuit
Updates: RFC 7519 (if approved) D. Hardt
Intended status: Best Current Practice
Expires: April 15, 2020 M. Jones
Microsoft
October 13, 2019
JSON Web Token Best Current Practices
draft-ietf-oauth-jwt-bcp-07
Abstract
JSON Web Tokens, also known as JWTs, are URL-safe JSON-based security
tokens that contain a set of claims that can be signed and/or
encrypted. JWTs are being widely used and deployed as a simple
security token format in numerous protocols and applications, both in
the area of digital identity, and in other application areas. The
goal of this Best Current Practices document is to provide actionable
guidance leading to secure implementation and deployment of JWTs.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 15, 2020.
Copyright Notice
Copyright (c) 2019 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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Target Audience . . . . . . . . . . . . . . . . . . . . . 4
1.2. Conventions used in this document . . . . . . . . . . . . 4
2. Threats and Vulnerabilities . . . . . . . . . . . . . . . . . 4
2.1. Weak Signatures and Insufficient Signature Validation . . 4
2.2. Weak Symmetric Keys . . . . . . . . . . . . . . . . . . . 5
2.3. Incorrect Composition of Encryption and Signature . . . . 5
2.4. Plaintext Leakage through Analysis of Ciphertext Length . 5
2.5. Insecure Use of Elliptic Curve Encryption . . . . . . . . 5
2.6. Multiplicity of JSON Encodings . . . . . . . . . . . . . 6
2.7. Substitution Attacks . . . . . . . . . . . . . . . . . . 6
2.8. Cross-JWT Confusion . . . . . . . . . . . . . . . . . . . 6
2.9. Indirect Attacks on the Server . . . . . . . . . . . . . 6
3. Best Practices . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. Perform Algorithm Verification . . . . . . . . . . . . . 7
3.2. Use Appropriate Algorithms . . . . . . . . . . . . . . . 7
3.3. Validate All Cryptographic Operations . . . . . . . . . . 8
3.4. Validate Cryptographic Inputs . . . . . . . . . . . . . . 8
3.5. Ensure Cryptographic Keys have Sufficient Entropy . . . . 8
3.6. Avoid Length-Dependent Encryption Inputs . . . . . . . . 9
3.7. Use UTF-8 . . . . . . . . . . . . . . . . . . . . . . . . 9
3.8. Validate Issuer and Subject . . . . . . . . . . . . . . . 9
3.9. Use and Validate Audience . . . . . . . . . . . . . . . . 9
3.10. Do Not Trust Received Claims . . . . . . . . . . . . . . 10
3.11. Use Explicit Typing . . . . . . . . . . . . . . . . . . . 10
3.12. Use Mutually Exclusive Validation Rules for Different
Kinds of JWTs . . . . . . . . . . . . . . . . . . . . . . 11
4. Security Considerations . . . . . . . . . . . . . . . . . . . 11
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Normative References . . . . . . . . . . . . . . . . . . 12
7.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. Document History . . . . . . . . . . . . . . . . . . 15
A.1. draft-ietf-oauth-jwt-bcp-07 . . . . . . . . . . . . . . . 15
A.2. draft-ietf-oauth-jwt-bcp-06 . . . . . . . . . . . . . . . 15
A.3. draft-ietf-oauth-jwt-bcp-05 . . . . . . . . . . . . . . . 15
A.4. draft-ietf-oauth-jwt-bcp-04 . . . . . . . . . . . . . . . 15
A.5. draft-ietf-oauth-jwt-bcp-03 . . . . . . . . . . . . . . . 15
A.6. draft-ietf-oauth-jwt-bcp-02 . . . . . . . . . . . . . . . 15
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A.7. draft-ietf-oauth-jwt-bcp-01 . . . . . . . . . . . . . . . 15
A.8. draft-ietf-oauth-jwt-bcp-00 . . . . . . . . . . . . . . . 15
A.9. draft-sheffer-oauth-jwt-bcp-01 . . . . . . . . . . . . . 15
A.10. draft-sheffer-oauth-jwt-bcp-00 . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
JSON Web Tokens, also known as JWTs [RFC7519], are URL-safe JSON-
based security tokens that contain a set of claims that can be signed
and/or encrypted. The JWT specification has seen rapid adoption
because it encapsulates security-relevant information in one easy-to-
protect location, and because it is easy to implement using widely-
available tools. One application area in which JWTs are commonly
used is representing digital identity information, such as OpenID
Connect ID Tokens [OpenID.Core] and OAuth 2.0 [RFC6749] access tokens
and refresh tokens, the details of which are deployment-specific.
Since the JWT specification was published, there have been several
widely published attacks on implementations and deployments. Such
attacks are the result of under-specified security mechanisms, as
well as incomplete implementations and incorrect usage by
applications.
The goal of this document is to facilitate secure implementation and
deployment of JWTs. Many of the recommendations in this document are
about implementation and use of the cryptographic mechanisms
underlying JWTs that are defined by JSON Web Signature (JWS)
[RFC7515], JSON Web Encryption (JWE) [RFC7516], and JSON Web
Algorithms (JWA) [RFC7518]. Others are about use of the JWT claims
themselves.
These are intended to be minimum recommendations for the use of JWTs
in the vast majority of implementation and deployment scenarios.
Other specifications that reference this document can have stricter
requirements related to one or more aspects of the format, based on
their particular circumstances; when that is the case, implementers
are advised to adhere to those stricter requirements. Furthermore,
this document provides a floor, not a ceiling, so stronger options
are always allowed (e.g., depending on differing evaluations of the
importance of cryptographic strength vs. computational load).
Community knowledge about the strength of various algorithms and
feasible attacks can change quickly, and experience shows that a Best
Current Practice (BCP) document about security is a point-in-time
statement. Readers are advised to seek out any errata or updates
that apply to this document.
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1.1. Target Audience
The intended audience of this document is:
- Implementers of JWT libraries (and the JWS and JWE libraries used
by those libraries),
- Implementers of code that uses such libraries (to the extent that
some mechanisms may not be provided by libraries, or until they
are), and
- Developers of specifications that rely on JWTs, both inside and
outside the IETF.
1.2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Threats and Vulnerabilities
This section lists some known and possible problems with JWT
implementations and deployments. Each problem description is
followed by references to one or more mitigations to those problems.
2.1. Weak Signatures and Insufficient Signature Validation
Signed JSON Web Tokens carry an explicit indication of the signing
algorithm, in the form of the "alg" header parameter, to facilitate
cryptographic agility. This, in conjunction with design flaws in
some libraries and applications, have led to several attacks:
- The algorithm can be changed to "none" by an attacker, and some
libraries would trust this value and "validate" the JWT without
checking any signature.
- An "RS256" (RSA, 2048 bit) parameter value can be changed into
"HS256" (HMAC, SHA-256), and some libraries would try to validate
the signature using HMAC-SHA256 and using the RSA public key as
the HMAC shared secret (see [McLean] and CVE-2015-9235).
For mitigations, see Section 3.1 and Section 3.2.
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2.2. Weak Symmetric Keys
In addition, some applications use a keyed MAC algorithm such as
"HS256" to sign tokens, but supply a weak symmetric key with
insufficient entropy (such as a human memorable password). Such keys
are vulnerable to offline brute-force or dictionary attacks once an
attacker gets hold of such a token [Langkemper].
For mitigations, see Section 3.5.
2.3. Incorrect Composition of Encryption and Signature
Some libraries that decrypt a JWE-encrypted JWT to obtain a JWS-
signed object do not always validate the internal signature.
For mitigations, see Section 3.3.
2.4. Plaintext Leakage through Analysis of Ciphertext Length
Many encryption algorithms leak information about the length of the
plaintext, with a varying amount of leakage depending on the
algorithm and mode of operation. This problem is exacerbated when
the plaintext is initially compressed, because the length of the
compressed plaintext and, thus, the ciphertext depend not only on the
length of the original plaintext but also on its content.
Compression attacks are particularly powerful when there is attacker-
controlled data in the same compression space as secret data, as is
the case for some attacks on HTTPS.
See [Kelsey] for general background on compression and encryption,
and [Alawatugoda] for a specific example of attacks on HTTP cookies.
For mitigations, see Section 3.6.
2.5. Insecure Use of Elliptic Curve Encryption
Per [Sanso], several JOSE libraries fail to validate their inputs
correctly when performing elliptic curve key agreement (the "ECDH-ES"
algorithm). An attacker that is able to send JWEs of its choosing
that use invalid curve points and observe the cleartext outputs
resulting from decryption with the invalid curve points can use this
vulnerability to recover the recipient's private key.
For mitigations, see Section 3.4.
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2.6. Multiplicity of JSON Encodings
Previous versions of the JSON format such as the obsoleted [RFC7159]
allowed several different character encodings: UTF-8, UTF-16 and UTF-
32. This is not the case anymore, with the latest standard [RFC8259]
only allowing UTF-8 except for internal use within a "closed
ecosystem". This ambiguity where older implementations and those
used within closed environments may generate non-standard encodings,
may result in the JWT being misinterpreted by its recipient. This in
turn could be used by a malicious sender to bypass the recipient's
validation checks.
For mitigations, see Section 3.7.
2.7. Substitution Attacks
There are attacks in which one recipient will be given a JWT that was
intended for it, and will attempt to use it at a different recipient
for which that JWT was not intended. For instance, if an OAuth 2.0
[RFC6749] access token is legitimately presented to an OAuth 2.0
protected resource for which it is intended, that protected resource
might then present that same access token to a different protected
resource for which the access token is not intended, in an attempt to
gain access. If such situations are not caught, this can result in
the attacker gaining access to resources that it is not entitled to
access.
For mitigations, see Section 3.8 and Section 3.9.
2.8. Cross-JWT Confusion
As JWTs are being used by more different protocols in diverse
application areas, it becomes increasingly important to prevent cases
of JWT tokens that have been issued for one purpose being subverted
and used for another. Note that this is a specific type of
substitution attack. If the JWT could be used in an application
context in which it could be confused with other kinds of JWTs, then
mitigations MUST be employed to prevent these substitution attacks.
For mitigations, see Section 3.8, Section 3.9, Section 3.11, and
Section 3.12.
2.9. Indirect Attacks on the Server
Various JWT claims are used by the recipient to perform lookup
operations, such as database and LDAP searches. Others include URLs
that are similarly looked up by the server. Any of these claims can
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be used by an attacker as vectors for injection attacks or server-
side request forgery (SSRF) attacks.
For mitigations, see Section 3.10.
3. Best Practices
The best practices listed below should be applied by practitioners to
mitigate the threats listed in the preceding section.
3.1. Perform Algorithm Verification
Libraries MUST enable the caller to specify a supported set of
algorithms and MUST NOT use any other algorithms when performing
cryptographic operations. The library MUST ensure that the "alg" or
"enc" header specifies the same algorithm that is used for the
cryptographic operation. Moreover, each key MUST be used with
exactly one algorithm, and this MUST be checked when the
cryptographic operation is performed.
3.2. Use Appropriate Algorithms
As Section 5.2 of [RFC7515] says, "it is an application decision
which algorithms may be used in a given context. Even if a JWS can
be successfully validated, unless the algorithm(s) used in the JWS
are acceptable to the application, it SHOULD consider the JWS to be
invalid."
Therefore, applications MUST only allow the use of cryptographically
current algorithms that meet the security requirements of the
application. This set will vary over time as new algorithms are
introduced and existing algorithms are deprecated due to discovered
cryptographic weaknesses. Applications MUST therefore be designed to
enable cryptographic agility.
That said, if a JWT is cryptographically protected end-to-end by a
transport layer, such as TLS using cryptographically current
algorithms, there may be no need to apply another layer of
cryptographic protections to the JWT. In such cases, the use of the
"none" algorithm can be perfectly acceptable. The "none" algorithm
should only be used when the JWT is cryptographically protected by
other means. JWTs using "none" are often used in application
contexts in which the content is optionally signed; then the URL-safe
claims representation and processing can be the same in both the
signed and unsigned cases. JWT libraries SHOULD NOT generate JWTs
using "none" unless explicitly requested to do by the caller.
Similarly, JWT libraries SHOULD NOT consume JWTs using "none" unless
explicitly requested by the caller.
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Applications SHOULD follow these algorithm-specific recommendations:
- Avoid all RSA-PKCS1 v1.5 encryption algorithms ([RFC8017], Sec.
7.2}, preferring RSA-OAEP ([RFC8017], Sec. 7.1).
- ECDSA signatures [ANSI-X962-2005] require a unique random value
for every message that is signed. If even just a few bits of the
random value are predictable across multiple messages then the
security of the signature scheme may be compromised. In the worst
case, the private key may be recoverable by an attacker. To
counter these attacks, JWT libraries SHOULD implement ECDSA using
the deterministic approach defined in [RFC6979]. This approach is
completely compatible with existing ECDSA verifiers and so can be
implemented without new algorithm identifiers being required.
3.3. Validate All Cryptographic Operations
All cryptographic operations used in the JWT MUST be validated and
the entire JWT MUST be rejected if any of them fail to validate.
This is true not only of JWTs with a single set of Header Parameters
but also for Nested JWTs, in which both outer and inner operations
MUST be validated using the keys and algorithms supplied by the
application.
3.4. Validate Cryptographic Inputs
Some cryptographic operations, such as Elliptic Curve Diffie-Hellman
key agreement ("ECDH-ES") take inputs that may contain invalid
values, such as points not on the specified elliptic curve or other
invalid points (see, e.g. [Valenta], Sec. 7.1). The JWS/JWE library
itself must validate these inputs before using them or it must use
underlying cryptographic libraries that do so (or both!).
ECDH-ES ephemeral public key (epk) inputs should be validated
according to the recipient's chosen elliptic curve. For the NIST
prime-order curves P-256, P-384 and P-521, validation MUST be
performed according to Section 5.6.2.3.4 "ECC Partial Public-Key
Validation Routine" of NIST Special Publication 800-56A revision 3
[nist-sp-800-56a-r3]. Likewise, if the "X25519" or "X448" [RFC8037]
algorithms are used, then the security considerations in [RFC8037]
apply.
3.5. Ensure Cryptographic Keys have Sufficient Entropy
The Key Entropy and Random Values advice in Section 10.1 of [RFC7515]
and the Password Considerations in Section 8.8 of [RFC7518] MUST be
followed. In particular, human-memorizable passwords MUST NOT be
directly used as the key to a keyed-MAC algorithm such as "HS256".
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In particular, passwords should only be used to perform key
encryption, rather than content encryption, as described in
Section 4.8 of [RFC7518]. Note that even when used for key
encryption, password-based encryption is still subject to brute-force
attacks.
3.6. Avoid Length-Dependent Encryption Inputs
Compression of data SHOULD NOT be done before encryption, because
such compressed data often reveals information about the plaintext.
3.7. Use UTF-8
[RFC7515], [RFC7516], and [RFC7519] all specify that UTF-8 be used
for encoding and decoding JSON used in Header Parameters and JWT
Claims Sets. This is also in line with the latest JSON specification
[RFC8259]. Implementations and applications MUST do this, and not
use or admit the use of other Unicode encodings for these purposes.
3.8. Validate Issuer and Subject
When a JWT contains an "iss" (issuer) claim, the application MUST
validate that the cryptographic keys used for the cryptographic
operations in the JWT belong to the issuer. If they do not, the
application MUST reject the JWT.
The means of determining the keys owned by an issuer is application-
specific. As one example, OpenID Connect [OpenID.Core] issuer values
are "https" URLs that reference a JSON metadata document that
contains a "jwks_uri" value that is an "https" URL from which the
issuer's keys are retrieved as a JWK Set [RFC7517]. This same
mechanism is used by [RFC8414]. Other applications may use different
means of binding keys to issuers.
Similarly, when the JWT contains a "sub" (subject) claim, the
application MUST validate that the subject value corresponds to a
valid subject and/or issuer/subject pair at the application. This
may include confirming that the issuer is trusted by the application.
If the issuer, subject, or the pair are invalid, the application MUST
reject the JWT.
3.9. Use and Validate Audience
If the same issuer can issue JWTs that are intended for use by more
than one relying party or application, the JWT MUST contain an "aud"
(audience) claim that can be used to determine whether the JWT is
being used by an intended party or was substituted by an attacker at
an unintended party.
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In such cases, the relying party or application MUST validate the
audience value and if the audience value is not present or not
associated with the recipient, it MUST reject the JWT.
3.10. Do Not Trust Received Claims
The "kid" (key ID) header is used by the relying application to
perform key lookup. Applications should ensure that this does not
create SQL or LDAP injection vulnerabilities, by validating and/or
sanitizing the received value.
Similarly, blindly following a "jku" (JWK set URL) or "x5u" (X.509
URL) header, which may contain an arbitrary URL, could result in
server-side request forgery (SSRF) attacks. Applications SHOULD
protect against such attacks, e.g., by matching the URL to a
whitelist of allowed locations, and ensuring no cookies are sent in
the GET request.
3.11. Use Explicit Typing
Sometimes, one kind of JWT can be confused for another. If a
particular kind of JWT is subject to such confusion, that JWT can
include an explicit JWT type value, and the validation rules can
specify checking the type. This mechanism can prevent such
confusion. Explicit JWT typing is accomplished by using the "typ"
header parameter. For instance, the [RFC8417] specification uses the
"application/secevent+jwt" media type to perform explicit typing of
Security Event Tokens (SETs).
Per the definition of "typ" in Section 4.1.9 of [RFC7515], it is
RECOMMENDED that the "application/" prefix be omitted from the "typ"
value. Therefore, for example, the "typ" value used to explicitly
include a type for a SET SHOULD be "secevent+jwt". When explicit
typing is employed for a JWT, it is RECOMMENDED that a media type
name of the format "application/example+jwt" be used, where "example"
is replaced by the identifier for the specific kind of JWT.
When applying explicit typing to a Nested JWT, the "typ" header
parameter containing the explicit type value MUST be present in the
inner JWT of the Nested JWT (the JWT whose payload is the JWT Claims
Set). In some cases the same "typ" header parameter value will be
present in the outer JWT as well, to explicitly type the entire
Nested JWT.
Note that the use of explicit typing may not achieve disambiguation
from existing kinds of JWTs, as the validation rules for existing
kinds JWTs often do not use the "typ" header parameter value.
Explicit typing is RECOMMENDED for new uses of JWTs.
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3.12. Use Mutually Exclusive Validation Rules for Different Kinds of
JWTs
Each application of JWTs defines a profile specifying the required
and optional JWT claims and the validation rules associated with
them. If more than one kind of JWT can be issued by the same issuer,
the validation rules for those JWTs MUST be written such that they
are mutually exclusive, rejecting JWTs of the wrong kind. To prevent
substitution of JWTs from one context into another, application
developers may employ a number of strategies:
- Use explicit typing for different kinds of JWTs. Then the
distinct "typ" values can be used to differentiate between the
different kinds of JWTs.
- Use different sets of required claims or different required claim
values. Then the validation rules for one kind of JWT will reject
those with different claims or values.
- Use different sets of required header parameters or different
required header parameter values. Then the validation rules for
one kind of JWT will reject those with different header parameters
or values.
- Use different keys for different kinds of JWTs. Then the keys
used to validate one kind of JWT will fail to validate other kinds
of JWTs.
- Use different "aud" values for different uses of JWTs from the
same issuer. Then audience validation will reject JWTs
substituted into inappropriate contexts.
- Use different issuers for different kinds of JWTs. Then the
distinct "iss" values can be used to segregate the different kinds
of JWTs.
Given the broad diversity of JWT usage and applications, the best
combination of types, required claims, values, header parameters, key
usages, and issuers to differentiate among different kinds of JWTs
will, in general, be application specific. As discussed in
Section 3.11, for new JWT applications, the use of explicit typing is
RECOMMENDED.
4. Security Considerations
This entire document is about security considerations when
implementing and deploying JSON Web Tokens.
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5. IANA Considerations
This document requires no IANA actions.
6. Acknowledgements
Thanks to Antonio Sanso for bringing the "ECDH-ES" invalid point
attack to the attention of JWE and JWT implementers. Tim McLean
[McLean] published the RSA/HMAC confusion attack. Thanks to Nat
Sakimura for advocating the use of explicit typing. Thanks to Neil
Madden for his numerous comments, and to Carsten Bormann, Brian
Campbell, Brian Carpenter, Alissa Cooper, Roman Danyliw, Ben Kaduk,
Mirja Kuehlewind, Barry Leiba, Eric Rescorla, Adam Roach, Martin
Vigoureux, and Eric Vyncke for their reviews.
7. References
7.1. Normative References
[nist-sp-800-56a-r3]
Barker, E., Chen, L., Keller, S., Roginsky, A., Vassilev,
A., and R. Davis, "Recommendation for Pair-Wise Key
Establishment Schemes Using Discrete Logarithm
Cryptography, Draft NIST Special Publication 800-56A
Revision 3", April 2018,
<https://doi.org/10.6028/NIST.SP.800-56Ar3>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC6979] Pornin, T., "Deterministic Usage of the Digital Signature
Algorithm (DSA) and Elliptic Curve Digital Signature
Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979, August
2013, <https://www.rfc-editor.org/info/rfc6979>.
[RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
2015, <https://www.rfc-editor.org/info/rfc7515>.
[RFC7516] Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)",
RFC 7516, DOI 10.17487/RFC7516, May 2015,
<https://www.rfc-editor.org/info/rfc7516>.
[RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
DOI 10.17487/RFC7518, May 2015,
<https://www.rfc-editor.org/info/rfc7518>.
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[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
<https://www.rfc-editor.org/info/rfc7519>.
[RFC8017] Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
"PKCS #1: RSA Cryptography Specifications Version 2.2",
RFC 8017, DOI 10.17487/RFC8017, November 2016,
<https://www.rfc-editor.org/info/rfc8017>.
[RFC8037] Liusvaara, I., "CFRG Elliptic Curve Diffie-Hellman (ECDH)
and Signatures in JSON Object Signing and Encryption
(JOSE)", RFC 8037, DOI 10.17487/RFC8037, January 2017,
<https://www.rfc-editor.org/info/rfc8037>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
7.2. Informative References
[Alawatugoda]
Alawatugoda, J., Stebila, D., and C. Boyd, "Protecting
Encrypted Cookies from Compression Side-Channel Attacks",
Financial Cryptography and Data Security pp. 86-106,
DOI 10.1007/978-3-662-47854-7_6, 2015.
[ANSI-X962-2005]
"American National Standard X9.62: The Elliptic Curve
Digital Signature Algorithm (ECDSA)", November 2005.
[Kelsey] Kelsey, J., "Compression and Information Leakage of
Plaintext", Fast Software Encryption pp. 263-276,
DOI 10.1007/3-540-45661-9_21, 2002.
[Langkemper]
Langkemper, S., "Attacking JWT Authentication", September
2016, <https://www.sjoerdlangkemper.nl/2016/09/28/
attacking-jwt-authentication/>.
[McLean] McLean, T., "Critical vulnerabilities in JSON Web Token
libraries", March 2015, <https://auth0.com/blog/critical-
vulnerabilities-in-json-web-token-libraries//>.
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[OpenID.Core]
Sakimura, N., Bradley, J., Jones, M., Medeiros, B., and C.
Mortimore, "OpenID Connect Core 1.0", November 2014,
<http://openid.net/specs/openid-connect-core-1_0.html>.
[RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
RFC 6749, DOI 10.17487/RFC6749, October 2012,
<https://www.rfc-editor.org/info/rfc6749>.
[RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
2014, <https://www.rfc-editor.org/info/rfc7159>.
[RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517,
DOI 10.17487/RFC7517, May 2015,
<https://www.rfc-editor.org/info/rfc7517>.
[RFC8414] Jones, M., Sakimura, N., and J. Bradley, "OAuth 2.0
Authorization Server Metadata", RFC 8414,
DOI 10.17487/RFC8414, June 2018,
<https://www.rfc-editor.org/info/rfc8414>.
[RFC8417] Hunt, P., Ed., Jones, M., Denniss, W., and M. Ansari,
"Security Event Token (SET)", RFC 8417,
DOI 10.17487/RFC8417, July 2018,
<https://www.rfc-editor.org/info/rfc8417>.
[Sanso] Sanso, A., "Critical Vulnerability Uncovered in JSON
Encryption", March 2017,
<https://blogs.adobe.com/security/2017/03/critical-
vulnerability-uncovered-in-json-encryption.html>.
[Valenta] Valenta, L., Sullivan, N., Sanso, A., and N. Heninger, "In
search of CurveSwap: Measuring elliptic curve
implementations in the wild", March 2018,
<https://ia.cr/2018/298>.
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Appendix A. Document History
[[ to be removed by the RFC editor before publication as an RFC ]]
A.1. draft-ietf-oauth-jwt-bcp-07
- IESG review comments.
A.2. draft-ietf-oauth-jwt-bcp-06
- Second AD review.
- Removed unworkable recommendation to pad encrypted passwords.
A.3. draft-ietf-oauth-jwt-bcp-05
- Genart review comments.
A.4. draft-ietf-oauth-jwt-bcp-04
- AD review comments.
A.5. draft-ietf-oauth-jwt-bcp-03
- Acknowledgements.
A.6. draft-ietf-oauth-jwt-bcp-02
- Implemented WGLC feedback.
A.7. draft-ietf-oauth-jwt-bcp-01
- Feedback from Brian Campbell.
A.8. draft-ietf-oauth-jwt-bcp-00
- Initial WG draft. No change from the latest individual version.
A.9. draft-sheffer-oauth-jwt-bcp-01
- Added explicit typing.
A.10. draft-sheffer-oauth-jwt-bcp-00
- Initial version.
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Authors' Addresses
Yaron Sheffer
Intuit
EMail: yaronf.ietf@gmail.com
Dick Hardt
EMail: dick.hardt@gmail.com
Michael B. Jones
Microsoft
EMail: mbj@microsoft.com
URI: http://self-issued.info/
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