v1.0.0

Changelog

• [CLEANUP] Removed api.header. #85
• [DOCS] README details how to extract public / private keys from an x509 certificate. #100
• [ENHANCEMENT] Refactor api.py functions into an object (PyJWT). #101
• [ENHANCEMENT] Support PyCrypto and ecdsa when cryptography isn't available. #103
• [SECURITY] Added some fixes related to algorithm and key choice. #109
• [SECURITY] Added support for whitelist validation of the alg header. #110

Security

A security researcher has notified JSON Web Token library maintainers about a number of vulnerabilities allowing attackers to bypass the verification step. Read more about some of this issues here.

This release fixes the vulnerabilities reported, continue reading for details.

None algorithm

Applies if you

• rely on and do not validate the alg field in the token header.
• implement the "none" algorithm.

Impact

Attackers can craft a malicious token containing an arbitrary payload that passes the verification step.

Exploit

Create a token with the header {"typ":"JWT","alg":"none"}. Include any payload. Do not include a signature (i.e. the token should end with a period). Note: some implementations include some basic but insufficient checking for a missing signature -- some minor fiddling may be required to produce an exploit.

Asymmetric key of a token signed with a symmetric key

Applies if you

• rely on and do not validate the alg field in the token header.
• implement at least one of the HMAC algorithms and at least one of the asymmetric algorithms (e.g. HS256 and RS256).

Impact

If the system is expecting a token signed with one of the asymmetric algorithms, an attacker can bypass the verification step by knowing only the public key.

Exploit

Create an HS256 token. Generate the HMAC signature using the literal bytes of the public key file (often in the PEM format). This will confuse the implementation into interpreting the public key file as an HMAC key.

This release was possible thanks to the awesome @mark-adams.

v0.4.2

• Include LICENSE and AUTHORS in the release tarball. #94
• PyPI package cleanup #91

v0.4.1

• [Fix] Invalid validation of audience claim. #72
• [Enhancement] Verify that decoded header and payload are JSON objects. #66
• [Enhancement] Use constant time string comparison routine from hmac module. #64
• [Enhancement] Add base exception InvalidTokenError for invalid tokens. #60
• [Enhancement] Allow datetime.timedelta for leeway argument. #56

Pending Deprecation

The following exceptions have been marked for deprecation in favor of a renamed one to follow a better convention and will be removed in the next major version release.

• ExpiredSignature will be deprecated in favor of ExpiredSignatureError.
• InvalidAudience will be deprecated in favor of InvalidAudienceError.
• InvalidIssuer will be deprecated in favor of InvalidIssuerError.

Thanks to @mark-adams and @wbolster for all the work and feedback that went into this release.

v0.4.0

Switch from PyCrypto to cryptography.

PR: #51 by @mark-adams

v0.3.2

Allow using a custom JSON encoder in jwt.encode()

PR #49 by @defyrlt
Ref #37

Example

import json
import decimal
import jwt


class CustomJSONEncoder(json.JSONEncoder):
    def default(self, o):
        if isinstance(o, decimal.Decimal):
            return float(o)
        return super(CustomJSONEncoder, self).default(o)

data = {
    'some_decimal': decimal.Decimal('2.2')
}

token = jwt.encode(data, 'secret', json_encoder=CustomJSONEncoder)

v0.3.1

• Let header() support unicode input, like decode(). #48

0.3.0

• Add support for the "nbf" (Not Before) Claim by @skion.
• Add support for encoding Plaintext JWTs (decode them with verify=False) by @skion.
• Add support for Elliptic Curve signatures (ES256 / ES384 / ES512) by @sullivanmatt.
• Fix import and reference of datetime functions in README by @glarrain.
• Add support for the "aud" (Audience) Claim.
• Add support for the "iss" (Issuer) Claim.

0.2.3

• Allow keys of type "bytes" in Python 3 by @cjlarose

0.2.0

Bump up version to 0.2.0 #31