jsonwebtoken unrestricted key type could lead to legacy keys usage

# Overview Versions `<=8.5.1` of `jsonwebtoken` library could be misconfigured so that legacy, insecure key types are used for signature verification. For example, DSA keys could be used with the RS256 algorithm. # Am I affected? You are affected if you are using an algorithm and a key type other than the combinations mentioned below | Key type | algorithm | |----------|------------------------------------------| | ec | ES256, ES384, ES512 | | rsa | RS256, RS384, RS512, PS256, PS384, PS512 | | rsa-pss | PS256, PS384, PS512 | And for Elliptic Curve algorithms: | `alg` | Curve | |-------|------------| | ES256 | prime256v1 | | ES384 | secp384r1 | | ES512 | secp521r1 | # How do I fix it? Update to version 9.0.0. This version validates for asymmetric key type and algorithm combinations. Please refer to the above mentioned algorithm / key type combinations for the valid secure configuration. After updating to version 9.0.0, If you still intend to continue with signing or verifying tokens using invalid key type/algorithm value combinations, you’ll need to set the `allowInvalidAsymmetricKeyTypes` option to `true` in the `sign()` and/or `verify()` functions. # Will the fix impact my users? There will be no impact, if you update to version 9.0.0 and you already use a valid secure combination of key type and algorithm. Otherwise, use the `allowInvalidAsymmetricKeyTypes` option to `true` in the `sign()` and `verify()` functions to continue usage of invalid key type/algorithm combination in 9.0.0 for legacy compatibility.