
JOSE is "JSON Web Almost Everything" – JWA, JWS, JWE, JWT, JWK, JWKS with no dependencies using runtime's native crypto in Node.js, Browser, Cloudflare Workers, Electron, and Deno. The PBKDF2-based JWE key management algorithms expect a JOSE Header Parameter named p2c PBES2 Count, which determines how many PBKDF2 iterations must be executed in order to derive a CEK wrapping key. The purpose of this parameter is to intentionally slow down the key derivation function in order to make password brute-force and dictionary attacks more expensive. This makes the PBES2 algorithms unsuitable for situations where the JWE is coming from an untrusted source: an adversary can intentionally pick an extremely high PBES2 Count value, that will initiate a CPU-bound computation that may take an unreasonable amount of time to finish. Under certain conditions, it is possible to have the user's environment consume unreasonable amount of CPU time. The impact is limited only to users utilizing the JWE decryption APIs with symmetric secrets to decrypt JWEs from untrusted parties who do not limit the accepted JWE Key Management Algorithms (alg Header Parameter) using the keyManagementAlgorithms (or algorithms in v1.x) decryption option or through other means. The v1.28.2, v2.0.6, v3.20.4, and v4.9.2 releases limit the maximum PBKDF2 iteration count to 10000 by default. It is possible to adjust this limit with a newly introduced maxPBES2Count decryption option. If users are unable to upgrade their…Read More
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