The generateKeys() API function returned from crypto.createDiffieHellman() only generates missing (or outdated) keys, that is, it only generates a private key if none has been set yet.

However, the documentation says this API call: "Generates private and public Diffie-Hellman key values".

The documented behavior is different from the actual behavior, and this difference could easily lead to security issues in applications that use these APIs as the DiffieHellman may be used as the basis for application-level security.

Please note that this is a documentation change an the vulnerability has been classified under CWE-1068 - Inconsistency Between Implementation and Documented Design. This change applies to all Node.js active versions: v16, v18, and, v20.