Why { ext: true } for JWK?

[coolaj86]

You use ext: true in many of the JWK examples. I couldn't find reference to it in the spec at https://tools.ietf.org/html/draft-ietf-jose-json-web-key-41

Is it deprecated? new? What did / does it mean?

    "jwk", //can be "jwk" (public or private), "spki" (public only), or "pkcs8" (private only)
    {   //this is an example jwk key, other key types are Uint8Array objects
        kty: "RSA",
        e: "AQAB",
        n: "vGO3eU16ag9zRkJ4AK8ZUZrjbtp5xWK0LyFMNT8933evJoHeczexMUzSiXaLrEFSyQZortk81zJH3y41MBO_UFDO_X0crAquNrkjZDrf9Scc5-MdxlWU2Jl7Gc4Z18AC9aNibWVmXhgvHYkEoFdLCFG-2Sq-qIyW4KFkjan05IE",
        alg: "RS256",
        ext: true,
    },

[diafygi]

WebCryptoAPI registers a new parameter "ext" in JWK that signifies whether the key is extractable or not.

See Section 38.2: https://dvcs.w3.org/hg/webcrypto-api/raw-file/tip/spec/Overview.html#iana-section-jwk