JWK JSON public key gerneration.

[unnikrishnan kv]

Hi Brian, Could you please clarify my doubt regarding JWK JSON public key gerneration. Client provided JSON like { "jwk": [ { "alg": "RSA", "mod": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", "exp": "AQAB" } ] } How i can create public key from above JOSN. Could you please help me to slove this. Thanks, Unnikrishnan

[Brian Campbell]

Something like this with the just the JSON object from the array:

        PublicJsonWebKey publicJsonWebKey = PublicJsonWebKey.Factory.newPublicJwk("\"{ \"alg\": \"RSA\", \"mod\": \"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\", \"exp\": \"AQAB\" }\"");
        PublicKey publicKey = publicJsonWebKey.getPublicKey();

Or if you can parse that object into a map, there's a PublicJsonWebKey.Factory.newPublicJwk method that takes a map too.

Or something like this to make that JSON into a proper JWKS first and give that to a new JsonWebKeySet object:

        String json = "{\"jwk\": [ { \"alg\": \"RSA\", \"mod\": \"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\", \"exp\": \"AQAB\" }]}";;
        json = jwkJson.replaceFirst("jwks", JsonWebKeySet.JWK_SET_MEMBER_NAME);
        JsonWebKeySet jwks = new JsonWebKeySet(json);
        JsonWebKey next = jwks.getJsonWebKeys().iterator().next();
        Key key = next.getKey();
        PublicKey publicKey = (PublicKey) key;

[Brian Campbell]

Actually, that's not right. Per https://tools.ietf.org/html/rfc7518#section-6.3 there should be a "kty":"RSA" rather than "alg":"RSA" and an "n" rather than "mod" and "e" rather than "exp"). So more like this:

        json = json.replaceFirst("jwk", JsonWebKeySet.JWK_SET_MEMBER_NAME);
        json = json.replaceFirst(JsonWebKey.ALGORITHM_PARAMETER, JsonWebKey.KEY_TYPE_PARAMETER);
        json = json.replaceFirst("\"mod\"", "\"" + RsaJsonWebKey.MODULUS_MEMBER_NAME + "\"");
        json = json.replaceFirst("\"exp\"", "\"" + RsaJsonWebKey.EXPONENT_MEMBER_NAME + "\"");

        JsonWebKeySet jwks = new JsonWebKeySet(json);
        JsonWebKey next = jwks.getJsonWebKeys().iterator().next();
        Key key = next.getKey();
        PublicKey publicKey = (PublicKey) key;