How to convert from cborHex to VRFKeyHash using both cardanocli-js and cardano-serialization-lib?

Question

I'm using cardanocli-js to create both VRF files for running a stake pool: vrf.vkey and vrf.skey:

const vrfKeyAccount = cardanocliJs.nodeKeyGenVRF("Totem");

Then I want to read the vrf.vkey file and convert the cborHex value to VRFKeyHash format, from the Cardano Serialization Lib. For that, I do:

CardanoWasm.VRFKeyHash.from_hex(JSON.parse(vrfKeyFile).cborHex);

But I'm getting the following error:

/cardano-multiplatform-lib/rust/pkg/package/cardano_multiplatform_lib.js:16780
    throw takeObject(arg0);
    ^
JsValue("Deserialization failed in VRFKeyHash because: Invalid cbor: expected tuple 'hash length' of length 32 but got length Len(34).")
(Use `node --trace-uncaught ...` to show where the exception was thrown)

Answer 1

Maybe this could help,

as cborHex is in hex, and you can pass a Uint8Array (bytes) to initialize a VRFKeyHash like in many cardano-serialization-lib objects, in theory you can use Buffer.from(hexValue,"hex"), like this:

CardanoWasm.VRFKeyHash.from_bytes(Buffer.from((JSON.parse(vrfKeyFile).cborHex,"hex")));

not tested!

Answer 2

I have checked that every cborHex on vrf.vkey files starts with the prefix "5820" and every cborHex on vrf.skey files starts with the prefix "5840". If I remove those prefixes from the conversion, then it works:

CardanoWasm.VRFKeyHash.from_hex(JSON.parse(vrfKeyFile).cborHex.substring(4)));