Function loadDpopKey

loadDpopKey(path: string): Promise<DpopKey>
Reads a DPoP key from a PKCS#8 PEM file or a private JWK file.
Parameters
- path: string
  The file; on POSIX it must not be accessible by group or others.
Returns Promise<DpopKey>
The key.

Throws
When the file mode is too open, the JWK has no private member d, or the key is neither P-256 nor Ed25519.