fromPem static method
Parses a PEM string into a private key.
Throws if pem is not a single PRIVATE KEY block holding an X-Wing
private key. The block starts at the first byte, uses strict base64 and
ends all its lines in LF or all in CRLF.
Implementation
static SecretKey fromPem(String pem) =>
SecretKey._(ffi.XhpkeSecretKey.fromPem(pem: pem));