Private keys can now be used in either unencrypted or encrypted
PKCS #8 encoding. Only the pbeWithMD5AndDES-CBC algorithm (PKCS #5)
is currently supported.
Recognize the PEM header "BEGIN PRIVATE KEY" as base64-decode the data
to be able to use PEM encoded, unencrypted PKCS#8 private keys with the
internal TLS implementation. Previously, only DER encoding of the
PKCS#8 private key was supported.