topk8

Convert private keys to PKCS#8 format in pure Rust.

The following formats are supported at the moment:

• PKCS#1 PEM (RSA PRIVATE KEY)
• SEC1 PEM (EC PRIVATE KEY)

TODO

• Test against OpenSSL
• Upgrade rsa when RustCrypto/RSA#120 is resolved to avoid duplicate crates (der, pkcs8)