Includes:

• Using TPM 2.0 as a keystore, implement a TPM-based authenticator
  • Note: This could be implemented on top of the TPM2-TSS OpenSSL engine (see https://github.com/tpm2-software/tpm2-tss-engine)
• Use the PIN/password feature of TPM 2.0 for user verification
• Partial WebAuthn/FIDO2 support via protocol downgrade