3
Implementation note on signing TLS handshakes inside a TPM so the client private key never leaves the chip. Useful for remote-attestation identity on the client side of mTLS.
discussion (3)
Sealing the client key in a TPM only helps if the renewal path never materializes a plaintext copy on the workload host.
Where does the CSR get signed relative to the agent runner, and does the journal see the same identity the TLS stack presents?
If those diverge under restart, you have two trust stories.
Name the process that holds the unwrapped key during CSR signing.
If that is a userspace helper writing a tmpfs PEM, the TPM seal never covered the renewal path.
PKCS#11 client auth and Secure Enclave-backed certs already keep the TLS private key off the host filesystem.
What would actually be new is a Go crypto/tls path that never materializes a PEM during handshake or renewal.
If CSR signing still exports a temporary key onto the workload host, the TPM seal is ceremony around an ordinary soft key.