Firmware TPMs (fTPMs) are faster, but I doubt they're really fast enough to use as an HSM.
There are TPM APIs for Java, so you can do this, but it's not surprising that the Java keystore providers lack builtin support because of the performance issues.
Ideally fTPMs should come with EKcerts and platform certificates and they would be very fast and as secure as (more so than) dTPMs. Then using fTPMs as HSMs might take off.
I know it's awful, but probably not as awful as a hardcoded passphrase.
If the chain is protected by the tpm, this method if implemented correctly through the whole chain should protect your cert and pkey.
that being said _should_ is the keyword,. i dont think any platform really managed to escape all attacks, though a lot in this area do need hw access (the tweezers previously implemented by the author :)).
This is a common misconception.
Afaik, if you want access to a chip like TPM, the OS will need to cooperate as such I/O access or MMIO or however it's accessed, will be privileged instructions likely.
I'd find it somewhat logical an OS or loader component starts verification, and then components upwards in the chain are well, chained together via verification, taking away the need to access the TPM after the initial modules are verified.
- Do you have any examples of how else the TPM is used? I'm very keen to learn more about it's use-cases.
The TPM as a device is completely democratized and accessible by the normal user.
You can use it for platform attestation (which is this post is trying to point out might be broken in some cases), but it also works as a "discount" smartcard where you can seal data and shield keys.
Two examples here which I have written:
A file encryption utility for `age` that shields the keys in the TPM.
https://github.com/Foxboron/age-plugin-tpm
`ssh-tpm-agent` is an `ssh-agent` implementation that enables you to create TPM shielded keys and does signing operation on the TPM.
https://github.com/Foxboron/ssh-tpm-agent
Conceptually both of these tools can also use PCR policy sealing as a form of platform attestation, but I have not implemented that yet as it's a bit hard to do this in a user friendly way UX wise.
As noted by others, you can also do disk encryption. `systemd-cryptsetup` does this on Linux.
https://www.freedesktop.org/software/systemd/man/latest/syst...
> Afaik, if you want access to a chip like TPM, the OS will need to cooperate as such I/O access or MMIO or however it's accessed, will be privileged instructions likely.
Not really? `/dev/tpmrm0` is a TPM resource manager for Linux that is accessible by being part of the `tss` group.
> I'd find it somewhat logical an OS or loader component starts verification, and then components upwards in the chain are well, chained together via verification, taking away the need to access the TPM after the initial modules are verified.
This is only one of several use-cases of a TPM :)
This is also orthogonal of whether or not Secure Boot is part of the chain, depending on the operating system.
It's just not widely used for other applications.
For some people, this is a useful increase in security. Those people set up their own TPM according to their own rules. For the rest of us, who had one forced on us by Microsoft, it's just more anti-right-to-repair.
Also, I'd be pretty frustrated if I was sharing a PC with someone and they got me banned from a game.