stpm-keygen1

Usage

Overview

stpm-keygen generates a 2048 RSA key inside the TPM chip, and saves the public key and the SRK-encrypted private key (the "blob") in the output file.

Options

-h

Show usage info.

-o output file

Output file, where the public key and key blob will be written.

-p

Create the key with a PIN / password. The password will be prompted for inteactively.

-s

Ask for the SRK password interactively. By default the "Well Known Secret" (20 nulls) is used. The SRK password is an access token that must be presented for the TPM to perform any operation that involves the TPM, and an actual secret password is usually not required or useful.

-S

Generate key in software instead of hardware. The choice between generating the key in software and hardware is not an obvious one. It’s hard to verify the quality of keys generated in hardware (e.g. bugs or backdoors), but software keys have existed in RAM at some point. And because software generated keys have to be generated as migratable keys, they can be extracted by someone who knows the TPM owner password. The recommended choice is to generate in hardware, which is also the default.

Examples

stpm-keygen -o ~/.simple-tpm-pk11/my.key

stpm-keygen -p -o ~/.simple-tpm-pk11/my.key Enter key PIN: my secret password here

stpm-keygen -sp -o ~/.simple-tpm-pk11/my.key Enter SRK PIN: 12345678 Enter key PIN: my secret password here

Diagnostics

Most errors will probably be related to interacting with the TPM chip. Resetting the TPM chip and taking ownership should take care of most of them. See the TPM-TROUBLESHOOTING section of simple-tpm-pk11(7).