awesome, new milestone reached: tpm2sh and tpm2-protocol compile with the Rust toolchain of Buildroot 2025.02.6.

Couple of recursive dependencies needed to be downgraded, and some code tweaks but nothing heavy (phew). I also found that even you set your edition to 2021, the chances are that there is some nested dependency that is allowed to be in edition 2024.

#buildroot

A good exercise for Rust code IMHO in order to get it to the level that actually is fluent in production is to create BuildRoot package for it ;-)

All sorts of minor tweaks have had to done for tpm2sh and tpm2-protocol in order to get them to my kernel testing images.

Or at least a good exercise if planning to target and scale Rust crate to embedded systems (in production).

#buildroot #rust

I've started to support more proactively TrenchBoot efforts because D-RTM despite being a bit rough compared to enclaves, is at least fully open. It also draws me a positive picture about Oracle as a company as it proves to me that they push technologies to upstream that don't only support Oracle's proprietary technologies but also is benefical work for the wider developer ecosystem (unlike e.g., Intel and AMD). It's good cause IMHO plain and simple.

my favorite patches are those that rip of over 100 lines of code :-) https://lore.kernel.org/linux-integrity/20250919112448.2543343-1-jarkko@kernel.org/T/#u

rasn crate is the best thing for custom ASN.1 parsers imho:

https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2sh.git/tree/src/key/tpm_key.rs?h=main

See: https://github.com/librasn/rasn

relocated:

https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2sh.git/about/?h=main

"precious oneliners" ;-) had to go look this up from lore

make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 tinyconfig && ./scripts/config --file .config -e CONFIG_KEYS -e CONFIG_TCG_TPM -e CONFIG_64BIT -e CONFIG_TRUSTED_KEYS -e CONFIG_TTY -e CONFIG_PROCFS -e CONFIG_SYSFS -e CONFIG_TCG_VTPM_PROXY -e CONFIG_EFI -e CONFIG_ACPI -e CONFIG_ARM_FFA_TRANSPORT -e CONFIG_TCG_CRB && yes '' | make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 oldconfig && make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 -j$(nproc)

I'm planning a new kernel feature based on patch set that I never finished:

https://lore.kernel.org/linux-integrity/aMwh95tMxB7sMEzy@kernel.org/

The gist is to harden selected AIKs, and perform signing and quotes through kernel, and filtered out from /dev/tpm0.

They'd be wrapped into keyring asymmetric keys. You can lock-in remote attestation pretty well then with UKI images having signed command-line.

getting hmac session together in tpm2sh:

❯ sudo target/debug/tpm2sh start-session -s hmac
data://utf8,session(handle=0x02000000;nonce=d19da78d903f3c3a2350b857da368ba02eb911bc2dfe307435e0eec9621083bd;attrs=00;key=1abf23e3cb74a40b1b093f5a7fbad330dc0f63c51e415f4523d98122e507a3b0;alg=sha256)

There used to be session:// but I migrated sessions as portion of the policy expression language grammar. Previously I migrated from pcr:// to language constructs.

if there is one open source project, which i hope to succeed more than any other project, it must be Servo. it's super important that it will become game changer and real distruptor.

i realized that you an do mustache templates with just plain jq:

jq -n -r \
  --arg domains "$TENANT_DOMAIN" \
  --arg hsm_type "$HSM_TYPE" \
  --argjson enable_hello "$ENABLE_HELLO" \
  '
    "[global]\ndebug = true\ndomains = \($domains)\nhome_alias = CN\nhome_attr = CN\nid_attr_map = name\npam_allow_groups =\nuse_etc_skel = true\nlocal_groups = users\nhsm_type = \($hsm_type)\nenable_hello = \($enable_hello)"
  ' > "$BUILD_DIR/himmelblau.conf"

need to apply this idea to my kernel pull request scripts :-)

template here is:

[global]
debug = true
domains = {{domains}}
home_alias = CN
home_attr = CN
id_attr_map = name
pam_allow_groups =
use_etc_skel = true
local_groups = users
hsm_type = {{hsm_type}}
enable_hello = {{enable_hello}}

Copilotin tekoälyavustaja todettiin hyödyttömäksi https://www.mikrobitti.fi/uutiset/a/5e914bbc-0b78-4eaf-8295-51811364515c?ref=aggregaatit%3A2fb1&utm_source=dlvr.it&utm_medium=mastodon

I've been thinking that post 0.11 tpm2sh cool feature would be remote attestation and demo would be remote attestation client and server in bash.

yay, now tpm2sh has software digest calculator for policy expressions (which can query e.g. PCR values but does not exercise policy tpm commands), the remaining errata is not a huge stretch:

https://github.com/puavo-org/tpm2sh/issues/2

Many of the things are just minor collapses while turning this over and over again. Sessions need still a bit of work but lot of the functionality is already there...

I'd like to add quote generation etc. for Remote Attestation purposes but it is definitely out of scope and better just to stabilize the command set.

Sessions are represented like this (to be cosmetic tweaked in some places):

session://handle=0x02000000;nonce=135eac83db00e0c691fba1653405e79f8f285964e18add0488337fc7caf90606;attrs=00;key=;alg=sha256

And there's already `--session` argument but further I'll add an environment variable TPM2SH_SESSION, which command not only read but also update (to enable chaining e.g., nonce needs to be updated).

The general gist and main goal of the command set and "command-line experience" is to enable both user interactive experience and also TPM2 access for shell implemented tools such as password managers.

Load loads both external PKCS#8 and TPM ASN.1. Convert command converts PKCS#8 to TPM ASN.1.

So instead of this:

tpm2_createprimary --hierarchy o -G rsa2048 -c owner.txt
tpm2_evictcontrol -c owner.txt 0x81000001
openssl genrsa -out private.pem 2048
tpm2_import -C 0x81000001 -G rsa -i private.pem -u key.pub -r key.priv
tpm2_encodeobject -C 0x81000001 -u key.pub -r key.priv -o key.priv.pem
openssl asn1parse -inform pem -in key.priv.pem -noout -out key.priv.der

You can just:

tpm2sh create-primary rsa:2048:sha256 --output file://owner.txt
openssl genrsa -out private.pem 2048
tpm2sh convert --parent "tpm://0x81000001" file://private.pem --output file://key.priv.der

#linux #rust #tpm

two fun facts about kiova and tampere:

1. last year it was 70th anniversary of twin town friendship between tampere and kiova (tampere is my hown town).
2. kiova has a street called "tampere", which was named in 2014 to celebrate 60th anniversary of friendship, which has lasted well over its "soviet origins".

my generation does not know what it is like to be at war obviously and it would be obnoxious to say that "i get it" when it comes to war at ukraine. however, we owe to our grandparents to not forget, not make compromises and generally not to be ignorant of the situation.

🇺🇦 🇫🇮

The current feature set of upcoming tpm2sh 0.11. It’s quite basic but everything is tested with care and e.g., load does all the import dance for PKCS8 RSA and ECC keys without having to mess with openssl command line. I.e. single robust load command instead of:

tpm2_createprimary --hierarchy o -G ecc -c owner.txt
tpm2_evictcontrol -c owner.txt 0x81000001
openssl ecparam -name prime256v1 -genkey -noout -out private.pem
tpm2_import -C 0x81000001 -G ecc -i private.pem -u key.pub -r key.priv
tpm2_encodeobject -C 0x81000001 -u key.pub -r key.priv -o key.priv.pem
openssl asn1parse -inform pem -in key.priv.pem -noout -out key.priv.der

And generally flows are somewhat polished and will be polished further before released to not have any rough corners. Finally most of non-trivial functionality is tested against built-in TPM emulator MockTPM.

Sometime after 0.11 release I’ll add also --dry-run switch that can exercise TPM commands with the emulator before applying them to the chip.

#linux #rust #tpm

rasn is good stuff for custom non-established DER formats. Full TPM key ASN.1 spec + my extensions (parentName, parentPubKey):

https://github.com/puavo-org/tpm2sh/blob/main/src/key/tpm_key.rs

It took me like 30 minutes after reading tutorial a bit get ongoing.

great now i have a single data-drive test where test cases translate between legacy (build/parse) and new (zerocopy fat pointers):

# ...

TPM_CC_Startup Response TPM_RC_FAILURE 80010000000a00000101
TPM_CC_Startup Response TPM_RC_CONTEXT_GAP 80010000000a00000901
TPM_CC_PCR_Read Response Success 800100000038000000000000000100000000000000010020dededededededededededededededededededededededededededededededed
# ...

something i randomly noticed in TPM key ASN.1 format:

https://lore.kernel.org/linux-integrity/aMboFXNNX7WZaOaS@kernel.org/

PoC: https://github.com/puavo-org/tpm2sh/commit/18ec3c2169b23523d8866c58fa7b8a89a79bd3d4

#linux #kernel #tpm

yay, the most complex macros, tpm_enum! and tpm_struct! have been converted to the parallel universum:

https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2-protocol.git/commit/?id=4f48396e0df888ee6a5e8a2df92d71cfc05d26d8

After this it is downhill.

I'm doing this like an idiot, i.e. learning as I bump e.g., up until yesterday I was not even aware of Ref and Deref trait :-)