SPDM-Utils

SPDM-Utils is an open source Linux application designed to support, test and develop SPDM requesters and responders. SPDM-Utils is written in Rust and uses libspdm as the backend.

It can be used as a requester CLI to interface with SPDM devices. It includes support for the PCIe Data Object Exchange (DOE) Capability and MCTP transport layers.

SPDM-Utils can also be used as a responder. It can be an embedded MCTP responder running on Tock. It can also be used as a responder running on Linux, and exposed to QEMU or other applications via sockets.

SPDM-Utils can use Unix sockets as well. So you can test it all locally as a requester and responder.

Copyright

Copyright (c) 2022 Western Digital

SPDM-Utils source code is dual licensed under the Apache-2.0 license and MIT license. A copy of these licenses can be found either in the LICENSE-APACHE or LICENSE-MIT files. Versions are also available at http://www.apache.org/licenses/LICENSE-2.0 and http://opensource.org/licenses/MIT.

See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.

Table of Contents

• Dependencies
  • Fedora
• Building
  • Build libspdm
  • Build the binary
  • Build the no_std library
  • Generate mutable certificates
  • Configuring the Logger
• Testing
  • Running libspdm tests
  • Testing completely on the host
  • Testing a real device
  • Setting the certificate
  • Getting a Certificate Signing Request
  • Signing a Certificate Signing Request
• QEMU SPDM Device Emulation

Dependencies

First you need to install Rust, instructions for that are available at: https://rustup.rs/

You will also need a few host dependencies

Fedora

sudo dnf install cmake clang-libs clang-devel pciutils-devel openssl openssl-devel python3-devel

Ruby

spdm-utils uses the cbor-diag ruby gem for manifest encoding and decoding. Similar to the implementation of this CBOR parsing online tool.

You will first need to have gem installed, this is a the package manager for ruby. For example, for Fedora you can install it with:

$ sudo dnf install gem

After which, you can install cbor-diag

$ gem install cbor-diag

The default binary path should be, $HOME/bin/, which you may need to add to your PATH. You can test that the scripts are usable with

$ which cbor2diag.rb
home/<user>/bin/cbor2diag.rb

When building spdm-utils it will generate a manifest.out.cbor which contains the serialised cbor manifest, and also a manifest.pretty which is the pretty format of the manifest (user friendly).

Building

Initialise all sub-modules

cd third-party/
git submodule init; git submodule update --recursive

Build libspdm

To build libspdm in the third-party directory

cd libspdm/
mkdir build; cd build
cmake -DARCH=x64 -DTOOLCHAIN=GCC -DTARGET=Debug -DCRYPTO=openssl -DENABLE_BINARY_BUILD=1 -DCOMPILED_LIBCRYPTO_PATH=/usr/lib/ -DCOMPILED_LIBSSL_PATH=/usr/lib/ -DDISABLE_TESTS=1 CFLAGS="-DLIBSPDM_ENABLE_CAPABILITY_CHUNK_CAP=1" ..
make -j8

Note that we build libspdm with chunking enabled. Chunking allows us to keep the maximum data transferred in a single burst down by chunking the SPDM message data into frames of digestible size(s).

For example, usb_i2c communication with the tock-responder requires it, so we enable it by default. You can disable LIBSPDM_ENABLE_CAPABILITY_CHUNK_CAP for other targets if required by omitting the CFLAGS="-DLIBSPDM_ENABLE_CAPABILITY_CHUNK_CAP=1 in the invocation of cmake.

Build the binary

Then you can build SPDM-Utils with

cargo build --bin spdm_utils

Build the no_std library

This is currently a work in progress

cargo build --lib --features=no_std

Configuring the Logger

SPDM-Utils supports logging. The following log levels are supported:

• trace
• debug
• info
• warn
• error

By default SPDM-Utils will build with trace log level, meaning that the log outputs are very verbose containing all logs. To change this, set the LOG_LEVEL environment variable to the desired level when building. The logger also takes a LOG_STYLE parameter which may be used to set the character style. This defaults to always but can be changed to one of (see here for more):

• always
• never
• auto

LOG_LEVEL=info LOG_STYLE=never cargo build

Testing

All changes should go through the Cargo formatter and tests, which can be run with

cargo fmt; cargo clippy; cargo test

Running libspdm tests

Setup and build SPDM-Responder-Validator in the third-party directory

cd third-party/
git submodule init; git submodule update --recursive
cd SPDM-Responder-Validator/
rm -rf libspdm/

# This assumes that `third-party/libspdm` is configured correctly as above
# The symlink here ensures that the tests are build against the same version of libspdm
ln -s ../libspdm/ libspdm
mkdir build; cd build

cmake -DARCH=x64 -DTOOLCHAIN=GCC -DTARGET=Debug -DCRYPTO=openssl ..
make -j8

We can now build SPDM-Utils with

RUSTFLAGS='--cfg libspdm_tests' cargo build

Testing completely on the host

You can run SPDM-Utils completely on the host using unix sockets. In this case you can run the server side with

cargo run -- --socket-server request get-digests

and the client side with

./target/debug/spdm_utils --socket-client response

Note that the server must be run first. You can also swap the server/client specification between the request or response side as well.

You can also run the libspdm tests by running tests on the socket server with:

cargo run -- --socket-server tests

Testing a real device

You can run SPDM-Utils on the host to interact with a real DOE device. To do that you can run the following example to get digest information

./target/debug/spdm_utils --doe-pci-cfg request get-digests

Setting the certificate

From a host you can set the certificate of the device. As SPDM-Utils uses the Alias cert model you can only set the root certificate to the device certificate with the SET_CERTIFICATE command (see section 117 on the SPDM spec).

For example to set the certificate run:

spdm_utils --doe-pci-cfg request --cert-path ./certs/slot0/immutable.der set-certificate

You can additionally specify --cert-slot-id to specify the target slot number, valid slot numbers range from 0-7.

Getting a Certificate Signing Request

A requester can get the Certificate Signing Request (CSR) from the device with a command similar to this:

spdm_utils --doe-pci-cfg request get-csr

Which will save the file to csr_response.der. You can then verify the CSR with openssl

openssl req -text -noout -inform der -verify -in ./csr_response.der

Signing a Certificate Signing Request

Once you have a csr_response.der from the responder, you first want to convert it to a PEM format with

openssl req -inform der -in ./csr_response.der -out csr_response.req

You can now sign the CSR

openssl x509 -req -in csr_response.req -out csr_response.cert -CA ./certs/slot0/inter.der -sha384 -days 3650 -set_serial 3 -extensions v3_inter -extfile ./certs/openssl-alias.cnf

Then convert the certificate back to DER

openssl asn1parse -in csr_response.cert -out csr_response.cert.der

Combine all of the immutable certs

cat ./certs/slot0/ca.cert.der ./certs/slot0/inter.cert.der ./csr_response.cert.der > set-cert.der

Now you can set the certificate of a slot

spdm_utils --doe-pci-cfg request --cert-slot-id 1 --cert-path ./set-cert.der set-certificate

Then you request the certificate back

spdm_utils --doe-pci-cfg request --cert-slot-id 1 get-certificate

If you are running the socket/client mode you will have to simulate a device reset and certificate re-gen. That can be done by running this

cd certs
./setup_certs.sh ../target/debug/spdm_utils
cd ../

QEMU SPDM Device Emulation

SPDM-Utils supports binding to QEMU to implement an SPDM responder side to an emulated device in QEMU. SPDM support for QEMU is not upstream yet, however, this fork has the necessary changes required to emulated an NVMe device with SPDM support over DOE.

For example, this may be an emulated NVMe device in QEMU that binds to SPDM-Utils for the SPDM responder implementation.

With the current SPDM implementation in QEMU, the only transport layer supported is DOE. SPDM-Utils must be started before QEMU for this to work.

$ ./target/debug/spdm_utils --qemu-server response

[2023-08-29T06:21:47Z DEBUG SPDM-Utils] Logger initialisation [OK]
[2023-08-29T06:21:47Z DEBUG SPDM-Utils::qemu_server] Setting up a server on [port: 2323, ip: 127.0.0.1]
[2023-08-29T06:21:47Z INFO  SPDM-Utils::qemu_server] Server started, waiting for qemu on port: 2323

Note: You can provide --qemu-port <QEMU_PORT> to specify a port for the server and also --spdm-transport-protocol <TRANSPORT> to specify the transport layer.

This will start SPDM-Utils responder server on port 2323 (default). QEMU can now be started. Once QEMU starts, if the connection is successful, the following logs should show (ensure that INFO log level is enabled in SPDM-Utils).

[2023-08-29T06:22:01Z INFO  SPDM-Utils::qemu_server] New connection: 127.0.0.1:40528
[2023-08-29T06:22:01Z INFO  SPDM-Utils::responder] Running in a response loop

Now QEMU is ready to use SPDM-Utils as an SPDM responder for an emulated device.