From: alistair23@gmail.com
To: alistair@alistair23.me, linux-kernel@vger.kernel.org,
lukas@wunner.de, Jonathan.Cameron@huawei.com,
bhelgaas@google.com, rust-for-linux@vger.kernel.org,
akpm@linux-foundation.org, linux-cxl@vger.kernel.org,
djbw@kernel.org, linux-pci@vger.kernel.org
Cc: alex.gaynor@gmail.com, wilfred.mallawa@wdc.com, gary@garyguo.net,
bjorn3_gh@protonmail.com, benno.lossin@proton.me,
aliceryhl@google.com, boqun.feng@gmail.com,
a.hindborg@kernel.org, tmgross@umich.edu, ojeda@kernel.org,
alistair23@gmail.com
Subject: [PATCH 14/18] lib: rspdm: Support SPDM get_digests
Date: Fri, 8 May 2026 13:17:06 +1000 [thread overview]
Message-ID: <20260508031710.514574-15-alistair.francis@wdc.com> (raw)
In-Reply-To: <20260508031710.514574-1-alistair.francis@wdc.com>
From: Alistair Francis <alistair@alistair23.me>
Support the GET_DIGESTS SPDM command.
Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
lib/rspdm/consts.rs | 7 +++-
lib/rspdm/lib.rs | 4 ++
lib/rspdm/state.rs | 85 +++++++++++++++++++++++++++++++++++++++++-
lib/rspdm/validator.rs | 54 +++++++++++++++++++++++++++
4 files changed, 147 insertions(+), 3 deletions(-)
diff --git a/lib/rspdm/consts.rs b/lib/rspdm/consts.rs
index e4652b18eb2a..092205dab74d 100644
--- a/lib/rspdm/consts.rs
+++ b/lib/rspdm/consts.rs
@@ -19,10 +19,11 @@
pub(crate) const SPDM_VER_10: u8 = 0x10;
pub(crate) const SPDM_VER_11: u8 = 0x11;
pub(crate) const SPDM_VER_12: u8 = 0x12;
-#[allow(dead_code)]
pub(crate) const SPDM_VER_13: u8 = 0x13;
pub(crate) const SPDM_VER_14: u8 = 0x14;
+pub(crate) const SPDM_SLOTS: usize = 8;
+
pub(crate) const SPDM_MIN_VER: u8 = SPDM_VER_10;
pub(crate) const SPDM_MAX_VER: u8 = SPDM_VER_14;
@@ -73,7 +74,7 @@ fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
pub(crate) const SPDM_GET_VERSION_LEN: usize = mem::size_of::<SpdmHeader>() + u8::MAX as usize;
pub(crate) const SPDM_GET_CAPABILITIES: u8 = 0xe1;
-pub(crate) const SPDM_MIN_DATA_TRANSFER_SIZE: u32 = 42;
+pub(crate) const SPDM_MIN_DATA_TRANSFER_SIZE: u32 = 42; // SPDM 1.2.0 margin no 226
// SPDM cryptographic timeout of this implementation:
// Assume calculations may take up to 1 sec on a busy machine, which equals
@@ -111,6 +112,8 @@ fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
pub(crate) const SPDM_HASH_SHA_384: u32 = bit_u32(1);
pub(crate) const SPDM_HASH_SHA_512: u32 = bit_u32(2);
+pub(crate) const SPDM_GET_DIGESTS: u8 = 0x81;
+
// If the crypto support isn't enabled don't offer the algorithms
// to the responder
#[cfg(CONFIG_CRYPTO_RSA)]
diff --git a/lib/rspdm/lib.rs b/lib/rspdm/lib.rs
index 72886a5dfd69..e42cfdd35524 100644
--- a/lib/rspdm/lib.rs
+++ b/lib/rspdm/lib.rs
@@ -120,6 +120,10 @@
return e.to_errno() as c_int;
}
+ if let Err(e) = state.get_digests() {
+ return e.to_errno() as c_int;
+ }
+
0
}
diff --git a/lib/rspdm/state.rs b/lib/rspdm/state.rs
index 34676744e509..bcb1cc955c4c 100644
--- a/lib/rspdm/state.rs
+++ b/lib/rspdm/state.rs
@@ -46,13 +46,17 @@
SPDM_OPAQUE_DATA_FMT_GENERAL,
SPDM_REQ,
SPDM_RSP_MIN_CAPS,
+ SPDM_SLOTS,
SPDM_VER_10,
SPDM_VER_11,
- SPDM_VER_12, //
+ SPDM_VER_12,
+ SPDM_VER_13, //
};
use crate::validator::{
GetCapabilitiesReq,
GetCapabilitiesRsp,
+ GetDigestsReq,
+ GetDigestsRsp,
GetVersionReq,
GetVersionRsp,
NegotiateAlgsReq,
@@ -83,6 +87,10 @@
/// Selected by responder during NEGOTIATE_ALGORITHMS exchange.
/// @meas_hash_alg: Hash algorithm for measurement blocks.
/// Selected by responder during NEGOTIATE_ALGORITHMS exchange.
+/// @supported_slots: Bitmask of responder's supported certificate slots.
+/// Received during GET_DIGESTS exchange (from SPDM 1.3).
+/// @provisioned_slots: Bitmask of responder's provisioned certificate slots.
+/// Received during GET_DIGESTS exchange.
/// @base_asym_enc: Human-readable name of @base_asym_alg's signature encoding.
/// Passed to crypto subsystem when calling verify_signature().
/// @sig_len: Signature length of @base_asym_alg (in bytes).
@@ -94,6 +102,8 @@
/// @desc: Synchronous hash context for @base_hash_alg computation.
/// @hash_len: Hash length of @base_hash_alg (in bytes).
/// H in SPDM specification.
+/// @certs: Certificate chain in each of the 8 slots. Empty KVec if a slot is
+/// not populated. Prefixed by the 4 + H header per SPDM 1.0.0 table 15.
#[expect(dead_code)]
pub struct SpdmState {
pub(crate) dev: *mut bindings::device,
@@ -108,6 +118,8 @@ pub struct SpdmState {
pub(crate) base_asym_alg: u32,
pub(crate) base_hash_alg: u32,
pub(crate) meas_hash_alg: u32,
+ pub(crate) supported_slots: u8,
+ pub(crate) provisioned_slots: u8,
/* Signature algorithm */
base_asym_enc: &'static CStr,
@@ -118,6 +130,9 @@ pub struct SpdmState {
pub(crate) shash: *mut bindings::crypto_shash,
pub(crate) desc: Option<&'static mut bindings::shash_desc>,
pub(crate) hash_len: usize,
+
+ // Certificates
+ pub(crate) certs: [KVec<u8>; SPDM_SLOTS],
}
impl SpdmState {
@@ -139,12 +154,15 @@ pub(crate) fn new(
base_asym_alg: 0,
base_hash_alg: 0,
meas_hash_alg: 0,
+ supported_slots: 0,
+ provisioned_slots: 0,
base_asym_enc: unsafe { CStr::from_bytes_with_nul_unchecked(b"\0") },
sig_len: 0,
base_hash_alg_name: unsafe { CStr::from_bytes_with_nul_unchecked(b"\0") },
shash: core::ptr::null_mut(),
desc: None,
hash_len: 0,
+ certs: [const { KVec::new() }; SPDM_SLOTS],
}
}
@@ -578,4 +596,69 @@ pub(crate) fn negotiate_algs(&mut self) -> Result<(), Error> {
Ok(())
}
+
+ pub(crate) fn get_digests(&mut self) -> Result<(), Error> {
+ let mut request = GetDigestsReq::default();
+ request.version = self.version;
+
+ let req_sz = core::mem::size_of::<GetDigestsReq>();
+ let rsp_sz = core::mem::size_of::<GetDigestsRsp>() + SPDM_SLOTS * self.hash_len;
+
+ // SAFETY: `request` is repr(C) and packed, so we can convert it to a slice
+ let request_buf = unsafe { from_raw_parts_mut(&mut request as *mut _ as *mut u8, req_sz) };
+
+ let mut response_vec: KVec<u8> = KVec::with_capacity(rsp_sz, GFP_KERNEL)?;
+ // SAFETY: `response_vec` is rsp_sz length, initialised, aligned
+ // and won't be mutated
+ let response_buf = unsafe { from_raw_parts_mut(response_vec.as_mut_ptr(), rsp_sz) };
+
+ let len = self.spdm_exchange(request_buf, response_buf)?;
+
+ if len < (core::mem::size_of::<GetDigestsRsp>() as i32) {
+ pr_err!("Truncated digests response\n");
+ to_result(-(bindings::EIO as i32))?;
+ }
+
+ // SAFETY: `len` is the length of data read, which will be smaller
+ // then the capacity of the vector
+ unsafe { response_vec.inc_len(len as usize) };
+
+ let response: &mut GetDigestsRsp = Untrusted::new_mut(&mut response_vec).validate_mut()?;
+
+ if len
+ < (core::mem::size_of::<GetDigestsReq>()
+ + response.param2.count_ones() as usize * self.hash_len) as i32
+ {
+ pr_err!("Truncated digests response\n");
+ to_result(-(bindings::EIO as i32))?;
+ }
+
+ let mut deprovisioned_slots = self.provisioned_slots & !response.param2;
+ while (deprovisioned_slots.trailing_zeros() as usize) < SPDM_SLOTS {
+ let slot = deprovisioned_slots.trailing_zeros() as usize;
+ self.certs[slot].clear();
+ deprovisioned_slots &= !(1 << slot);
+ }
+
+ self.provisioned_slots = response.param2;
+ if self.provisioned_slots == 0 {
+ pr_err!("No certificates provisioned\n");
+ to_result(-(bindings::EPROTO as i32))?;
+ }
+
+ if self.version >= SPDM_VER_13 && (response.param2 & !response.param1 != 0) {
+ pr_err!("Malformed digests response\n");
+ to_result(-(bindings::EPROTO as i32))?;
+ }
+
+ let supported_slots = if self.version >= SPDM_VER_13 {
+ response.param1
+ } else {
+ 0xFF
+ };
+
+ self.supported_slots = supported_slots;
+
+ Ok(())
+ }
}
diff --git a/lib/rspdm/validator.rs b/lib/rspdm/validator.rs
index 9d738133399d..1e5ee8a7582b 100644
--- a/lib/rspdm/validator.rs
+++ b/lib/rspdm/validator.rs
@@ -30,6 +30,7 @@
SPDM_ASYM_ALGOS,
SPDM_CTEXPONENT,
SPDM_GET_CAPABILITIES,
+ SPDM_GET_DIGESTS,
SPDM_GET_VERSION,
SPDM_HASH_ALGOS,
SPDM_MEAS_SPEC_DMTF,
@@ -349,3 +350,56 @@ fn validate(unvalidated: &mut Unvalidated<KVec<u8>>) -> Result<Self, Self::Err>
Ok(rsp)
}
}
+
+#[repr(C, packed)]
+pub(crate) struct GetDigestsReq {
+ pub(crate) version: u8,
+ pub(crate) code: u8,
+ pub(crate) param1: u8,
+ pub(crate) param2: u8,
+}
+
+impl Default for GetDigestsReq {
+ fn default() -> Self {
+ GetDigestsReq {
+ version: 0,
+ code: SPDM_GET_DIGESTS,
+ param1: 0,
+ param2: 0,
+ }
+ }
+}
+
+#[repr(C, packed)]
+pub(crate) struct GetDigestsRsp {
+ pub(crate) version: u8,
+ pub(crate) code: u8,
+ pub(crate) param1: u8,
+ pub(crate) param2: u8,
+
+ pub(crate) digests: __IncompleteArrayField<u8>,
+ // KeyPairIDs, added in 1.3
+
+ // CertificatInfo, added in 1.3
+
+ // KeyUsageMask, added in 1.3
+}
+
+impl Validate<&mut Unvalidated<KVec<u8>>> for &mut GetDigestsRsp {
+ type Err = Error;
+
+ fn validate(unvalidated: &mut Unvalidated<KVec<u8>>) -> Result<Self, Self::Err> {
+ let raw = unvalidated.raw_mut();
+ if raw.len() < mem::size_of::<GetDigestsRsp>() {
+ return Err(EINVAL);
+ }
+
+ let ptr = raw.as_mut_ptr();
+ // CAST: `GetDigestsRsp` only contains integers and has `repr(C)`.
+ let ptr = ptr.cast::<GetDigestsRsp>();
+ // SAFETY: `ptr` came from a reference and the cast above is valid.
+ let rsp: &mut GetDigestsRsp = unsafe { &mut *ptr };
+
+ Ok(rsp)
+ }
+}
--
2.52.0
next prev parent reply other threads:[~2026-05-08 3:19 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-08 3:16 [PATCH 00/18] lib: Rust implementation of SPDM alistair23
2026-05-08 3:16 ` [PATCH 01/18] rust: add untrusted data abstraction alistair23
2026-05-08 3:52 ` sashiko-bot
2026-05-08 5:17 ` Dirk Behme
2026-05-15 5:49 ` Alistair Francis
2026-05-08 3:16 ` [PATCH 02/18] X.509: Make certificate parser public alistair23
2026-05-08 3:45 ` sashiko-bot
2026-05-14 7:22 ` Lukas Wunner
2026-05-08 3:16 ` [PATCH 03/18] X.509: Parse Subject Alternative Name in certificates alistair23
2026-05-08 3:16 ` [PATCH 04/18] X.509: Move certificate length retrieval into new helper alistair23
2026-05-08 3:39 ` sashiko-bot
2026-05-14 6:59 ` Lukas Wunner
2026-05-08 3:16 ` [PATCH 05/18] rust: add bindings for hash.h alistair23
2026-05-08 3:43 ` sashiko-bot
2026-05-08 3:16 ` [PATCH 06/18] rust: error: impl From<FromBytesWithNulError> for Kernel Error alistair23
2026-05-08 3:51 ` sashiko-bot
2026-05-08 3:16 ` [PATCH 07/18] lib: rspdm: Initial commit of Rust SPDM alistair23
2026-05-08 3:41 ` sashiko-bot
2026-05-08 3:17 ` [PATCH 08/18] PCI/TSM: Support connecting to PCIe CMA devices alistair23
2026-05-20 5:56 ` Alistair Francis
2026-06-18 2:04 ` Alistair Francis
2026-06-18 22:51 ` Dan Williams (nvidia)
2026-05-08 3:17 ` [PATCH 09/18] PCI/CMA: Add a PCI TSM CMA driver using SPDM alistair23
2026-05-08 5:02 ` sashiko-bot
2026-05-08 3:17 ` [PATCH 10/18] PCI/CMA: Validate Subject Alternative Name in certificates alistair23
2026-05-08 3:58 ` sashiko-bot
2026-05-14 2:45 ` Alistair Francis
2026-05-14 13:14 ` Lukas Wunner
2026-05-08 3:17 ` [PATCH 11/18] lib: rspdm: Support SPDM get_version alistair23
2026-05-08 3:50 ` sashiko-bot
2026-05-08 3:17 ` [PATCH 12/18] lib: rspdm: Support SPDM get_capabilities alistair23
2026-05-08 4:05 ` sashiko-bot
2026-05-08 3:17 ` [PATCH 13/18] lib: rspdm: Support SPDM negotiate_algorithms alistair23
2026-05-08 4:05 ` sashiko-bot
2026-05-08 3:17 ` alistair23 [this message]
2026-05-08 4:06 ` [PATCH 14/18] lib: rspdm: Support SPDM get_digests sashiko-bot
2026-05-08 3:17 ` [PATCH 15/18] lib: rspdm: Support SPDM get_certificate alistair23
2026-05-08 4:23 ` sashiko-bot
2026-05-08 3:17 ` [PATCH 16/18] lib: rspdm: Support SPDM certificate validation alistair23
2026-05-08 4:25 ` sashiko-bot
2026-05-08 3:17 ` [PATCH 17/18] rust: allow extracting the buffer from a CString alistair23
2026-05-08 3:17 ` [PATCH 18/18] lib: rspdm: Support SPDM challenge alistair23
2026-05-08 4:19 ` sashiko-bot
2026-05-17 8:09 ` Dirk Behme
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