Support the NEGOTIATE_ALGORITHMS SPDM command. Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx> --- lib/rspdm/consts.rs | 53 ++++++++ lib/rspdm/lib.rs | 16 ++- lib/rspdm/state.rs | 213 +++++++++++++++++++++++++++++++- lib/rspdm/validator.rs | 115 ++++++++++++++++- rust/bindgen_static_functions | 5 + rust/bindings/bindings_helper.h | 2 + 6 files changed, 398 insertions(+), 6 deletions(-) diff --git a/lib/rspdm/consts.rs b/lib/rspdm/consts.rs index 8a58351bf268..d2f245c858cc 100644 --- a/lib/rspdm/consts.rs +++ b/lib/rspdm/consts.rs @@ -65,6 +65,59 @@ pub(crate) enum SpdmErrorCode { pub(crate) const SPDM_CERT_CAP: u32 = 1 << 1; pub(crate) const SPDM_CHAL_CAP: u32 = 1 << 2; +pub(crate) const SPDM_MEAS_CAP_MASK: u32 = 3 << 3; +pub(crate) const SPDM_KEY_EX_CAP: u32 = 1 << 9; pub(crate) const SPDM_REQ_CAPS: u32 = SPDM_CERT_CAP | SPDM_CHAL_CAP; pub(crate) const SPDM_RSP_MIN_CAPS: u32 = SPDM_CERT_CAP | SPDM_CHAL_CAP; + +pub(crate) const SPDM_NEGOTIATE_ALGS: u8 = 0xe3; + +pub(crate) const SPDM_MEAS_SPEC_DMTF: u8 = 1 << 0; + +pub(crate) const SPDM_ASYM_RSASSA_2048: u32 = 1 << 0; +pub(crate) const _SPDM_ASYM_RSAPSS_2048: u32 = 1 << 1; +pub(crate) const SPDM_ASYM_RSASSA_3072: u32 = 1 << 2; +pub(crate) const _SPDM_ASYM_RSAPSS_3072: u32 = 1 << 3; +pub(crate) const SPDM_ASYM_ECDSA_ECC_NIST_P256: u32 = 1 << 4; +pub(crate) const SPDM_ASYM_RSASSA_4096: u32 = 1 << 5; +pub(crate) const _SPDM_ASYM_RSAPSS_4096: u32 = 1 << 6; +pub(crate) const SPDM_ASYM_ECDSA_ECC_NIST_P384: u32 = 1 << 7; +pub(crate) const SPDM_ASYM_ECDSA_ECC_NIST_P521: u32 = 1 << 8; +pub(crate) const _SPDM_ASYM_SM2_ECC_SM2_P256: u32 = 1 << 9; +pub(crate) const _SPDM_ASYM_EDDSA_ED25519: u32 = 1 << 10; +pub(crate) const _SPDM_ASYM_EDDSA_ED448: u32 = 1 << 11; + +pub(crate) const SPDM_HASH_SHA_256: u32 = 1 << 0; +pub(crate) const SPDM_HASH_SHA_384: u32 = 1 << 1; +pub(crate) const SPDM_HASH_SHA_512: u32 = 1 << 2; + +#[cfg(CONFIG_CRYPTO_RSA)] +pub(crate) const SPDM_ASYM_RSA: u32 = + SPDM_ASYM_RSASSA_2048 | SPDM_ASYM_RSASSA_3072 | SPDM_ASYM_RSASSA_4096; +#[cfg(not(CONFIG_CRYPTO_RSA))] +pub(crate) const SPDM_ASYM_RSA: u32 = 0; + +#[cfg(CONFIG_CRYPTO_ECDSA)] +pub(crate) const SPDM_ASYM_ECDSA: u32 = + SPDM_ASYM_ECDSA_ECC_NIST_P256 | SPDM_ASYM_ECDSA_ECC_NIST_P384 | SPDM_ASYM_ECDSA_ECC_NIST_P521; +#[cfg(not(CONFIG_CRYPTO_ECDSA))] +pub(crate) const SPDM_ASYM_ECDSA: u32 = 0; + +#[cfg(CONFIG_CRYPTO_SHA256)] +pub(crate) const SPDM_HASH_SHA2_256: u32 = SPDM_HASH_SHA_256; +#[cfg(not(CONFIG_CRYPTO_SHA256))] +pub(crate) const SPDM_HASH_SHA2_256: u32 = 0; + +#[cfg(CONFIG_CRYPTO_SHA512)] +pub(crate) const SPDM_HASH_SHA2_384_512: u32 = SPDM_HASH_SHA_384 | SPDM_HASH_SHA_512; +#[cfg(not(CONFIG_CRYPTO_SHA512))] +pub(crate) const SPDM_HASH_SHA2_384_512: u32 = 0; + +pub(crate) const SPDM_ASYM_ALGOS: u32 = SPDM_ASYM_RSA | SPDM_ASYM_ECDSA; +pub(crate) const SPDM_HASH_ALGOS: u32 = SPDM_HASH_SHA2_256 | SPDM_HASH_SHA2_384_512; + +/* Maximum number of ReqAlgStructs sent by this implementation */ +// pub(crate) const SPDM_MAX_REQ_ALG_STRUCT: usize = 4; + +pub(crate) const SPDM_OPAQUE_DATA_FMT_GENERAL: u8 = 1 << 1; diff --git a/lib/rspdm/lib.rs b/lib/rspdm/lib.rs index fe36333b2d24..5eee5116d791 100644 --- a/lib/rspdm/lib.rs +++ b/lib/rspdm/lib.rs @@ -118,6 +118,10 @@ return e.to_errno() as c_int; } + if let Err(e) = state.negotiate_algs() { + return e.to_errno() as c_int; + } + 0 } @@ -125,4 +129,14 @@ /// /// @spdm_state: SPDM session state #[no_mangle] -pub unsafe extern "C" fn spdm_destroy(_state: &'static mut SpdmState) {} +pub unsafe extern "C" fn spdm_destroy(state: &'static mut SpdmState) { + if let Some(desc) = &mut state.desc { + unsafe { + bindings::kfree(*desc as *mut _ as *mut c_void); + } + } + + unsafe { + bindings::crypto_free_shash(state.shash); + } +} diff --git a/lib/rspdm/state.rs b/lib/rspdm/state.rs index 288a77b3ab56..0aff45339e0b 100644 --- a/lib/rspdm/state.rs +++ b/lib/rspdm/state.rs @@ -13,15 +13,21 @@ use kernel::{ bindings, error::{code::EINVAL, to_result, Error}, + str::CStr, validate::Untrusted, }; use crate::consts::{ - SpdmErrorCode, SPDM_ERROR, SPDM_GET_VERSION_LEN, SPDM_MAX_VER, SPDM_MIN_DATA_TRANSFER_SIZE, - SPDM_MIN_VER, SPDM_REQ, SPDM_RSP_MIN_CAPS, SPDM_VER_10, SPDM_VER_11, SPDM_VER_12, + SpdmErrorCode, SPDM_ASYM_ALGOS, SPDM_ASYM_ECDSA_ECC_NIST_P256, SPDM_ASYM_ECDSA_ECC_NIST_P384, + SPDM_ASYM_ECDSA_ECC_NIST_P521, SPDM_ASYM_RSASSA_2048, SPDM_ASYM_RSASSA_3072, + SPDM_ASYM_RSASSA_4096, SPDM_ERROR, SPDM_GET_VERSION_LEN, SPDM_HASH_ALGOS, SPDM_HASH_SHA_256, + SPDM_HASH_SHA_384, SPDM_HASH_SHA_512, SPDM_KEY_EX_CAP, SPDM_MAX_VER, SPDM_MEAS_CAP_MASK, + SPDM_MEAS_SPEC_DMTF, SPDM_MIN_DATA_TRANSFER_SIZE, SPDM_MIN_VER, SPDM_OPAQUE_DATA_FMT_GENERAL, + SPDM_REQ, SPDM_RSP_MIN_CAPS, SPDM_VER_10, SPDM_VER_11, SPDM_VER_12, }; use crate::validator::{ - GetCapabilitiesReq, GetCapabilitiesRsp, GetVersionReq, GetVersionRsp, SpdmErrorRsp, SpdmHeader, + GetCapabilitiesReq, GetCapabilitiesRsp, GetVersionReq, GetVersionRsp, NegotiateAlgsReq, + NegotiateAlgsRsp, RegAlg, SpdmErrorRsp, SpdmHeader, }; /// The current SPDM session state for a device. Based on the @@ -40,6 +46,28 @@ /// Negotiated during GET_VERSION exchange. /// @rsp_caps: Cached capabilities of responder. /// Received during GET_CAPABILITIES exchange. +/// @base_asym_alg: Asymmetric key algorithm for signature verification of +/// CHALLENGE_AUTH and MEASUREMENTS messages. +/// Selected by responder during NEGOTIATE_ALGORITHMS exchange. +/// @base_hash_alg: Hash algorithm for signature verification of +/// CHALLENGE_AUTH and MEASUREMENTS messages. +/// Selected by responder during NEGOTIATE_ALGORITHMS exchange. +/// @meas_hash_alg: Hash algorithm for measurement blocks. +/// Selected by responder during NEGOTIATE_ALGORITHMS 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). +/// S or SigLen in SPDM specification. +/// @base_hash_alg_name: Human-readable name of @base_hash_alg. +/// Passed to crypto subsystem when calling crypto_alloc_shash() and +/// verify_signature(). +/// @base_hash_alg_name: Human-readable name of @base_hash_alg. +/// Passed to crypto subsystem when calling crypto_alloc_shash() and +/// verify_signature(). +/// @shash: Synchronous hash handle for @base_hash_alg computation. +/// @desc: Synchronous hash context for @base_hash_alg computation. +/// @hash_len: Hash length of @base_hash_alg (in bytes). +/// H in SPDM specification. /// /// `authenticated`: Whether device was authenticated successfully. #[expect(dead_code)] @@ -54,6 +82,19 @@ pub struct SpdmState { // Negotiated state pub(crate) version: u8, pub(crate) rsp_caps: u32, + pub(crate) base_asym_alg: u32, + pub(crate) base_hash_alg: u32, + pub(crate) meas_hash_alg: u32, + + /* Signature algorithm */ + base_asym_enc: &'static CStr, + sig_len: usize, + + /* Hash algorithm */ + base_hash_alg_name: &'static CStr, + pub(crate) shash: *mut bindings::crypto_shash, + pub(crate) desc: Option<&'static mut bindings::shash_desc>, + pub(crate) hash_len: usize, pub(crate) authenticated: bool, } @@ -76,6 +117,15 @@ pub(crate) fn new( validate, version: SPDM_MIN_VER, rsp_caps: 0, + base_asym_alg: 0, + base_hash_alg: 0, + meas_hash_alg: 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, authenticated: false, } } @@ -336,4 +386,161 @@ pub(crate) fn get_capabilities(&mut self) -> Result<(), Error> { Ok(()) } + + fn update_response_algs(&mut self) -> Result<(), Error> { + match self.base_asym_alg { + SPDM_ASYM_RSASSA_2048 => { + self.sig_len = 256; + self.base_asym_enc = CStr::from_bytes_with_nul(b"pkcs1\0")?; + } + SPDM_ASYM_RSASSA_3072 => { + self.sig_len = 384; + self.base_asym_enc = CStr::from_bytes_with_nul(b"pkcs1\0")?; + } + SPDM_ASYM_RSASSA_4096 => { + self.sig_len = 512; + self.base_asym_enc = CStr::from_bytes_with_nul(b"pkcs1\0")?; + } + SPDM_ASYM_ECDSA_ECC_NIST_P256 => { + self.sig_len = 64; + self.base_asym_enc = CStr::from_bytes_with_nul(b"p1363\0")?; + } + SPDM_ASYM_ECDSA_ECC_NIST_P384 => { + self.sig_len = 96; + self.base_asym_enc = CStr::from_bytes_with_nul(b"p1363\0")?; + } + SPDM_ASYM_ECDSA_ECC_NIST_P521 => { + self.sig_len = 132; + self.base_asym_enc = CStr::from_bytes_with_nul(b"p1363\0")?; + } + _ => { + pr_err!("Unknown asym algorithm\n"); + return Err(EINVAL); + } + } + + match self.base_hash_alg { + SPDM_HASH_SHA_256 => { + self.base_hash_alg_name = CStr::from_bytes_with_nul(b"sha256\0")?; + } + SPDM_HASH_SHA_384 => { + self.base_hash_alg_name = CStr::from_bytes_with_nul(b"sha384\0")?; + } + SPDM_HASH_SHA_512 => { + self.base_hash_alg_name = CStr::from_bytes_with_nul(b"sha512\0")?; + } + _ => { + pr_err!("Unknown hash algorithm\n"); + return Err(EINVAL); + } + } + + /* + * shash and desc allocations are reused for subsequent measurement + * retrieval, hence are not freed until spdm_reset(). + */ + self.shash = + unsafe { bindings::crypto_alloc_shash(self.base_hash_alg_name.as_char_ptr(), 0, 0) }; + if self.shash.is_null() { + return Err(ENOMEM); + } + + let desc_len = core::mem::size_of::<bindings::shash_desc>() + + unsafe { bindings::crypto_shash_descsize(self.shash) } as usize; + + let mut desc_vec: KVec<u8> = KVec::with_capacity(desc_len, GFP_KERNEL)?; + // SAFETY: `desc_vec` is `desc_len` long + let desc_buf = unsafe { from_raw_parts_mut(desc_vec.as_mut_ptr(), desc_len) }; + + let desc = unsafe { + core::mem::transmute::<*mut c_void, &mut bindings::shash_desc>( + desc_buf.as_mut_ptr() as *mut c_void + ) + }; + desc.tfm = self.shash; + + self.desc = Some(desc); + + /* Used frequently to compute offsets, so cache H */ + self.hash_len = unsafe { bindings::crypto_shash_digestsize(self.shash) as usize }; + + if let Some(desc) = &mut self.desc { + unsafe { to_result(bindings::crypto_shash_init(*desc)) } + } else { + Err(ENOMEM) + } + } + + pub(crate) fn negotiate_algs(&mut self) -> Result<(), Error> { + let mut request = NegotiateAlgsReq::default(); + request.version = self.version; + + if self.version >= SPDM_VER_12 && (self.rsp_caps & SPDM_KEY_EX_CAP) == SPDM_KEY_EX_CAP { + request.other_params_support = SPDM_OPAQUE_DATA_FMT_GENERAL; + } + + // TODO support more algs + let reg_alg_entries = 0; + + let req_sz = core::mem::size_of::<NegotiateAlgsReq>() + + core::mem::size_of::<RegAlg>() * reg_alg_entries; + let rsp_sz = core::mem::size_of::<NegotiateAlgsRsp>() + + core::mem::size_of::<RegAlg>() * reg_alg_entries; + + request.length = req_sz as u16; + request.param1 = reg_alg_entries as u8; + + // 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: `request` is repr(C) and packed, so we can convert it to a slice + let response_buf = unsafe { from_raw_parts_mut(response_vec.as_mut_ptr(), rsp_sz) }; + + let rc = self.spdm_exchange(request_buf, response_buf)?; + + if rc < (rsp_sz as i32) { + pr_err!("Truncated capabilities response\n"); + to_result(-(bindings::EIO as i32))?; + } + + // SAFETY: `rc` bytes where inserted to the raw pointer by spdm_exchange + unsafe { response_vec.set_len(rc as usize) }; + + let response: &mut NegotiateAlgsRsp = + Untrusted::new_mut(&mut response_vec).validate_mut()?; + + self.base_asym_alg = response.base_asym_sel; + self.base_hash_alg = response.base_hash_sel; + self.meas_hash_alg = response.measurement_hash_algo; + + if self.base_asym_alg & SPDM_ASYM_ALGOS == 0 || self.base_hash_alg & SPDM_HASH_ALGOS == 0 { + pr_err!("No common supported algorithms\n"); + to_result(-(bindings::EPROTO as i32))?; + } + + // /* Responder shall select exactly 1 alg (SPDM 1.0.0 table 14) */ + if self.base_asym_alg.count_ones() != 1 + || self.base_hash_alg.count_ones() != 1 + || response.ext_asym_sel_count != 0 + || response.ext_hash_sel_count != 0 + || response.param1 > request.param1 + || response.other_params_sel != request.other_params_support + { + pr_err!("Malformed algorithms response\n"); + to_result(-(bindings::EPROTO as i32))?; + } + + if self.rsp_caps & SPDM_MEAS_CAP_MASK == SPDM_MEAS_CAP_MASK + && (self.meas_hash_alg.count_ones() != 1 + || response.measurement_specification_sel != SPDM_MEAS_SPEC_DMTF) + { + pr_err!("Malformed algorithms response\n"); + to_result(-(bindings::EPROTO as i32))?; + } + + self.update_response_algs()?; + + Ok(()) + } } diff --git a/lib/rspdm/validator.rs b/lib/rspdm/validator.rs index cd792c46767a..036a077c71c3 100644 --- a/lib/rspdm/validator.rs +++ b/lib/rspdm/validator.rs @@ -7,7 +7,7 @@ //! Rust implementation of the DMTF Security Protocol and Data Model (SPDM) //! <https://www.dmtf.org/dsp/DSP0274> -use crate::bindings::{__IncompleteArrayField, __le16}; +use crate::bindings::{__IncompleteArrayField, __le16, __le32}; use crate::consts::SpdmErrorCode; use core::mem; use kernel::prelude::*; @@ -16,7 +16,10 @@ validate::{Unvalidated, Validate}, }; -use crate::consts::{SPDM_CTEXPONENT, SPDM_GET_CAPABILITIES, SPDM_GET_VERSION, SPDM_REQ_CAPS}; +use crate::consts::{ + SPDM_ASYM_ALGOS, SPDM_CTEXPONENT, SPDM_GET_CAPABILITIES, SPDM_GET_VERSION, SPDM_HASH_ALGOS, + SPDM_MEAS_SPEC_DMTF, SPDM_NEGOTIATE_ALGS, SPDM_REQ_CAPS, +}; #[repr(C, packed)] pub(crate) struct SpdmHeader { @@ -205,3 +208,111 @@ fn validate(unvalidated: &mut Unvalidated<KVec<u8>>) -> Result<Self, Self::Err> Ok(rsp) } } + +#[repr(C, packed)] +pub(crate) struct RegAlg { + pub(crate) alg_type: u8, + pub(crate) alg_count: u8, + pub(crate) alg_supported: u16, + pub(crate) alg_external: __IncompleteArrayField<__le32>, +} + +#[repr(C, packed)] +pub(crate) struct NegotiateAlgsReq { + pub(crate) version: u8, + pub(crate) code: u8, + pub(crate) param1: u8, + pub(crate) param2: u8, + + pub(crate) length: u16, + pub(crate) measurement_specification: u8, + pub(crate) other_params_support: u8, + + pub(crate) base_asym_algo: u32, + pub(crate) base_hash_algo: u32, + + reserved1: [u8; 12], + + pub(crate) ext_asym_count: u8, + pub(crate) ext_hash_count: u8, + reserved2: u8, + pub(crate) mel_specification: u8, + + pub(crate) ext_asym: __IncompleteArrayField<__le32>, + pub(crate) ext_hash: __IncompleteArrayField<__le32>, + pub(crate) req_alg_struct: __IncompleteArrayField<RegAlg>, +} + +impl Default for NegotiateAlgsReq { + fn default() -> Self { + NegotiateAlgsReq { + version: 0, + code: SPDM_NEGOTIATE_ALGS, + param1: 0, + param2: 0, + length: 0, + measurement_specification: SPDM_MEAS_SPEC_DMTF, + other_params_support: 0, + base_asym_algo: SPDM_ASYM_ALGOS.to_le(), + base_hash_algo: SPDM_HASH_ALGOS.to_le(), + reserved1: [0u8; 12], + ext_asym_count: 0, + ext_hash_count: 0, + reserved2: 0, + mel_specification: 0, + ext_asym: __IncompleteArrayField::new(), + ext_hash: __IncompleteArrayField::new(), + req_alg_struct: __IncompleteArrayField::new(), + } + } +} + +#[repr(C, packed)] +pub(crate) struct NegotiateAlgsRsp { + pub(crate) version: u8, + pub(crate) code: u8, + pub(crate) param1: u8, + pub(crate) param2: u8, + + pub(crate) length: u16, + pub(crate) measurement_specification_sel: u8, + pub(crate) other_params_sel: u8, + + pub(crate) measurement_hash_algo: u32, + pub(crate) base_asym_sel: u32, + pub(crate) base_hash_sel: u32, + + reserved1: [u8; 11], + + pub(crate) mel_specification_sel: u8, + pub(crate) ext_asym_sel_count: u8, + pub(crate) ext_hash_sel_count: u8, + reserved2: [u8; 2], + + pub(crate) ext_asym: __IncompleteArrayField<__le32>, + pub(crate) ext_hash: __IncompleteArrayField<__le32>, + pub(crate) req_alg_struct: __IncompleteArrayField<RegAlg>, +} + +impl Validate<&mut Unvalidated<KVec<u8>>> for &mut NegotiateAlgsRsp { + 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::<NegotiateAlgsRsp>() { + return Err(EINVAL); + } + + let ptr = raw.as_mut_ptr(); + // CAST: `NegotiateAlgsRsp` only contains integers and has `repr(C)`. + let ptr = ptr.cast::<NegotiateAlgsRsp>(); + // SAFETY: `ptr` came from a reference and the cast above is valid. + let rsp: &mut NegotiateAlgsRsp = unsafe { &mut *ptr }; + + rsp.base_asym_sel = rsp.base_asym_sel.to_le(); + rsp.base_hash_sel = rsp.base_hash_sel.to_le(); + rsp.measurement_hash_algo = rsp.measurement_hash_algo.to_le(); + + Ok(rsp) + } +} diff --git a/rust/bindgen_static_functions b/rust/bindgen_static_functions index ec48ad2e8c78..978276e17754 100644 --- a/rust/bindgen_static_functions +++ b/rust/bindgen_static_functions @@ -30,3 +30,8 @@ --allowlist-function copy_from_user --allowlist-function copy_to_user + +--allowlist-function crypto_shash_descsize +--allowlist-function crypto_shash_init +--allowlist-function crypto_shash_digestsize +--allowlist-function crypto_free_shash diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 42aa62f0c8f5..5ba1191429f8 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -6,6 +6,7 @@ * Sorted alphabetically. */ +#include <crypto/hash.h> #include <kunit/test.h> #include <linux/blk-mq.h> #include <linux/blk_types.h> @@ -17,6 +18,7 @@ #include <linux/file.h> #include <linux/firmware.h> #include <linux/fs.h> +#include <linux/hash.h> #include <linux/jiffies.h> #include <linux/jump_label.h> #include <linux/mdio.h> -- 2.48.1