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Fri, 15 Nov 2024 00:46:40 -0500 (EST) From: Alistair Francis To: lukas@wunner.de, Jonathan.Cameron@huawei.com, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, akpm@linux-foundation.org, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-cxl@vger.kernel.org Cc: bjorn3_gh@protonmail.com, ojeda@kernel.org, tmgross@umich.edu, boqun.feng@gmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, wilfred.mallawa@wdc.com, alistair23@gmail.com, alex.gaynor@gmail.com, gary@garyguo.net, aliceryhl@google.com, Alistair Francis Subject: [RFC 3/6] lib: rspdm: Initial commit of Rust SPDM Date: Fri, 15 Nov 2024 15:46:13 +1000 Message-ID: <20241115054616.1226735-4-alistair@alistair23.me> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241115054616.1226735-1-alistair@alistair23.me> References: <20241115054616.1226735-1-alistair@alistair23.me> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This is the initial commit of the Rust SPDM library. It is based on and compatible with the C SPDM library in the kernel (lib/spdm). Signed-off-by: Alistair Francis --- MAINTAINERS | 6 ++ drivers/pci/Kconfig | 2 +- lib/Kconfig | 17 ++++ lib/Makefile | 1 + lib/rspdm/Makefile | 11 +++ lib/rspdm/consts.rs | 39 ++++++++ lib/rspdm/lib.rs | 134 +++++++++++++++++++++++++ lib/rspdm/req-sysfs.c | 174 +++++++++++++++++++++++++++++++++ lib/rspdm/state.rs | 217 +++++++++++++++++++++++++++++++++++++++++ lib/rspdm/sysfs.rs | 27 +++++ lib/rspdm/validator.rs | 65 ++++++++++++ 11 files changed, 692 insertions(+), 1 deletion(-) create mode 100644 lib/rspdm/Makefile create mode 100644 lib/rspdm/consts.rs create mode 100644 lib/rspdm/lib.rs create mode 100644 lib/rspdm/req-sysfs.c create mode 100644 lib/rspdm/state.rs create mode 100644 lib/rspdm/sysfs.rs create mode 100644 lib/rspdm/validator.rs diff --git a/MAINTAINERS b/MAINTAINERS index a30aca77b17b..2c2d4ddcfb1d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20785,6 +20785,12 @@ F: drivers/pci/cma* F: include/linux/spdm.h F: lib/spdm/ +RUST SECURITY PROTOCOL AND DATA MODEL (SPDM) +M: Alistair Francis +L: linux-pci@vger.kernel.org +S: Maintained +F: lib/rspdm/ + SECURITY SUBSYSTEM M: Paul Moore M: James Morris diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 690a2a38cb52..744d35d28dc7 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -128,7 +128,7 @@ config PCI_CMA select CRYPTO_SHA256 select CRYPTO_SHA512 select PCI_DOE - depends on SPDM + depends on SPDM || RSPDM help Authenticate devices on enumeration per PCIe r6.2 sec 6.31. A PCI DOE mailbox is used as transport for DMTF SPDM based diff --git a/lib/Kconfig b/lib/Kconfig index 4db9bc8e29f8..a47650a6757c 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -754,6 +754,23 @@ config SPDM in .config. Drivers selecting SPDM therefore need to also select any algorithms they deem mandatory. +config RSPDM + bool "Rust SPDM" + select CRYPTO + select KEYS + select ASYMMETRIC_KEY_TYPE + select ASYMMETRIC_PUBLIC_KEY_SUBTYPE + select X509_CERTIFICATE_PARSER + depends on SPDM = "n" + help + The Rust implementation of the Security Protocol and Data Model (SPDM) + allows for device authentication, measurement, key exchange and + encrypted sessions. + + Crypto algorithms negotiated with SPDM are limited to those enabled + in .config. Drivers selecting SPDM therefore need to also select + any algorithms they deem mandatory. + endmenu config GENERIC_IOREMAP diff --git a/lib/Makefile b/lib/Makefile index 5c6a48365993..4b55542c1aed 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -302,6 +302,7 @@ obj-$(CONFIG_ASN1) += asn1_decoder.o obj-$(CONFIG_ASN1_ENCODER) += asn1_encoder.o obj-$(CONFIG_SPDM) += spdm/ +obj-$(CONFIG_RSPDM) += rspdm/ obj-$(CONFIG_FONT_SUPPORT) += fonts/ diff --git a/lib/rspdm/Makefile b/lib/rspdm/Makefile new file mode 100644 index 000000000000..f15b1437196b --- /dev/null +++ b/lib/rspdm/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Rust implementation of the DMTF Security Protocol and Data Model (SPDM) +# https://www.dmtf.org/dsp/DSP0274 +# +# Copyright (C) 2024 Western Digital + +obj-$(CONFIG_RSPDM) += spdm.o + +spdm-y := lib.o +spdm-$(CONFIG_SYSFS) += req-sysfs.o diff --git a/lib/rspdm/consts.rs b/lib/rspdm/consts.rs new file mode 100644 index 000000000000..017e673ff194 --- /dev/null +++ b/lib/rspdm/consts.rs @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +//! Rust implementation of the DMTF Security Protocol and Data Model (SPDM) +//! https://www.dmtf.org/dsp/DSP0274 +//! +//! Constants used by the library +//! +//! Copyright (C) 2024 Western Digital + +pub(crate) const SPDM_REQ: u8 = 0x80; +pub(crate) const SPDM_ERROR: u8 = 0x7f; + +#[allow(dead_code)] +#[repr(u8)] +#[derive(Clone, Copy)] +pub(crate) enum SpdmErrorCode { + InvalidRequest = 0x01, + InvalidSession = 0x02, + Busy = 0x03, + UnexpectedRequest = 0x04, + Unspecified = 0x05, + DecryptError = 0x06, + UnsupportedRequest = 0x07, + RequestInFlight = 0x08, + InvalidResponseCode = 0x09, + SessionLimitExceeded = 0x0a, + SessionRequired = 0x0b, + ResetRequired = 0x0c, + ResponseTooLarge = 0x0d, + RequestTooLarge = 0x0e, + LargeResponse = 0x0f, + MessageLost = 0x10, + InvalidPolicy = 0x11, + VersionMismatch = 0x41, + ResponseNotReady = 0x42, + RequestResynch = 0x43, + OperationFailed = 0x44, + NoPendingRequests = 0x45, + VendorDefinedError = 0xff, +} diff --git a/lib/rspdm/lib.rs b/lib/rspdm/lib.rs new file mode 100644 index 000000000000..edfd94ab56dd --- /dev/null +++ b/lib/rspdm/lib.rs @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 +//! Rust implementation of the DMTF Security Protocol and Data Model (SPDM) +//! https://www.dmtf.org/dsp/DSP0274 +//! +//! Top level library, including C compatible public functions to be called +//! from other subsytems. +//! +//! This mimics the C SPDM implementation in the kernel +//! +//! Copyright (C) 2024 Western Digital + +use core::ffi::{c_int, c_void}; +use core::ptr; +use core::slice::from_raw_parts_mut; +use kernel::prelude::*; +use kernel::{alloc::flags, bindings}; + +use crate::state::SpdmState; + +const __LOG_PREFIX: &[u8] = b"spdm\0"; + +mod consts; +mod state; +pub mod sysfs; +mod validator; + +/// spdm_create() - Allocate SPDM session +/// +/// @dev: Responder device +/// @transport: Transport function to perform one message exchange +/// @transport_priv: Transport private data +/// @transport_sz: Maximum message size the transport is capable of (in bytes) +/// @keyring: Trusted root certificates +/// @validate: Function to validate additional leaf certificate requirements +/// (optional, may be %NULL) +/// +/// Return a pointer to the allocated SPDM session state or NULL on error. +#[no_mangle] +pub unsafe extern "C" fn spdm_create( + dev: *mut bindings::device, + transport: bindings::spdm_transport, + transport_priv: *mut c_void, + transport_sz: u32, + keyring: *mut bindings::key, + validate: bindings::spdm_validate, +) -> *mut SpdmState { + match KBox::new( + SpdmState::new( + dev, + transport, + transport_priv, + transport_sz, + keyring, + validate, + ), + flags::GFP_KERNEL, + ) { + Ok(ret) => KBox::into_raw(ret) as *mut SpdmState, + Err(_) => ptr::null_mut(), + } +} + +/// spdm_exchange() - Perform SPDM message exchange with device +/// +/// @spdm_state: SPDM session state +/// @req: Request message +/// @req_sz: Size of @req +/// @rsp: Response message +/// @rsp_sz: Size of @rsp +/// +/// Send the request @req to the device via the @transport in @spdm_state and +/// receive the response into @rsp, respecting the maximum buffer size @rsp_sz. +/// The request version is automatically populated. +/// +/// Return response size on success or a negative errno. Response size may be +/// less than @rsp_sz and the caller is responsible for checking that. It may +/// also be more than expected (though never more than @rsp_sz), e.g. if the +/// transport receives only dword-sized chunks. +#[no_mangle] +pub unsafe extern "C" fn spdm_exchange( + state: &'static mut SpdmState, + req: *mut c_void, + req_sz: usize, + rsp: *mut c_void, + rsp_sz: usize, +) -> isize { + let request_buf: &mut [u8] = unsafe { from_raw_parts_mut(req as *mut u8, req_sz) }; + let response_buf: &mut [u8] = unsafe { from_raw_parts_mut(rsp as *mut u8, rsp_sz) }; + + match state.spdm_exchange(request_buf, response_buf) { + Ok(ret) => ret as isize, + Err(e) => e.to_errno() as isize, + } +} + +/// spdm_authenticate() - Authenticate device +/// +/// @spdm_state: SPDM session state +/// +/// Authenticate a device through a sequence of GET_VERSION, GET_CAPABILITIES, +/// NEGOTIATE_ALGORITHMS, GET_DIGESTS, GET_CERTIFICATE and CHALLENGE exchanges. +/// +/// Perform internal locking to serialize multiple concurrent invocations. +/// Can be called repeatedly for reauthentication. +/// +/// Return 0 on success or a negative errno. In particular, -EPROTONOSUPPORT +/// indicates authentication is not supported by the device. +#[no_mangle] +pub unsafe extern "C" fn spdm_authenticate(_state: &'static mut SpdmState) -> c_int { + 0 +} + +/// spdm_publish_log() - Publish log of received SPDM signatures in sysfs +/// +/// @spdm_state: SPDM session state +/// +/// sysfs attributes representing received SPDM signatures are not static, +/// but created dynamically upon authentication or measurement. If a device +/// was authenticated or measured before it became visible in sysfs, the +/// attributes could not be created. This function retroactively creates +/// those attributes in sysfs after the device has become visible through +/// device_add(). +#[no_mangle] +pub unsafe extern "C" fn spdm_publish_log(_spdm_state: *mut SpdmState) { + todo!() +} + +/// spdm_destroy() - Destroy SPDM session +/// +/// @spdm_state: SPDM session state +#[no_mangle] +pub unsafe extern "C" fn spdm_destroy(_spdm_state: *mut SpdmState) { + todo!() +} diff --git a/lib/rspdm/req-sysfs.c b/lib/rspdm/req-sysfs.c new file mode 100644 index 000000000000..aff79eb0c4ee --- /dev/null +++ b/lib/rspdm/req-sysfs.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Rust implementation of the DMTF Security Protocol and Data Model (SPDM) + * https://www.dmtf.org/dsp/DSP0274 + * + * Requester role: sysfs interface + * + * Copyright (C) 2023-24 Intel Corporation + * Copyright (C) 2024 Western Digital + */ + +#include + +#define SPDM_NONCE_SZ 32 /* SPDM 1.0.0 table 20 */ + +int rust_authenticated_show(void *spdm_state, char *buf); + +/** + * dev_to_spdm_state() - Retrieve SPDM session state for given device + * + * @dev: Responder device + * + * Returns a pointer to the device's SPDM session state, + * %NULL if the device doesn't have one or + * %ERR_PTR if it couldn't be determined whether SPDM is supported. + * + * In the %ERR_PTR case, attributes are visible but return an error on access. + * This prevents downgrade attacks where an attacker disturbs memory allocation + * or communication with the device in order to create the appearance that SPDM + * is unsupported. E.g. with PCI devices, the attacker may foil CMA or DOE + * initialization by simply hogging memory. + */ +static void *dev_to_spdm_state(struct device *dev) +{ + if (dev_is_pci(dev)) + return pci_dev_to_spdm_state(to_pci_dev(dev)); + + /* Insert mappers for further bus types here. */ + + return NULL; +} + +/* authenticated attribute */ + +static umode_t spdm_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + void *spdm_state = dev_to_spdm_state(dev); + + if (IS_ERR_OR_NULL(spdm_state)) + return SYSFS_GROUP_INVISIBLE; + + return a->mode; +} + +static ssize_t authenticated_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + void *spdm_state = dev_to_spdm_state(dev); + int rc; + + if (IS_ERR_OR_NULL(spdm_state)) + return PTR_ERR(spdm_state); + + if (sysfs_streq(buf, "re")) { + rc = spdm_authenticate(spdm_state); + if (rc) + return rc; + } else { + return -EINVAL; + } + + return count; +} + +static ssize_t authenticated_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + void *spdm_state = dev_to_spdm_state(dev); + + if (IS_ERR_OR_NULL(spdm_state)) + return PTR_ERR(spdm_state); + + return rust_authenticated_show(spdm_state, buf); +} +static DEVICE_ATTR_RW(authenticated); + +static struct attribute *spdm_attrs[] = { + &dev_attr_authenticated.attr, + NULL +}; + +const struct attribute_group spdm_attr_group = { + .attrs = spdm_attrs, + .is_visible = spdm_attrs_are_visible, +}; + +/* certificates attributes */ + +static umode_t spdm_certificates_are_visible(struct kobject *kobj, + struct bin_attribute *a, int n) +{ + return SYSFS_GROUP_INVISIBLE; +} + +static ssize_t spdm_cert_read(struct file *file, struct kobject *kobj, + struct bin_attribute *a, char *buf, loff_t off, + size_t count) +{ + return 0; +} + +static BIN_ATTR(slot0, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot1, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot2, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot3, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot4, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot5, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot6, 0444, spdm_cert_read, NULL, 0xffff); +static BIN_ATTR(slot7, 0444, spdm_cert_read, NULL, 0xffff); + +static struct bin_attribute *spdm_certificates_bin_attrs[] = { + &bin_attr_slot0, + &bin_attr_slot1, + &bin_attr_slot2, + &bin_attr_slot3, + &bin_attr_slot4, + &bin_attr_slot5, + &bin_attr_slot6, + &bin_attr_slot7, + NULL +}; + +const struct attribute_group spdm_certificates_group = { + .name = "certificates", + .bin_attrs = spdm_certificates_bin_attrs, + .is_bin_visible = spdm_certificates_are_visible, +}; + +/* signatures attributes */ + +static umode_t spdm_signatures_are_visible(struct kobject *kobj, + struct bin_attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + void *spdm_state = dev_to_spdm_state(dev); + + if (IS_ERR_OR_NULL(spdm_state)) + return SYSFS_GROUP_INVISIBLE; + + return a->attr.mode; +} + +static ssize_t next_requester_nonce_write(struct file *file, + struct kobject *kobj, + struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + return 0; +} +static BIN_ATTR_WO(next_requester_nonce, SPDM_NONCE_SZ); + +static struct bin_attribute *spdm_signatures_bin_attrs[] = { + &bin_attr_next_requester_nonce, + NULL +}; + +const struct attribute_group spdm_signatures_group = { + .name = "signatures", + .bin_attrs = spdm_signatures_bin_attrs, + .is_bin_visible = spdm_signatures_are_visible, +}; diff --git a/lib/rspdm/state.rs b/lib/rspdm/state.rs new file mode 100644 index 000000000000..5b55c4655e2e --- /dev/null +++ b/lib/rspdm/state.rs @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0 +//! Rust implementation of the DMTF Security Protocol and Data Model (SPDM) +//! https://www.dmtf.org/dsp/DSP0274 +//! +//! The `SpdmState` struct and implementation. +//! +//! Copyright (C) 2024 Western Digital + +use core::ffi::c_void; +use kernel::prelude::*; +use kernel::{ + bindings, + error::{code::EINVAL, to_result, Error}, + validate::Untrusted, +}; + +use crate::consts::{SpdmErrorCode, SPDM_ERROR, SPDM_REQ}; +use crate::validator::{SpdmErrorRsp, SpdmHeader}; + +/// The current SPDM session state for a device. Based on the +/// C `struct spdm_state`. +/// +/// @dev: Responder device. Used for error reporting and passed to @transport. +/// @transport: Transport function to perform one message exchange. +/// @transport_priv: Transport private data. +/// @transport_sz: Maximum message size the transport is capable of (in bytes). +/// Used as DataTransferSize in GET_CAPABILITIES exchange. +/// @keyring: Keyring against which to check the first certificate in +/// responder's certificate chain. +/// @validate: Function to validate additional leaf certificate requirements. +/// +/// @version: Maximum common supported version of requester and responder. +/// Negotiated during GET_VERSION exchange. +/// +/// @authenticated: Whether device was authenticated successfully. +#[allow(dead_code)] +pub struct SpdmState { + pub(crate) dev: *mut bindings::device, + pub(crate) transport: bindings::spdm_transport, + pub(crate) transport_priv: *mut c_void, + pub(crate) transport_sz: u32, + pub(crate) keyring: *mut bindings::key, + pub(crate) validate: bindings::spdm_validate, + + /* Negotiated state */ + pub(crate) version: u8, + + pub(crate) authenticated: bool, +} + +impl SpdmState { + pub(crate) fn new( + dev: *mut bindings::device, + transport: bindings::spdm_transport, + transport_priv: *mut c_void, + transport_sz: u32, + keyring: *mut bindings::key, + validate: bindings::spdm_validate, + ) -> Self { + SpdmState { + dev, + transport, + transport_priv, + transport_sz, + keyring, + validate, + version: 0x10, + authenticated: false, + } + } + + fn spdm_err(&self, rsp: &SpdmErrorRsp) -> Result<(), Error> { + let ret = match rsp.error_code { + SpdmErrorCode::InvalidRequest => { + pr_err!("Invalid request\n"); + bindings::EINVAL + } + SpdmErrorCode::InvalidSession => { + if rsp.version == 0x11 { + pr_err!("Invalid session {:#x}\n", rsp.error_data); + bindings::EINVAL + } else { + pr_err!("Undefined error {:#x}\n", rsp.error_code as u8); + bindings::EINVAL + } + } + SpdmErrorCode::Busy => { + pr_err!("Busy\n"); + bindings::EBUSY + } + SpdmErrorCode::UnexpectedRequest => { + pr_err!("Unexpected request\n"); + bindings::EINVAL + } + SpdmErrorCode::Unspecified => { + pr_err!("Unspecified error\n"); + bindings::EINVAL + } + SpdmErrorCode::DecryptError => { + pr_err!("Decrypt error\n"); + bindings::EIO + } + SpdmErrorCode::UnsupportedRequest => { + pr_err!("Unsupported request {:#x}\n", rsp.error_data); + bindings::EINVAL + } + SpdmErrorCode::RequestInFlight => { + pr_err!("Request in flight\n"); + bindings::EINVAL + } + SpdmErrorCode::InvalidResponseCode => { + pr_err!("Invalid response code\n"); + bindings::EINVAL + } + SpdmErrorCode::SessionLimitExceeded => { + pr_err!("Session limit exceeded\n"); + bindings::EBUSY + } + SpdmErrorCode::SessionRequired => { + pr_err!("Session required\n"); + bindings::EINVAL + } + SpdmErrorCode::ResetRequired => { + pr_err!("Reset required\n"); + bindings::ECONNRESET + } + SpdmErrorCode::ResponseTooLarge => { + pr_err!("Response too large\n"); + bindings::EINVAL + } + SpdmErrorCode::RequestTooLarge => { + pr_err!("Request too large\n"); + bindings::EINVAL + } + SpdmErrorCode::LargeResponse => { + pr_err!("Large response\n"); + bindings::EMSGSIZE + } + SpdmErrorCode::MessageLost => { + pr_err!("Message lost\n"); + bindings::EIO + } + SpdmErrorCode::InvalidPolicy => { + pr_err!("Invalid policy\n"); + bindings::EINVAL + } + SpdmErrorCode::VersionMismatch => { + pr_err!("Version mismatch\n"); + bindings::EINVAL + } + SpdmErrorCode::ResponseNotReady => { + pr_err!("Response not ready\n"); + bindings::EINPROGRESS + } + SpdmErrorCode::RequestResynch => { + pr_err!("Request resynchronization\n"); + bindings::ECONNRESET + } + SpdmErrorCode::OperationFailed => { + pr_err!("Operation failed\n"); + bindings::EINVAL + } + SpdmErrorCode::NoPendingRequests => bindings::ENOENT, + SpdmErrorCode::VendorDefinedError => { + pr_err!("Vendor defined error\n"); + bindings::EINVAL + } + }; + + to_result(-(ret as i32)) + } + + /// Start a SPDM exchange + /// + /// The data in `request_buf` is sent to the device and the response is + /// stored in `response_buf`. + pub(crate) fn spdm_exchange( + &self, + request_buf: &mut [u8], + response_buf: &mut [u8], + ) -> Result { + let header_size = core::mem::size_of::(); + let request: &mut SpdmHeader = Untrusted::new_mut(request_buf).validate_mut()?; + let response: &SpdmHeader = Untrusted::new_ref(response_buf).validate()?; + + let transport_function = self.transport.ok_or(EINVAL)?; + let length = unsafe { + transport_function( + self.transport_priv, + self.dev, + request_buf.as_ptr() as *const c_void, + request_buf.len(), + response_buf.as_mut_ptr() as *mut c_void, + response_buf.len(), + ) as i32 + }; + to_result(length)?; + + if (length as usize) < header_size { + return Ok(length); /* Truncated response is handled by callers */ + } + if response.code == SPDM_ERROR { + self.spdm_err(unsafe { &*(response_buf.as_ptr() as *const SpdmErrorRsp) })?; + } + + if response.code != request.code & !SPDM_REQ { + pr_err!( + "Response code {:#x} does not match request code {:#x}\n", + response.code, + request.code + ); + to_result(-(bindings::EPROTO as i32))?; + } + + Ok(length) + } +} diff --git a/lib/rspdm/sysfs.rs b/lib/rspdm/sysfs.rs new file mode 100644 index 000000000000..5deffdbf2b0c --- /dev/null +++ b/lib/rspdm/sysfs.rs @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 +//! Rust implementation of the DMTF Security Protocol and Data Model (SPDM) +//! https://www.dmtf.org/dsp/DSP0274 +//! +//! Rust sysfs helper functions +//! +//! Copyright (C) 2024 Western Digital + +use crate::SpdmState; +use kernel::prelude::*; +use kernel::{bindings, fmt, str::CString}; + +/// Helper function for the sysfs `authenticated_show()`. +#[no_mangle] +pub unsafe extern "C" fn rust_authenticated_show( + spdm_state: *mut SpdmState, + buf: *mut core::ffi::c_char, +) -> isize { + let state = unsafe { KBox::from_raw(spdm_state) }; + + let fmt = match CString::try_from_fmt(fmt!("{}\n", state.authenticated)) { + Ok(f) => f, + Err(_e) => return 0, + }; + + unsafe { bindings::sysfs_emit(buf, fmt.as_char_ptr()) as isize } +} diff --git a/lib/rspdm/validator.rs b/lib/rspdm/validator.rs new file mode 100644 index 000000000000..5004804f85c8 --- /dev/null +++ b/lib/rspdm/validator.rs @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0 +//! Rust implementation of the DMTF Security Protocol and Data Model (SPDM) +//! https://www.dmtf.org/dsp/DSP0274 +//! +//! Related structs and their Validate implementations. +//! +//! Copyright (C) 2024 Western Digital + +use crate::consts::SpdmErrorCode; +use core::mem; +use kernel::prelude::*; +use kernel::{ + error::{code::EINVAL, Error}, + validate::{Unvalidated, Validate}, +}; + +#[repr(C, packed)] +pub(crate) struct SpdmHeader { + pub(crate) version: u8, + pub(crate) code: u8, /* RequestResponseCode */ + pub(crate) param1: u8, + pub(crate) param2: u8, +} + +impl Validate<&Unvalidated<[u8]>> for &SpdmHeader { + type Err = Error; + + fn validate(unvalidated: &Unvalidated<[u8]>) -> Result { + let raw = unvalidated.raw(); + if raw.len() < mem::size_of::() { + return Err(EINVAL); + } + + let ptr = raw.as_ptr(); + // CAST: `SpdmHeader` only contains integers and has `repr(C)`. + let ptr = ptr.cast::(); + // SAFETY: `ptr` came from a reference and the cast above is valid. + Ok(unsafe { &*ptr }) + } +} + +impl Validate<&mut Unvalidated<[u8]>> for &mut SpdmHeader { + type Err = Error; + + fn validate(unvalidated: &mut Unvalidated<[u8]>) -> Result { + let raw = unvalidated.raw_mut(); + if raw.len() < mem::size_of::() { + return Err(EINVAL); + } + + let ptr = raw.as_mut_ptr(); + // CAST: `SpdmHeader` only contains integers and has `repr(C)`. + let ptr = ptr.cast::(); + // SAFETY: `ptr` came from a reference and the cast above is valid. + Ok(unsafe { &mut *ptr }) + } +} + +#[repr(C, packed)] +pub(crate) struct SpdmErrorRsp { + pub(crate) version: u8, + pub(crate) code: u8, + pub(crate) error_code: SpdmErrorCode, + pub(crate) error_data: u8, +}