AA/attester: add check_init_data support for TDX and SNP

In TDX, we use tdx_attest crate to get a raw hardware tdx report to
parse the MRCONFIGID field.

In SNP, we use sev crate to get a hardware report to parse HOSTDATA
field.

The input one should be resize as the evidence field inside the TEE
evidence to compare.

Signed-off-by: Magnus Kulke <[email protected]>
Signed-off-by: Dan Mihai <[email protected]>
Signed-off-by: Xynnn007 <[email protected]>

attestation-agent/attester/Cargo.toml

@@ -19,13 +19,15 @@ kbs-types.workspace = true
 log.workspace = true
 nix = { version = "0.26.2", optional = true }
 occlum_dcap = { git = "https://github.com/occlum/occlum", tag = "v0.29.7", optional = true }
+scroll = { version = "0.11.0", default-features = false, features = ["derive"], optional = true }
 serde.workspace = true
 serde_json.workspace = true
 sev = { version = "1.2.0", default-features = false, features = [
     "snp",
 ], optional = true }
 strum.workspace = true
 tdx-attest-rs = { git = "https://github.com/intel/SGXDataCenterAttestationPrimitives", tag = "DCAP_1.16", optional = true }
+thiserror.workspace = true
 # TODO: change it to "0.1", once released.
 csv-rs = { git = "https://github.com/openanolis/csv-rs", rev = "b74aa8c", optional = true }
 codicon = { version = "3.0", optional = true }
@@ -52,7 +54,7 @@ all-attesters = [
     "cca-attester",
 ]
 
-tdx-attester = ["tdx-attest-rs"]
+tdx-attester = ["scroll", "tdx-attest-rs"]
 sgx-attester = ["occlum_dcap"]
 az-snp-vtpm-attester = ["az-snp-vtpm"]
 az-tdx-vtpm-attester = ["az-tdx-vtpm"]

attestation-agent/attester/src/lib.rs

@@ -7,6 +7,7 @@ use anyhow::*;
 use kbs_types::Tee;
 
 pub mod sample;
+pub mod utils;
 
 #[cfg(feature = "az-snp-vtpm-attester")]
 pub mod az_snp_vtpm;

attestation-agent/attester/src/snp/hostdata.rs

@@ -0,0 +1,24 @@
+// Copyright (c) 2024 Microsoft Corporation
+// Copyright (c) 2024 Alibaba Cloud
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum GetHostDataError {
+    #[error("Open Sev guest firmware failed: {0}")]
+    OpenSevGuestFirmware(#[from] std::io::Error),
+
+    #[error("Get report failed: {0}")]
+    GetReportError(#[from] sev::error::UserApiError),
+}
+
+pub fn get_snp_host_data() -> Result<[u8; 32], GetHostDataError> {
+    let mut firmware = sev::firmware::guest::Firmware::open()?;
+    let report_data: [u8; 64] = [0; 64];
+    let report = firmware.get_report(None, Some(report_data), Some(0))?;
+
+    Ok(report.host_data)
+}

attestation-agent/attester/src/snp/mod.rs

@@ -3,6 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
+use crate::utils::pad;
+
 use super::Attester;
 use anyhow::*;
 use serde::{Deserialize, Serialize};
@@ -11,6 +13,8 @@ use sev::firmware::guest::Firmware;
 use sev::firmware::host::CertTableEntry;
 use std::path::Path;
 
+mod hostdata;
+
 pub fn detect_platform() -> bool {
     Path::new("/sys/devices/platform/sev-guest").exists()
 }
@@ -47,4 +51,14 @@ impl Attester for SnpAttester {
 
         serde_json::to_string(&evidence).context("Serialize SNP evidence failed")
     }
+
+    async fn check_init_data(&self, init_data: &[u8]) -> Result<()> {
+        let hostdata = hostdata::get_snp_host_data().context("Get HOSTDATA failed")?;
+        let init_data: [u8; 32] = pad(init_data);
+        if init_data != hostdata {
+            bail!("HOSTDATA does not match.");
+        }
+
+        Ok(())
+    }
 }

attestation-agent/attester/src/tdx/mod.rs

@@ -3,12 +3,18 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
+use crate::utils::pad;
+
 use super::Attester;
 use anyhow::*;
 use base64::Engine;
+use log::debug;
+use scroll::Pread;
 use serde::{Deserialize, Serialize};
 use std::path::Path;
-use tdx_attest_rs;
+use tdx_attest_rs::{self, tdx_report_t};
+
+mod report;
 
 const TDX_REPORT_DATA_SIZE: usize = 64;
 const CCEL_PATH: &str = "/sys/firmware/acpi/tables/data/CCEL";
@@ -90,6 +96,33 @@ impl Attester for TdxAttester {
 
         Ok(())
     }
+
+    async fn check_init_data(&self, init_data: &[u8]) -> Result<()> {
+        let mut report = tdx_report_t { d: [0; 1024] };
+        match tdx_attest_rs::tdx_att_get_report(None, &mut report) {
+            tdx_attest_rs::tdx_attest_error_t::TDX_ATTEST_SUCCESS => {
+                debug!("Successfully get report")
+            }
+            error_code => {
+                bail!(
+                    "TDX Attester: Failed to get TD report. Error code: {:?}",
+                    error_code
+                );
+            }
+        };
+
+        let td_report = report
+            .d
+            .pread::<report::TdReport>(0)
+            .map_err(|e| anyhow!("Parse TD report failed: {:?}", e))?;
+
+        let init_data: [u8; 48] = pad(init_data);
+        if init_data != td_report.tdinfo.mrconfigid {
+            bail!("Init data does not match!");
+        }
+
+        Ok(())
+    }
 }
 
 #[cfg(test)]

attestation-agent/attester/src/tdx/report.rs

@@ -0,0 +1,99 @@
+// Copyright (c) 2024 Microsoft Corporation
+// Copyright (c) 2024 Alibaba Cloud
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+use scroll::Pread;
+
+#[repr(C)]
+#[derive(Pread)]
+/// Type header of TDREPORT_STRUCT.
+pub struct TdTransportType {
+    /// Type of the TDREPORT (0 - SGX, 81 - TDX, rest are reserved).
+    pub type_: u8,
+
+    /// Subtype of the TDREPORT (Default value is 0).
+    pub sub_type: u8,
+
+    /// TDREPORT version (Default value is 0).
+    pub version: u8,
+
+    /// Added for future extension.
+    pub reserved: u8,
+}
+
+#[repr(C)]
+#[derive(Pread)]
+/// TDX guest report data, MAC and TEE hashes.
+pub struct ReportMac {
+    /// TDREPORT type header.
+    pub type_: TdTransportType,
+
+    /// Reserved for future extension.
+    pub reserved1: [u8; 12],
+
+    /// CPU security version.
+    pub cpu_svn: [u8; 16],
+
+    /// SHA384 hash of TEE TCB INFO.
+    pub tee_tcb_info_hash: [u8; 48],
+
+    /// SHA384 hash of TDINFO_STRUCT.
+    pub tee_td_info_hash: [u8; 48],
+
+    /// User defined unique data passed in TDG.MR.REPORT request.
+    pub reportdata: [u8; 64],
+
+    /// Reserved for future extension.
+    pub reserved2: [u8; 32],
+
+    /// CPU MAC ID.
+    pub mac: [u8; 32],
+}
+
+#[repr(C)]
+#[derive(Pread)]
+/// TDX guest measurements and configuration.
+pub struct TdInfo {
+    /// TDX Guest attributes (like debug, spet_disable, etc).
+    pub attr: [u8; 8],
+
+    /// Extended features allowed mask.
+    pub xfam: u64,
+
+    /// Build time measurement register.
+    pub mrtd: [u64; 6],
+
+    /// Software-defined ID for non-owner-defined configuration of the guest - e.g., run-time or OS configuration.
+    pub mrconfigid: [u8; 48],
+
+    /// Software-defined ID for the guest owner.
+    pub mrowner: [u64; 6],
+
+    /// Software-defined ID for owner-defined configuration of the guest - e.g., specific to the workload.
+    pub mrownerconfig: [u64; 6],
+
+    /// Run time measurement registers.
+    pub rtmr: [u64; 24],
+
+    /// For future extension.
+    pub reserved: [u64; 14],
+}
+
+#[repr(C)]
+#[derive(Pread)]
+/// Output of TDCALL[TDG.MR.REPORT].
+pub struct TdReport {
+    /// Mac protected header of size 256 bytes.
+    pub report_mac: ReportMac,
+
+    /// Additional attestable elements in the TCB are not reflected in the report_mac.
+    pub tee_tcb_info: [u8; 239],
+
+    /// Added for future extension.
+    pub reserved: [u8; 17],
+
+    /// Measurements and configuration data of size 512 bytes.
+    pub tdinfo: TdInfo,
+}

attestation-agent/attester/src/utils.rs

@@ -0,0 +1,15 @@
+// Copyright (c) 2024 Microsoft Corporation
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+pub fn pad<const T: usize>(input: &[u8]) -> [u8; T] {
+    let mut output = [0; T];
+    let len = input.len();
+    if len > T {
+        output.copy_from_slice(&input[..T]);
+    } else {
+        output[..len].copy_from_slice(input);
+    }
+    output
+}