policy: add checks for PolicyEvaluationInfo fields

A new() constructor is added to centralize validation logic.

Conditionally requires MigTD TCB information, allowing it to be absent only when the test_disable_tcb_mapping_check feature is enabled for testing.

Signed-off-by: Jiaqi Gao <[email protected]>

Author: gaojiaqi7

.github/workflows/integration-tdx.yml

@@ -64,7 +64,7 @@ jobs:
           popd
       
       - name: Build Migration TD binary with policy v2
-        run: cargo image  --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem --root-ca config/Intel_SGX_Provisioning_Certification_RootCA_preproduction.cer
+        run: cargo image --features test_disable_tcb_mapping_check --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem --root-ca config/Intel_SGX_Provisioning_Certification_RootCA_preproduction.cer
 
       - name: Run Tests - Test policy v2
         run: |
@@ -114,7 +114,7 @@ jobs:
           popd
       
       - name: Build Migration TD binary with policy v2
-        run: cargo image --no-default-features --features stack-guard,virtio-serial --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem --root-ca config/Intel_SGX_Provisioning_Certification_RootCA_preproduction.cer
+        run: cargo image --no-default-features --features stack-guard,virtio-serial,test_disable_tcb_mapping_check --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem --root-ca config/Intel_SGX_Provisioning_Certification_RootCA_preproduction.cer
 
       - name: Run Tests - Test policy v2
         run: |
@@ -228,7 +228,7 @@ jobs:
         run: echo "SPDM_CONFIG=../../../config/spdm_config_policy_v2.json" >> "$GITHUB_ENV"
 
       - name: Build Migration TD binary with SPDM feature and Policy V2
-        run: cargo image --features spdm_attestation --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem
+        run: cargo image --features spdm_attestation,test_disable_tcb_mapping_check --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem
 
       - name: Run Tests - Test Migration TD 20 Cycles
         run: |
@@ -237,7 +237,7 @@ jobs:
           popd
 
       - name: Build Migration TD binary with SPDM feature and Policy V2
-        run: cargo image --no-default-features --features stack-guard,virtio-serial,spdm_attestation --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem
+        run: cargo image --no-default-features --features stack-guard,virtio-serial,spdm_attestation,test_disable_tcb_mapping_check --policy-v2 --policy config/templates/policy_v2_signed.json --policy-issuer-chain config/templates/policy_issuer_chain.pem
 
       - name: Run Tests - Test Migration TD 20 Cycles
         run: |

src/migtd/Cargo.toml

@@ -71,6 +71,7 @@ oneshot-apic = []
 test_heap_size = ["td-benchmark", "td-payload/test_heap_size"]
 test_stack_size = ["td-benchmark"]
 test_disable_ra_and_accept_all = ["attestation/test"] # Dangerous: can only be used for test purpose to bypass the remote attestation
+test_disable_tcb_mapping_check = ["policy/test_disable_tcb_mapping_check"]# Dangerous: can only be used for test purpose to bypass the tcb mapping check
 spdm_attestation = ["main"]
 
 [patch.crates-io]

src/migtd/src/mig_policy.rs

@@ -262,14 +262,13 @@ mod v2 {
 
         let migtd_tcb = migtd_svn.and_then(|svn| policy.servtd_identity.get_tcb_level_by_svn(svn));
 
-        Ok(PolicyEvaluationInfo {
-            tcb_date: Some(tcb_date.to_string()),
-            tcb_status: Some(tcb_status.as_str().to_string()),
-            tcb_evaluation_number: Some(tcb_evaluation_number),
-            fmspc: Some(fmspc),
-            migtd_tcb_date: migtd_tcb.map(|tcb| tcb.tcb_date.clone()),
-            migtd_tcb_status: migtd_tcb.map(|tcb| tcb.tcb_status.clone()),
-        })
+        PolicyEvaluationInfo::new(
+            Some(tcb_date.to_string()),
+            Some(tcb_status.as_str().to_string()),
+            Some(tcb_evaluation_number),
+            Some(fmspc),
+            migtd_tcb,
+        )
     }
 
     fn get_tcb_date_and_status_from_suppl_data(

src/policy/Cargo.toml

@@ -18,3 +18,4 @@ td-shim-interface = { path = "../../deps/td-shim/td-shim-interface"}
 [features]
 std = []
 policy_v2 = []
+test_disable_tcb_mapping_check = []

src/policy/src/lib.rs

@@ -52,6 +52,8 @@ pub enum PolicyError {
     InvalidReference,
     InvalidServtdIdentity,
     InvalidServtdTcbMapping,
+    PlatformTcbNotFound,
+    ServtdTcbNotFound,
     PolicyHashMismatch,
     InvalidQuote,
     SvnMismatch,

src/policy/src/v2/policy.rs

@@ -10,7 +10,7 @@ use serde_json::{self, value::RawValue};
 use crate::{
     parse_events,
     v2::{bytes_to_hex_string, hex_string_to_bytes, policy, verify_event_hash},
-    Collaterals, EventName, PolicyError, ServtdCollateral, TdIdentity, TdTcbMapping,
+    Collaterals, EventName, PolicyError, ServtdCollateral, TcbLevel, TdIdentity, TdTcbMapping,
 };
 
 #[derive(Debug)]
@@ -58,22 +58,57 @@ impl TryFrom<&str> for TcbStatus {
 #[derive(Debug, Clone, Default)]
 pub struct PolicyEvaluationInfo {
     /// The date of the Trusted Computing Base (TCB) in ISO-8601 format, e.g. "2023-06-19T00:00:00Z"
-    pub tcb_date: Option<String>,
+    tcb_date: Option<String>,
 
     /// The status of the TCB
-    pub tcb_status: Option<String>,
+    tcb_status: Option<String>,
 
     /// The TCB evaluation data number used to track TCB revocations and updates
-    pub tcb_evaluation_number: Option<u32>,
+    tcb_evaluation_number: Option<u32>,
 
     /// The FMSPC of platform
-    pub fmspc: Option<[u8; 6]>,
+    fmspc: Option<[u8; 6]>,
 
     /// The status of the MigTD TCB
-    pub migtd_tcb_status: Option<String>,
+    migtd_tcb_status: Option<String>,
 
     /// The date of the MigTD TCB in ISO-8601 format, e.g. "2023-06-19T00:00:00Z"
-    pub migtd_tcb_date: Option<String>,
+    migtd_tcb_date: Option<String>,
+}
+
+impl PolicyEvaluationInfo {
+    /// Creates a new `PolicyEvaluationInfo` instance, validating that required fields are present.
+    pub fn new(
+        tcb_date: Option<String>,
+        tcb_status: Option<String>,
+        tcb_evaluation_number: Option<u32>,
+        fmspc: Option<[u8; 6]>,
+        migtd_tcb: Option<&TcbLevel>,
+    ) -> Result<Self, PolicyError> {
+        let info = Self {
+            tcb_date,
+            tcb_status,
+            tcb_evaluation_number,
+            fmspc,
+            migtd_tcb_date: migtd_tcb.map(|tcb| tcb.tcb_date.clone()),
+            migtd_tcb_status: migtd_tcb.map(|tcb| tcb.tcb_status.clone()),
+        };
+
+        if info.tcb_date.is_none()
+            || info.tcb_status.is_none()
+            || tcb_evaluation_number.is_none()
+            || fmspc.is_none()
+        {
+            return Err(PolicyError::PlatformTcbNotFound);
+        }
+
+        #[cfg(not(feature = "test_disable_tcb_mapping_check"))]
+        if info.migtd_tcb_date.is_none() || info.migtd_tcb_status.is_none() {
+            return Err(PolicyError::ServtdTcbNotFound);
+        }
+
+        Ok(info)
+    }
 }
 
 pub struct VerifiedPolicy<'a> {