Merge pull request #6331 from oasisprotocol/peternose/feature/whitelist-fmspcs

go/common/sgx/pcs/policy: Add FMSP whitelist to quote policy

Author: peternose

.changelog/6331.breaking.md

@@ -0,0 +1 @@
+go/common/sgx/pcs/policy: Add FMSPC whitelist to quote policy

go/common/node/node.go

@@ -574,7 +574,7 @@ func HashRAK(rak signature.PublicKey) hash.Hash {
 }
 
 // Verify verifies the node's TEE capabilities, at the provided timestamp and height.
-func (c *CapabilityTEE) Verify(teeCfg *TEEFeatures, ts time.Time, height uint64, constraints []byte, nodeID signature.PublicKey) error {
+func (c *CapabilityTEE) Verify(teeCfg *TEEFeatures, ts time.Time, height uint64, constraints []byte, nodeID signature.PublicKey, isFeatureVersion242 bool) error {
 	switch c.Hardware {
 	case TEEHardwareIntelSGX:
 		// Parse SGX remote attestation.
@@ -591,7 +591,7 @@ func (c *CapabilityTEE) Verify(teeCfg *TEEFeatures, ts time.Time, height uint64,
 		if err := cbor.Unmarshal(constraints, &sc); err != nil {
 			return fmt.Errorf("node: malformed SGX constraints: %w", err)
 		}
-		if err := sc.ValidateBasic(teeCfg); err != nil {
+		if err := sc.ValidateBasic(teeCfg, isFeatureVersion242); err != nil {
 			return fmt.Errorf("node: malformed SGX constraints: %w", err)
 		}
 

go/common/node/sgx.go

@@ -97,7 +97,7 @@ func (sc *SGXConstraints) MarshalCBOR() ([]byte, error) {
 }
 
 // ValidateBasic performs basic structure validity checks.
-func (sc *SGXConstraints) ValidateBasic(cfg *TEEFeatures) error {
+func (sc *SGXConstraints) ValidateBasic(cfg *TEEFeatures, isFeatureVersion242 bool) error {
 	if cfg == nil {
 		cfg = &emptyFeatures
 	}
@@ -116,6 +116,13 @@ func (sc *SGXConstraints) ValidateBasic(cfg *TEEFeatures) error {
 		return fmt.Errorf("TDX policy not supported")
 	}
 
+	// Check that policy is compliant with the current feature version.
+	if sc.Policy != nil {
+		if err := sc.Policy.Validate(isFeatureVersion242); err != nil {
+			return fmt.Errorf("invalid policy: %w", err)
+		}
+	}
+
 	return nil
 }
 

go/common/node/sgx_test.go

@@ -27,7 +27,7 @@ func TestSGXConstraintsV0(t *testing.T) {
 	err = cbor.Unmarshal(raw, &sc)
 	require.NoError(err, "Decode V0 SGX constraints")
 
-	err = sc.ValidateBasic(nil)
+	err = sc.ValidateBasic(nil, true)
 	require.NoError(err, "ValidateBasic V0 SGX constraints")
 
 	enc := cbor.Marshal(sc)
@@ -60,11 +60,11 @@ func TestSGXConstraintsV1(t *testing.T) {
 			},
 		},
 	}
-	err = sc.ValidateBasic(nil)
+	err = sc.ValidateBasic(nil, true)
 	require.Error(err, "ValidateBasic V1 SGX constraints without PCS support")
-	err = sc.ValidateBasic(&TEEFeatures{})
+	err = sc.ValidateBasic(&TEEFeatures{}, true)
 	require.Error(err, "ValidateBasic V1 SGX constraints without PCS support")
-	err = sc.ValidateBasic(&TEEFeatures{SGX: TEEFeaturesSGX{PCS: true}})
+	err = sc.ValidateBasic(&TEEFeatures{SGX: TEEFeaturesSGX{PCS: true}}, true)
 	require.NoError(err, "ValidateBasic V1 SGX constraints")
 }
 

go/common/sgx/pcs/policy.go

@@ -16,6 +16,10 @@ type QuotePolicy struct {
 	// valid. TCB bundles containing smaller values will be invalid.
 	MinTCBEvaluationDataNumber uint32 `json:"min_tcb_evaluation_data_number" yaml:"min_tcb_evaluation_data_number"`
 
+	// FMSPCWhitelist is a list of hexadecimal encoded FMSPCs specifying which processor
+	// packages and platform instances are allowed.
+	FMSPCWhitelist []string `json:"fmspc_whitelist,omitempty" yaml:"fmspc_whitelist,omitempty"`
+
 	// FMSPCBlacklist is a list of hexadecimal encoded FMSPCs specifying which processor
 	// packages and platform instances are blocked.
 	FMSPCBlacklist []string `json:"fmspc_blacklist,omitempty" yaml:"fmspc_blacklist,omitempty"`

go/common/sgx/pcs/quote.go

@@ -144,7 +144,8 @@ func (q *Quote) Verify(policy *QuotePolicy, ts time.Time, tcb *TCBBundle) (*sgx.
 		policy = &QuotePolicy{
 			TCBValidityPeriod:          30,
 			MinTCBEvaluationDataNumber: DefaultMinTCBEvaluationDataNumber,
-			FMSPCBlacklist:             []string{},
+			FMSPCWhitelist:             make([]string, 0),
+			FMSPCBlacklist:             make([]string, 0),
 		}
 	}
 

go/common/sgx/pcs/quote_test.go

@@ -121,14 +121,37 @@ func TestQuoteV3_ECDSA_P256_PCK_CertificateChain(t *testing.T) {
 	require.Error(err, "Quote verification should fail for invalid TCB evaluation data number")
 	require.ErrorContains(err, "pcs/quote: failed to verify TCB bundle: pcs/tcb: failed to verify QE identity: pcs/tcb: invalid QE identity: pcs/tcb: invalid QE evaluation data number")
 
+	// Test whitelisted FMSPC.
+	quotePolicy = &QuotePolicy{
+		TCBValidityPeriod: 90,
+		FMSPCWhitelist:    []string{},
+	}
+	_, err = quote.Verify(quotePolicy, now, &tcbBundle)
+	require.NoError(err, "Quote verification should succeed for whitelisted FMSPCs")
+
+	quotePolicy = &QuotePolicy{
+		TCBValidityPeriod: 90,
+		FMSPCWhitelist:    []string{"00606A000000"},
+	}
+	_, err = quote.Verify(quotePolicy, now, &tcbBundle)
+	require.NoError(err, "Quote verification should succeed for whitelisted FMSPCs")
+
+	quotePolicy = &QuotePolicy{
+		TCBValidityPeriod: 90,
+		FMSPCWhitelist:    []string{"00606A000001"},
+	}
+	_, err = quote.Verify(quotePolicy, now, &tcbBundle)
+	require.Error(err, "Quote verification should fail for non-whitelisted FMSPCs")
+	require.ErrorContains(err, "pcs/quote: failed to verify TCB bundle: pcs/tcb: failed to verify TCB info: pcs/tcb: invalid TCB info: pcs/tcb: FMSPC is not whitelisted")
+
 	// Test blacklisted FMSPC.
 	quotePolicy = &QuotePolicy{
 		TCBValidityPeriod: 90,
 		FMSPCBlacklist:    []string{"00606A000000"},
 	}
 	_, err = quote.Verify(quotePolicy, now, &tcbBundle)
 	require.Error(err, "Quote verification should fail for blacklisted FMSPCs")
-	require.ErrorContains(err, "pcs/quote: failed to verify TCB bundle: pcs/tcb: failed to verify TCB info: pcs/tcb: invalid TCB info: pcs/tcb: blacklisted FMSPC")
+	require.ErrorContains(err, "pcs/quote: failed to verify TCB bundle: pcs/tcb: failed to verify TCB info: pcs/tcb: invalid TCB info: pcs/tcb: FMSPC is blacklisted")
 
 	// Test TCB info certificates missing.
 	tcbBundle2 := TCBBundle{

go/common/sgx/pcs/tcb.go

@@ -270,9 +270,14 @@ func (ti *TCBInfo) validate(teeType TeeType, ts time.Time, policy *QuotePolicy)
 		return fmt.Errorf("pcs/tcb: invalid TCB evaluation data number")
 	}
 
-	// Validate FMSPC not blacklisted.
+	// Validate FMSPC is whitelisted.
+	if len(policy.FMSPCWhitelist) > 0 && !slices.Contains(policy.FMSPCWhitelist, ti.FMSPC) {
+		return fmt.Errorf("pcs/tcb: FMSPC is not whitelisted")
+	}
+
+	// Validate FMSPC is not blacklisted.
 	if slices.Contains(policy.FMSPCBlacklist, ti.FMSPC) {
-		return fmt.Errorf("pcs/tcb: blacklisted FMSPC")
+		return fmt.Errorf("pcs/tcb: FMSPC is blacklisted")
 	}
 
 	return nil

go/common/sgx/quote/quote.go

@@ -64,3 +64,20 @@ type Policy struct {
 	IAS *ias.QuotePolicy `json:"ias,omitempty" yaml:"ias,omitempty"`
 	PCS *pcs.QuotePolicy `json:"pcs,omitempty" yaml:"pcs,omitempty"`
 }
+
+// Validate validates the policy.
+func (p *Policy) Validate(isFeatureVersion242 bool) error {
+	if isFeatureVersion242 {
+		return nil
+	}
+
+	if p.PCS == nil {
+		return nil
+	}
+
+	if len(p.PCS.FMSPCWhitelist) == 0 {
+		return nil
+	}
+
+	return fmt.Errorf("fmspc whitelist should be empty")
+}

go/common/sgx/quote/quote_test.go

@@ -15,9 +15,12 @@ pcs:
     disabled: false
     tcb_validity_period: 30
     min_tcb_evaluation_data_number: 17
-    fmspc_blacklist:
+    fmspc_whitelist:
         - "000000000000"
         - "00606A000000"
+    fmspc_blacklist:
+        - "000000000001"
+        - "00606A000001"
 `
 	var dec Policy
 	err := yaml.Unmarshal([]byte(testCase1), &dec)
@@ -27,7 +30,10 @@ pcs:
 	require.EqualValues(false, dec.PCS.Disabled)
 	require.EqualValues(30, dec.PCS.TCBValidityPeriod)
 	require.EqualValues(17, dec.PCS.MinTCBEvaluationDataNumber)
+	require.Len(dec.PCS.FMSPCWhitelist, 2)
+	require.EqualValues("000000000000", dec.PCS.FMSPCWhitelist[0])
+	require.EqualValues("00606A000000", dec.PCS.FMSPCWhitelist[1])
 	require.Len(dec.PCS.FMSPCBlacklist, 2)
-	require.EqualValues("000000000000", dec.PCS.FMSPCBlacklist[0])
-	require.EqualValues("00606A000000", dec.PCS.FMSPCBlacklist[1])
+	require.EqualValues("000000000001", dec.PCS.FMSPCBlacklist[0])
+	require.EqualValues("00606A000001", dec.PCS.FMSPCBlacklist[1])
 }