vault: validate encrypted value size in request validator

core/capabilities/vault/capability.go

@@ -408,6 +408,10 @@ func NewCapability(
 	if err != nil {
 		return nil, fmt.Errorf("could not create request batch size limiter: %w", err)
 	}
+	ciphertextLimiter, err := limits.MakeUpperBoundLimiter(limitsFactory, cresettings.Default.VaultCiphertextSizeLimit)
+	if err != nil {
+		return nil, fmt.Errorf("could not create ciphertext size limiter: %w", err)
+	}
 	return &Capability{
 		lggr:                 logger.Named(lggr, "VaultCapability"),
 		clock:                clock,
@@ -416,6 +420,6 @@ func NewCapability(
 		requestAuthorizer:    requestAuthorizer,
 		capabilitiesRegistry: capabilitiesRegistry,
 		publicKey:            publicKey,
-		RequestValidator:     NewRequestValidator(limiter),
+		RequestValidator:     NewRequestValidator(limiter, ciphertextLimiter),
 	}, nil
 }

core/capabilities/vault/validator.go

@@ -11,12 +11,14 @@ import (
 	"github.com/smartcontractkit/tdh2/go/tdh2/tdh2easy"
 
 	vaultcommon "github.com/smartcontractkit/chainlink-common/pkg/capabilities/actions/vault"
+	pkgconfig "github.com/smartcontractkit/chainlink-common/pkg/config"
 	"github.com/smartcontractkit/chainlink-common/pkg/settings/limits"
 	"github.com/smartcontractkit/chainlink/v2/core/capabilities/vault/vaulttypes"
 )
 
 type RequestValidator struct {
 	MaxRequestBatchSizeLimiter limits.BoundLimiter[int]
+	MaxCiphertextLengthLimiter limits.BoundLimiter[pkgconfig.Size]
 }
 
 func (r *RequestValidator) ValidateCreateSecretsRequest(publicKey *tdh2easy.PublicKey, request *vaultcommon.CreateSecretsRequest) error {
@@ -60,6 +62,9 @@ func (r *RequestValidator) validateWriteRequest(publicKey *tdh2easy.PublicKey, i
 		if req.EncryptedValue == "" {
 			return errors.New("secret must have encrypted value set at index " + strconv.Itoa(idx) + ":" + req.Id.String())
 		}
+		if err := r.validateCiphertextSize(req.EncryptedValue); err != nil {
+			return fmt.Errorf("secret encrypted value at index %d is invalid: %w", idx, err)
+		}
 		err := EnsureRightLabelOnSecret(publicKey, req.EncryptedValue, req.Id.Owner)
 		if err != nil {
 			return errors.New("Encrypted Secret at index [" + strconv.Itoa(idx) + "] doesn't have owner as the label. Error: " + err.Error())
@@ -75,6 +80,21 @@ func (r *RequestValidator) validateWriteRequest(publicKey *tdh2easy.PublicKey, i
 	return nil
 }
 
+func (r *RequestValidator) validateCiphertextSize(encryptedValue string) error {
+	rawCiphertext, err := hex.DecodeString(encryptedValue)
+	if err != nil {
+		return fmt.Errorf("failed to decode encrypted value: %w", err)
+	}
+	if err := r.MaxCiphertextLengthLimiter.Check(context.Background(), pkgconfig.Size(len(rawCiphertext))*pkgconfig.Byte); err != nil {
+		var errBoundLimited limits.ErrorBoundLimited[pkgconfig.Size]
+		if errors.As(err, &errBoundLimited) {
+			return fmt.Errorf("ciphertext size exceeds maximum allowed size: %s", errBoundLimited.Limit)
+		}
+		return fmt.Errorf("failed to check ciphertext size limit: %w", err)
+	}
+	return nil
+}
+
 func (r *RequestValidator) ValidateGetSecretsRequest(request *vaultcommon.GetSecretsRequest) error {
 	if len(request.Requests) == 0 {
 		return errors.New("no GetSecret request specified in request")
@@ -129,9 +149,13 @@ func (r *RequestValidator) ValidateDeleteSecretsRequest(request *vaultcommon.Del
 	return nil
 }
 
-func NewRequestValidator(maxRequestBatchSizeLimiter limits.BoundLimiter[int]) *RequestValidator {
+func NewRequestValidator(
+	maxRequestBatchSizeLimiter limits.BoundLimiter[int],
+	maxCiphertextLengthLimiter limits.BoundLimiter[pkgconfig.Size],
+) *RequestValidator {
 	return &RequestValidator{
 		MaxRequestBatchSizeLimiter: maxRequestBatchSizeLimiter,
+		MaxCiphertextLengthLimiter: maxCiphertextLengthLimiter,
 	}
 }
 

core/capabilities/vault/validator_test.go

@@ -0,0 +1,96 @@
+package vault
+
+import (
+	"encoding/hex"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	vaultcommon "github.com/smartcontractkit/chainlink-common/pkg/capabilities/actions/vault"
+	pkgconfig "github.com/smartcontractkit/chainlink-common/pkg/config"
+	"github.com/smartcontractkit/chainlink-common/pkg/settings/limits"
+)
+
+func TestRequestValidator_CiphertextSizeLimit(t *testing.T) {
+	validator := NewRequestValidator(
+		limits.NewUpperBoundLimiter(10),
+		limits.NewUpperBoundLimiter[pkgconfig.Size](10*pkgconfig.Byte),
+	)
+
+	id := &vaultcommon.SecretIdentifier{
+		Key:       "key",
+		Namespace: "namespace",
+		Owner:     "0x1111111111111111111111111111111111111111",
+	}
+
+	tests := []struct {
+		name      string
+		call      func(*testing.T, *RequestValidator, string) error
+		value     string
+		errSubstr string
+	}{
+		{
+			name: "create accepts ciphertext at the limit",
+			call: func(t *testing.T, validator *RequestValidator, value string) error {
+				return validator.ValidateCreateSecretsRequest(nil, &vaultcommon.CreateSecretsRequest{
+					RequestId: "request-id",
+					EncryptedSecrets: []*vaultcommon.EncryptedSecret{
+						{Id: id, EncryptedValue: value},
+					},
+				})
+			},
+			value: hex.EncodeToString(make([]byte, 10)),
+		},
+		{
+			name: "create rejects ciphertext above the limit",
+			call: func(t *testing.T, validator *RequestValidator, value string) error {
+				return validator.ValidateCreateSecretsRequest(nil, &vaultcommon.CreateSecretsRequest{
+					RequestId: "request-id",
+					EncryptedSecrets: []*vaultcommon.EncryptedSecret{
+						{Id: id, EncryptedValue: value},
+					},
+				})
+			},
+			value:     hex.EncodeToString(make([]byte, 11)),
+			errSubstr: "ciphertext size exceeds maximum allowed size",
+		},
+		{
+			name: "update accepts ciphertext at the limit",
+			call: func(t *testing.T, validator *RequestValidator, value string) error {
+				return validator.ValidateUpdateSecretsRequest(nil, &vaultcommon.UpdateSecretsRequest{
+					RequestId: "request-id",
+					EncryptedSecrets: []*vaultcommon.EncryptedSecret{
+						{Id: id, EncryptedValue: value},
+					},
+				})
+			},
+			value: hex.EncodeToString(make([]byte, 10)),
+		},
+		{
+			name: "update rejects ciphertext above the limit",
+			call: func(t *testing.T, validator *RequestValidator, value string) error {
+				return validator.ValidateUpdateSecretsRequest(nil, &vaultcommon.UpdateSecretsRequest{
+					RequestId: "request-id",
+					EncryptedSecrets: []*vaultcommon.EncryptedSecret{
+						{Id: id, EncryptedValue: value},
+					},
+				})
+			},
+			value:     hex.EncodeToString(make([]byte, 11)),
+			errSubstr: "ciphertext size exceeds maximum allowed size",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.call(t, validator, tt.value)
+			if tt.errSubstr == "" {
+				require.NoError(t, err)
+				return
+			}
+
+			require.Error(t, err)
+			require.ErrorContains(t, err, tt.errSubstr)
+		})
+	}
+}

core/services/gateway/handlers/vault/handler.go

@@ -197,6 +197,10 @@ func NewHandler(methodConfig json.RawMessage, donConfig *config.DONConfig, don g
 	if err != nil {
 		return nil, fmt.Errorf("could not create request batch size limiter: %w", err)
 	}
+	ciphertextLimiter, err := limits.MakeUpperBoundLimiter(limitsFactory, cresettings.Default.VaultCiphertextSizeLimit)
+	if err != nil {
+		return nil, fmt.Errorf("could not create ciphertext size limiter: %w", err)
+	}
 
 	writeMethodsEnabled, err := limits.MakeGateLimiter(limitsFactory, cresettings.Default.GatewayVaultManagementEnabled)
 	if err != nil {
@@ -218,7 +222,7 @@ func NewHandler(methodConfig json.RawMessage, donConfig *config.DONConfig, don g
 		metrics:             metrics,
 		aggregator:          &baseAggregator{capabilitiesRegistry: capabilitiesRegistry},
 		clock:               clock,
-		RequestValidator:    vaultcap.NewRequestValidator(limiter),
+		RequestValidator:    vaultcap.NewRequestValidator(limiter, ciphertextLimiter),
 	}, nil
 }