tdx: support extracting host data from quote & fill in extensions

coordinator/internal/authority/credentials.go

@@ -5,21 +5,20 @@ package authority
 
 import (
  "context"
- "encoding/asn1"
  "errors"
  "fmt"
  "log/slog"
  "net"
  "time"
 
  "github.com/edgelesssys/contrast/internal/atls"
+ "github.com/edgelesssys/contrast/internal/attestation"
  "github.com/edgelesssys/contrast/internal/attestation/certcache"
  "github.com/edgelesssys/contrast/internal/attestation/snp"
  "github.com/edgelesssys/contrast/internal/attestation/tdx"
  "github.com/edgelesssys/contrast/internal/logger"
  "github.com/edgelesssys/contrast/internal/manifest"
  "github.com/edgelesssys/contrast/internal/memstore"
- "github.com/google/go-sev-guest/proto/sevsnp"
  "github.com/prometheus/client_golang/prometheus"
  "github.com/prometheus/client_golang/prometheus/promauto"
  "google.golang.org/grpc/credentials"
@@ -90,7 +89,7 @@ func (c *Credentials) ServerHandshake(rawConn net.Conn) (net.Conn, credentials.A
  }
 
  for _, opt := range opts {
- validator := snp.NewValidatorWithCallbacks(opt.VerifyOpts, opt.ValidateOpts, allowedHostDataEntries,
+ validator := snp.NewValidatorWithReportSetter(opt.VerifyOpts, opt.ValidateOpts, allowedHostDataEntries,
  logger.NewWithAttrs(logger.NewNamed(c.logger, "validator"), map[string]string{"tee-type": "snp"}),
  &authInfo)
  validators = append(validators, validator)
@@ -101,8 +100,8 @@ func (c *Credentials) ServerHandshake(rawConn net.Conn) (net.Conn, credentials.A
  return nil, nil, fmt.Errorf("generating TDX validation options: %w", err)
  }
  for _, opt := range tdxOpts {
- validators = append(validators, tdx.NewValidator(&tdx.StaticValidateOptsGenerator{Opts: opt},
- logger.NewWithAttrs(logger.NewNamed(c.logger, "validator"), map[string]string{"tee-type": "tdx"})))
+ validators = append(validators, tdx.NewValidatorWithReportSetter(&tdx.StaticValidateOptsGenerator{Opts: opt},
+ logger.NewWithAttrs(logger.NewNamed(c.logger, "validator"), map[string]string{"tee-type": "tdx"}), &authInfo))
  }
 
  serverCfg, err := atls.CreateAttestationServerTLSConfig(c.issuer, validators, c.attestationFailuresCounter)
@@ -153,11 +152,10 @@ type AuthInfo struct {
  // State is the coordinator state at the time of the TLS handshake.
  State *State
  // Report is the attestation report sent by the peer.
- Report *sevsnp.Report
+ Report attestation.Report
 }
 
-// ValidateCallback takes the validated report and attaches it to the [AuthInfo].
-func (a *AuthInfo) ValidateCallback(_ context.Context, report *sevsnp.Report, _ asn1.ObjectIdentifier, _, _, _ []byte) error {
+// SetReport takes the validated report and attaches it to the [AuthInfo].
+func (a *AuthInfo) SetReport(report attestation.Report) {
  a.Report = report
- return nil
 }

coordinator/meshapi.go

@@ -14,7 +14,6 @@ import (
  "github.com/edgelesssys/contrast/coordinator/internal/authority"
  "github.com/edgelesssys/contrast/coordinator/internal/seedengine"
  "github.com/edgelesssys/contrast/internal/atls"
- "github.com/edgelesssys/contrast/internal/attestation/snp"
  "github.com/edgelesssys/contrast/internal/manifest"
  "github.com/edgelesssys/contrast/internal/meshapi"
  grpcprometheus "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
@@ -106,7 +105,7 @@ func (i *meshAPIServer) NewMeshCert(ctx context.Context, _ *meshapi.NewMeshCertR
  return nil, fmt.Errorf("could not marshal public key: %w", err)
  }
 
- hostData := manifest.NewHexString(report.HostData)
+ hostData := manifest.NewHexString(report.HostData())
  entry, ok := state.Manifest.Policies[hostData]
  if !ok {
  return nil, fmt.Errorf("report data %s not found in manifest", hostData)
@@ -118,7 +117,7 @@ func (i *meshAPIServer) NewMeshCert(ctx context.Context, _ *meshapi.NewMeshCertR
  return nil, fmt.Errorf("failed to parse peer public key: %w", err)
  }
 
- extensions, err := snp.ClaimsToCertExtension(report)
+ extensions, err := report.ClaimsToCertExtension()
  if err != nil {
  return nil, fmt.Errorf("failed to construct extensions: %w", err)
  }

internal/atls/atls.go

@@ -26,8 +26,6 @@ import (
  "github.com/prometheus/client_golang/prometheus"
 )
 
-const attestationTimeout = 30 * time.Second
-
 var (
  // NoValidators skips validation of the server's attestation document.
  NoValidators = []Validator{}
@@ -94,7 +92,7 @@ type Issuer interface {
 // Validator is able to validate an attestation document.
 type Validator interface {
  Getter
- Validate(ctx context.Context, attDoc []byte, nonce []byte, peerPublicKey []byte) error
+ Validate(attDoc []byte, nonce []byte, peerPublicKey []byte) error
 }
 
 // getATLSConfigForClientFunc returns a config setup function that is called once for every client connecting to the server.
@@ -242,10 +240,7 @@ func verifyEmbeddedReport(validators []Validator, cert *x509.Certificate, peerPu
  // We've found a matching validator. Let's validate the document.
  foundMatchingValidator = true
 
- ctx, cancel := context.WithTimeout(context.Background(), attestationTimeout)
- defer cancel()
-
- validationErr := validator.Validate(ctx, ex.Value, nonce, peerPublicKey)
+ validationErr := validator.Validate(ex.Value, nonce, peerPublicKey)
  if validationErr == nil {
  // The validator has successfully verified the document. We can exit.
  return nil
@@ -429,7 +424,7 @@ func NewFakeValidators(oid Getter) []Validator {
 }
 
 // Validate unmarshals the attestation document and verifies the nonce.
-func (v FakeValidator) Validate(_ context.Context, attDoc []byte, nonce []byte, _ []byte) error {
+func (v FakeValidator) Validate(attDoc []byte, nonce []byte, _ []byte) error {
  var doc FakeAttestationDoc
  if err := json.Unmarshal(attDoc, &doc); err != nil {
  return err

internal/attestation/callback.go

@@ -0,0 +1,19 @@
+// Copyright 2024 Edgeless Systems GmbH
+// SPDX-License-Identifier: AGPL-3.0-only
+
+package attestation
+
+import (
+ "crypto/x509/pkix"
+)
+
+// Report is a verified and validates TEE attestation report.
+type Report interface {
+ HostData() []byte
+ ClaimsToCertExtension() ([]pkix.Extension, error)
+}
+
+// ReportSetter is called by a validator after it verified and validated an attestation report.
+type ReportSetter interface {
+ SetReport(report Report)
+}

internal/attestation/extension/extension.go

@@ -0,0 +1,87 @@
+// Copyright 2024 Edgeless Systems GmbH
+// SPDX-License-Identifier: AGPL-3.0-only
+
+package extension
+
+import (
+ "crypto/x509/pkix"
+ "encoding/asn1"
+ "fmt"
+ "math/big"
+
+ "golang.org/x/exp/constraints"
+)
+
+// NewBigIntExtension returns a new extension containing an unsigned integer value.
+func NewBigIntExtension[T constraints.Unsigned](oid asn1.ObjectIdentifier, value T) Extension {
+ bigInt := &big.Int{}
+ bigInt.SetUint64(uint64(value))
+ return bigIntExtension{OID: oid, Val: bigInt}
+}
+
+type bigIntExtension struct {
+ OID asn1.ObjectIdentifier
+ Val *big.Int
+}
+
+func (b bigIntExtension) toExtension() (pkix.Extension, error) {
+ bytes, err := asn1.Marshal(b.Val)
+ if err != nil {
+ return pkix.Extension{}, fmt.Errorf("marshaling big int: %w", err)
+ }
+ return pkix.Extension{Id: b.OID, Value: bytes}, nil
+}
+
+// NewBytesExtension returns a new extension containing bytes.
+func NewBytesExtension(oid asn1.ObjectIdentifier, val []byte) Extension {
+ return bytesExtension{OID: oid, Val: val}
+}
+
+type bytesExtension struct {
+ OID asn1.ObjectIdentifier
+ Val []byte
+}
+
+func (b bytesExtension) toExtension() (pkix.Extension, error) {
+ bytes, err := asn1.Marshal(b.Val)
+ if err != nil {
+ return pkix.Extension{}, fmt.Errorf("marshaling bytes: %w", err)
+ }
+ return pkix.Extension{Id: b.OID, Value: bytes}, nil
+}
+
+// NewBoolExtension returns a new extension containing a boolean value.
+func NewBoolExtension(oid asn1.ObjectIdentifier, val bool) Extension {
+ return boolExtension{OID: oid, Val: val}
+}
+
+type boolExtension struct {
+ OID asn1.ObjectIdentifier
+ Val bool
+}
+
+func (b boolExtension) toExtension() (pkix.Extension, error) {
+ bytes, err := asn1.Marshal(b.Val)
+ if err != nil {
+ return pkix.Extension{}, fmt.Errorf("marshaling bool: %w", err)
+ }
+ return pkix.Extension{Id: b.OID, Value: bytes}, nil
+}
+
+// Extension is a yet-to-be-marshalled pkix extension.
+type Extension interface {
+ toExtension() (pkix.Extension, error)
+}
+
+// ConvertExtensions converts the extensions into pkix extensions.
+func ConvertExtensions(extensions []Extension) ([]pkix.Extension, error) {
+ var exts []pkix.Extension
+ for _, extension := range extensions {
+ ext, err := extension.toExtension()
+ if err != nil {
+ return nil, fmt.Errorf("converting extension to pkix: %w", err)
+ }
+ exts = append(exts, ext)
+ }
+ return exts, nil
+}