attestation: add insecure issuer and validator

Author: msanft

internal/attestation/insecure/insecure_test.go

@@ -0,0 +1,60 @@
+// Copyright 2026 Edgeless Systems GmbH
+// SPDX-License-Identifier: BUSL-1.1
+
+package insecure
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/edgelesssys/contrast/internal/attestation"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIssueAndValidate(t *testing.T) {
+	hostData := []byte("hostdata")
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, "/hostdata", r.URL.Path)
+		_, err := w.Write(hostData)
+		assert.NoError(t, err)
+	}))
+	defer server.Close()
+
+	issuer := &Issuer{hostdataURL: server.URL + "/hostdata", client: server.Client()}
+	var reportData [64]byte
+	copy(reportData[:], []byte("report-data"))
+
+	attDoc, err := issuer.Issue(context.Background(), reportData)
+	require.NoError(t, err)
+
+	setter := &stubReportSetter{}
+	validator := NewValidatorWithReportSetter(slog.Default(), setter, "insecure")
+	require.NoError(t, validator.Validate(context.Background(), attDoc, reportData[:]))
+	require.NotNil(t, setter.report)
+	assert.Equal(t, hostData, setter.report.HostData())
+}
+
+func TestValidateMismatchingReportData(t *testing.T) {
+	validator := NewValidator(slog.Default(), "insecure")
+	attDoc := []byte(`{"reportData":"AQ==","hostData":"Ag=="}`)
+
+	err := validator.Validate(context.Background(), attDoc, []byte{0x02})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "reportData mismatch")
+}
+
+func TestAttestationDocumentOID(t *testing.T) {
+	assert.True(t, attestation.IsAttestationDocumentExtension(NewIssuer().OID()))
+}
+
+type stubReportSetter struct {
+	report attestation.Report
+}
+
+func (s *stubReportSetter) SetReport(report attestation.Report) {
+	s.report = report
+}

internal/attestation/insecure/issuer.go

@@ -0,0 +1,74 @@
+// Copyright 2025 Edgeless Systems GmbH
+// SPDX-License-Identifier: BUSL-1.1
+
+// Package insecure provides a fake aTLS issuer and validator for development
+// platforms without confidential computing hardware.
+package insecure
+
+import (
+	"context"
+	"encoding/asn1"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/edgelesssys/contrast/internal/oid"
+)
+
+// HostdataAddr is the address where the initdata-processor serves the
+// hostdata digest on insecure platforms.
+const HostdataAddr = "127.0.0.1:19629"
+
+// HostdataURL is the full URL for fetching the hostdata digest.
+const HostdataURL = "http://" + HostdataAddr + "/hostdata"
+
+// Issuer issues fake attestation documents for insecure (non-CC) platforms.
+//
+// It fetches the initdata digest from the local initdata-processor HTTP server
+// and packages it with the report data into a JSON attestation document.
+type Issuer struct {
+	hostdataURL string
+	client      *http.Client
+}
+
+// NewIssuer creates a new insecure issuer.
+func NewIssuer() *Issuer {
+	return &Issuer{hostdataURL: HostdataURL, client: http.DefaultClient}
+}
+
+// OID returns the OID for the insecure attestation.
+func (i *Issuer) OID() asn1.ObjectIdentifier {
+	return oid.RawInsecureReport
+}
+
+// Issue creates a fake attestation document containing the report data and
+// the initdata digest fetched from the local hostdata server.
+func (i *Issuer) Issue(ctx context.Context, reportData [64]byte) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, i.hostdataURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("creating hostdata request: %w", err)
+	}
+	resp, err := i.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("fetching hostdata from %q: %w", i.hostdataURL, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("fetching hostdata: status %s", resp.Status)
+	}
+	hostData, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("reading hostdata response: %w", err)
+	}
+	return json.Marshal(attestationDoc{
+		ReportData: reportData[:],
+		HostData:   hostData,
+	})
+}
+
+// attestationDoc is the fake attestation document exchanged between issuer and validator.
+type attestationDoc struct {
+	ReportData []byte `json:"reportData"`
+	HostData   []byte `json:"hostData"`
+}

internal/attestation/insecure/validator.go

@@ -0,0 +1,74 @@
+// Copyright 2025 Edgeless Systems GmbH
+// SPDX-License-Identifier: BUSL-1.1
+
+package insecure
+
+import (
+	"bytes"
+	"context"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+
+	"github.com/edgelesssys/contrast/internal/attestation"
+	"github.com/edgelesssys/contrast/internal/oid"
+)
+
+// Validator validates fake attestation documents from insecure (non-CC) platforms.
+type Validator struct {
+	reportSetter attestation.ReportSetter
+	logger       *slog.Logger
+	name         string
+}
+
+// NewValidator creates a new insecure validator.
+func NewValidator(log *slog.Logger, name string) *Validator {
+	return &Validator{logger: log, name: name}
+}
+
+// NewValidatorWithReportSetter creates a new insecure validator with a report setter callback.
+func NewValidatorWithReportSetter(log *slog.Logger, reportSetter attestation.ReportSetter, name string) *Validator {
+	return &Validator{reportSetter: reportSetter, logger: log, name: name}
+}
+
+// OID returns the OID for the insecure attestation.
+func (v *Validator) OID() asn1.ObjectIdentifier {
+	return oid.RawInsecureReport
+}
+
+// Validate verifies the fake attestation document and extracts the host data.
+func (v *Validator) Validate(_ context.Context, attDocRaw []byte, reportData []byte) error {
+	var doc attestationDoc
+	if err := json.Unmarshal(attDocRaw, &doc); err != nil {
+		return fmt.Errorf("unmarshaling insecure attestation: %w", err)
+	}
+	if !bytes.Equal(doc.ReportData, reportData) {
+		return fmt.Errorf("reportData mismatch: expected %x, got %x", reportData, doc.ReportData)
+	}
+	if v.reportSetter != nil {
+		v.reportSetter.SetReport(report{hostData: doc.HostData})
+	}
+	return nil
+}
+
+// String returns the validator's name.
+func (v *Validator) String() string {
+	return v.name
+}
+
+// report implements the [attestation.Report] interface for insecure platforms.
+type report struct {
+	hostData []byte
+}
+
+// HostData returns the initdata digest.
+func (r report) HostData() []byte {
+	return r.hostData
+}
+
+// ClaimsToCertExtension returns no extensions for insecure platforms.
+func (r report) ClaimsToCertExtension() ([]pkix.Extension, error) {
+	return nil, nil
+}

internal/attestation/oid.go

@@ -10,7 +10,7 @@ import (
 )
 
 // IsAttestationDocumentExtension checks whether the given OID corresponds to an attestation document extension
-// supported by Contrast (i.e. TDX or SNP).
+// supported by Contrast (i.e. TDX, SNP, or insecure).
 func IsAttestationDocumentExtension(oid asn1.ObjectIdentifier) bool {
-	return oid.Equal(oids.RawTDXReport) || oid.Equal(oids.RawSNPReport)
+	return oid.Equal(oids.RawTDXReport) || oid.Equal(oids.RawSNPReport) || oid.Equal(oids.RawInsecureReport)
 }

internal/oid/oid.go

@@ -13,6 +13,10 @@ var RawSNPReport = asn1.ObjectIdentifier{1, 3, 9901, 2, 1}
 // used by the aTLS issuer and validator.
 var RawTDXReport = asn1.ObjectIdentifier{1, 3, 9901, 2, 2}
 
+// RawInsecureReport is the OID for the insecure (non-CC) attestation,
+// used on development platforms without CC hardware.
+var RawInsecureReport = asn1.ObjectIdentifier{1, 3, 9901, 2, 99}
+
 // WorkloadSecretOID is the root OID for the workloadSecretID report
 // extension, added to the mesh certificates to allow verification
 // and authorization based on the workloadSecretID.