sdk: remove Linux dependencies

coordinator/main.go

@@ -16,6 +16,7 @@ import (
 	"github.com/edgelesssys/contrast/coordinator/history"
 	"github.com/edgelesssys/contrast/coordinator/internal/authority"
 	"github.com/edgelesssys/contrast/internal/atls"
+	"github.com/edgelesssys/contrast/internal/atls/issuer"
 	"github.com/edgelesssys/contrast/internal/grpc/atlscredentials"
 	"github.com/edgelesssys/contrast/internal/logger"
 	"github.com/edgelesssys/contrast/internal/meshapi"
@@ -154,7 +155,7 @@ func newServerMetrics(reg *prometheus.Registry) *grpcprometheus.ServerMetrics {
 }
 
 func newGRPCServer(serverMetrics *grpcprometheus.ServerMetrics, log *slog.Logger) (*grpc.Server, error) {
-	issuer, err := atls.PlatformIssuer(log)
+	issuer, err := issuer.New(log)
 	if err != nil {
 		return nil, fmt.Errorf("creating issuer: %w", err)
 	}

initializer/main.go

@@ -18,6 +18,7 @@ import (
 	"time"
 
 	"github.com/edgelesssys/contrast/internal/atls"
+	"github.com/edgelesssys/contrast/internal/atls/issuer"
 	"github.com/edgelesssys/contrast/internal/grpc/dialer"
 	"github.com/edgelesssys/contrast/internal/logger"
 	"github.com/edgelesssys/contrast/internal/meshapi"
@@ -55,7 +56,7 @@ func run() (retErr error) {
 		return fmt.Errorf("generating key: %w", err)
 	}
 
-	issuer, err := atls.PlatformIssuer(log)
+	issuer, err := issuer.New(log)
 	if err != nil {
 		return fmt.Errorf("creating issuer: %w", err)
 	}

internal/atls/issuer/issuer.go

@@ -0,0 +1,44 @@
+// Copyright 2024 Edgeless Systems GmbH
+// SPDX-License-Identifier: AGPL-3.0-only
+
+package issuer
+
+import (
+	"context"
+	"encoding/asn1"
+	"fmt"
+	"log/slog"
+
+	snpissuer "github.com/edgelesssys/contrast/internal/attestation/snp/issuer"
+	tdxissuer "github.com/edgelesssys/contrast/internal/attestation/tdx/issuer"
+	"github.com/edgelesssys/contrast/internal/logger"
+	"github.com/klauspost/cpuid/v2"
+)
+
+// New creates an attestation issuer for the current platform.
+func New(log *slog.Logger) (Issuer, error) {
+	cpuid.Detect()
+	switch {
+	case cpuid.CPU.Supports(cpuid.SEV_SNP):
+		return snpissuer.New(
+			logger.NewWithAttrs(logger.NewNamed(log, "issuer"), map[string]string{"tee-type": "snp"}),
+		), nil
+	case cpuid.CPU.Supports(cpuid.TDX_GUEST):
+		return tdxissuer.New(
+			logger.NewWithAttrs(logger.NewNamed(log, "issuer"), map[string]string{"tee-type": "tdx"}),
+		), nil
+	default:
+		return nil, fmt.Errorf("unsupported platform: %T", cpuid.CPU)
+	}
+}
+
+// Issuer issues an attestation document.
+type Issuer interface {
+	Getter
+	Issue(ctx context.Context, userData []byte, nonce []byte) (quote []byte, err error)
+}
+
+// Getter returns an ASN.1 Object Identifier.
+type Getter interface {
+	OID() asn1.ObjectIdentifier
+}

internal/attestation/snp/issuer.go → internal/attestation/snp/issuer/issuer.go

@@ -1,7 +1,8 @@
 // Copyright 2024 Edgeless Systems GmbH
 // SPDX-License-Identifier: AGPL-3.0-only
 
-package snp
+// package issuer provides functions to create an aTLS issuer.
+package issuer
 
 import (
 	"context"
@@ -27,8 +28,8 @@ type Issuer struct {
 	logger     *slog.Logger
 }
 
-// NewIssuer returns a new Issuer.
-func NewIssuer(log *slog.Logger) *Issuer {
+// New returns a new Issuer.
+func New(log *slog.Logger) *Issuer {
 	return &Issuer{
 		thimGetter: NewTHIMGetter(http.DefaultClient),
 		logger:     log,

internal/attestation/snp/thim.go → internal/attestation/snp/issuer/thim.go

@@ -1,7 +1,7 @@
 // Copyright 2024 Edgeless Systems GmbH
 // SPDX-License-Identifier: AGPL-3.0-only
 
-package snp
+package issuer
 
 import (
 	"encoding/json"

internal/attestation/tdx/issuer.go → internal/attestation/tdx/issuer/issuer.go

@@ -1,7 +1,7 @@
 // Copyright 2024 Edgeless Systems GmbH
 // SPDX-License-Identifier: AGPL-3.0-only
 
-package tdx
+package issuer
 
 import (
 	"context"
@@ -23,8 +23,8 @@ type Issuer struct {
 	logger *slog.Logger
 }
 
-// NewIssuer returns a new Issuer.
-func NewIssuer(log *slog.Logger) *Issuer {
+// New returns a new Issuer.
+func New(log *slog.Logger) *Issuer {
 	return &Issuer{
 		logger: log,
 	}