Refactor how host data is signed, now it's simpler and probably more secure

default.nix

@@ -168,6 +168,7 @@ in rec {
     export PATH=${pkgs.lib.makeBinPath [
       appImage
       pkgs.busybox
+      pkgs.yq-go
       pkgs.jq
       pkgs.dig
     ]}

go/bootstrap/bootstrap.go

@@ -10,6 +10,7 @@ import (
 	"isle/admin"
 	"isle/garage"
 	"isle/nebula"
+	"net"
 	"os"
 	"path/filepath"
 	"sort"
@@ -27,31 +28,81 @@ func AppDirPath(appDirPath string) string {
 	return filepath.Join(appDirPath, "share/bootstrap.json")
 }
 
+// Garage contains parameters needed to connect to and use the garage cluster.
+type Garage struct {
+	// TODO RPCSecret and GlobalBucketS3APICredentials are duplicated here and
+	// in AdminCreationParams, might as well just use them from there
+	RPCSecret                    string
+	AdminToken                   string
+	GlobalBucketS3APICredentials garage.S3APICredentials
+}
+
 // Bootstrap is used for accessing all information contained within a
 // bootstrap.json file.
 type Bootstrap struct {
 	AdminCreationParams admin.CreationParams
+	CAPublicCredentials nebula.CAPublicCredentials
+	Garage              Garage
 
-	Hosts    map[string]Host
+	PrivateCredentials nebula.HostPrivateCredentials
-	HostName string
+	HostAssigned       `json:"-"`
+	SignedHostAssigned nebula.Signed[HostAssigned] // signed by CA
 
-	Nebula struct {
+	Hosts map[string]Host
-		CAPublicCredentials     nebula.CAPublicCredentials
+}
-		HostCredentials         nebula.HostCredentials
+
-		SignedPublicCredentials string
+// New initializes and returns a new Bootstrap file for a new host. This
+// function assigns Hosts an empty map.
+func New(
+	caCreds nebula.CACredentials,
+	adminCreationParams admin.CreationParams,
+	garage Garage,
+	name string,
+	ip net.IP,
+) (
+	Bootstrap, error,
+) {
+	hostPubCreds, hostPrivCreds, err := nebula.NewHostCredentials(
+		caCreds, name, ip,
+	)
+	if err != nil {
+		return Bootstrap{}, fmt.Errorf("generating host credentials: %w", err)
 	}
 
-	Garage struct {
+	assigned := HostAssigned{
-		RPCSecret                    string
+		Name:              name,
-		AdminToken                   string
+		PublicCredentials: hostPubCreds,
-		GlobalBucketS3APICredentials garage.S3APICredentials
 	}
+
+	signedAssigned, err := nebula.Sign(assigned, caCreds.SigningPrivateKey)
+	if err != nil {
+		return Bootstrap{}, fmt.Errorf("signing assigned fields: %w", err)
+	}
+
+	return Bootstrap{
+		AdminCreationParams: adminCreationParams,
+		CAPublicCredentials: caCreds.Public,
+		Garage:              garage,
+		PrivateCredentials:  hostPrivCreds,
+		HostAssigned:        assigned,
+		SignedHostAssigned:  signedAssigned,
+		Hosts:               map[string]Host{},
+	}, nil
 }
 
 // FromReader reads a bootstrap file from the given io.Reader.
 func FromReader(r io.Reader) (Bootstrap, error) {
 	var b Bootstrap
+
 	err := json.NewDecoder(r).Decode(&b)
+	if err != nil {
+		return Bootstrap{}, fmt.Errorf("decoding json: %w", err)
+	}
+
+	if b.HostAssigned, err = b.SignedHostAssigned.UnwrapUnsafe(); err != nil {
+		return Bootstrap{}, fmt.Errorf("unwrapping host assigned: %w", err)
+	}
+
 	return b, err
 }
 
@@ -76,9 +127,9 @@ func (b Bootstrap) WriteTo(into io.Writer) error {
 // HostName isn't found in the Hosts map.
 func (b Bootstrap) ThisHost() Host {
 
-	host, ok := b.Hosts[b.HostName]
+	host, ok := b.Hosts[b.Name]
 	if !ok {
-		panic(fmt.Sprintf("hostname %q not defined in bootstrap's hosts", b.HostName))
+		panic(fmt.Sprintf("hostname %q not defined in bootstrap's hosts", b.Name))
 	}
 
 	return host

go/bootstrap/garage_global_bucket.go

@@ -8,7 +8,6 @@ import (
 	"isle/garage"
 	"isle/nebula"
 	"path/filepath"
-	"strings"
 
 	"github.com/mediocregopher/mediocre-go-lib/v2/mctx"
 	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
@@ -24,26 +23,24 @@ const (
 // into garage so that other hosts are able to see relevant configuration for
 // it.
 func (b Bootstrap) PutGarageBoostrapHost(ctx context.Context) error {
+	var (
+		host   = b.ThisHost()
+		client = b.GlobalBucketS3APIClient()
+	)
 
-	host := b.ThisHost()
+	configured, err := nebula.Sign(
-	client := b.GlobalBucketS3APIClient()
+		host.HostConfigured, b.PrivateCredentials.SigningPrivateKey,
-
+	)
-	// the base Bootstrap has the public credentials signed by the CA, but we
-	// need this to be presented in the data stored into garage, so other hosts
-	// can verify that the stored host object is signed by the host public key,
-	// and that the host public key is signed by the CA.
-	host.Nebula.SignedPublicCredentials = b.Nebula.SignedPublicCredentials
-
-	hostB, err := json.Marshal(host)
 	if err != nil {
-		return fmt.Errorf("encoding host data: %w", err)
+		return fmt.Errorf("signing host configured data: %w", err)
 	}
 
-	buf := new(bytes.Buffer)
+	hostB, err := json.Marshal(AuthenticatedHost{
-
+		Assigned:   b.SignedHostAssigned,
-	err = nebula.SignAndWrap(buf, b.Nebula.HostCredentials.SigningPrivateKeyPEM, hostB)
+		Configured: configured,
+	})
 	if err != nil {
-		return fmt.Errorf("signing encoded host data: %w", err)
+		return fmt.Errorf("encoding host data: %w", err)
 	}
 
 	filePath := filepath.Join(
@@ -52,7 +49,11 @@ func (b Bootstrap) PutGarageBoostrapHost(ctx context.Context) error {
 	)
 
 	_, err = client.PutObject(
-		ctx, garage.GlobalBucket, filePath, buf, int64(buf.Len()),
+		ctx,
+		garage.GlobalBucket,
+		filePath,
+		bytes.NewReader(hostB),
+		int64(len(hostB)),
 		minio.PutObjectOptions{},
 	)
 
@@ -119,49 +120,19 @@ func (b Bootstrap) GetGarageBootstrapHosts(
 			return nil, fmt.Errorf("retrieving object %q: %w", objInfo.Key, err)
 		}
 
-		hostB, hostSig, err := nebula.Unwrap(obj)
+		var authedHost AuthenticatedHost
+
+		err = json.NewDecoder(obj).Decode(&authedHost)
 		obj.Close()
 
 		if err != nil {
-			return nil, fmt.Errorf("unwrapping signature from %q: %w", objInfo.Key, err)
+			logger.Warn(ctx, "object contains invalid json", err)
+			continue
 		}
 
-		var host Host
+		host, err := authedHost.Unwrap(b.CAPublicCredentials)
-		if err = json.Unmarshal(hostB, &host); err != nil {
-			return nil, fmt.Errorf("decoding object %q: %w", objInfo.Key, err)
-		}
-
-		hostPublicCredsB, hostPublicCredsSig, err := nebula.Unwrap(
-			strings.NewReader(host.Nebula.SignedPublicCredentials),
-		)
-
 		if err != nil {
-			logger.Warn(ctx, "unwrapping signed public creds", err)
+			logger.Warn(ctx, "host could not be authenticated", err)
-			continue
-		}
-
-		err = nebula.ValidateSignature(
-			b.Nebula.CAPublicCredentials.SigningKeyPEM,
-			hostPublicCredsB,
-			hostPublicCredsSig,
-		)
-
-		if err != nil {
-			logger.Warn(ctx, "invalid signed public creds", err)
-			continue
-		}
-
-		var hostPublicCreds nebula.HostPublicCredentials
-		if err := json.Unmarshal(hostPublicCredsB, &hostPublicCreds); err != nil {
-			logger.Warn(ctx, "unmarshaling signed public creds", err)
-			continue
-		}
-
-		err = nebula.ValidateSignature(hostPublicCreds.SigningKeyPEM, hostB, hostSig)
-
-		if err != nil {
-			logger.Warn(ctx, "invalid host data", err)
-			continue
 		}
 
 		hosts[host.Name] = host

go/bootstrap/hosts.go

@@ -1,44 +1,15 @@
 package bootstrap
 
 import (
-	"bytes"
-	"encoding/json"
 	"fmt"
 	"isle/nebula"
 	"net"
-	"strings"
 )
 
 // NebulaHost describes the nebula configuration of a Host which is relevant for
 // other hosts to know.
 type NebulaHost struct {
-	SignedPublicCredentials string
+	PublicAddr string
-	PublicAddr              string
-}
-
-// NewNebulaHostSignedPublicCredentials constructs the SignedPublicCredentials
-// field of the NebulaHost struct, using the CACredentials to sign the
-// HostPublicCredentials.
-func NewNebulaHostSignedPublicCredentials(
-	caCreds nebula.CACredentials,
-	hostPublicCreds nebula.HostPublicCredentials,
-) (
-	string, error,
-) {
-
-	hostPublicCredsB, err := json.Marshal(hostPublicCreds)
-	if err != nil {
-		return "", fmt.Errorf("marshaling host's public credentials: %w", err)
-	}
-
-	buf := new(bytes.Buffer)
-
-	err = nebula.SignAndWrap(buf, caCreds.SigningPrivateKeyPEM, hostPublicCredsB)
-	if err != nil {
-		return "", fmt.Errorf("signing host's public credentials: %w", err)
-	}
-
-	return buf.String(), nil
 }
 
 // GarageHost describes a single garage instance in the GarageHost.
@@ -54,12 +25,51 @@ type GarageHost struct {
 	Instances []GarageHostInstance
 }
 
-// Host consolidates all information about a single host from the bootstrap
+// HostAssigned are all fields related to a host which were assigned to it by an
-// file.
+// admin.
+type HostAssigned struct {
+	Name              string
+	PublicCredentials nebula.HostPublicCredentials
+}
+
+// HostConfigured are all the fields a host can configure for itself.
+type HostConfigured struct {
+	Nebula NebulaHost `json:",omitempty"`
+	Garage GarageHost `json:",omitempty"`
+}
+
+// AuthenticatedHost wraps all the data about a host which other hosts may know
+// about it, such that those hosts can authenticate that the data is valid and
+// approved by an admin.
+type AuthenticatedHost struct {
+	Assigned   nebula.Signed[HostAssigned]   // signed by CA
+	Configured nebula.Signed[HostConfigured] // signed by host
+}
+
+// Unwrap attempts to authenticate and unwrap the Host embedded in this
+// instance. nebula.ErrInvalidSignature is returned if any signatures are
+// invalid.
+func (ah AuthenticatedHost) Unwrap(caCreds nebula.CAPublicCredentials) (Host, error) {
+	assigned, err := ah.Assigned.Unwrap(caCreds.SigningKey)
+	if err != nil {
+		return Host{}, fmt.Errorf("unwrapping assigned fields using CA public key: %w", err)
+	}
+
+	configured, err := ah.Configured.Unwrap(assigned.PublicCredentials.SigningKey)
+	if err != nil {
+		return Host{}, fmt.Errorf("unwrapping configured fields using host public key: %w", err)
+	}
+
+	return Host{assigned, configured}, nil
+}
+
+// Host contains all data bout a host which other hosts may know about it.
+//
+// A Host should only be obtained over the network as an AuthenticatedHost, and
+// subsequently Unwrapped.
 type Host struct {
-	Name   string
+	HostAssigned
-	Nebula NebulaHost
+	HostConfigured
-	Garage GarageHost
 }
 
 // IP returns the IP address encoded in the Host's nebula certificate, or panics
@@ -68,21 +78,7 @@ type Host struct {
 // This assumes that the Host and its data has already been verified against the
 // CA signing key.
 func (h Host) IP() net.IP {
-
+	ip, err := nebula.IPFromHostCertPEM(h.PublicCredentials.CertPEM)
-	hostPublicCredsB, _, err := nebula.Unwrap(
-		strings.NewReader(h.Nebula.SignedPublicCredentials),
-	)
-
-	if err != nil {
-		panic(fmt.Errorf("unwrapping host's signed public credentials: %w", err))
-	}
-
-	var hostPublicCreds nebula.HostPublicCredentials
-	if err := json.Unmarshal(hostPublicCredsB, &hostPublicCreds); err != nil {
-		panic(fmt.Errorf("unmarshaling host's public credentials: %w", err))
-	}
-
-	ip, err := nebula.IPFromHostCertPEM(hostPublicCreds.CertPEM)
 	if err != nil {
 		panic(fmt.Errorf("could not parse IP out of cert for host %q: %w", h.Name, err))
 	}

go/cmd/entrypoint/admin.go

@@ -142,46 +142,28 @@ var subCmdAdminCreateNetwork = subCmd{
 			return fmt.Errorf("creating nebula CA cert: %w", err)
 		}
 
-		nebulaHostCreds, err := nebula.NewHostCredentials(nebulaCACreds, *hostName, ip)
-		if err != nil {
-			return fmt.Errorf("creating nebula cert for host: %w", err)
-		}
-
-		nebulaHostSignedPublicCreds, err := bootstrap.NewNebulaHostSignedPublicCredentials(
-			nebulaCACreds,
-			nebulaHostCreds.Public,
-		)
-
-		if err != nil {
-			return fmt.Errorf("creating signed public credentials for host: %w", err)
-		}
-
 		adminCreationParams := admin.CreationParams{
 			ID:     randStr(32),
 			Name:   *name,
 			Domain: *domain,
 		}
 
-		hostBootstrap := bootstrap.Bootstrap{
+		garageBootstrap := bootstrap.Garage{
-			AdminCreationParams: adminCreationParams,
+			RPCSecret:                    randStr(32),
-			Hosts: map[string]bootstrap.Host{
+			AdminToken:                   randStr(32),
-				*hostName: bootstrap.Host{
+			GlobalBucketS3APICredentials: garage.NewS3APICredentials(),
-					Name: *hostName,
-					Nebula: bootstrap.NebulaHost{
-						SignedPublicCredentials: nebulaHostSignedPublicCreds,
-					},
-				},
-			},
-			HostName: *hostName,
 		}
 
-		hostBootstrap.Nebula.CAPublicCredentials = nebulaCACreds.Public
+		hostBootstrap, err := bootstrap.New(
-		hostBootstrap.Nebula.HostCredentials = nebulaHostCreds
+			nebulaCACreds,
-		hostBootstrap.Nebula.SignedPublicCredentials = nebulaHostSignedPublicCreds
+			adminCreationParams,
-
+			garageBootstrap,
-		hostBootstrap.Garage.RPCSecret = randStr(32)
+			*hostName,
-		hostBootstrap.Garage.AdminToken = randStr(32)
+			ip,
-		hostBootstrap.Garage.GlobalBucketS3APICredentials = garage.NewS3APICredentials()
+		)
+		if err != nil {
+			return fmt.Errorf("initializing bootstrap data: %w", err)
+		}
 
 		if hostBootstrap, daemonConfig, err = coalesceDaemonConfigAndBootstrap(hostBootstrap, daemonConfig); err != nil {
 			return fmt.Errorf("merging daemon config into bootstrap data: %w", err)
@@ -263,7 +245,7 @@ var subCmdAdminCreateNetwork = subCmd{
 var subCmdAdminCreateBootstrap = subCmd{
 	name:      "create-bootstrap",
 	descr:     "Creates a new bootstrap.json file for a particular host and writes it to stdout",
-	checkLock: true,
+	checkLock: false,
 	do: func(subCmdCtx subCmdCtx) error {
 
 		flags := subCmdCtx.flagSet(false)
@@ -306,39 +288,29 @@ var subCmdAdminCreateBootstrap = subCmd{
 			return fmt.Errorf("reading admin.json with --admin-path of %q: %w", *adminPath, err)
 		}
 
+		garageBootstrap := bootstrap.Garage{
+			RPCSecret:                    adm.Garage.RPCSecret,
+			AdminToken:                   randStr(32),
+			GlobalBucketS3APICredentials: adm.Garage.GlobalBucketS3APICredentials,
+		}
+
+		newHostBootstrap, err := bootstrap.New(
+			adm.Nebula.CACredentials,
+			adm.CreationParams,
+			garageBootstrap,
+			*hostName,
+			ip,
+		)
+		if err != nil {
+			return fmt.Errorf("initializing bootstrap data: %w", err)
+		}
+
 		hostBootstrap, err := loadHostBootstrap()
 		if err != nil {
 			return fmt.Errorf("loading host bootstrap: %w", err)
 		}
 
-		nebulaHostCreds, err := nebula.NewHostCredentials(adm.Nebula.CACredentials, *hostName, ip)
+		newHostBootstrap.Hosts = hostBootstrap.Hosts
-		if err != nil {
-			return fmt.Errorf("creating new nebula host key/cert: %w", err)
-		}
-
-		nebulaHostSignedPublicCreds, err := bootstrap.NewNebulaHostSignedPublicCredentials(
-			adm.Nebula.CACredentials,
-			nebulaHostCreds.Public,
-		)
-
-		if err != nil {
-			return fmt.Errorf("creating signed public credentials for host: %w", err)
-		}
-
-		newHostBootstrap := bootstrap.Bootstrap{
-			AdminCreationParams: adm.CreationParams,
-
-			Hosts:    hostBootstrap.Hosts,
-			HostName: *hostName,
-		}
-
-		newHostBootstrap.Nebula.CAPublicCredentials = adm.Nebula.CACredentials.Public
-		newHostBootstrap.Nebula.HostCredentials = nebulaHostCreds
-		newHostBootstrap.Nebula.SignedPublicCredentials = nebulaHostSignedPublicCreds
-
-		newHostBootstrap.Garage.RPCSecret = adm.Garage.RPCSecret
-		newHostBootstrap.Garage.AdminToken = randStr(32)
-		newHostBootstrap.Garage.GlobalBucketS3APICredentials = adm.Garage.GlobalBucketS3APICredentials
 
 		return newHostBootstrap.WriteTo(os.Stdout)
 	},

go/cmd/entrypoint/daemon_util.go

@@ -2,10 +2,10 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"isle/bootstrap"
 	"isle/daemon"
 	"isle/garage"
-	"fmt"
 	"time"
 )
 
@@ -17,10 +17,11 @@ func coalesceDaemonConfigAndBootstrap(
 ) {
 
 	host := bootstrap.Host{
-		Name: hostBootstrap.HostName,
+		HostAssigned: hostBootstrap.HostAssigned,
-		Nebula: bootstrap.NebulaHost{
+		HostConfigured: bootstrap.HostConfigured{
-			SignedPublicCredentials: hostBootstrap.Nebula.SignedPublicCredentials,
+			Nebula: bootstrap.NebulaHost{
-			PublicAddr:              daemonConfig.VPN.PublicAddr,
+				PublicAddr: daemonConfig.VPN.PublicAddr,
+			},
 		},
 	}
 

go/cmd/entrypoint/nebula.go

@@ -23,7 +23,7 @@ var subCmdNebulaShow = subCmd{
 			return fmt.Errorf("loading host bootstrap: %w", err)
 		}
 
-		caPublicCreds := hostBootstrap.Nebula.CAPublicCredentials
+		caPublicCreds := hostBootstrap.CAPublicCredentials
 		caCert, _, err := cert.UnmarshalNebulaCertificateFromPEM([]byte(caPublicCreds.CertPEM))
 		if err != nil {
 			return fmt.Errorf("unmarshaling ca.crt: %w", err)

go/cmd/entrypoint/nebula_util.go

@@ -58,9 +58,9 @@ func nebulaPmuxProcConfig(
 
 	config := map[string]interface{}{
 		"pki": map[string]string{
-			"ca":   hostBootstrap.Nebula.CAPublicCredentials.CertPEM,
+			"ca":   hostBootstrap.CAPublicCredentials.CertPEM,
-			"cert": hostBootstrap.Nebula.HostCredentials.Public.CertPEM,
+			"cert": hostBootstrap.PublicCredentials.CertPEM,
-			"key":  hostBootstrap.Nebula.HostCredentials.PrivateKeyPEM,
+			"key":  hostBootstrap.PrivateCredentials.PrivateKeyPEM,
 		},
 		"static_host_map": staticHostMap,
 		"punchy": map[string]bool{

go/nebula/keys.go

@@ -0,0 +1,72 @@
+package nebula
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/json"
+	"fmt"
+
+	"github.com/slackhq/nebula/cert"
+)
+
+// SigningPrivateKey wraps an ed25519.PrivateKey to provide convenient JSON
+// (un)marshaling methods.
+type SigningPrivateKey ed25519.PrivateKey
+
+// MarshalJSON implements the json.Marshaler interface.
+func (k SigningPrivateKey) MarshalJSON() ([]byte, error) {
+	pemStr := cert.MarshalEd25519PrivateKey(ed25519.PrivateKey(k))
+	return json.Marshal(string(pemStr))
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (k *SigningPrivateKey) UnmarshalJSON(b []byte) error {
+	var pemStr string
+	if err := json.Unmarshal(b, &pemStr); err != nil {
+		return fmt.Errorf("unmarshaling into string: %w", err)
+	}
+
+	key, _, err := cert.UnmarshalEd25519PrivateKey([]byte(pemStr))
+	if err != nil {
+		return fmt.Errorf("unmarshaling from PEM: %w", err)
+	}
+
+	*k = SigningPrivateKey(key)
+	return nil
+}
+
+// SigningPublicKey wraps an ed25519.PublicKey to provide convenient JSON
+// (un)marshaling methods.
+type SigningPublicKey ed25519.PublicKey
+
+// MarshalJSON implements the json.Marshaler interface.
+func (k SigningPublicKey) MarshalJSON() ([]byte, error) {
+	pemStr := cert.MarshalEd25519PublicKey(ed25519.PublicKey(k))
+	return json.Marshal(string(pemStr))
+}
+
+// MarshalJSON implements the json.Unmarshaler interface.
+func (k *SigningPublicKey) UnmarshalJSON(b []byte) error {
+	var pemStr string
+	if err := json.Unmarshal(b, &pemStr); err != nil {
+		return fmt.Errorf("unmarshaling into string: %w", err)
+	}
+
+	key, _, err := cert.UnmarshalEd25519PublicKey([]byte(pemStr))
+	if err != nil {
+		return fmt.Errorf("unmarshaling from PEM: %w", err)
+	}
+
+	*k = SigningPublicKey(key)
+	return nil
+}
+
+// GenerateSigningPair generates and returns a new key pair which can be used
+// for signing arbitrary blobs of bytes.
+func GenerateSigningPair() (SigningPublicKey, SigningPrivateKey) {
+	pub, priv, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		panic(fmt.Errorf("generating ed25519 key: %w", err))
+	}
+	return SigningPublicKey(pub), SigningPrivateKey(priv)
+}

go/nebula/keys_test.go

@@ -0,0 +1,52 @@
+package nebula
+
+import (
+	"bytes"
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+func TestSigningKeysJSON(t *testing.T) {
+	pub, priv := GenerateSigningPair()
+
+	t.Run("SigningPublicKey", func(t *testing.T) {
+		pubJSON, err := json.Marshal(pub)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !strings.HasPrefix(string(pubJSON), `"-----BEGIN `) {
+			t.Fatalf("pub key didn't marshal to PEM: %q", pubJSON)
+		}
+
+		var pub2 SigningPublicKey
+		if err := json.Unmarshal(pubJSON, &pub2); err != nil {
+			t.Fatal(err)
+		}
+
+		if !bytes.Equal([]byte(pub), []byte(pub2)) {
+			t.Fatalf("json unmarshaling got different result: %q", pub2)
+		}
+	})
+
+	t.Run("SigningPrivateKey", func(t *testing.T) {
+		privJSON, err := json.Marshal(priv)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !strings.HasPrefix(string(privJSON), `"-----BEGIN `) {
+			t.Fatalf("priv key didn't marshal to PEM: %q", privJSON)
+		}
+
+		var priv2 SigningPrivateKey
+		if err := json.Unmarshal(privJSON, &priv2); err != nil {
+			t.Fatal(err)
+		}
+
+		if !bytes.Equal([]byte(priv), []byte(priv2)) {
+			t.Fatalf("json unmarshaling got different result: %q", priv2)
+		}
+	})
+}

go/nebula/nebula.go

@@ -3,11 +3,7 @@
 package nebula
 
 import (
-	"crypto"
-	"crypto/ed25519"
 	"crypto/rand"
-	"encoding/pem"
-	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -17,38 +13,33 @@ import (
 	"golang.org/x/crypto/curve25519"
 )
 
-// ErrInvalidSignature is returned from functions when a signature validation
-// fails.
-var ErrInvalidSignature = errors.New("invalid signature")
-
 // HostPublicCredentials contains certificate and signing public keys which are
 // able to be broadcast publicly.
 type HostPublicCredentials struct {
-	CertPEM       string
+	CertPEM    string
-	SigningKeyPEM string
+	SigningKey SigningPublicKey
 }
 
-// HostCredentials contains the certificate and private key files which will
+// HostPrivateCredentials contains the private key files which will
-// need to be present on a particular host. Each file is PEM encoded.
+// need to be present on a particular host.
-type HostCredentials struct {
+type HostPrivateCredentials struct {
-	Public               HostPublicCredentials
+	PrivateKeyPEM     string
-	PrivateKeyPEM        string
+	SigningPrivateKey SigningPrivateKey
-	SigningPrivateKeyPEM string
 }
 
 // CAPublicCredentials contains certificate and signing public keys which are
 // able to be broadcast publicly. The signing public key is the same one which
 // is embedded into the certificate.
 type CAPublicCredentials struct {
-	CertPEM       string
+	CertPEM    string
-	SigningKeyPEM string // TODO remove redundant field
+	SigningKey SigningPublicKey
 }
 
 // CACredentials contains the certificate and private files which can be used to
 // create and validate HostCredentials. Each file is PEM encoded.
 type CACredentials struct {
-	Public               CAPublicCredentials
+	Public            CAPublicCredentials
-	SigningPrivateKeyPEM string
+	SigningPrivateKey SigningPrivateKey
 }
 
 // NewHostCertPEM generates and signs a new host certificate containing the
@@ -63,11 +54,6 @@ func NewHostCertPEM(
 		return "", fmt.Errorf("unmarshaling public key PEM: %w", err)
 	}
 
-	caSigningKey, _, err := cert.UnmarshalEd25519PrivateKey([]byte(caCreds.SigningPrivateKeyPEM))
-	if err != nil {
-		return "", fmt.Errorf("unmarshaling ca.key: %w", err)
-	}
-
 	caCert, _, err := cert.UnmarshalNebulaCertificateFromPEM([]byte(caCreds.Public.CertPEM))
 	if err != nil {
 		return "", fmt.Errorf("unmarshaling ca.crt: %w", err)
@@ -104,7 +90,7 @@ func NewHostCertPEM(
 		return "", fmt.Errorf("validating certificate constraints: %w", err)
 	}
 
-	if err := hostCert.Sign(caSigningKey); err != nil {
+	if err := signCert(&hostCert, caCreds.SigningPrivateKey); err != nil {
 		return "", fmt.Errorf("signing host cert with ca.key: %w", err)
 	}
 
@@ -121,46 +107,45 @@ func NewHostCertPEM(
 func NewHostCredentials(
 	caCreds CACredentials, hostName string, ip net.IP,
 ) (
-	HostCredentials, error,
+	pub HostPublicCredentials, priv HostPrivateCredentials, err error,
 ) {
 
 	// The logic here is largely based on
 	// https://github.com/slackhq/nebula/blob/v1.4.0/cmd/nebula-cert/sign.go
 
-	signingPubKey, signingPrivKey, err := ed25519.GenerateKey(rand.Reader)
-	if err != nil {
-		panic(fmt.Errorf("generating ed25519 key: %w", err))
-	}
-
-	signingPrivKeyPEM := cert.MarshalEd25519PrivateKey(signingPrivKey)
-	signingPubKeyPEM := cert.MarshalEd25519PublicKey(signingPubKey)
-
 	var hostPub, hostKey []byte
 	{
 		var pubkey, privkey [32]byte
-		if _, err := io.ReadFull(rand.Reader, privkey[:]); err != nil {
+		if _, err = io.ReadFull(rand.Reader, privkey[:]); err != nil {
-			return HostCredentials{}, fmt.Errorf("reading random bytes to form private key: %w", err)
+			err = fmt.Errorf("reading random bytes to form private key: %w", err)
+			return
 		}
 		curve25519.ScalarBaseMult(&pubkey, &privkey)
 		hostPub, hostKey = pubkey[:], privkey[:]
 	}
 
+	signingPubKey, signingPrivKey := GenerateSigningPair()
+
 	hostPubPEM := cert.MarshalX25519PublicKey(hostPub)
 	hostKeyPEM := cert.MarshalX25519PrivateKey(hostKey)
 
 	hostCertPEM, err := NewHostCertPEM(caCreds, string(hostPubPEM), hostName, ip)
 	if err != nil {
-		return HostCredentials{}, fmt.Errorf("creating host certificate: %w", err)
+		err = fmt.Errorf("creating host certificate: %w", err)
+		return
 	}
 
-	return HostCredentials{
+	pub = HostPublicCredentials{
-		Public: HostPublicCredentials{
+		CertPEM:    hostCertPEM,
-			CertPEM:       hostCertPEM,
+		SigningKey: signingPubKey,
-			SigningKeyPEM: string(signingPubKeyPEM),
+	}
-		},
+
-		PrivateKeyPEM:        string(hostKeyPEM),
+	priv = HostPrivateCredentials{
-		SigningPrivateKeyPEM: string(signingPrivKeyPEM),
+		PrivateKeyPEM:     string(hostKeyPEM),
-	}, nil
+		SigningPrivateKey: signingPrivKey,
+	}
+
+	return
 }
 
 // NewCACredentials generates a CACredentials. The domain should be the network's root domain,
@@ -170,10 +155,7 @@ func NewCACredentials(domain string, subnet *net.IPNet) (CACredentials, error) {
 	// The logic here is largely based on
 	// https://github.com/slackhq/nebula/blob/v1.4.0/cmd/nebula-cert/ca.go
 
-	signingPubKey, signingPrivKey, err := ed25519.GenerateKey(rand.Reader)
+	signingPubKey, signingPrivKey := GenerateSigningPair()
-	if err != nil {
-		panic(fmt.Errorf("generating ed25519 key: %w", err))
-	}
 
 	now := time.Now()
 	expireAt := now.Add(2 * 365 * 24 * time.Hour)
@@ -189,13 +171,10 @@ func NewCACredentials(domain string, subnet *net.IPNet) (CACredentials, error) {
 		},
 	}
 
-	if err := caCert.Sign(signingPrivKey); err != nil {
+	if err := signCert(&caCert, signingPrivKey); err != nil {
 		return CACredentials{}, fmt.Errorf("signing caCert: %w", err)
 	}
 
-	signingPrivKeyPEM := cert.MarshalEd25519PrivateKey(signingPrivKey)
-	signingPubKeyPEM := cert.MarshalEd25519PublicKey(signingPubKey)
-
 	certPEM, err := caCert.MarshalToPEM()
 	if err != nil {
 		return CACredentials{}, fmt.Errorf("marshaling caCert: %w", err)
@@ -203,10 +182,10 @@ func NewCACredentials(domain string, subnet *net.IPNet) (CACredentials, error) {
 
 	return CACredentials{
 		Public: CAPublicCredentials{
-			CertPEM:       string(certPEM),
+			CertPEM:    string(certPEM),
-			SigningKeyPEM: string(signingPubKeyPEM),
+			SigningKey: signingPubKey,
 		},
-		SigningPrivateKeyPEM: string(signingPrivKeyPEM),
+		SigningPrivateKey: signingPrivKey,
 	}, nil
 }
 
@@ -226,76 +205,3 @@ func IPFromHostCertPEM(hostCertPEM string) (net.IP, error) {
 
 	return ips[0].IP, nil
 }
-
-// SignAndWrap signs the given bytes using the host key, and writes an
-// encoded, versioned structure containing the signature and the given bytes.
-func SignAndWrap(into io.Writer, signingKeyPEM string, b []byte) error {
-
-	key, _, err := cert.UnmarshalEd25519PrivateKey([]byte(signingKeyPEM))
-	if err != nil {
-		return fmt.Errorf("unmarshaling private key: %w", err)
-	}
-
-	sig, err := key.Sign(rand.Reader, b, crypto.Hash(0))
-	if err != nil {
-		return fmt.Errorf("generating signature: %w", err)
-	}
-
-	if _, err := into.Write([]byte("0")); err != nil {
-		return fmt.Errorf("writing version byte: %w", err)
-	}
-
-	err = pem.Encode(into, &pem.Block{
-		Type:  "NEBULA ED25519 SIGNATURE",
-		Bytes: sig,
-	})
-
-	if err != nil {
-		return fmt.Errorf("writing PEM encoding of signature: %w", err)
-	}
-
-	if _, err := into.Write(b); err != nil {
-		return fmt.Errorf("writing input bytes: %w", err)
-	}
-
-	return nil
-}
-
-// Unwrap reads a stream of bytes which was produced by SignAndWrap, and returns
-// the original input to SignAndWrap as well as the signature which was
-// created. ValidateSignature can be used to validate the signature.
-func Unwrap(from io.Reader) (b, sig []byte, err error) {
-
-	full, err := io.ReadAll(from)
-	if err != nil {
-		return nil, nil, fmt.Errorf("reading full input: %w", err)
-	} else if len(full) < 3 {
-		return nil, nil, fmt.Errorf("input too small")
-	} else if full[0] != '0' {
-		return nil, nil, fmt.Errorf("unexpected version byte: %d", full[0])
-	}
-
-	full = full[1:]
-
-	pemBlock, rest := pem.Decode(full)
-	if pemBlock == nil {
-		return nil, nil, fmt.Errorf("PEM-encoded signature could not be decoded")
-	}
-
-	return rest, pemBlock.Bytes, nil
-}
-
-// ValidateSignature can be used to validate a signature produced by Unwrap.
-func ValidateSignature(signingPubKeyPEM string, b, sig []byte) error {
-
-	pubKey, _, err := cert.UnmarshalEd25519PublicKey([]byte(signingPubKeyPEM))
-	if err != nil {
-		return fmt.Errorf("unmarshaling certificate as PEM: %w", err)
-	}
-
-	if !ed25519.Verify(pubKey, b, sig) {
-		return ErrInvalidSignature
-	}
-
-	return nil
-}

go/nebula/nebula_test.go

@@ -1,17 +1,15 @@
 package nebula
 
 import (
-	"bytes"
-	"errors"
 	"net"
-	"testing"
 )
 
 var (
-	ip                     net.IP
+	ip                             net.IP
-	ipNet                  *net.IPNet
+	ipNet                          *net.IPNet
-	caCredsA, caCredsB     CACredentials
+	caCredsA, caCredsB             CACredentials
-	hostCredsA, hostCredsB HostCredentials
+	hostPubCredsA, hostPubCredsB   HostPublicCredentials
+	hostPrivCredsA, hostPrivCredsB HostPrivateCredentials
 )
 
 func init() {
@@ -32,40 +30,14 @@ func init() {
 		panic(err)
 	}
 
-	hostCredsA, err = NewHostCredentials(caCredsA, "foo", ip)
+	hostPubCredsA, hostPrivCredsA, err = NewHostCredentials(caCredsA, "foo", ip)
 	if err != nil {
 		panic(err)
 	}
 
-	hostCredsB, err = NewHostCredentials(caCredsB, "bar", ip)
+	hostPubCredsB, hostPrivCredsB, err = NewHostCredentials(caCredsB, "bar", ip)
 	if err != nil {
 		panic(err)
 	}
 
 }
-
-func TestSignAndWrap(t *testing.T) {
-
-	b := []byte("foo bar baz")
-	buf := new(bytes.Buffer)
-
-	if err := SignAndWrap(buf, hostCredsA.SigningPrivateKeyPEM, b); err != nil {
-		t.Fatal(err)
-	}
-
-	gotB, gotSig, err := Unwrap(buf)
-	if err != nil {
-		t.Fatal(err)
-
-	} else if !bytes.Equal(b, gotB) {
-		t.Fatalf("got %q but expected %q", gotB, b)
-	}
-
-	if err := ValidateSignature(hostCredsA.Public.SigningKeyPEM, b, gotSig); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := ValidateSignature(hostCredsB.Public.SigningKeyPEM, b, gotSig); !errors.Is(err, ErrInvalidSignature) {
-		t.Fatalf("expected ErrInvalidSignature but got %v", err)
-	}
-}

go/nebula/signed.go

@@ -0,0 +1,103 @@
+package nebula
+
+import (
+	"crypto"
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/slackhq/nebula/cert"
+)
+
+// ErrInvalidSignature is returned from functions when a signature validation
+// fails.
+var ErrInvalidSignature = errors.New("invalid signature")
+
+func signCert(c *cert.NebulaCertificate, k SigningPrivateKey) error {
+	return c.Sign(ed25519.PrivateKey(k))
+}
+
+// Signed wraps an arbitrary value with a signature which was generated using a
+// SigningPrivateKey. It can be JSON (un)marshaled while preserving all of its
+// properties.
+type Signed[T any] json.RawMessage
+
+type signed[T any] struct {
+	Signature []byte
+	Body      json.RawMessage
+}
+
+// Sign will generate a Signed of the given value by first JSON marshaling it,
+// and then signing the resulting bytes.
+func Sign[T any](v T, k SigningPrivateKey) (Signed[T], error) {
+	var res Signed[T]
+
+	b, err := json.Marshal(v)
+	if err != nil {
+		return res, fmt.Errorf("json marshaling: %w", err)
+	}
+
+	sig, err := ed25519.PrivateKey(k).Sign(rand.Reader, b, crypto.Hash(0))
+	if err != nil {
+		return res, fmt.Errorf("generating signature: %w", err)
+	}
+
+	return json.Marshal(signed[T]{Signature: sig, Body: json.RawMessage(b)})
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (s Signed[T]) MarshalJSON() ([]byte, error) {
+	return []byte(s), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (s *Signed[T]) UnmarshalJSON(b []byte) error {
+	*s = b
+	return nil
+}
+
+// Unwrap produces the original value which Sign was called on, or returns
+// ErrInvalidSignature if the signature is not valid for the value and public
+// key.
+func (s Signed[T]) Unwrap(pubK SigningPublicKey) (T, error) {
+	var (
+		res  T
+		into signed[T]
+	)
+
+	if err := json.Unmarshal(s, &into); err != nil {
+		return res, fmt.Errorf("json unmarshaling outer Signed: %w", err)
+	}
+
+	if !ed25519.Verify(
+		ed25519.PublicKey(pubK), []byte(into.Body), into.Signature,
+	) {
+		return res, ErrInvalidSignature
+	}
+
+	if err := json.Unmarshal(into.Body, &res); err != nil {
+		return res, fmt.Errorf("json unmarshaling: %w", err)
+	}
+
+	return res, nil
+}
+
+// UnwrapUnsafe is like Unwrap, but it will not check the signature.
+func (s Signed[T]) UnwrapUnsafe() (T, error) {
+	var (
+		res  T
+		into signed[T]
+	)
+
+	if err := json.Unmarshal(s, &into); err != nil {
+		return res, fmt.Errorf("json unmarshaling outer Signed: %w", err)
+	}
+
+	if err := json.Unmarshal(into.Body, &res); err != nil {
+		return res, fmt.Errorf("json unmarshaling: %w", err)
+	}
+
+	return res, nil
+}

go/nebula/signed_test.go

@@ -0,0 +1,48 @@
+package nebula
+
+import (
+	"encoding/json"
+	"errors"
+	"testing"
+)
+
+func TestSigned(t *testing.T) {
+	type msg struct {
+		A int
+		B string
+		C bool
+	}
+
+	a := msg{1, "FOO", true}
+
+	signedA, err := Sign(a, hostPrivCredsA.SigningPrivateKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	signedJSON, err := json.Marshal(signedA)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Log(string(signedJSON))
+
+	var signedB Signed[msg]
+	if err := json.Unmarshal(signedJSON, &signedB); err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = signedB.Unwrap(hostPubCredsB.SigningKey)
+	if !errors.Is(err, ErrInvalidSignature) {
+		t.Fatalf("expected ErrInvalidSignature but got %v", err)
+	}
+
+	b, err := signedB.Unwrap(hostPubCredsA.SigningKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if a != b {
+		t.Fatalf("expected:%+v, got:%+v", a, b)
+	}
+}

tests/cases/admin/01-create-network.sh

@@ -12,5 +12,5 @@ source "$UTILS"/with-1-data-1-empty-node-cluster.sh
 bootstrap_file="$XDG_DATA_HOME/isle/bootstrap.json"
 
 [ "$(jq -rc <"$bootstrap_file" '.AdminCreationParams')" = "$(jq -rc <admin.json '.CreationParams')" ]
-[ "$(jq -rc <"$bootstrap_file" '.Nebula.CAPublicCredentials')" = "$(jq -rc <admin.json '.Nebula.CACredentials.Public')" ]
+[ "$(jq -rc <"$bootstrap_file" '.CAPublicCredentials')" = "$(jq -rc <admin.json '.Nebula.CACredentials.Public')" ]
-[ "$(jq -r <"$bootstrap_file" '.HostName')" = "primus" ]
+[ "$(jq -r <"$bootstrap_file" '.SignedHostAssigned.Body.Name')" = "primus" ]

tests/cases/admin/02-create-bootstrap.sh

@@ -5,10 +5,10 @@ adminBS="$XDG_DATA_HOME"/isle/bootstrap.json
 bs="$secondus_bootstrap" # set in with-1-data-1-empty-node-cluster.sh
 
 [ "$(jq -r <"$bs" '.AdminCreationParams')" = "$(jq -r <admin.json '.CreationParams')" ]
-[ "$(jq -r <"$bs" '.HostName')" = "secondus" ]
+[ "$(jq -r <"$bs" '.SignedHostAssigned.Body.Name')" = "secondus" ]
 
-[ "$(jq -r <"$bs" '.Hosts.primus.Nebula.SignedPublicCredentials')" \
+[ "$(jq -r <"$bs" '.Hosts.primus.PublicCredentials')" \
-= "$(jq -r <"$adminBS" '.Nebula.SignedPublicCredentials')" ]
+= "$(jq -r <"$adminBS" '.SignedHostAssigned.Body.PublicCredentials')" ]
 
 [ "$(jq <"$bs" '.Hosts.primus.Garage.Instances|length')" = "3" ]