replace custom API keys with mtls package (#22)

.github/workflows/go.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v3
       with:
-        go-version: 1.22.5
+        go-version: 1.22.7
         check-latest: true
     - name: Check out code
       uses: actions/checkout@v3
@@ -40,7 +40,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v3
       with:
-        go-version: 1.22.5
+        go-version: 1.22.7
         check-latest: true
     - name: Check out code
       uses: actions/checkout@v3
@@ -57,7 +57,7 @@ jobs:
       uses: actions/checkout@v3
     - uses: actions/setup-go@v3
       with:
-        go-version: 1.22.5
+        go-version: 1.22.7
         check-latest: true
     - name: Get govulncheck
       run: go install golang.org/x/vuln/cmd/govulncheck@latest

go.work

@@ -1,4 +1,4 @@
-go 1.21
+go 1.22.0
 
 use (
 	./kes

kes/go.mod

@@ -1,6 +1,6 @@
 module github.com/minio/kms-go/kes
 
-go 1.21
+go 1.22.0
 
 require (
 	aead.dev/mem v0.2.0

kms/client-examples_test.go

@@ -14,11 +14,12 @@ import (
 	"log/slog"
 	"time"
 
+	"aead.dev/mtls"
 	"github.com/minio/kms-go/kms"
 )
 
 func ExampleNewClient() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -55,7 +56,7 @@ func ExampleNewClient() {
 // KMS cluster dynamically expanding it. The added KMS server must not
 // be part of an exisiting cluster.
 func ExampleClient_AddNode() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -85,7 +86,7 @@ func ExampleClient_AddNode() {
 // ExampleClient_RemoveNode shows how to remove a KMS server from the
 // cluster it is currently part of.
 func ExampleClient_RemoveNode() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -115,7 +116,7 @@ func ExampleClient_RemoveNode() {
 // ExampleClient_ClusterStatus shows how to fetch cluster status information
 // from a KMS cluster.
 func ExampleClient_ClusterStatus() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -143,7 +144,7 @@ func ExampleClient_ClusterStatus() {
 
 // ExampleClient_CreateEnclave shows how to create a new enclave.
 func ExampleClient_CreateEnclave() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -172,7 +173,7 @@ func ExampleClient_CreateEnclave() {
 
 // ExampleClient_DeleteEnclave shows how to delete an existing enclave.
 func ExampleClient_DeleteEnclave() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -202,7 +203,7 @@ func ExampleClient_DeleteEnclave() {
 // ExampleClient_EnclaveStatus shows how to fetch status information about two enclaves.
 // Fetching information about multiple enclaves requires just a single network request.
 func ExampleClient_EnclaveStatus() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -238,7 +239,7 @@ func ExampleClient_EnclaveStatus() {
 // ExampleClient_EnclaveStatus shows how to fetch status information about two enclaves.
 // Fetching information about multiple enclaves requires just a single network request.
 func ExampleClient_ListEnclaves() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}
@@ -270,7 +271,7 @@ func ExampleClient_ListEnclaves() {
 
 // ExampleClient_Logs shows how to fetch server log records.
 func ExampleClient_Logs() {
-	key, err := kms.ParseAPIKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
+	key, err := mtls.ParsePrivateKey("k1:d7cY_5k8HbBGkZpoy2hGmvkxg83QDBXsA_nFXDfTk2E")
 	if err != nil {
 		log.Fatalf("Failed to parse KMS API key: %v", err)
 	}

kms/client.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"aead.dev/mem"
+	"aead.dev/mtls"
 	"github.com/minio/kms-go/kms/cmds"
 	"github.com/minio/kms-go/kms/internal/api"
 	"github.com/minio/kms-go/kms/internal/headers"
@@ -42,7 +43,7 @@ type Config struct {
 	//
 	// When providing an API key, no TLS.Certificates
 	// or TLS.GetClientCertificate must be present.
-	APIKey APIKey
+	APIKey mtls.PrivateKey
 
 	// Optional TLS configuration.
 	//

kms/go.mod

@@ -1,8 +1,9 @@
 module github.com/minio/kms-go/kms
 
-go 1.21
+go 1.22.0
 
 require (
 	aead.dev/mem v0.2.0
+	aead.dev/mtls v0.1.0
 	google.golang.org/protobuf v1.33.0
 )

kms/go.sum

@@ -1,5 +1,7 @@
 aead.dev/mem v0.2.0 h1:ufgkESS9+lHV/GUjxgc2ObF43FLZGSemh+W+y27QFMI=
 aead.dev/mem v0.2.0/go.mod h1:4qj+sh8fjDhlvne9gm/ZaMRIX9EkmDrKOLwmyDtoMWM=
+aead.dev/mtls v0.1.0 h1:zT/p8BpBXol0bmRaJz4WyMW3wTjSjJztKlSoXl/a+rs=
+aead.dev/mtls v0.1.0/go.mod h1:QirwQiq697/G62Ug6LbzfeR4Nq1vBGch5ajUZdAzJaw=
 github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=

kms/identity.go

@@ -5,55 +5,18 @@
 package kms
 
 import (
-	"crypto"
-	"crypto/ed25519"
 	"crypto/rand"
-	"crypto/sha256"
 	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
-	"encoding/asn1"
-	"encoding/base64"
 	"encoding/pem"
 	"errors"
-	"io"
 	"math/big"
 	"strconv"
-	"strings"
 	"time"
-)
 
-// An Identity uniquely identifies a private/public key pair.
-// It consists of a prefix for the hash function followed by
-// the URL base64-encoded hash of the public key.
-//
-// For example:
-//
-//	h1:BPbFim5DqUozIYOjcaRAtImU6TdD6W2_chOgxDyCuDw
-//
-// This package uses the "h1:" prefix for SHA-256 and computes
-// the hash of X.509 certificates from the certificate's
-// DER-encoded public key info.
-//
-// For example:
-//
-//	shasum := sha256.Sum256(cert.RawSubjectPublicKeyInfo)
-//	identity := "h1:" + base64.RawURLEncoding.EncodeToString(shasum[:])
-//
-// By verifying the peer's identity, two parties can detect
-// MitM¹ attacks during a protocol handshake, like in TLS.
-// An identity pins the public key, similar to SSH² or HPKP³.
-//
-// The empty string represents a pseudo identity and indicates
-// that no public key has been provided.
-//
-// Ref:
-// [1] https://en.wikipedia.org/wiki/Man-in-the-middle_attack
-// [2] https://en.wikipedia.org/wiki/Key_fingerprint
-// [3] https://en.wikipedia.org/wiki/HTTP_Public_Key_Pinning
-type Identity string
-
-func (i Identity) String() string { return string(i) }
+	"aead.dev/mtls"
+)
 
 // Privilege represents an access control role of identities.
 // An identity with a higher privilege has access to more APIs.
@@ -111,85 +74,12 @@ func (p Privilege) String() string {
 	}
 }
 
-// An APIKey represents a public/private key pair.
-// An API key can be used to authenticate to a TLS server via
-// mTLS¹ by generating a X.509 certificate from the API key's
-// public key.
-//
-// Ref:
-// [1] https://en.wikipedia.org/wiki/Mutual_authentication#mTLS
-type APIKey interface {
-	// Public returns the API key's public key.
-	Public() crypto.PublicKey
-
-	// Private returns the API key's private key.
-	Private() crypto.PrivateKey
-
-	// Identity returns the Identity associated with the
-	// public key.
-	Identity() Identity
-
-	// String returns the API key's string representation.
-	String() string
-}
-
-// GenerateAPIKey generates a new API key using the given
-// io.Reader as source of randomness.
-//
-// If random is nil, the standard library crypto/rand.Reader
-// is used.
-func GenerateAPIKey(random io.Reader) (APIKey, error) {
-	pub, priv, err := ed25519.GenerateKey(random)
-	if err != nil {
-		return nil, err
-	}
-
-	id, err := ed25519Identity(pub)
-	if err != nil {
-		return nil, err
-	}
-	return &apiKey{
-		key:      priv,
-		identity: id,
-	}, nil
-}
-
-// ParseAPIKey parses s as formatted API key.
-func ParseAPIKey(s string) (APIKey, error) {
-	s, found := strings.CutPrefix(s, "k1:")
-	if !found {
-		return nil, errors.New("kms: invalid API key type")
-	}
-
-	if base64.RawURLEncoding.DecodedLen(len(s)) != ed25519.SeedSize {
-		return nil, errors.New("kms: invalid API key length")
-	}
-
-	b, err := base64.RawURLEncoding.DecodeString(s)
-	if err != nil {
-		return nil, err
-	}
-	if len(b) != ed25519.SeedSize {
-		return nil, errors.New("kms: invalid API key length")
-	}
-
-	key := ed25519.NewKeyFromSeed(b)
-	id, err := ed25519Identity(key[ed25519.SeedSize:])
-	if err != nil {
-		return nil, err
-	}
-	return &apiKey{
-		key:      key,
-		identity: id,
-	}, nil
-}
-
 // GenerateCertificate generates a new self-signed TLS certificate
 // from the given template using the APIKey's private and public key.
 //
 // The template may be nil. In such a case the returned certificate
 // is generated using a default template and valid for 90 days.
-func GenerateCertificate(key APIKey, template *x509.Certificate) (tls.Certificate, error) {
+func GenerateCertificate(key mtls.PrivateKey, template *x509.Certificate) (tls.Certificate, error) {
 	if template == nil {
 		serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
 		serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
@@ -232,41 +122,3 @@ func GenerateCertificate(key APIKey, template *x509.Certificate) (tls.Certificat
 	}
 	return cert, nil
 }
-
-// apiKey is an APIKey implementation using Ed25519 public/private keys.
-type apiKey struct {
-	key      ed25519.PrivateKey
-	identity Identity
-}
-
-func (ak *apiKey) Public() crypto.PublicKey { return ak.key.Public() }
-
-func (ak *apiKey) Private() crypto.PrivateKey {
-	private := make([]byte, 0, len(ak.key))
-	return ed25519.PrivateKey(append(private, ak.key...))
-}
-
-func (ak *apiKey) Identity() Identity { return ak.identity }
-
-func (ak *apiKey) String() string {
-	return "k1:" + base64.RawURLEncoding.EncodeToString(ak.key[:ed25519.SeedSize])
-}
-
-func ed25519Identity(pubKey []byte) (Identity, error) {
-	type publicKeyInfo struct {
-		Algorithm pkix.AlgorithmIdentifier
-		PublicKey asn1.BitString
-	}
-
-	derPublicKey, err := asn1.Marshal(publicKeyInfo{
-		Algorithm: pkix.AlgorithmIdentifier{
-			Algorithm: asn1.ObjectIdentifier{1, 3, 101, 112},
-		},
-		PublicKey: asn1.BitString{BitLength: len(pubKey) * 8, Bytes: pubKey},
-	})
-	if err != nil {
-		return "", err
-	}
-	id := sha256.Sum256(derPublicKey)
-	return "h1:" + Identity(base64.RawURLEncoding.EncodeToString(id[:])), nil
-}