Support for secp256k1

crypto/crypto.go

@@ -22,10 +22,13 @@ import (
 	"context"
 	"crypto"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rand"
+	"crypto/rsa"
 	"errors"
 	"fmt"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
 	"path"
 	"regexp"
 	"time"
@@ -153,13 +156,13 @@ func (client *Crypto) Configure(config core.ServerConfig) error {
 // New generates a new key pair.
 // Stores the private key, returns the public basicKey.
 // It returns an error when a key with the resulting ID already exists.
-func (client *Crypto) New(ctx context.Context, namingFunc KIDNamingFunc) (Key, error) {
-	keyPair, kid, err := generateKeyPairAndKID(namingFunc)
+func (client *Crypto) New(ctx context.Context, keyType KeyType, namingFunc KIDNamingFunc) (Key, error) {
+	keyPair, kid, err := generateKeyPairAndKID(keyType, namingFunc)
 	if err != nil {
 		return nil, err
 	}
 
-	audit.Log(ctx, log.Logger(), audit.CryptoNewKeyEvent).Infof("Generating new key pair: %s", kid)
+	audit.Log(ctx, log.Logger(), audit.CryptoNewKeyEvent).Infof("Generating new key pair (type: %s): %s", keyType, kid)
 	if client.storage.PrivateKeyExists(ctx, kid) {
 		return nil, errors.New("key with the given ID already exists")
 	}
@@ -172,24 +175,38 @@ func (client *Crypto) New(ctx context.Context, namingFunc KIDNamingFunc) (Key, e
 	}, nil
 }
 
-func generateKeyPairAndKID(namingFunc KIDNamingFunc) (*ecdsa.PrivateKey, string, error) {
-	keyPair, err := generateECKeyPair()
-	if err != nil {
-		return nil, "", err
+func generateKeyPairAndKID(keyType KeyType, namingFunc KIDNamingFunc) (crypto.Signer, string, error) {
+	var privateKey crypto.Signer
+	var err error
+	switch keyType {
+	case ECP256Key:
+		privateKey, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	case ECP256k1Key:
+		var pk *secp256k1.PrivateKey
+		pk, err = secp256k1.GeneratePrivateKey()
+		if err == nil {
+			privateKey = pk.ToECDSA()
+		}
+	case Ed25519Key:
+		_, privateKey, err = ed25519.GenerateKey(rand.Reader)
+	case RSA2048Key:
+		privateKey, err = rsa.GenerateKey(rand.Reader, 2048)
+	case RSA3072Key:
+		privateKey, err = rsa.GenerateKey(rand.Reader, 3072)
+	case RSA4096Key:
+		privateKey, err = rsa.GenerateKey(rand.Reader, 4096)
+	default:
+		return nil, "", fmt.Errorf("invalid key type: %s", keyType)
 	}
 
-	kid, err := namingFunc(keyPair.Public())
+	kid, err := namingFunc(privateKey.Public())
 	if err != nil {
 		return nil, "", err
 	}
 	log.Logger().
 		WithField(core.LogFieldKeyID, kid).
 		Debug("Generated new key pair")
-	return keyPair, kid, nil
-}
-
-func generateECKeyPair() (*ecdsa.PrivateKey, error) {
-	return ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	return privateKey, kid, nil
 }
 
 // Exists checks storage for an entry for the given legal entity and returns true if it exists

crypto/crypto_test.go

@@ -45,7 +45,7 @@ func TestCrypto_Exists(t *testing.T) {
 	client := createCrypto(t)
 
 	kid := "kid"
-	client.New(audit.TestContext(), StringNamingFunc(kid))
+	client.New(audit.TestContext(), ECP256Key, StringNamingFunc(kid))
 
 	t.Run("returns true for existing key", func(t *testing.T) {
 		assert.True(t, client.Exists(ctx, kid))
@@ -65,32 +65,48 @@ func TestCrypto_New(t *testing.T) {
 	logrus.StandardLogger().SetFormatter(&logrus.JSONFormatter{})
 	ctx := audit.TestContext()
 
-	t.Run("ok", func(t *testing.T) {
-		kid := "kid"
+	testCases := []KeyType{ECP256Key, ECP256k1Key, Ed25519Key, RSA2048Key}
+	for _, keyType := range testCases {
+		t.Run(string(keyType), func(t *testing.T) {
+			key, err := client.New(ctx, keyType, StringNamingFunc(string(keyType)))
+			require.NoError(t, err)
+			assert.NotNil(t, key.Public())
+		})
+	}
+
+	t.Run("audit logs", func(t *testing.T) {
+		const kid = "kid"
 		auditLogs := audit.CaptureLogs(t)
 
-		key, err := client.New(ctx, StringNamingFunc(kid))
+		key, err := client.New(ctx, ECP256Key, StringNamingFunc(kid))
 
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.NotNil(t, key.Public())
 		assert.Equal(t, kid, key.KID())
-		auditLogs.AssertContains(t, ModuleName, "CreateNewKey", audit.TestActor, "Generating new key pair: kid")
+		auditLogs.AssertContains(t, ModuleName, "CreateNewKey", audit.TestActor, "Generating new key pair (type: secp256r1): kid")
 	})
 
 	t.Run("error - invalid KID", func(t *testing.T) {
 		kid := "../certificate"
 
-		key, err := client.New(ctx, StringNamingFunc(kid))
+		key, err := client.New(ctx, ECP256Key, StringNamingFunc(kid))
 
 		assert.ErrorContains(t, err, "invalid key ID")
 		assert.Nil(t, key)
 	})
 
+	t.Run("error - invalid key type", func(t *testing.T) {
+		key, err := client.New(ctx, "caesar", StringNamingFunc("foo"))
+
+		assert.EqualError(t, err, "invalid key type: caesar")
+		assert.Nil(t, key)
+	})
+
 	t.Run("error - NamingFunction returns err", func(t *testing.T) {
 		errorNamingFunc := func(key crypto.PublicKey) (string, error) {
 			return "", errors.New("b00m!")
 		}
-		_, err := client.New(ctx, errorNamingFunc)
+		_, err := client.New(ctx, ECP256Key, errorNamingFunc)
 		assert.Error(t, err)
 	})
 
@@ -101,7 +117,7 @@ func TestCrypto_New(t *testing.T) {
 		storageMock.EXPECT().SavePrivateKey(ctx, gomock.Any(), gomock.Any()).Return(errors.New("foo"))
 
 		client := &Crypto{storage: storageMock}
-		key, err := client.New(ctx, StringNamingFunc("123"))
+		key, err := client.New(ctx, ECP256Key, StringNamingFunc("123"))
 		assert.Nil(t, key)
 		assert.Error(t, err)
 		assert.Equal(t, "could not create new keypair: could not save private key: foo", err.Error())
@@ -113,7 +129,7 @@ func TestCrypto_New(t *testing.T) {
 		storageMock.EXPECT().PrivateKeyExists(ctx, "123").Return(true)
 
 		client := &Crypto{storage: storageMock}
-		key, err := client.New(ctx, StringNamingFunc("123"))
+		key, err := client.New(ctx, ECP256Key, StringNamingFunc("123"))
 		assert.Nil(t, key)
 		assert.EqualError(t, err, "key with the given ID already exists", err)
 	})
@@ -123,7 +139,7 @@ func TestCrypto_Resolve(t *testing.T) {
 	ctx := context.Background()
 	client := createCrypto(t)
 	kid := "kid"
-	key, _ := client.New(audit.TestContext(), StringNamingFunc(kid))
+	key, _ := client.New(audit.TestContext(), ECP256Key, StringNamingFunc(kid))
 
 	t.Run("ok", func(t *testing.T) {
 		resolvedKey, err := client.Resolve(ctx, "kid")

crypto/decrypter_test.go

@@ -31,7 +31,7 @@ func TestCrypto_Decrypt(t *testing.T) {
 	t.Run("ok", func(t *testing.T) {
 		client := createCrypto(t)
 		kid := "kid"
-		key, _ := client.New(audit.TestContext(), StringNamingFunc(kid))
+		key, _ := client.New(audit.TestContext(), ECP256Key, StringNamingFunc(kid))
 		pubKey := key.Public().(*ecdsa.PublicKey)
 
 		cipherText, err := EciesEncrypt(pubKey, []byte("hello!"))

crypto/ecies_test.go

@@ -19,6 +19,9 @@
 package crypto
 
 import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -49,3 +52,7 @@ func TestEciesDecrypt(t *testing.T) {
 
 	assert.Equal(t, []byte("hello world"), plainText)
 }
+
+func generateECKeyPair() (*ecdsa.PrivateKey, error) {
+	return ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+}

crypto/ephemeral.go

@@ -21,7 +21,7 @@ package crypto
 
 // NewEphemeralKey returns a Key for single use.
 func NewEphemeralKey(namingFunc KIDNamingFunc) (Key, error) {
-	keyPair, kid, err := generateKeyPairAndKID(namingFunc)
+	keyPair, kid, err := generateKeyPairAndKID(ECP256Key, namingFunc)
 	if err != nil {
 		return nil, err
 	}

crypto/interface.go

@@ -30,11 +30,28 @@ var ErrPrivateKeyNotFound = errors.New("private key not found")
 // KIDNamingFunc is a function passed to New() which generates the kid for the pub/priv key
 type KIDNamingFunc func(key crypto.PublicKey) (string, error)
 
+type KeyType string
+
+const (
+	// ECP256Key is the key type for EC P-256
+	ECP256Key KeyType = "secp256r1"
+	// ECP256k1Key is the key type for EC P-256K (Koblitz curve)
+	ECP256k1Key = "secp256k1"
+	// Ed25519Key is the key type for ed25519
+	Ed25519Key = "ed25519"
+	// RSA2048Key is the key type for rsa2048
+	RSA2048Key = "rsa2048"
+	// RSA3072Key is the key type for rsa3072
+	RSA3072Key = "rsa3072"
+	// RSA4096Key is the key type for rsa4096
+	RSA4096Key = "rsa4096"
+)
+
 // KeyCreator is the interface for creating key pairs.
 type KeyCreator interface {
 	// New generates a keypair and returns a Key. The context is used to pass audit information.
 	// The KIDNamingFunc will provide the kid.
-	New(ctx context.Context, namingFunc KIDNamingFunc) (Key, error)
+	New(ctx context.Context, keyType KeyType, namingFunc KIDNamingFunc) (Key, error)
 }
 
 // KeyResolver is the interface for resolving keys.

crypto/jwx.go

@@ -27,6 +27,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
 	"github.com/lestrrat-go/jwx/v2/jwa"
 	"github.com/lestrrat-go/jwx/v2/jwe"
 	"github.com/lestrrat-go/jwx/v2/jwk"
@@ -41,7 +42,7 @@ import (
 // ErrUnsupportedSigningKey is returned when an unsupported private key is used to sign. Currently only ecdsa and rsa keys are supported
 var ErrUnsupportedSigningKey = errors.New("signing key algorithm not supported")
 
-var supportedAlgorithms = []jwa.SignatureAlgorithm{jwa.PS256, jwa.PS384, jwa.PS512, jwa.ES256, jwa.EdDSA, jwa.ES384, jwa.ES512}
+var supportedAlgorithms = []jwa.SignatureAlgorithm{jwa.PS256, jwa.PS384, jwa.PS512, jwa.ES256, jwa.EdDSA, jwa.ES256K, jwa.ES384, jwa.ES512}
 
 const defaultRsaEncryptionAlgorithm = jwa.RSA_OAEP_256
 const defaultEcEncryptionAlgorithm = jwa.ECDH_ES_A256KW
@@ -135,11 +136,15 @@ func jwkKey(signer crypto.Signer) (key jwk.Key, err error) {
 	case *rsa.PrivateKey:
 		key.Set(jwk.AlgorithmKey, jwa.PS256)
 	case *ecdsa.PrivateKey:
-		var alg jwa.SignatureAlgorithm
-		alg, err = ecAlg(k)
+		alg, err := ecAlgUsingPublicKey(k.PublicKey)
+		if err != nil {
+			return nil, err
+		}
 		key.Set(jwk.AlgorithmKey, alg)
+	case ed25519.PrivateKey:
+		key.Set(jwk.AlgorithmKey, jwa.EdDSA)
 	default:
-		err = errors.New("unsupported signing private key")
+		err = fmt.Errorf("unsupported signing private key: %T", k)
 	}
 	return
 }
@@ -159,7 +164,17 @@ func signJWT(key jwk.Key, claims map[string]interface{}, headers map[string]inte
 		return "", fmt.Errorf("invalid JWT headers: %w", err)
 	}
 
-	sig, err = jwt.Sign(t, jwt.WithKey(jwa.SignatureAlgorithm(key.Algorithm().String()), key, jws.WithProtectedHeaders(hdr)))
+	var publicKey crypto.PublicKey
+	if err = key.Raw(&publicKey); err != nil {
+		return "", err
+	}
+	alg, err := SignatureAlgorithm(publicKey)
+	if err != nil {
+		return "", err
+	}
+
+	sig, err = jwt.Sign(t, jwt.WithKey(alg, key, jws.WithProtectedHeaders(hdr)))
+
 	token = string(sig)
 
 	return
@@ -367,12 +382,11 @@ func convertHeaders(headers map[string]interface{}) (jws.Headers, error) {
 	return hdr, nil
 }
 
-func ecAlg(key *ecdsa.PrivateKey) (alg jwa.SignatureAlgorithm, err error) {
-	alg, err = ecAlgUsingPublicKey(key.PublicKey)
-	return
-}
-
 func ecAlgUsingPublicKey(key ecdsa.PublicKey) (alg jwa.SignatureAlgorithm, err error) {
+	if key.Curve == secp256k1.S256() {
+		return jwa.ES256K, nil
+	}
+	// Otherwise, assume it's a NIST curve
 	switch key.Params().BitSize {
 	case 256:
 		alg = jwa.ES256

crypto/jwx_test.go

@@ -153,7 +153,7 @@ func TestCrypto_SignJWT(t *testing.T) {
 	client := createCrypto(t)
 
 	kid := "kid"
-	key, _ := client.New(audit.TestContext(), StringNamingFunc(kid))
+	key, _ := client.New(audit.TestContext(), ECP256Key, StringNamingFunc(kid))
 
 	t.Run("creates valid JWT", func(t *testing.T) {
 		tokenString, err := client.SignJWT(audit.TestContext(), map[string]interface{}{"iss": "nuts", "sub": "subject"}, nil, key)
@@ -197,7 +197,7 @@ func TestCrypto_SignJWS(t *testing.T) {
 	client := createCrypto(t)
 
 	kid := "kid"
-	key, _ := client.New(audit.TestContext(), StringNamingFunc(kid))
+	key, _ := client.New(audit.TestContext(), ECP256Key, StringNamingFunc(kid))
 
 	t.Run("creates valid JWS", func(t *testing.T) {
 		payload, _ := json.Marshal(map[string]interface{}{"iss": "nuts"})
@@ -244,7 +244,7 @@ func TestCrypto_SignJWS(t *testing.T) {
 func TestCrypto_EncryptJWE(t *testing.T) {
 	client := createCrypto(t)
 
-	key, _ := client.New(audit.TestContext(), StringNamingFunc("did:nuts:1234#key-1"))
+	key, _ := client.New(audit.TestContext(), ECP256Key, StringNamingFunc("did:nuts:1234#key-1"))
 	public := key.Public()
 
 	headers := map[string]interface{}{"typ": "JWT", "kid": key.KID()}
@@ -327,7 +327,7 @@ func TestCrypto_DecryptJWE(t *testing.T) {
 	client := createCrypto(t)
 
 	kid := "did:nuts:1234#key-1"
-	key, _ := client.New(audit.TestContext(), StringNamingFunc(kid))
+	key, _ := client.New(audit.TestContext(), ECP256Key, StringNamingFunc(kid))
 
 	t.Run("decrypts valid JWE", func(t *testing.T) {
 		payload, _ := json.Marshal(map[string]interface{}{"iss": "nuts"})