support Ed25519

AndroidDemo/src/main/java/com/yubico/yubikit/android/app/MainActivity.kt

@@ -31,19 +31,16 @@ import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.navigateUp
 import androidx.navigation.ui.setupActionBarWithNavController
 import androidx.navigation.ui.setupWithNavController
-
 import com.google.android.material.navigation.NavigationView
-
 import com.yubico.yubikit.android.YubiKitManager
 import com.yubico.yubikit.android.app.databinding.DialogAboutBinding
 import com.yubico.yubikit.android.transport.nfc.NfcConfiguration
 import com.yubico.yubikit.android.transport.nfc.NfcNotAvailable
 import com.yubico.yubikit.android.transport.usb.UsbConfiguration
-
+import org.bouncycastle.jce.provider.BouncyCastleProvider
 import org.slf4j.LoggerFactory
-
-import java.util.*
-
+import java.security.Security
+import java.util.Locale
 import kotlin.properties.Delegates
 
 class MainActivity : AppCompatActivity() {
@@ -62,6 +59,9 @@ class MainActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
+        Security.removeProvider("BC")
+        Security.insertProviderAt(BouncyCastleProvider(), 1)
+
         val toolbar: Toolbar = findViewById(R.id.toolbar)
         setSupportActionBar(toolbar)
 

AndroidDemo/src/main/java/com/yubico/yubikit/android/app/ui/piv/PivCertificateFragment.kt

@@ -152,7 +152,7 @@ class PivCertificateFragment : Fragment() {
                 .generatePrivate(PKCS8EncodedKeySpec(Base64.decode(DER_KEY, Base64.DEFAULT)))
             lifecycleScope.launch(Dispatchers.Main) {
                 pivViewModel.pendingAction.value = {
-                    authenticate(pivViewModel.mgmtKeyType, pivViewModel.mgmtKey)
+                    authenticate(pivViewModel.getMgmtKeyType(this), pivViewModel.mgmtKey)
                     putKey(slot, PrivateKeyValues.fromPrivateKey(key), PinPolicy.DEFAULT, TouchPolicy.DEFAULT)
                     putCertificate(slot, cert)
                     "Imported certificate ${cert.subjectDN} issued by ${cert.issuerDN}"
@@ -165,7 +165,7 @@ class PivCertificateFragment : Fragment() {
             lifecycleScope.launch(Dispatchers.Main) {
                 getSecret(requireContext(), R.string.enter_pin)?.let { pin ->
                     pivViewModel.pendingAction.value = {
-                        authenticate(pivViewModel.mgmtKeyType, pivViewModel.mgmtKey)
+                        authenticate(pivViewModel.getMgmtKeyType(this), pivViewModel.mgmtKey)
 
                         val provider = PivProvider(this)
                         val factory = KeyPairGenerator.getInstance("YKPivEC", provider)
@@ -214,11 +214,66 @@ class PivCertificateFragment : Fragment() {
             }
         }
 
+        // Generate a key, then a self-signed certificate, and import
+        binding.generateEd25519Cert.setOnClickListener {
+            lifecycleScope.launch(Dispatchers.Main) {
+                getSecret(requireContext(), R.string.enter_pin)?.let { pin ->
+                    pivViewModel.pendingAction.value = {
+                        authenticate(pivViewModel.getMgmtKeyType(this), pivViewModel.mgmtKey)
+
+                        val provider = PivProvider(this)
+                        val factory = KeyPairGenerator.getInstance("YKPivEC", provider)
+                        factory.initialize(
+                            PivAlgorithmParameterSpec(
+                                slot,
+                                KeyType.ED25519,
+                                PinPolicy.DEFAULT,
+                                TouchPolicy.DEFAULT,
+                                pin.toCharArray()
+                            )
+                        )
+                        val keyPair = factory.generateKeyPair()
+
+                        // Generate a certificate
+                        val name = X500Name("CN=Generated Ed25519 Example")
+                        val serverCertGen = X509v3CertificateBuilder(
+                            name,
+                            BigInteger("123456789"),
+                            Date(),
+                            Date(),
+                            name,
+                            SubjectPublicKeyInfo.getInstance(ASN1Sequence.getInstance(keyPair.public.encoded))
+                        )
+
+                        val certBytes = serverCertGen.build(object : ContentSigner {
+                            val messageBuffer = ByteArrayOutputStream()
+                            override fun getAlgorithmIdentifier(): AlgorithmIdentifier =
+                                AlgorithmIdentifier(X9ObjectIdentifiers.ecdsa_with_SHA256)
+
+                            override fun getOutputStream(): OutputStream = messageBuffer
+                            override fun getSignature(): ByteArray {
+                                return Signature.getInstance("Ed25519", provider).apply {
+                                    initSign(keyPair.private)
+                                    update(messageBuffer.toByteArray())
+                                }.sign()
+                            }
+                        }).encoded
+
+                        val cert = CertificateFactory.getInstance("X.509")
+                            .generateCertificate(ByteArrayInputStream(certBytes)) as X509Certificate
+                        putCertificate(slot, cert)
+
+                        "Generated Ed25519 key in slot $slot"
+                    }
+                }
+            }
+        }
+
         binding.generateRsaCert.setOnClickListener {
             lifecycleScope.launch(Dispatchers.Main) {
                 getSecret(requireContext(), R.string.enter_pin)?.let { pin ->
                     pivViewModel.pendingAction.value = {
-                        authenticate(pivViewModel.mgmtKeyType, pivViewModel.mgmtKey)
+                        authenticate(pivViewModel.getMgmtKeyType(this), pivViewModel.mgmtKey)
 
                         val provider = PivProvider(this)
                         val factory = KeyPairGenerator.getInstance("YKPivRSA", provider)
@@ -278,7 +333,7 @@ class PivCertificateFragment : Fragment() {
         // Delete the certificate
         binding.delete.setOnClickListener {
             pivViewModel.pendingAction.value = {
-                authenticate(pivViewModel.mgmtKeyType, pivViewModel.mgmtKey)
+                authenticate(pivViewModel.getMgmtKeyType(this), pivViewModel.mgmtKey)
                 deleteCertificate(slot)
                 "Deleted certificate in slot $slot"
             }
@@ -296,9 +351,11 @@ class PivCertificateFragment : Fragment() {
                         keyStore.load(null)
                         val publicKey = keyStore.getCertificate(slot.stringAlias).publicKey
                         val privateKey = keyStore.getKey(slot.stringAlias, pin.toCharArray()) as PrivateKey
-                        val algorithm = when (KeyType.fromKey(publicKey).params.algorithm) {
+
+                        val keyType = KeyType.fromKey(publicKey)
+                        val algorithm = when (keyType.params.algorithm) {
                             KeyType.Algorithm.RSA -> "SHA256withRSA"
-                            KeyType.Algorithm.EC -> "SHA256withECDSA"
+                            KeyType.Algorithm.EC -> if (keyType == KeyType.ED25519) "Ed25519" else "SHA256withECDSA"
                         }
 
                         // Create signature

AndroidDemo/src/main/java/com/yubico/yubikit/android/app/ui/piv/PivViewModel.kt

@@ -48,10 +48,17 @@ class PivViewModel : YubiKeyViewModel<PivSession>() {
     private val _certificates = MutableLiveData<SparseArray<X509Certificate>?>()
     val certificates: LiveData<SparseArray<X509Certificate>?> = _certificates
 
-    var mgmtKeyType = ManagementKeyType.TDES
     var mgmtKey: ByteArray =
         byteArrayOf(1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8)
 
+    fun getMgmtKeyType(session: PivSession) : ManagementKeyType {
+        return try {
+            session.managementKeyMetadata.keyType
+        } catch (ignored: Exception) {
+            ManagementKeyType.TDES
+        }
+    }
+
     override fun getSession(
         device: YubiKeyDevice,
         onError: (Throwable) -> Unit,

AndroidDemo/src/main/res/layout/fragment_piv_certifiate.xml

@@ -73,6 +73,27 @@
                     android:text="@string/piv_generate_rsa_cert" />
             </TableRow>
 
+            <TableRow
+                android:layout_weight="1"
+                android:gravity="center"
+                android:weightSum="2" >
+
+                <Button
+                    android:id="@+id/generate_ed25519_cert"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_weight="1"
+                    android:text="@string/piv_generate_ed25519_cert" />
+
+                <Button
+                    android:id="@+id/generate_x25519_cert"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_weight="1"
+                    android:enabled="false"
+                    android:text="@string/piv_generate_x25519_cert" />
+            </TableRow>
+
             <TableRow
                 android:layout_weight="1"
                 android:gravity="center"

AndroidDemo/src/main/res/values/strings.xml

@@ -45,6 +45,8 @@
     <string name="piv_attest">Attest</string>
     <string name="piv_generate_ec_cert">Generate EC256</string>
     <string name="piv_generate_rsa_cert">Generate RSA2048</string>
+    <string name="piv_generate_ed25519_cert">Generate ED25519</string>
+    <string name="piv_generate_x25519_cert">Generate X25519</string>
     <string name="piv_import_cert">Import</string>
     <string name="piv_message_hint">Message</string>
     <string name="piv_sign">Sign</string>

core/src/main/java/com/yubico/yubikit/core/keys/PrivateKeyValues.java

@@ -102,7 +102,6 @@ public static class Ec extends PrivateKeyValues {
         private final EllipticCurveValues ellipticCurveValues;
         private final byte[] secret;
 
-
         protected Ec(EllipticCurveValues ellipticCurveValues, byte[] secret) {
             super(ellipticCurveValues.getBitLength());
             this.ellipticCurveValues = ellipticCurveValues;

piv/build.gradle

@@ -6,6 +6,10 @@ dependencies {
 
 test {
     systemProperty "org.slf4j.simpleLogger.defaultLogLevel", "trace"
+
+    dependencies {
+        implementation 'org.bouncycastle:bcpkix-jdk15to18:1.77'
+    }
 }
 
 ext.pomName = "Yubico YubiKit ${project.name.capitalize()}"

piv/src/main/java/com/yubico/yubikit/piv/KeyType.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2019-2022 Yubico.
+ * Copyright (C) 2019-2022,2024 Yubico.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,9 @@
 import com.yubico.yubikit.core.keys.PrivateKeyValues;
 import com.yubico.yubikit.core.keys.PublicKeyValues;
 
+import org.bouncycastle.jcajce.provider.asymmetric.edec.BCEdDSAPrivateKey;
+import org.bouncycastle.jcajce.provider.asymmetric.edec.BCEdDSAPublicKey;
+
 import java.security.Key;
 import java.security.interfaces.ECPrivateKey;
 import java.security.interfaces.ECPublicKey;
@@ -46,7 +49,15 @@ public enum KeyType {
     /**
      * Elliptic Curve key, using NIST Curve P-384.
      */
-    ECCP384((byte) 0x14, new EcKeyParams(EllipticCurveValues.SECP384R1));
+    ECCP384((byte) 0x14, new EcKeyParams(EllipticCurveValues.SECP384R1)),
+    /**
+     * Edwards Digital Signature Algorithm (EdDSA) key, using Curve25519.
+     */
+    ED25519((byte) 0xE0, new EcKeyParams(EllipticCurveValues.Ed25519)),
+    /**
+     * Elliptic-Curve Diffie-Hellman (ECDH) protocol key, using Curve25519.
+     */
+    X25519((byte) 0xE1, new EcKeyParams(EllipticCurveValues.X25519));
 
     public final byte value;
     public final KeyParams params;
@@ -105,6 +116,10 @@ public static KeyType fromKey(Key key) {
                 ellipticCurveValues = ((PublicKeyValues.Ec) PublicKeyValues.fromPublicKey((ECPublicKey) key)).getCurveParams();
             } else if (key instanceof ECPrivateKey) {
                 ellipticCurveValues = ((PrivateKeyValues.Ec) PrivateKeyValues.fromPrivateKey((ECPrivateKey) key)).getCurveParams();
+            } else if (key instanceof BCEdDSAPrivateKey) {
+                ellipticCurveValues = ((PrivateKeyValues.Ec) PrivateKeyValues.fromPrivateKey((BCEdDSAPrivateKey) key)).getCurveParams();
+            } else if (key instanceof BCEdDSAPublicKey) {
+                ellipticCurveValues = ((PublicKeyValues.Cv25519) PublicKeyValues.fromPublicKey((BCEdDSAPublicKey) key)).getCurveParams();
             } else {
                 throw new IllegalArgumentException("Unsupported key type");
             }

piv/src/main/java/com/yubico/yubikit/piv/PivSession.java

@@ -128,6 +128,11 @@ public boolean isSupportedBy(Version version) {
      */
     public static final Feature<PivSession> FEATURE_MOVE_KEY = new Feature.Versioned<>("Move or delete keys", 5, 7, 0);
 
+    /**
+     * Support for the curve 25519 keys.
+     */
+    public static final Feature<PivSession> FEATURE_CV25519 = new Feature.Versioned<>("Curve 25519", 5, 7, 0);
+
     private static final int PIN_LEN = 8;
 
     // Special slot for the Management Key
@@ -357,7 +362,9 @@ public byte[] sign(Slot slot, KeyType keyType, byte[] message, Signature algorit
     public byte[] rawSignOrDecrypt(Slot slot, KeyType keyType, byte[] payload) throws IOException, ApduException, BadResponseException {
         int byteLength = keyType.params.bitLength / 8;
         byte[] padded;
-        if (payload.length > byteLength) {
+        if (keyType == KeyType.ED25519 || keyType == KeyType.X25519) {
+            padded = payload;
+        } else if (payload.length > byteLength) {
             if (keyType.params.algorithm == KeyType.Algorithm.EC) {
                 // Truncate
                 padded = Arrays.copyOf(payload, byteLength);
@@ -842,8 +849,8 @@ static PublicKeyValues parsePublicKeyFromDevice(KeyType keyType, byte[] encoded)
             BigInteger exponent = new BigInteger(1, dataObjects.get(0x82));
             return new PublicKeyValues.Rsa(modulus, exponent);
         } else {
-            if (!(keyType.params instanceof KeyType.EcKeyParams)) {
-                throw new IllegalArgumentException("Unsupported key type");
+            if (keyType == KeyType.ED25519) {
+                return new PublicKeyValues.Cv25519(((KeyType.EcKeyParams) keyType.params).getCurveParams(), dataObjects.get(0x86));
             }
             return PublicKeyValues.Ec.fromEncodedPoint(((KeyType.EcKeyParams) keyType.params).getCurveParams(), dataObjects.get(0x86));
         }
@@ -862,6 +869,9 @@ public void checkKeySupport(KeyType keyType, PinPolicy pinPolicy, TouchPolicy to
             return;
         }
 
+        if (keyType == KeyType.ED25519 || keyType == KeyType.X25519) {
+            require(FEATURE_CV25519);
+        }
         if (keyType == KeyType.ECCP384) {
             require(FEATURE_P384);
         }
@@ -996,7 +1006,7 @@ public KeyType putKey(Slot slot, PrivateKeyValues key, PinPolicy pinPolicy, Touc
                 break;
             case EC:
                 PrivateKeyValues.Ec ecPrivateKey = (PrivateKeyValues.Ec) key;
-                tlvs.put(0x06, ecPrivateKey.getSecret());  // s
+                tlvs.put((keyType == KeyType.ED25519) ? 0x07 : 0x06, ecPrivateKey.getSecret());  // s
                 break;
         }
 

piv/src/main/java/com/yubico/yubikit/piv/jca/PivEcSignatureSpi.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022 Yubico.
+ * Copyright (C) 2022,2024 Yubico.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,7 +35,7 @@
 public abstract class PivEcSignatureSpi extends SignatureSpi {
     private final Callback<Callback<Result<PivSession, Exception>>> provider;
     @Nullable
-    private PivPrivateKey.EcKey privateKey;
+    private PivPrivateKey privateKey;
 
     protected PivEcSignatureSpi(Callback<Callback<Result<PivSession, Exception>>> provider) {
         this.provider = provider;
@@ -50,6 +50,8 @@ protected void engineInitVerify(PublicKey publicKey) throws InvalidKeyException
     protected void engineInitSign(PrivateKey privateKey) throws InvalidKeyException {
         if (privateKey instanceof PivPrivateKey.EcKey) {
             this.privateKey = (PivPrivateKey.EcKey) privateKey;
+        } else if (privateKey instanceof PivPrivateKey.Ed25519Key) {
+            this.privateKey = (PivPrivateKey.Ed25519Key) privateKey;
         } else {
             throw new InvalidKeyException("Unsupported key type");
         }

piv/src/main/java/com/yubico/yubikit/piv/jca/PivKeyPairGeneratorSpi.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022 Yubico.
+ * Copyright (C) 2022,2024 Yubico.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -71,7 +71,7 @@ public KeyPair generateKeyPair() {
             BlockingQueue<Result<KeyPair, Exception>> queue = new ArrayBlockingQueue<>(1);
             provider.invoke(result -> queue.add(Result.of(() -> {
                 PivSession session = result.getValue();
-                PublicKey publicKey = session.generateKey(spec.slot, spec.keyType, spec.pinPolicy, spec.touchPolicy);
+                PublicKey publicKey = session.generateKeyValues(spec.slot, spec.keyType, spec.pinPolicy, spec.touchPolicy).toPublicKey();
                 PrivateKey privateKey = PivPrivateKey.from(publicKey, spec.slot, spec.pinPolicy, spec.touchPolicy, spec.pin);
                 return new KeyPair(publicKey, privateKey);
             })));

piv/src/main/java/com/yubico/yubikit/piv/jca/PivKeyStoreSpi.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022 Yubico.
+ * Copyright (C) 2022,2024 Yubico.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package com.yubico.yubikit.piv.jca;
 
 import com.yubico.yubikit.core.application.BadResponseException;
+import com.yubico.yubikit.core.keys.PrivateKeyValues;
 import com.yubico.yubikit.core.smartcard.ApduException;
 import com.yubico.yubikit.core.smartcard.SW;
 import com.yubico.yubikit.core.util.Callback;
@@ -59,7 +60,7 @@ private void putEntry(Slot slot, @Nullable PrivateKey key, PinPolicy pinPolicy,
         provider.invoke(result -> queue.add(Result.of(() -> {
             PivSession piv = result.getValue();
             if (key != null) {
-                piv.putKey(slot, key, pinPolicy, touchPolicy);
+                piv.putKey(slot, PrivateKeyValues.fromPrivateKey(key), pinPolicy, touchPolicy);
             }
             if (certificate != null) {
                 piv.putCertificate(slot, certificate);
@@ -79,7 +80,7 @@ public Key engineGetKey(String alias, char[] password) throws UnrecoverableKeyEx
                 PivSession session = result.getValue();
                 if (session.supports(PivSession.FEATURE_METADATA)) {
                     SlotMetadata data = session.getSlotMetadata(slot);
-                    return PivPrivateKey.from(data.getPublicKey(), slot, data.getPinPolicy(), data.getTouchPolicy(), password);
+                    return PivPrivateKey.from(data.getPublicKeyValues().toPublicKey(), slot, data.getPinPolicy(), data.getTouchPolicy(), password);
                 } else {
                     PublicKey publicKey = session.getCertificate(slot).getPublicKey();
                     return PivPrivateKey.from(publicKey, slot, null, null, password);
@@ -143,7 +144,7 @@ public KeyStore.Entry engineGetEntry(String alias, KeyStore.ProtectionParameter
                 PrivateKey key;
                 if (session.supports(PivSession.FEATURE_METADATA)) {
                     SlotMetadata data = session.getSlotMetadata(slot);
-                    key = PivPrivateKey.from(data.getPublicKey(), slot, data.getPinPolicy(), data.getTouchPolicy(), pin);
+                    key = PivPrivateKey.from(data.getPublicKeyValues().toPublicKey(), slot, data.getPinPolicy(), data.getTouchPolicy(), pin);
                 } else {
                     PublicKey publicKey = certificate.getPublicKey();
                     key = PivPrivateKey.from(publicKey, slot, null, null, pin);