diff --git a/core/java/android/security/keymaster/KeymasterDefs.java b/core/java/android/security/keymaster/KeymasterDefs.java
index 8efc5eb..e720f1a 100644
--- a/core/java/android/security/keymaster/KeymasterDefs.java
+++ b/core/java/android/security/keymaster/KeymasterDefs.java
@@ -65,6 +65,7 @@
     public static final int KM_TAG_PADDING = Tag.PADDING; // KM_ENUM_REP | 6;
     public static final int KM_TAG_CALLER_NONCE = Tag.CALLER_NONCE; // KM_BOOL | 7;
     public static final int KM_TAG_MIN_MAC_LENGTH = Tag.MIN_MAC_LENGTH; // KM_UINT | 8;
+    public static final int KM_TAG_EC_CURVE = Tag.EC_CURVE; // KM_ENUM | 10;
 
     public static final int KM_TAG_RSA_PUBLIC_EXPONENT = Tag.RSA_PUBLIC_EXPONENT; // KM_ULONG | 200;
     public static final int KM_TAG_INCLUDE_UNIQUE_ID = Tag.INCLUDE_UNIQUE_ID; // KM_BOOL | 202;
diff --git a/keystore/java/android/security/keystore2/AndroidKeyStoreECPublicKey.java b/keystore/java/android/security/keystore2/AndroidKeyStoreECPublicKey.java
index b631999..4e73bd9 100644
--- a/keystore/java/android/security/keystore2/AndroidKeyStoreECPublicKey.java
+++ b/keystore/java/android/security/keystore2/AndroidKeyStoreECPublicKey.java
@@ -18,13 +18,19 @@
 
 import android.annotation.NonNull;
 import android.security.KeyStoreSecurityLevel;
+import android.security.keymaster.KeymasterDefs;
 import android.security.keystore.KeyProperties;
+import android.system.keystore2.Authorization;
 import android.system.keystore2.KeyDescriptor;
 import android.system.keystore2.KeyMetadata;
 
+import java.security.AlgorithmParameters;
+import java.security.NoSuchAlgorithmException;
 import java.security.interfaces.ECPublicKey;
+import java.security.spec.ECGenParameterSpec;
 import java.security.spec.ECParameterSpec;
 import java.security.spec.ECPoint;
+import java.security.spec.InvalidParameterSpecException;
 
 /**
  * {@link ECPublicKey} backed by keystore.
@@ -56,11 +62,45 @@
         }
     }
 
+    private static String getEcCurveFromKeymaster(int ecCurve) {
+        switch (ecCurve) {
+            case android.hardware.security.keymint.EcCurve.P_224:
+                return "secp224r1";
+            case android.hardware.security.keymint.EcCurve.P_256:
+                return "secp256r1";
+            case android.hardware.security.keymint.EcCurve.P_384:
+                return "secp384r1";
+            case android.hardware.security.keymint.EcCurve.P_521:
+                return "secp521r1";
+        }
+        return "";
+    }
+
+    private ECParameterSpec getCurveSpec(String name)
+            throws NoSuchAlgorithmException, InvalidParameterSpecException {
+        AlgorithmParameters parameters = AlgorithmParameters.getInstance("EC");
+        parameters.init(new ECGenParameterSpec(name));
+        return parameters.getParameterSpec(ECParameterSpec.class);
+    }
+
     @Override
     public AndroidKeyStorePrivateKey getPrivateKey() {
+        ECParameterSpec params = mParams;
+        for (Authorization a : getAuthorizations()) {
+            try {
+                if (a.keyParameter.tag == KeymasterDefs.KM_TAG_EC_CURVE) {
+                    params = getCurveSpec(getEcCurveFromKeymaster(
+                            a.keyParameter.value.getEcCurve()));
+                    break;
+                }
+            } catch (Exception e) {
+                throw new RuntimeException("Unable to parse EC curve "
+                        + a.keyParameter.value.getEcCurve());
+            }
+        }
         return new AndroidKeyStoreECPrivateKey(
                 getUserKeyDescriptor(), getKeyIdDescriptor().nspace, getAuthorizations(),
-                getSecurityLevel(), mParams);
+                getSecurityLevel(), params);
     }
 
     @Override
diff --git a/keystore/java/android/security/keystore2/AndroidKeyStoreKeyAgreementSpi.java b/keystore/java/android/security/keystore2/AndroidKeyStoreKeyAgreementSpi.java
index b1338d1..4caa47f 100644
--- a/keystore/java/android/security/keystore2/AndroidKeyStoreKeyAgreementSpi.java
+++ b/keystore/java/android/security/keystore2/AndroidKeyStoreKeyAgreementSpi.java
@@ -31,6 +31,8 @@
 import java.security.ProviderException;
 import java.security.PublicKey;
 import java.security.SecureRandom;
+import java.security.interfaces.ECKey;
+import java.security.interfaces.XECKey;
 import java.security.spec.AlgorithmParameterSpec;
 import java.util.ArrayList;
 import java.util.List;
@@ -132,6 +134,15 @@
             throw new InvalidKeyException("key == null");
         } else if (!(key instanceof PublicKey)) {
             throw new InvalidKeyException("Only public keys supported. Key: " + key);
+        } else if (!(mKey instanceof ECKey && key instanceof ECKey)
+                && !(mKey instanceof XECKey && key instanceof XECKey)) {
+            throw new InvalidKeyException(
+                    "Public and Private key should be of the same type:");
+        } else if (mKey instanceof ECKey
+                && !((ECKey) key).getParams().getCurve()
+                .equals(((ECKey) mKey).getParams().getCurve())) {
+            throw new InvalidKeyException(
+                    "Public and Private key parameters should be same.");
         } else if (!lastPhase) {
             throw new IllegalStateException(
                     "Only one other party supported. lastPhase must be set to true.");
diff --git a/keystore/java/android/security/keystore2/AndroidKeyStoreXDHPrivateKey.java b/keystore/java/android/security/keystore2/AndroidKeyStoreXDHPrivateKey.java
index 42589640..e392c8d 100644
--- a/keystore/java/android/security/keystore2/AndroidKeyStoreXDHPrivateKey.java
+++ b/keystore/java/android/security/keystore2/AndroidKeyStoreXDHPrivateKey.java
@@ -22,16 +22,18 @@
 import android.system.keystore2.KeyDescriptor;
 
 import java.security.PrivateKey;
-import java.security.interfaces.EdECKey;
+import java.security.interfaces.XECPrivateKey;
 import java.security.spec.NamedParameterSpec;
+import java.util.Optional;
 
 /**
  * X25519 Private Key backed by Keystore.
- * instance of {@link PrivateKey} and {@link EdECKey}
+ * instance of {@link PrivateKey} and {@link XECPrivateKey}
  *
  * @hide
  */
-public class AndroidKeyStoreXDHPrivateKey extends AndroidKeyStorePrivateKey implements EdECKey {
+public class AndroidKeyStoreXDHPrivateKey extends AndroidKeyStorePrivateKey
+        implements XECPrivateKey {
     public AndroidKeyStoreXDHPrivateKey(
             @NonNull KeyDescriptor descriptor, long keyId,
             @NonNull Authorization[] authorizations,
@@ -44,4 +46,12 @@
     public NamedParameterSpec getParams() {
         return NamedParameterSpec.X25519;
     }
+
+    @Override
+    public Optional<byte[]> getScalar() {
+        /* An empty Optional if the scalar cannot be extracted (e.g. if the provider is a hardware
+         * token and the private key is not allowed to leave the crypto boundary).
+         */
+        return Optional.empty();
+    }
 }