Android Keystore keys are no longer backed by Conscrypt.

This switches Android Keystore asymmetric keys from being backed by
Conscrypt (via keystore-engine which is an OpenSSL/BoringSSL ENGINE
which talks to keystore via the old KeyStore API) to being backed by
the AndroidKeyStore Provider which talks to keystore via the new
KeyStore API. In effect, this switches asymmetric crypto offered by
Android Keystore from old Keystore API to new KeyStore API, enabling
all the new features such as enforcement of authorizations on key use.

Some algorithms offered by Android Keystore, such as RSA with OAEP
or PSS padding schemes, are not supported by other providers. This
complicates matters because Android Keystore only supports public key
operations if the corresponding private key is in the keystore. Thus,
Android Keystore can only offer these operations for its own public
keys only. This requires AndroidKeyStore to use its own subclasses of
PublicKey everywhere. The ugliest place is where it needs to return
its own subclass of X509Certificate only to be able to return its
own subclass of PublicKey from Certificate.getPublicKey().

Bug: 18088752
Bug: 19284418
Bug: 20912868
Change-Id: Id234f9ab9ff72d353ca1ff66768bd3d46da50d64

12 files changed, 603 insertions, 146 deletions

diff --git a/keystore/java/android/security/KeyChain.java b/keystore/java/android/security/KeyChain.java
index 059d8e6..f482bf0 100644
--- a/keystore/java/android/security/KeyChain.java
+++ b/keystore/java/android/security/KeyChain.java
@@ -29,15 +29,14 @@ import android.os.Looper;
 import android.os.Process;
 import android.os.RemoteException;
 import android.os.UserHandle;
-import android.security.keystore.KeyInfo;
+import android.security.keystore.AndroidKeyStoreProvider;
 import android.security.keystore.KeyProperties;
 
 import java.io.ByteArrayInputStream;
 import java.io.Closeable;
-import java.security.InvalidKeyException;
-import java.security.KeyFactory;
 import java.security.Principal;
 import java.security.PrivateKey;
+import java.security.UnrecoverableKeyException;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
@@ -47,7 +46,6 @@ import java.util.Locale;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 
-import com.android.org.conscrypt.OpenSSLEngine;
 import com.android.org.conscrypt.TrustedCertificateStore;
 
 /**
@@ -90,8 +88,6 @@ import com.android.org.conscrypt.TrustedCertificateStore;
 // TODO reference intent for credential installation when public
 public final class KeyChain {
 
-    private static final String TAG = "KeyChain";
-
     /**
      * @hide Also used by KeyChainService implementation
      */
@@ -372,15 +368,14 @@ public final class KeyChain {
             if (keyId == null) {
                 throw new KeyChainException("keystore had a problem");
             }
-
-            final OpenSSLEngine engine = OpenSSLEngine.getInstance("keystore");
-            return engine.getPrivateKeyById(keyId);
+            return AndroidKeyStoreProvider.loadAndroidKeyStorePrivateKeyFromKeystore(
+                    KeyStore.getInstance(), keyId);
         } catch (RemoteException e) {
             throw new KeyChainException(e);
         } catch (RuntimeException e) {
             // only certain RuntimeExceptions can be propagated across the IKeyChainService call
             throw new KeyChainException(e);
-        } catch (InvalidKeyException e) {
+        } catch (UnrecoverableKeyException e) {
             throw new KeyChainException(e);
         } finally {
             keyChainConnection.close();
diff --git a/keystore/java/android/security/KeyPairGeneratorSpec.java b/keystore/java/android/security/KeyPairGeneratorSpec.java
index efbce41..d849317 100644
--- a/keystore/java/android/security/KeyPairGeneratorSpec.java
+++ b/keystore/java/android/security/KeyPairGeneratorSpec.java
@@ -331,7 +331,9 @@ public final class KeyPairGeneratorSpec implements AlgorithmParameterSpec {
             if (keyType == null) {
                 throw new NullPointerException("keyType == null");
             } else {
-                if (KeyStore.getKeyTypeForAlgorithm(keyType) == -1) {
+                try {
+                    KeyProperties.KeyAlgorithm.toKeymasterAsymmetricKeyAlgorithm(keyType);
+                } catch (IllegalArgumentException e) {
                     throw new NoSuchAlgorithmException("Unsupported key type: " + keyType);
                 }
             }
diff --git a/keystore/java/android/security/KeyStore.java b/keystore/java/android/security/KeyStore.java
index 893771a..35fcda6 100644
--- a/keystore/java/android/security/KeyStore.java
+++ b/keystore/java/android/security/KeyStore.java
@@ -19,7 +19,6 @@ package android.security;
 import android.app.ActivityThread;
 import android.app.Application;
 import android.app.KeyguardManager;
-import com.android.org.conscrypt.NativeConstants;
 
 import android.content.Context;
 import android.hardware.fingerprint.FingerprintManager;
@@ -38,7 +37,6 @@ import android.security.keymaster.OperationResult;
 import android.security.keystore.KeyExpiredException;
 import android.security.keystore.KeyNotYetValidException;
 import android.security.keystore.KeyPermanentlyInvalidatedException;
-import android.security.keystore.KeyProperties;
 import android.security.keystore.UserNotAuthenticatedException;
 import android.util.Log;
 
@@ -136,16 +134,6 @@ public class KeyStore {
         return mToken;
     }
 
-    public static int getKeyTypeForAlgorithm(@KeyProperties.KeyAlgorithmEnum String keyType) {
-        if (KeyProperties.KEY_ALGORITHM_RSA.equalsIgnoreCase(keyType)) {
-            return NativeConstants.EVP_PKEY_RSA;
-        } else if (KeyProperties.KEY_ALGORITHM_EC.equalsIgnoreCase(keyType)) {
-            return NativeConstants.EVP_PKEY_EC;
-        } else {
-            return -1;
-        }
-    }
-
     public State state(int userId) {
         final int ret;
         try {
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreECPrivateKey.java b/keystore/java/android/security/keystore/AndroidKeyStoreECPrivateKey.java
new file mode 100644
index 0000000..5dbcd68
--- /dev/null
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreECPrivateKey.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.security.keystore;
+
+import java.security.PrivateKey;
+import java.security.interfaces.ECKey;
+import java.security.spec.ECParameterSpec;
+
+/**
+ * EC private key (instance of {@link PrivateKey} and {@link ECKey}) backed by keystore.
+ *
+ * @hide
+ */
+public class AndroidKeyStoreECPrivateKey extends AndroidKeyStorePrivateKey implements ECKey {
+    private final ECParameterSpec mParams;
+
+    public AndroidKeyStoreECPrivateKey(String alias, ECParameterSpec params) {
+        super(alias, KeyProperties.KEY_ALGORITHM_EC);
+        mParams = params;
+    }
+
+    @Override
+    public ECParameterSpec getParams() {
+        return mParams;
+    }
+}
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreKey.java b/keystore/java/android/security/keystore/AndroidKeyStoreKey.java
index 1751aa5..e76802f 100644
--- a/keystore/java/android/security/keystore/AndroidKeyStoreKey.java
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreKey.java
@@ -52,4 +52,42 @@ public class AndroidKeyStoreKey implements Key {
         // This key does not export its key material
         return null;
     }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((mAlgorithm == null) ? 0 : mAlgorithm.hashCode());
+        result = prime * result + ((mAlias == null) ? 0 : mAlias.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        AndroidKeyStoreKey other = (AndroidKeyStoreKey) obj;
+        if (mAlgorithm == null) {
+            if (other.mAlgorithm != null) {
+                return false;
+            }
+        } else if (!mAlgorithm.equals(other.mAlgorithm)) {
+            return false;
+        }
+        if (mAlias == null) {
+            if (other.mAlias != null) {
+                return false;
+            }
+        } else if (!mAlias.equals(other.mAlias)) {
+            return false;
+        }
+        return true;
+    }
 }
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreKeyPairGeneratorSpi.java b/keystore/java/android/security/keystore/AndroidKeyStoreKeyPairGeneratorSpi.java
index 69155a8..35af34f 100644
--- a/keystore/java/android/security/keystore/AndroidKeyStoreKeyPairGeneratorSpi.java
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreKeyPairGeneratorSpi.java
@@ -20,7 +20,6 @@ import android.annotation.Nullable;
 import android.security.Credentials;
 import android.security.KeyPairGeneratorSpec;
 import android.security.KeyStore;
-import android.security.keymaster.ExportResult;
 import android.security.keymaster.KeyCharacteristics;
 import android.security.keymaster.KeymasterArguments;
 import android.security.keymaster.KeymasterDefs;
@@ -44,29 +43,24 @@ import com.android.org.bouncycastle.asn1.x9.X9ObjectIdentifiers;
 import com.android.org.bouncycastle.jce.X509Principal;
 import com.android.org.bouncycastle.jce.provider.X509CertificateObject;
 import com.android.org.bouncycastle.x509.X509V3CertificateGenerator;
-import com.android.org.conscrypt.OpenSSLEngine;
 
 import libcore.util.EmptyArray;
 
 import java.math.BigInteger;
 import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.KeyFactory;
 import java.security.KeyPair;
 import java.security.KeyPairGenerator;
 import java.security.KeyPairGeneratorSpi;
-import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
 import java.security.ProviderException;
 import java.security.PublicKey;
 import java.security.SecureRandom;
+import java.security.UnrecoverableKeyException;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.X509Certificate;
 import java.security.spec.AlgorithmParameterSpec;
 import java.security.spec.ECGenParameterSpec;
-import java.security.spec.InvalidKeySpecException;
 import java.security.spec.RSAKeyGenParameterSpec;
-import java.security.spec.X509EncodedKeySpec;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
@@ -147,6 +141,7 @@ public abstract class AndroidKeyStoreKeyPairGeneratorSpi extends KeyPairGenerato
         SUPPORTED_EC_NIST_CURVE_NAMES.addAll(SUPPORTED_EC_NIST_CURVE_NAME_TO_SIZE.keySet());
         Collections.sort(SUPPORTED_EC_NIST_CURVE_NAMES);
     }
+
     private final int mOriginalKeymasterAlgorithm;
 
     private KeyStore mKeyStore;
@@ -431,24 +426,6 @@ public abstract class AndroidKeyStoreKeyPairGeneratorSpi extends KeyPairGenerato
         args.addInts(KeymasterDefs.KM_TAG_PADDING, mKeymasterSignaturePaddings);
         args.addInts(KeymasterDefs.KM_TAG_DIGEST, mKeymasterDigests);
 
-        // TODO: Remove the digest and padding NONE workaround below once Android Keystore returns
-        // keys which are backed by AndroidKeyStoreBCWorkaround provider instead of Conscrypt. The
-        // workaround is needed because Conscrypt (via keystore-engine) uses old KeyStore API which
-        // translates into digest NONE and padding NONE in the new API. keystore-engine cannot be
-        // updated to pass in the correct padding and digest values because it uses
-        // OpenSSL/BoringSSL engine which performs digesting and padding prior before invoking
-        // KeyStore API.
-        if (!com.android.internal.util.ArrayUtils.contains(
-                mKeymasterDigests, KeymasterDefs.KM_DIGEST_NONE)) {
-            args.addInt(KeymasterDefs.KM_TAG_DIGEST, KeymasterDefs.KM_DIGEST_NONE);
-        }
-        if ((!com.android.internal.util.ArrayUtils.contains(
-                mKeymasterSignaturePaddings, KeymasterDefs.KM_PAD_NONE))
-                && (!com.android.internal.util.ArrayUtils.contains(
-                        mKeymasterEncryptionPaddings, KeymasterDefs.KM_PAD_NONE))) {
-            args.addInt(KeymasterDefs.KM_TAG_PADDING, KeymasterDefs.KM_PAD_NONE);
-        }
-
         KeymasterUtils.addUserAuthArgs(args,
                 mSpec.isUserAuthenticationRequired(),
                 mSpec.getUserAuthenticationValidityDurationSeconds());
@@ -483,40 +460,23 @@ public abstract class AndroidKeyStoreKeyPairGeneratorSpi extends KeyPairGenerato
                         "Failed to generate key pair", KeyStore.getKeyStoreException(errorCode));
             }
 
-            final PrivateKey privKey;
-            final OpenSSLEngine engine = OpenSSLEngine.getInstance("keystore");
+            KeyPair result;
             try {
-                privKey = engine.getPrivateKeyById(privateKeyAlias);
-            } catch (InvalidKeyException e) {
-                throw new ProviderException("Failed to obtain generated private key", e);
+                result = AndroidKeyStoreProvider.loadAndroidKeyStoreKeyPairFromKeystore(
+                        mKeyStore, privateKeyAlias);
+            } catch (UnrecoverableKeyException e) {
+                throw new ProviderException("Failed to load generated key pair from keystore", e);
             }
 
-            ExportResult exportResult =
-                    mKeyStore.exportKey(
-                            privateKeyAlias, KeymasterDefs.KM_KEY_FORMAT_X509, null, null);
-            if (exportResult == null) {
-                throw new KeyStoreConnectException();
-            } else if (exportResult.resultCode != KeyStore.NO_ERROR) {
-                throw new ProviderException(
-                        "Failed to obtain X.509 form of generated public key",
-                        KeyStore.getKeyStoreException(exportResult.resultCode));
-            }
-            final byte[] pubKeyBytes = exportResult.exportData;
-
-            final PublicKey pubKey;
-            try {
-                final KeyFactory keyFact = KeyFactory.getInstance(mJcaKeyAlgorithm);
-                pubKey = keyFact.generatePublic(new X509EncodedKeySpec(pubKeyBytes));
-            } catch (NoSuchAlgorithmException e) {
+            if (!mJcaKeyAlgorithm.equalsIgnoreCase(result.getPrivate().getAlgorithm())) {
                 throw new ProviderException(
-                        "Failed to obtain " + mJcaKeyAlgorithm + " KeyFactory", e);
-            } catch (InvalidKeySpecException e) {
-                throw new ProviderException("Invalid X.509 encoding of generated public key", e);
+                        "Generated key pair algorithm does not match requested algorithm: "
+                        + result.getPrivate().getAlgorithm() + " vs " + mJcaKeyAlgorithm);
             }
 
             final X509Certificate cert;
             try {
-                cert = generateSelfSignedCertificate(privKey, pubKey);
+                cert = generateSelfSignedCertificate(result.getPrivate(), result.getPublic());
             } catch (Exception e) {
                 throw new ProviderException("Failed to generate self-signed certificate", e);
             }
@@ -539,7 +499,6 @@ public abstract class AndroidKeyStoreKeyPairGeneratorSpi extends KeyPairGenerato
                         KeyStore.getKeyStoreException(insertErrorCode));
             }
 
-            KeyPair result = new KeyPair(pubKey, privKey);
             success = true;
             return result;
         } finally {
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreProvider.java b/keystore/java/android/security/keystore/AndroidKeyStoreProvider.java
index cb270bb..967319a 100644
--- a/keystore/java/android/security/keystore/AndroidKeyStoreProvider.java
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreProvider.java
@@ -16,11 +16,28 @@
 
 package android.security.keystore;
 
+import android.annotation.NonNull;
 import android.security.KeyStore;
+import android.security.keymaster.ExportResult;
+import android.security.keymaster.KeyCharacteristics;
+import android.security.keymaster.KeymasterDefs;
 
+import java.security.KeyFactory;
+import java.security.KeyPair;
+import java.security.NoSuchAlgorithmException;
 import java.security.Provider;
+import java.security.ProviderException;
+import java.security.PublicKey;
 import java.security.Security;
 import java.security.Signature;
+import java.security.UnrecoverableKeyException;
+import java.security.interfaces.ECKey;
+import java.security.interfaces.ECPublicKey;
+import java.security.interfaces.RSAKey;
+import java.security.interfaces.RSAPublicKey;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.List;
 
 import javax.crypto.Cipher;
 import javax.crypto.Mac;
@@ -146,4 +163,145 @@ public class AndroidKeyStoreProvider extends Provider {
         }
         return ((KeyStoreCryptoOperation) spi).getOperationHandle();
     }
+
+    @NonNull
+    public static AndroidKeyStorePublicKey getAndroidKeyStorePublicKey(
+            @NonNull String alias,
+            @NonNull @KeyProperties.KeyAlgorithmEnum String keyAlgorithm,
+            @NonNull byte[] x509EncodedForm) {
+        PublicKey publicKey;
+        try {
+            KeyFactory keyFactory = KeyFactory.getInstance(keyAlgorithm);
+            publicKey = keyFactory.generatePublic(new X509EncodedKeySpec(x509EncodedForm));
+        } catch (NoSuchAlgorithmException e) {
+            throw new ProviderException(
+                    "Failed to obtain " + keyAlgorithm + " KeyFactory", e);
+        } catch (InvalidKeySpecException e) {
+            throw new ProviderException("Invalid X.509 encoding of public key", e);
+        }
+        if (KeyProperties.KEY_ALGORITHM_EC.equalsIgnoreCase(keyAlgorithm)) {
+            return new AndroidKeyStoreECPublicKey(alias, (ECPublicKey) publicKey);
+        } else if (KeyProperties.KEY_ALGORITHM_RSA.equalsIgnoreCase(keyAlgorithm)) {
+            return new AndroidKeyStoreRSAPublicKey(alias, (RSAPublicKey) publicKey);
+        } else {
+            throw new ProviderException("Unsupported Android Keystore public key algorithm: "
+                    + keyAlgorithm);
+        }
+    }
+
+    @NonNull
+    public static AndroidKeyStorePrivateKey getAndroidKeyStorePrivateKey(
+            @NonNull AndroidKeyStorePublicKey publicKey) {
+        String keyAlgorithm = publicKey.getAlgorithm();
+        if (KeyProperties.KEY_ALGORITHM_EC.equalsIgnoreCase(keyAlgorithm)) {
+            return new AndroidKeyStoreECPrivateKey(
+                    publicKey.getAlias(), ((ECKey) publicKey).getParams());
+        } else if (KeyProperties.KEY_ALGORITHM_RSA.equalsIgnoreCase(keyAlgorithm)) {
+            return new AndroidKeyStoreRSAPrivateKey(
+                    publicKey.getAlias(), ((RSAKey) publicKey).getModulus());
+        } else {
+            throw new ProviderException("Unsupported Android Keystore public key algorithm: "
+                    + keyAlgorithm);
+        }
+    }
+
+    @NonNull
+    public static AndroidKeyStorePublicKey loadAndroidKeyStorePublicKeyFromKeystore(
+            @NonNull KeyStore keyStore, @NonNull String privateKeyAlias)
+            throws UnrecoverableKeyException {
+        KeyCharacteristics keyCharacteristics = new KeyCharacteristics();
+        int errorCode = keyStore.getKeyCharacteristics(
+                privateKeyAlias, null, null, keyCharacteristics);
+        if (errorCode != KeyStore.NO_ERROR) {
+            throw (UnrecoverableKeyException)
+                    new UnrecoverableKeyException("Failed to obtain information about private key")
+                    .initCause(KeyStore.getKeyStoreException(errorCode));
+        }
+        ExportResult exportResult = keyStore.exportKey(
+                privateKeyAlias, KeymasterDefs.KM_KEY_FORMAT_X509, null, null);
+        if (exportResult.resultCode != KeyStore.NO_ERROR) {
+            throw (UnrecoverableKeyException)
+                    new UnrecoverableKeyException("Failed to obtain X.509 form of public key")
+                    .initCause(KeyStore.getKeyStoreException(errorCode));
+        }
+        final byte[] x509EncodedPublicKey = exportResult.exportData;
+
+        int keymasterAlgorithm = keyCharacteristics.getInt(KeymasterDefs.KM_TAG_ALGORITHM, -1);
+        if (keymasterAlgorithm == -1) {
+            throw new UnrecoverableKeyException("Key algorithm unknown");
+        }
+
+        String jcaKeyAlgorithm;
+        try {
+            jcaKeyAlgorithm = KeyProperties.KeyAlgorithm.fromKeymasterAsymmetricKeyAlgorithm(
+                    keymasterAlgorithm);
+        } catch (IllegalArgumentException e) {
+            throw (UnrecoverableKeyException)
+                    new UnrecoverableKeyException("Failed to load private key")
+                    .initCause(e);
+        }
+
+        return AndroidKeyStoreProvider.getAndroidKeyStorePublicKey(
+                privateKeyAlias, jcaKeyAlgorithm, x509EncodedPublicKey);
+    }
+
+    @NonNull
+    public static KeyPair loadAndroidKeyStoreKeyPairFromKeystore(
+            @NonNull KeyStore keyStore, @NonNull String privateKeyAlias)
+            throws UnrecoverableKeyException {
+        AndroidKeyStorePublicKey publicKey =
+                loadAndroidKeyStorePublicKeyFromKeystore(keyStore, privateKeyAlias);
+        AndroidKeyStorePrivateKey privateKey =
+                AndroidKeyStoreProvider.getAndroidKeyStorePrivateKey(publicKey);
+        return new KeyPair(publicKey, privateKey);
+    }
+
+    @NonNull
+    public static AndroidKeyStorePrivateKey loadAndroidKeyStorePrivateKeyFromKeystore(
+            @NonNull KeyStore keyStore, @NonNull String privateKeyAlias)
+            throws UnrecoverableKeyException {
+        KeyPair keyPair = loadAndroidKeyStoreKeyPairFromKeystore(keyStore, privateKeyAlias);
+        return (AndroidKeyStorePrivateKey) keyPair.getPrivate();
+    }
+
+    @NonNull
+    public static AndroidKeyStoreSecretKey loadAndroidKeyStoreSecretKeyFromKeystore(
+            @NonNull KeyStore keyStore, @NonNull String secretKeyAlias)
+            throws UnrecoverableKeyException {
+        KeyCharacteristics keyCharacteristics = new KeyCharacteristics();
+        int errorCode = keyStore.getKeyCharacteristics(
+                secretKeyAlias, null, null, keyCharacteristics);
+        if (errorCode != KeyStore.NO_ERROR) {
+            throw (UnrecoverableKeyException)
+                    new UnrecoverableKeyException("Failed to obtain information about key")
+                            .initCause(KeyStore.getKeyStoreException(errorCode));
+        }
+
+        int keymasterAlgorithm = keyCharacteristics.getInt(KeymasterDefs.KM_TAG_ALGORITHM, -1);
+        if (keymasterAlgorithm == -1) {
+            throw new UnrecoverableKeyException("Key algorithm unknown");
+        }
+
+        List<Integer> keymasterDigests =
+                keyCharacteristics.getInts(KeymasterDefs.KM_TAG_DIGEST);
+        int keymasterDigest;
+        if (keymasterDigests.isEmpty()) {
+            keymasterDigest = -1;
+        } else {
+            // More than one digest can be permitted for this key. Use the first one to form the
+            // JCA key algorithm name.
+            keymasterDigest = keymasterDigests.get(0);
+        }
+
+        @KeyProperties.KeyAlgorithmEnum String keyAlgorithmString;
+        try {
+            keyAlgorithmString = KeyProperties.KeyAlgorithm.fromKeymasterSecretKeyAlgorithm(
+                    keymasterAlgorithm, keymasterDigest);
+        } catch (IllegalArgumentException e) {
+            throw (UnrecoverableKeyException)
+                    new UnrecoverableKeyException("Unsupported secret key type").initCause(e);
+        }
+
+        return new AndroidKeyStoreSecretKey(secretKeyAlias, keyAlgorithmString);
+    }
 }
diff --git a/keystore/java/android/security/keystore/AndroidKeyStorePublicKey.java b/keystore/java/android/security/keystore/AndroidKeyStorePublicKey.java
index 8133d46..9fea30d 100644
--- a/keystore/java/android/security/keystore/AndroidKeyStorePublicKey.java
+++ b/keystore/java/android/security/keystore/AndroidKeyStorePublicKey.java
@@ -17,6 +17,7 @@
 package android.security.keystore;
 
 import java.security.PublicKey;
+import java.util.Arrays;
 
 /**
  * {@link PublicKey} backed by Android Keystore.
@@ -41,4 +42,30 @@ public class AndroidKeyStorePublicKey extends AndroidKeyStoreKey implements Publ
     public byte[] getEncoded() {
         return ArrayUtils.cloneIfNotEmpty(mEncoded);
     }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = super.hashCode();
+        result = prime * result + Arrays.hashCode(mEncoded);
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!super.equals(obj)) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        AndroidKeyStorePublicKey other = (AndroidKeyStorePublicKey) obj;
+        if (!Arrays.equals(mEncoded, other.mEncoded)) {
+            return false;
+        }
+        return true;
+    }
 }
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreRSAPrivateKey.java b/keystore/java/android/security/keystore/AndroidKeyStoreRSAPrivateKey.java
new file mode 100644
index 0000000..179ffd8
--- /dev/null
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreRSAPrivateKey.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.security.keystore;
+
+import java.math.BigInteger;
+import java.security.PrivateKey;
+import java.security.interfaces.RSAKey;
+
+/**
+ * RSA private key (instance of {@link PrivateKey} and {@link RSAKey}) backed by keystore.
+ *
+ * @hide
+ */
+public class AndroidKeyStoreRSAPrivateKey extends AndroidKeyStorePrivateKey implements RSAKey {
+
+    private final BigInteger mModulus;
+
+    public AndroidKeyStoreRSAPrivateKey(String alias, BigInteger modulus) {
+        super(alias, KeyProperties.KEY_ALGORITHM_RSA);
+        mModulus = modulus;
+    }
+
+    @Override
+    public BigInteger getModulus() {
+        return mModulus;
+    }
+}
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreSignatureSpiBase.java b/keystore/java/android/security/keystore/AndroidKeyStoreSignatureSpiBase.java
index 4c4062f..f072ae7 100644
--- a/keystore/java/android/security/keystore/AndroidKeyStoreSignatureSpiBase.java
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreSignatureSpiBase.java
@@ -25,7 +25,7 @@ import android.security.keymaster.KeymasterArguments;
 import android.security.keymaster.KeymasterDefs;
 import android.security.keymaster.OperationResult;
 
-import com.android.org.conscrypt.util.EmptyArray;
+import libcore.util.EmptyArray;
 
 import java.nio.ByteBuffer;
 import java.security.InvalidKeyException;
diff --git a/keystore/java/android/security/keystore/AndroidKeyStoreSpi.java b/keystore/java/android/security/keystore/AndroidKeyStoreSpi.java
index c03be63..831a106 100644
--- a/keystore/java/android/security/keystore/AndroidKeyStoreSpi.java
+++ b/keystore/java/android/security/keystore/AndroidKeyStoreSpi.java
@@ -16,9 +16,6 @@
 
 package android.security.keystore;
 
-import com.android.org.conscrypt.OpenSSLEngine;
-import com.android.org.conscrypt.OpenSSLKeyHolder;
-
 import libcore.util.EmptyArray;
 
 import android.security.Credentials;
@@ -35,7 +32,6 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.security.InvalidKeyException;
 import java.security.Key;
 import java.security.KeyStore.Entry;
 import java.security.KeyStore.PrivateKeyEntry;
@@ -45,6 +41,7 @@ import java.security.KeyStoreException;
 import java.security.KeyStoreSpi;
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
+import java.security.PublicKey;
 import java.security.UnrecoverableKeyException;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateEncodingException;
@@ -59,7 +56,6 @@ import java.util.Date;
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.List;
 import java.util.Set;
 
 import javax.crypto.SecretKey;
@@ -92,59 +88,17 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
     public Key engineGetKey(String alias, char[] password) throws NoSuchAlgorithmException,
             UnrecoverableKeyException {
         if (isPrivateKeyEntry(alias)) {
-            final OpenSSLEngine engine = OpenSSLEngine.getInstance("keystore");
-            try {
-                return engine.getPrivateKeyById(Credentials.USER_PRIVATE_KEY + alias);
-            } catch (InvalidKeyException e) {
-                UnrecoverableKeyException t = new UnrecoverableKeyException("Can't get key");
-                t.initCause(e);
-                throw t;
-            }
+            String privateKeyAlias = Credentials.USER_PRIVATE_KEY + alias;
+            return AndroidKeyStoreProvider.loadAndroidKeyStorePrivateKeyFromKeystore(
+                    mKeyStore, privateKeyAlias);
         } else if (isSecretKeyEntry(alias)) {
-            KeyCharacteristics keyCharacteristics = new KeyCharacteristics();
-            String keyAliasInKeystore = Credentials.USER_SECRET_KEY + alias;
-            int errorCode = mKeyStore.getKeyCharacteristics(
-                    keyAliasInKeystore, null, null, keyCharacteristics);
-            if (errorCode != KeyStore.NO_ERROR) {
-                throw (UnrecoverableKeyException)
-                        new UnrecoverableKeyException("Failed to load information about key")
-                                .initCause(mKeyStore.getInvalidKeyException(alias, errorCode));
-            }
-
-            int keymasterAlgorithm =
-                    keyCharacteristics.hwEnforced.getInt(KeymasterDefs.KM_TAG_ALGORITHM, -1);
-            if (keymasterAlgorithm == -1) {
-                keymasterAlgorithm =
-                        keyCharacteristics.swEnforced.getInt(KeymasterDefs.KM_TAG_ALGORITHM, -1);
-            }
-            if (keymasterAlgorithm == -1) {
-                throw new UnrecoverableKeyException("Key algorithm unknown");
-            }
-
-            List<Integer> keymasterDigests =
-                    keyCharacteristics.getInts(KeymasterDefs.KM_TAG_DIGEST);
-            int keymasterDigest;
-            if (keymasterDigests.isEmpty()) {
-                keymasterDigest = -1;
-            } else {
-                // More than one digest can be permitted for this key. Use the first one to form the
-                // JCA key algorithm name.
-                keymasterDigest = keymasterDigests.get(0);
-            }
-
-            @KeyProperties.KeyAlgorithmEnum String keyAlgorithmString;
-            try {
-                keyAlgorithmString = KeyProperties.KeyAlgorithm.fromKeymasterSecretKeyAlgorithm(
-                        keymasterAlgorithm, keymasterDigest);
-            } catch (IllegalArgumentException e) {
-                throw (UnrecoverableKeyException)
-                        new UnrecoverableKeyException("Unsupported secret key type").initCause(e);
-            }
-
-            return new AndroidKeyStoreSecretKey(keyAliasInKeystore, keyAlgorithmString);
+            String secretKeyAlias = Credentials.USER_SECRET_KEY + alias;
+            return AndroidKeyStoreProvider.loadAndroidKeyStoreSecretKeyFromKeystore(
+                    mKeyStore, secretKeyAlias);
+        } else {
+            // Key not found
+            return null;
         }
-
-        return null;
     }
 
     @Override
@@ -188,22 +142,36 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
 
         byte[] certificate = mKeyStore.get(Credentials.USER_CERTIFICATE + alias);
         if (certificate != null) {
-            return toCertificate(certificate);
+            return wrapIntoKeyStoreCertificate(
+                    Credentials.USER_PRIVATE_KEY + alias, toCertificate(certificate));
         }
 
         certificate = mKeyStore.get(Credentials.CA_CERTIFICATE + alias);
         if (certificate != null) {
-            return toCertificate(certificate);
+            return wrapIntoKeyStoreCertificate(
+                    Credentials.USER_PRIVATE_KEY + alias, toCertificate(certificate));
         }
 
         return null;
     }
 
+    /**
+     * Wraps the provided cerificate into {@link KeyStoreX509Certificate} so that the public key
+     * returned by the certificate contains information about the alias of the private key in
+     * keystore. This is needed so that Android Keystore crypto operations using public keys can
+     * find out which key alias to use. These operations cannot work without an alias.
+     */
+    private static KeyStoreX509Certificate wrapIntoKeyStoreCertificate(
+            String privateKeyAlias, X509Certificate certificate) {
+        return (certificate != null)
+                ? new KeyStoreX509Certificate(privateKeyAlias, certificate) : null;
+    }
+
     private static X509Certificate toCertificate(byte[] bytes) {
         try {
             final CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
-            return (X509Certificate) certFactory
-                    .generateCertificate(new ByteArrayInputStream(bytes));
+            return (X509Certificate) certFactory.generateCertificate(
+                    new ByteArrayInputStream(bytes));
         } catch (CertificateException e) {
             Log.w(NAME, "Couldn't parse certificate in keystore", e);
             return null;
@@ -214,8 +182,8 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
     private static Collection<X509Certificate> toCertificates(byte[] bytes) {
         try {
             final CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
-            return (Collection<X509Certificate>) certFactory
-                    .generateCertificates(new ByteArrayInputStream(bytes));
+            return (Collection<X509Certificate>) certFactory.generateCertificates(
+                            new ByteArrayInputStream(bytes));
         } catch (CertificateException e) {
             Log.w(NAME, "Couldn't parse certificates in keystore", e);
             return new ArrayList<X509Certificate>();
@@ -406,9 +374,7 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
         }
 
         final String pkeyAlias;
-        if (key instanceof OpenSSLKeyHolder) {
-            pkeyAlias = ((OpenSSLKeyHolder) key).getOpenSSLKey().getAlias();
-        } else if (key instanceof AndroidKeyStorePrivateKey) {
+        if (key instanceof AndroidKeyStorePrivateKey) {
             pkeyAlias = ((AndroidKeyStoreKey) key).getAlias();
         } else {
             pkeyAlias = null;
@@ -851,6 +817,19 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
         if (cert == null) {
             return null;
         }
+        if (!"X.509".equalsIgnoreCase(cert.getType())) {
+            // Only X.509 certificates supported
+            return null;
+        }
+        byte[] targetCertBytes;
+        try {
+            targetCertBytes = cert.getEncoded();
+        } catch (CertificateEncodingException e) {
+            return null;
+        }
+        if (targetCertBytes == null) {
+            return null;
+        }
 
         final Set<String> nonCaEntries = new HashSet<String>();
 
@@ -868,10 +847,9 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
                     continue;
                 }
 
-                final Certificate c = toCertificate(certBytes);
                 nonCaEntries.add(alias);
 
-                if (cert.equals(c)) {
+                if (Arrays.equals(certBytes, targetCertBytes)) {
                     return alias;
                 }
             }
@@ -893,9 +871,7 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
                     continue;
                 }
 
-                final Certificate c =
-                        toCertificate(mKeyStore.get(Credentials.CA_CERTIFICATE + alias));
-                if (cert.equals(c)) {
+                if (Arrays.equals(certBytes, targetCertBytes)) {
                     return alias;
                 }
             }
@@ -954,4 +930,25 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
         }
     }
 
+    /**
+     * {@link X509Certificate} which returns {@link AndroidKeyStorePublicKey} from
+     * {@link #getPublicKey()}. This is so that crypto operations on these public keys contain
+     * can find out which keystore private key entry to use. This is needed so that Android Keystore
+     * crypto operations using public keys can find out which key alias to use. These operations
+     * require an alias.
+     */
+    static class KeyStoreX509Certificate extends DelegatingX509Certificate {
+        private final String mPrivateKeyAlias;
+        KeyStoreX509Certificate(String privateKeyAlias, X509Certificate delegate) {
+            super(delegate);
+            mPrivateKeyAlias = privateKeyAlias;
+        }
+
+        @Override
+        public PublicKey getPublicKey() {
+            PublicKey original = super.getPublicKey();
+            return AndroidKeyStoreProvider.getAndroidKeyStorePublicKey(
+                    mPrivateKeyAlias, original.getAlgorithm(), original.getEncoded());
+        }
+    }
 }
diff --git a/keystore/java/android/security/keystore/DelegatingX509Certificate.java b/keystore/java/android/security/keystore/DelegatingX509Certificate.java
new file mode 100644
index 0000000..03d202f
--- /dev/null
+++ b/keystore/java/android/security/keystore/DelegatingX509Certificate.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.security.keystore;
+
+import java.math.BigInteger;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.Principal;
+import java.security.PublicKey;
+import java.security.SignatureException;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateExpiredException;
+import java.security.cert.CertificateNotYetValidException;
+import java.security.cert.CertificateParsingException;
+import java.security.cert.X509Certificate;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+import java.util.Set;
+
+import javax.security.auth.x500.X500Principal;
+
+class DelegatingX509Certificate extends X509Certificate {
+    private final X509Certificate mDelegate;
+
+    DelegatingX509Certificate(X509Certificate delegate) {
+        mDelegate = delegate;
+    }
+
+    @Override
+    public Set<String> getCriticalExtensionOIDs() {
+        return mDelegate.getCriticalExtensionOIDs();
+    }
+
+    @Override
+    public byte[] getExtensionValue(String oid) {
+        return mDelegate.getExtensionValue(oid);
+    }
+
+    @Override
+    public Set<String> getNonCriticalExtensionOIDs() {
+        return mDelegate.getNonCriticalExtensionOIDs();
+    }
+
+    @Override
+    public boolean hasUnsupportedCriticalExtension() {
+        return mDelegate.hasUnsupportedCriticalExtension();
+    }
+
+    @Override
+    public void checkValidity() throws CertificateExpiredException,
+            CertificateNotYetValidException {
+        mDelegate.checkValidity();
+    }
+
+    @Override
+    public void checkValidity(Date date) throws CertificateExpiredException,
+            CertificateNotYetValidException {
+        mDelegate.checkValidity(date);
+    }
+
+    @Override
+    public int getBasicConstraints() {
+        return mDelegate.getBasicConstraints();
+    }
+
+    @Override
+    public Principal getIssuerDN() {
+        return mDelegate.getIssuerDN();
+    }
+
+    @Override
+    public boolean[] getIssuerUniqueID() {
+        return mDelegate.getIssuerUniqueID();
+    }
+
+    @Override
+    public boolean[] getKeyUsage() {
+        return mDelegate.getKeyUsage();
+    }
+
+    @Override
+    public Date getNotAfter() {
+        return mDelegate.getNotAfter();
+    }
+
+    @Override
+    public Date getNotBefore() {
+        return mDelegate.getNotBefore();
+    }
+
+    @Override
+    public BigInteger getSerialNumber() {
+        return mDelegate.getSerialNumber();
+    }
+
+    @Override
+    public String getSigAlgName() {
+        return mDelegate.getSigAlgName();
+    }
+
+    @Override
+    public String getSigAlgOID() {
+        return mDelegate.getSigAlgOID();
+    }
+
+    @Override
+    public byte[] getSigAlgParams() {
+        return mDelegate.getSigAlgParams();
+    }
+
+    @Override
+    public byte[] getSignature() {
+        return mDelegate.getSignature();
+    }
+
+    @Override
+    public Principal getSubjectDN() {
+        return mDelegate.getSubjectDN();
+    }
+
+    @Override
+    public boolean[] getSubjectUniqueID() {
+        return mDelegate.getSubjectUniqueID();
+    }
+
+    @Override
+    public byte[] getTBSCertificate() throws CertificateEncodingException {
+        return mDelegate.getTBSCertificate();
+    }
+
+    @Override
+    public int getVersion() {
+        return mDelegate.getVersion();
+    }
+
+    @Override
+    public byte[] getEncoded() throws CertificateEncodingException {
+        return mDelegate.getEncoded();
+    }
+
+    @Override
+    public PublicKey getPublicKey() {
+        return mDelegate.getPublicKey();
+    }
+
+    @Override
+    public String toString() {
+        return mDelegate.toString();
+    }
+
+    @Override
+    public void verify(PublicKey key)
+            throws CertificateException,
+            NoSuchAlgorithmException,
+            InvalidKeyException,
+            NoSuchProviderException,
+            SignatureException {
+        mDelegate.verify(key);
+    }
+
+    @Override
+    public void verify(PublicKey key, String sigProvider)
+            throws CertificateException,
+            NoSuchAlgorithmException,
+            InvalidKeyException,
+            NoSuchProviderException,
+            SignatureException {
+        mDelegate.verify(key, sigProvider);
+    }
+
+    @Override
+    public List<String> getExtendedKeyUsage() throws CertificateParsingException {
+        return mDelegate.getExtendedKeyUsage();
+    }
+
+    @Override
+    public Collection<List<?>> getIssuerAlternativeNames() throws CertificateParsingException {
+        return mDelegate.getIssuerAlternativeNames();
+    }
+
+    @Override
+    public X500Principal getIssuerX500Principal() {
+        return mDelegate.getIssuerX500Principal();
+    }
+
+    @Override
+    public Collection<List<?>> getSubjectAlternativeNames() throws CertificateParsingException {
+        return mDelegate.getSubjectAlternativeNames();
+    }
+
+    @Override
+    public X500Principal getSubjectX500Principal() {
+        return mDelegate.getSubjectX500Principal();
+    }
+}