Keystore 2.0 SPI: Bug fixes

* Correctly recover public key from certificate.
* KeyStore2ParameterUtils: iterate through set flags instead of unset
  flags.
* Return private key on Keystore.getKey() instead of public key.

Test: Keystore CTS tests
Change-Id: I99c1bd49ff5cf7a2d89b54559504e67b3def0cd3

keystore/java/android/security/keystore2/AndroidKeyStoreProvider.java

@@ -31,9 +31,7 @@ import android.system.keystore2.KeyEntryResponse;
 import android.system.keystore2.KeyMetadata;
 import android.system.keystore2.ResponseCode;
 
-import java.security.KeyFactory;
 import java.security.KeyPair;
-import java.security.NoSuchAlgorithmException;
 import java.security.Provider;
 import java.security.ProviderException;
 import java.security.PublicKey;
@@ -42,8 +40,6 @@ import java.security.Signature;
 import java.security.UnrecoverableKeyException;
 import java.security.interfaces.ECPublicKey;
 import java.security.interfaces.RSAPublicKey;
-import java.security.spec.InvalidKeySpecException;
-import java.security.spec.X509EncodedKeySpec;
 
 import javax.crypto.Cipher;
 import javax.crypto.Mac;
@@ -237,28 +233,11 @@ public class AndroidKeyStoreProvider extends Provider {
             throw new UnrecoverableKeyException("Failed to obtain X.509 form of public key."
                     + " Keystore has no public certificate stored.");
         }
-        final byte[] x509EncodedPublicKey = metadata.certificate;
+        final byte[] x509PublicCert = metadata.certificate;
 
-        String jcaKeyAlgorithm;
-        try {
-            jcaKeyAlgorithm = KeyProperties.KeyAlgorithm.fromKeymasterAsymmetricKeyAlgorithm(
-                    algorithm);
-        } catch (IllegalArgumentException e) {
-            throw (UnrecoverableKeyException)
-                    new UnrecoverableKeyException("Failed to load private key")
-                            .initCause(e);
-        }
+        PublicKey publicKey = AndroidKeyStoreSpi.toCertificate(x509PublicCert).getPublicKey();
 
-        PublicKey publicKey;
-        try {
-            KeyFactory keyFactory = KeyFactory.getInstance(jcaKeyAlgorithm);
-            publicKey = keyFactory.generatePublic(new X509EncodedKeySpec(x509EncodedPublicKey));
-        } catch (NoSuchAlgorithmException e) {
-            throw new ProviderException(
-                    "Failed to obtain " + jcaKeyAlgorithm + " KeyFactory", e);
-        } catch (InvalidKeySpecException e) {
-            throw new ProviderException("Invalid X.509 encoding of public key", e);
-        }
+        String jcaKeyAlgorithm = publicKey.getAlgorithm();
 
         KeyStoreSecurityLevel securityLevel = iSecurityLevel;
         if (KeyProperties.KEY_ALGORITHM_EC.equalsIgnoreCase(jcaKeyAlgorithm)) {
@@ -358,7 +337,7 @@ public class AndroidKeyStoreProvider extends Provider {
 
         KeyDescriptor descriptor = new KeyDescriptor();
         if (namespace == KeyProperties.NAMESPACE_APPLICATION) {
-            descriptor.nspace = 0; // ignored;
+            descriptor.nspace = KeyProperties.NAMESPACE_APPLICATION; // ignored;
             descriptor.domain = Domain.APP;
         } else {
             descriptor.nspace = namespace;
@@ -407,7 +386,7 @@ public class AndroidKeyStoreProvider extends Provider {
                 keymasterAlgorithm == KeymasterDefs.KM_ALGORITHM_EC) {
             return makeAndroidKeyStorePublicKeyFromKeyEntryResponse(descriptor, response.metadata,
                     new KeyStoreSecurityLevel(response.iSecurityLevel),
-                    keymasterAlgorithm);
+                    keymasterAlgorithm).getPrivateKey();
         } else {
             throw new UnrecoverableKeyException("Key algorithm unknown");
         }

keystore/java/android/security/keystore2/AndroidKeyStoreRSACipherSpi.java

@@ -158,7 +158,7 @@ abstract class AndroidKeyStoreRSACipherSpi extends AndroidKeyStoreCipherSpiBase
     }
 
     /**
-     * RSA cipher with OAEP encryption padding. Only SHA-1 based MGF1 is supported as MGF.
+     * RSA cipher with OAEP encryption padding.
      */
     abstract static class OAEPWithMGF1Padding extends AndroidKeyStoreRSACipherSpi {
 

keystore/java/android/security/keystore2/AndroidKeyStoreSpi.java

@@ -219,7 +219,7 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
         return null;
     }
 
-    private static X509Certificate toCertificate(byte[] bytes) {
+    static X509Certificate toCertificate(byte[] bytes) {
         try {
             final CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
             return (X509Certificate) certFactory.generateCertificate(

keystore/java/android/security/keystore2/KeyStore2ParameterUtils.java

@@ -177,7 +177,7 @@ public abstract class KeyStore2ParameterUtils {
     static void forEachSetFlag(int flags, Consumer<Integer> consumer) {
         int offset = 0;
         while (flags != 0) {
-            if ((flags & 1) == 0) {
+            if ((flags & 1) == 1) {
                 consumer.accept(1 << offset);
             }
             offset += 1;