ユーザーが Android M Fingerprint API によって認証された後、暗号化されたテキストを復号化しようとしています。私は主にAndroid セキュリティのサンプルKeyGenParameterSpecと、ドキュメントで提供されている例に従うように努めてきました。公開鍵でテキストを正常に暗号化できましたが、 で秘密鍵を使用して呼び出すcipher.doFinalと、「不明なエラー」が発生します。CipherDECRYPT_MODEKeyStoreException
03-15 10:06:58.074 14702-14702/com.example.app E/LoginFragment: Failed to decrypt password
javax.crypto.IllegalBlockSizeException
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:486)
at javax.crypto.Cipher.doFinal(Cipher.java:1502)
at com.example.app.ui.fragment.util.LoginFragment.onAuthenticationSucceeded(LoginFragment.java:251)
at com.example.app.ui.controller.FingerprintCallback.onAuthenticationSucceeded(FingerprintCallback.java:21)
at android.support.v4.hardware.fingerprint.FingerprintManagerCompat$Api23FingerprintManagerCompatImpl$1.onAuthenticationSucceeded(FingerprintManagerCompat.java:301)
at android.support.v4.hardware.fingerprint.FingerprintManagerCompatApi23$1.onAuthenticationSucceeded(FingerprintManagerCompatApi23.java:96)
at android.hardware.fingerprint.FingerprintManager$MyHandler.sendAuthenticatedSucceeded(FingerprintManager.java:805)
at android.hardware.fingerprint.FingerprintManager$MyHandler.handleMessage(FingerprintManager.java:757)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: android.security.KeyStoreException: Unknown error
at android.security.KeyStore.getKeyStoreException(KeyStore.java:632)
at android.security.keystore.KeyStoreCryptoOperationChunkedStreamer.doFinal(KeyStoreCryptoOperationChunkedStreamer.java:224)
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:473)
at javax.crypto.Cipher.doFinal(Cipher.java:1502)
at com.example.app.ui.fragment.util.LoginFragment.onAuthenticationSucceeded(LoginFragment.java:251)
at com.example.app.ui.controller.FingerprintCallback.onAuthenticationSucceeded(FingerprintCallback.java:21)
at android.support.v4.hardware.fingerprint.FingerprintManagerCompat$Api23FingerprintManagerCompatImpl$1.onAuthenticationSucceeded(FingerprintManagerCompat.java:301)
at android.support.v4.hardware.fingerprint.FingerprintManagerCompatApi23$1.onAuthenticationSucceeded(FingerprintManagerCompatApi23.java:96)
at android.hardware.fingerprint.FingerprintManager$MyHandler.sendAuthenticatedSucceeded(FingerprintManager.java:805)
at android.hardware.fingerprint.FingerprintManager$MyHandler.handleMessage(FingerprintManager.java:757)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
関連する現在のコードは次のとおりです。
public KeyStore getKeyStore() {
try {
return KeyStore.getInstance("AndroidKeyStore");
} catch (KeyStoreException exception) {
throw new RuntimeException("Failed to get an instance of KeyStore", exception);
}
}
public KeyPairGenerator getKeyPairGenerator() {
try {
return KeyPairGenerator.getInstance("RSA", "AndroidKeyStore");
} catch(NoSuchAlgorithmException | NoSuchProviderException exception) {
throw new RuntimeException("Failed to get an instance of KeyPairGenerator", exception);
}
}
public Cipher getCipher() {
try {
return Cipher.getInstance("RSA/ECB/OAEPWithSHA-256AndMGF1Padding");
} catch(NoSuchAlgorithmException | NoSuchPaddingException exception) {
throw new RuntimeException("Failed to get an instance of Cipher", exception);
}
}
private void createKeyPair() {
try {
mKeyPairGenerator.initialize(
new KeyGenParameterSpec.Builder(KEY_ALIAS, KeyProperties.PURPOSE_DECRYPT)
.setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA512)
.setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_OAEP)
.setUserAuthenticationRequired(true)
.build());
mKeyPairGenerator.generateKeyPair();
} catch(InvalidAlgorithmParameterException exception) {
throw new RuntimeException("Failed to generate key pair", exception);
}
}
private boolean initCipher(int opmode) {
try {
mKeyStore.load(null);
if(opmode == Cipher.ENCRYPT_MODE) {
PublicKey key = mKeyStore.getCertificate(KEY_ALIAS).getPublicKey();
PublicKey unrestricted = KeyFactory.getInstance(key.getAlgorithm())
.generatePublic(new X509EncodedKeySpec(key.getEncoded()));
mCipher.init(opmode, unrestricted);
} else {
PrivateKey key = (PrivateKey) mKeyStore.getKey(KEY_ALIAS, null);
mCipher.init(opmode, key);
}
return true;
} catch (KeyPermanentlyInvalidatedException exception) {
return false;
} catch(KeyStoreException | CertificateException | UnrecoverableKeyException
| IOException | NoSuchAlgorithmException | InvalidKeyException
| InvalidAlgorithmParameterException exception) {
throw new RuntimeException("Failed to initialize Cipher", exception);
}
}
private void encrypt(String password) {
try {
initCipher(Cipher.ENCRYPT_MODE);
byte[] bytes = mCipher.doFinal(password.getBytes());
String encryptedPassword = Base64.encodeToString(bytes, Base64.NO_WRAP);
mPreferences.getString("password").set(encryptedPassword);
} catch(IllegalBlockSizeException | BadPaddingException exception) {
throw new RuntimeException("Failed to encrypt password", exception);
}
}
private String decrypt(Cipher cipher) {
try {
String encryptedPassword = mPreferences.getString("password").get();
byte[] bytes = Base64.decode(encryptedPassword, Base64.NO_WRAP);
return new String(cipher.doFinal(bytes));
} catch (IllegalBlockSizeException | BadPaddingException exception) {
throw new RuntimeException("Failed to decrypt password", exception);
}
}
この「不明なエラー」の原因は何ですか? を除外しましたがsetUserAuthenticationRequired、何が原因なのかわかりません。また、提供されたもののmCipher代わりにグローバルを使用してみました（ただし、それらは同じである必要があると思います）同じ結果が得られました。CipherFragmentManagerCompat.AuthenticationCallback.onAuthenticationSucceeded
別の質問への回答を探しているときに、この問題に遭遇しました。