我正在尝试在Android M指纹API通过用户验证后解密加密文本。我一直在尝试遵循Android安全示例和KeyGenParameterSpec文档中提供的示例。我已经成功使用公钥对文本进行了加密，但是当我使用Cipher中的私钥以DECRYPT_MODE调用cipher.doFinal时，我会收到一个KeyStoreException "未知错误"：
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)
相关的当前代码如下：
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);
}
}
setUserAuthenticationRequired，但我无法找出原因。我还尝试使用全局的mCipher代替FragmentManagerCompat.AuthenticationCallback.onAuthenticationSucceeded提供的Cipher（虽然我认为它们应该是相同的），但结果相同。
我在寻找答案我的其他问题时遇到了这个问题。