我正在尝试在Marshmallow上加密和解密一些数据。加密很好，但是当尝试解密时，我会收到一个 RuntimeException 错误，指出 "iv == null"。
基本上，cipher.getIV() 和 cipher.getParameters() 返回 null。我有什么遗漏吗？
private static final String ALGORITHM_NAME = "AES/GCM/NoPadding";
private static final int IV_SIZE = 128;
private static final int ALGORITHM_SIZE = 256;
private static final String KEYSTORE_PROVIDER = "AndroidKeyStore";
private static final String SYMMETRIC_ALIAS = "secret_key";
private static SecretKey getSymmetricKey()
throws NoSuchProviderException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, IOException,
CertificateException, KeyStoreException, UnrecoverableEntryException {
KeyStore ks = KeyStore.getInstance(KEYSTORE_PROVIDER);
ks.load(null);
return (SecretKey) ks.getKey(SYMMETRIC_ALIAS, null);
}
private static SecretKey createSecretKey()
throws NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException {
KeyGenerator keyGenerator = KeyGenerator.getInstance(
KeyProperties.KEY_ALGORITHM_AES, KEYSTORE_PROVIDER);
keyGenerator.init(new KeyGenParameterSpec.Builder(SYMMETRIC_ALIAS,
KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
.setBlockModes(KeyProperties.BLOCK_MODE_GCM)
.setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
.setKeySize(ALGORITHM_SIZE)
.setRandomizedEncryptionRequired(true)
.setUserAuthenticationRequired(false)
.build());
return keyGenerator.generateKey();
}
public static byte[] encrypt(byte[] data)
throws CertificateException, NoSuchAlgorithmException, IOException, UnrecoverableEntryException,
KeyStoreException, NoSuchProviderException, InvalidAlgorithmParameterException, NoSuchPaddingException,
InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
SecretKey secretKey = getSymmetricKey();
if (secretKey == null) {
secretKey = createSecretKey();
}
Cipher cipher = Cipher.getInstance(ALGORITHM_NAME);
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
return cipher.doFinal(data);
}
public static byte[] decrypt(byte[] data)
throws CertificateException, NoSuchAlgorithmException, IOException, UnrecoverableEntryException,
KeyStoreException, NoSuchProviderException, InvalidAlgorithmParameterException, NoSuchPaddingException,
InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
SecretKey secretKey = getSymmetricKey();
Cipher cipher = Cipher.getInstance(ALGORITHM_NAME);
GCMParameterSpec spec = new GCMParameterSpec(IV_SIZE, cipher.getIV());
cipher.init(Cipher.DECRYPT_MODE, secretKey, spec);
return cipher.doFinal(data.getBytes());
}