java - Android 字符串加密/解密

Question

我想String从EditTextusing加密和解密 a AndroidKeyStore。我的问题是在解密过程中得到一个BadPaddingException.

密钥生成器代码：

        KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");

        KeyGenParameterSpec keyGenParameterSpec = new KeyGenParameterSpec.Builder(ALIAS, KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT).
                setBlockModes(KeyProperties.BLOCK_MODE_GCM).setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE).build();

        keyGenerator.init(keyGenParameterSpec);
        keyGenerator.generateKey();

加密代码：

            KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore");
            keyStore.load(null);

            KeyStore.SecretKeyEntry secretKeyEntry = (KeyStore.SecretKeyEntry) keyStore.getEntry(ALIAS, null);
            SecretKey secretKey = secretKeyEntry.getSecretKey();

            Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);

            cipherIV = cipher.getIV();

            plainText.setText(new String(cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8)), StandardCharsets.UTF_8));

解密代码：

            KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore");
            keyStore.load(null);

            final KeyStore.SecretKeyEntry secretKeyEntry = (KeyStore.SecretKeyEntry) keyStore.getEntry(ALIAS, null);
            final SecretKey secretKey = secretKeyEntry.getSecretKey();

            final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
            final GCMParameterSpec spec = new GCMParameterSpec(128, cipherIV);
            cipher.init(Cipher.DECRYPT_MODE, secretKey, spec);

            byte[] decrypted = cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8));
            plainText.setText(new String(decrypted, StandardCharsets.UTF_8));

标签： javaandroidencryptionandroid-keystore

Answer 1

byte[] decrypted = cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8));

由于getBytes(StandardCharsets.UTF_8). 如果您EditText是十六进制表示，请尝试将其转换为字符串，然后调用getBytes(). 例如

public static byte[] convertHexStringToByteArray(String hexString) {

    int l = hexString.length();
    byte[] data = new byte[l/2];
    for (int i = 0; i < l; i += 2) {
        data[i/2] = (byte)((Character.digit(hexString.charAt(i), 16) << 4) + Character.digit(hexString.charAt(i+1), 16));
    }

    return data;
}