我想String從EditTextusing加密和解密 a AndroidKeyStore。我的問題是在解密過程中得到一個BadPaddingException.密鑰生成器代碼： 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();加密代碼： 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));解密代碼： 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));
2 回答
肥皂起泡泡
TA貢獻1829條經驗 獲得超6個贊
這一行是錯誤的：
plainText.setText(new String(cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8)), StandardCharsets.UTF_8));
如果我們把它分開，我們有類似的東西
byte [] cipherBytes = cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8)); plainText.setText(new String(cipherBytes, StandardCharsets.UTF_8);
問題是這cipherBytes是一個任意字節序列而不是字符串的字符。String 構造函數會悄悄地用其他東西替換無效字符，這是一個破壞數據的過程。
如果要顯示密碼字節或以其他方式將其發送到面向字符的通道，則必須對其進行編碼。通常編碼是 base64 或十六進制。要解密字符串，您必須先將其解碼為字節，然后再解密。
例子：
byte [] cipherBytes = cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8)); plainText.setText(Base64.encodeToString(cipherBytes, Base64.DEFAULT));
并解密：
byte[] cipherBytes = Base64.decode(plainText.getText().toString(), Base64.DEFAULT); byte[] decrypted = cipher.doFinal(cipherBytes);
牧羊人nacy
TA貢獻1862條經驗 獲得超7個贊
byte[] decrypted = cipher.doFinal(plainText.getText().toString().getBytes(StandardCharsets.UTF_8));
由于 的調用，此行可能無法正常工作getBytes(StandardCharsets.UTF_8)。如果您EditText是十六進制表示，請嘗試將其轉換為字符串，然后調用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;
}
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