我正在尝试使用 Java 中的 JCA 和 JCE 编写一个简单的应用程序来加密和解密一段文本。
到目前为止,加密部分有效,但在解密时它给了我以下异常:
javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
这是我初始化两个密码 encCipher 和 decCipher 的部分。
PBEKeySpec pbeKeySpec;
PBEParameterSpec paramSpec;
SecretKeyFactory keyFac;
byte[] salt = {(byte) 0xc7, (byte) 0x73, (byte) 0x21, (byte) 0x8c,
(byte) 0x7e, (byte) 0xc8, (byte) 0xee, (byte) 0x99};
int count = 20;
paramSpec = new PBEParameterSpec(salt, count);
try {
pbeKeySpec = new PBEKeySpec("my_password".toCharArray(), salt, count);
SecretKey secretKey = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(pbeKeySpec);
encCipher = Cipher.getInstance(secretKey.getAlgorithm());
encCipher.init(Cipher.ENCRYPT_MODE, secretKey, paramSpec);
decCipher = Cipher.getInstance(secretKey.getAlgorithm());
decCipher.init(Cipher.DECRYPT_MODE, secretKey, paramSpec);
} catch (Exception ex) {
ex.printStackTrace();
}
我没有使用 Java Cryptography Architecture 的经验,我想知道如何修复该错误。
异常发生在 loadClients 的 decCipher.doFinal 行。
private void saveClients() {
String plainText = "";
String encText = "";
Set<String> clients = my_clients.keySet();
try {
PrintWriter out = new PrintWriter(new File(output_file));
for (String client : clients) {
long client_time = my_clients.get(client);
plainText = client + " " + client_time;
encText = new String(encCipher.doFinal(plainText.getBytes()));
out.println(encText);
}
out.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
private void loadClients() {
BufferedReader in;
String line;
try {
in = new BufferedReader(new FileReader(output_file));
while ((line = in.readLine()) != null) {
byte[] decBytes = decCipher.doFinal(line.getBytes());
String decText = new String(decBytes);
String[] client_data = decText.split("[ ]");
my_clients.put(client_data[0], Long.parseLong(client_data[1]));
}
in.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}