java 7:Caused 中的填充异常：javax.crypto.BadPaddingException：给定的最终块未正确填充

Question

您好，我正在使用 tripedes 键从输入流读取并写入输出流。在 java7/8 中获取此 execption：原因：javax.crypto.BadPaddingException：给定的最终块未正确填充

byte[] passwd = Base64Util.decode(pwd);
bais = new ByteArrayInputStream(passwd);
baos = new ByteArrayOutputStream();
Cipher cipher = Cipher.getInstance("DESede");
cipher.init(Cipher.DECRYPT_MODE, key);
// Read bytes, decrypt, and write them out.
byte[] buffer = new byte[2048];
int bytesRead;
while ((bytesRead = bais.read(buffer)) != -1) {
    out.write(cipher.update(buffer, 0, bytesRead));
}
// Write out the final bunch of decrypted bytes
out.write(cipher.doFinal());
out.flush();

谁能告诉我 cipher.doFinal 中可能有什么错误？

更新，加密代码复制自评论：

Cipher cipher = Cipher.getInstance("DESede");
cipher.init(Cipher.ENCRYPT_MODE, key);

// Create a special output stream to do the work for us
CipherOutputStream cos = new CipherOutputStream(out, cipher);

// Read from the input and write to the encrypting output stream
byte[] buffer = new byte[2048];
int bytesRead;
while ((bytesRead = in.read(buffer)) != -1) {
    cos.write(buffer, 0, bytesRead);
}
cos.close();

Answer 1

如果输入数据不总是块大小的倍数，则必须向输入数据添加填充；指定填充，PKCS#5 是 DES/3DES.

的首选填充

getInstance 调用未完全指定，缺少模式和填充选项。添加完整规范，例如："DESede/ECB/PKCS5Padding (168)"。参见 Class Cipher documentation。

不要在新代码中使用 3DES，它是不安全的，也不要使用 ECB 模式，它也是不安全的，请参阅 ECB mode，向下滚动到 Penguin。

java 7:Caused 中的填充异常：javax.crypto.BadPaddingException：给定的最终块未正确填充

Padding exception in java 7:Caused by: javax.crypto.BadPaddingException: Given final block not properly padded

java

encryption

des

badpaddingexception