我在安卓应用程序中使用了一个用PHP编写的REST服务，没有遇到太多麻烦。现在我正试图在Windows Phone应用程序中使用它，我已经疯了！
到目前为止我所知道的：Silverlight将只接受CBC模式下的Aes和PKCS7填充。
我得到的："填充无效，无法删除"异常（见底部的完整代码）：
plaintext = srDecrypt.ReadToEnd();
如果我在C#中使用相同的配置进行加密和解密，它会正常工作。当我试图在C#中从PHP加密的字符串中解密时，它失败了，并出现了上面提到的错误。
我的PHP脚本执行以下操作：
function encrypt128($message) {
$vector = "DB96A56CCA7A69FC";
$key = "6DBC44F54CA3CFDEDDCA140CA46A99C1"; // PHP md5 function leaves it in lower case, so I just copied the key from C# debug.
//PKCS7 Padding
$block = mcrypt_get_block_size('rijndael_128', 'cbc');
$pad = $block - (strlen($message) % $block);
$message.= str_repeat(chr($pad), $pad);
$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', 'cbc', '');
mcrypt_generic_init($cipher, $key, $vector);
$result = mcrypt_generic($cipher, $message);
mcrypt_generic_deinit($cipher);
return base64_encode($result);
}
在C#（Silverlight/Windows Phone 7）中，我使用以下内容进行解密：
//Where buffer is the string data I got after calling the PHP REST service.
DecryptStringFromBytes(Convert.FromBase64String(buffer), MD5Core.GetHash("7a272d3e41372c547a272d3e41372c54"), System.Text.Encoding.UTF8.GetBytes("DB96A56CCA7A69FC"));
static string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
{
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
if (Key == null || Key.Length <= 0)
throw new ArgumentNullException("Key");
if (IV == null || IV.Length <= 0)
throw new ArgumentNullException("Key");
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
// Create an RijndaelManaged object
// with the specified key and IV.
using (AesManaged rijAlg = new AesManaged())
{
rijAlg.Key = Key;
rijAlg.IV = IV;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
最大的问题是：我做错了什么？
提前感谢！
答案如下：
我去掉了PHP和C#中的MD5垃圾，它们现在可以正常工作了。
为了防止您在这里寻找相同的答案，这里有一个示例代码。别忘了制作你自己的钥匙和iv（尽管下面的这些可以使用，但不建议使用！）
PHP:
function encrypt128($message) {
$vector = "0000000000000000";
$key = "00000000000000000000000000000000";
$block = mcrypt_get_block_size('rijndael_128', 'cbc');
$pad = $block - (strlen($message) % $block);
$message .= str_repeat(chr($pad), $pad);
$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', 'cbc', '');
mcrypt_generic_init($cipher, $key, $vector);
$result = mcrypt_generic($cipher, $message);
mcrypt_generic_deinit($cipher);
return base64_encode($result);
}
C#：
byte[] cripted = EncryptStringToBytes("Test", System.Text.Encoding.UTF8.GetBytes("00000000000000000000000000000000"), System.Text.Encoding.UTF8.GetBytes("0000000000000000"));
使用PHP:加密/解密
class Cipher {
private $key, $iv;
function __construct() {
$this->key = "edrtjfjfjlldldld";
$this->iv = "56666852251557009888889955123458";
}
function encrypt($text) {
$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC);
$padding = $block - (strlen($text) % $block);
$text .= str_repeat(chr($padding), $padding);
$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $this->key, $text, MCRYPT_MODE_CBC, $this->iv);
return base64_encode($crypttext);
}
function decrypt($input) {
$dectext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $this->key, base64_decode($input), MCRYPT_MODE_CBC, $this->iv);
return $dectext;
}
}
使用C#加密/解密：
public class RijndaelSimple
{
const string iv = "56666852251557009888889955123458";
const string key = "edrtjfjfjlldldld";
static public String EncryptRJ256(string plainText)
{
var encoding = new UTF8Encoding();
var Key = encoding.GetBytes(key);
var IV = encoding.GetBytes(iv);
byte[] encrypted;
using (var rj = new RijndaelManaged())
{
try
{
rj.Padding = PaddingMode.PKCS7;
rj.Mode = CipherMode.CBC;
rj.KeySize = 256;
rj.BlockSize = 256;
rj.Key = Key;
rj.IV = IV;
var ms = new MemoryStream();
using (var cs = new CryptoStream(ms, rj.CreateEncryptor(Key, IV), CryptoStreamMode.Write))
{
using (var sr = new StreamWriter(cs))
{
sr.Write(plainText);
}
encrypted = ms.ToArray();
}
}
finally
{
rj.Clear();
}
}
return Convert.ToBase64String(encrypted);
}
static public String DecryptRJ256(string input)
{
byte[] cypher = Convert.FromBase64String(input);
var sRet = "";
var encoding = new UTF8Encoding();
var Key = encoding.GetBytes(key);
var IV = encoding.GetBytes(iv);
using (var rj = new RijndaelManaged())
{
try
{
rj.Padding = PaddingMode.PKCS7;
rj.Mode = CipherMode.CBC;
rj.KeySize = 256;
rj.BlockSize = 256;
rj.Key = Key;
rj.IV = IV;
var ms = new MemoryStream(cypher);
using (var cs = new CryptoStream(ms, rj.CreateDecryptor(Key, IV), CryptoStreamMode.Read))
{
using (var sr = new StreamReader(cs))
{
sRet = sr.ReadLine();
}
}
}
finally
{
rj.Clear();
}
}
return sRet;
}
}