問題描述
我目前在解密由 php mcrypt 加密的消息時遇到了一些問題.php代碼如下:
I'm currently having a bit of problem with decrypting a message encrypted by php mcrypt. The php code is as following:
<?php
//$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC);
$iv = "45287112549354892144548565456541";
$key = "anjueolkdiwpoida";
$text = "This is my encrypted message";
$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_CBC, $iv);
$crypttext = urlencode($crypttext);
$crypttext64=base64_encode($crypttext);
print($crypttext64) . "
<br/>";
?>
然后將加密的消息發送到 ASP.NET 平臺 (C#).但是，我在保留解密順序(base64 解碼到 urldecode)時遇到了問題.我在 ASP.NET 中的代碼如下(iv 和 key 與 php 中的相同):
The the encrypted message is then sent to a ASP.NET platform (C#). However, I'm having problem retaining the order of decryption (base64 decode to urldecode). The code I had in ASP.NET is as the following (iv and key is the same as in php):
public string Decode(string str)
{
byte[] decbuff = Convert.FromBase64String(str);
return System.Text.Encoding.UTF8.GetString(decbuff);
}
static public String DecryptRJ256(string cypher, string KeyString, string IVString)
{
string sRet = "";
RijndaelManaged rj = new RijndaelManaged();
UTF8Encoding encoding = new UTF8Encoding();
try
{
//byte[] message = Convert.FromBase64String(cypher);
byte[] message = encoding.GetBytes(cypher);
byte[] Key = encoding.GetBytes(KeyString);
byte[] IV = encoding.GetBytes(IVString);
rj.Padding = PaddingMode.Zeros;
rj.Mode = CipherMode.CBC;
rj.KeySize = 256;
rj.BlockSize = 256;
rj.Key = Key;
rj.IV = IV;
MemoryStream ms = new MemoryStream(message);
using (CryptoStream cs = new CryptoStream(ms, rj.CreateDecryptor(Key, IV), CryptoStreamMode.Read))
{
using (StreamReader sr = new StreamReader(cs))
{
sRet = sr.ReadToEnd();
}
}
}
finally
{
rj.Clear();
}
return sRet;
}
string temp = DecryptRJ256(Server.UrlDecode(Decode(cypher)), keyString, ivString);
我遇到的問題是，在收到來自 php 的加密消息后，我將其轉換為 byte[]，然后再轉換回 UTF8 編碼字符串，以便我可以對其進行 urldecode.然后我將結果提供給函數，在那里我將字符串轉換回 byte[] 并通過解密過程運行它.但是，我無法得到想要的結果……有什么想法嗎?
The problem I'm having is that after I recieved the encrypted message from php, I converted it into byte[] and then converted back to UTF8 encoded string so I can urldecode it. then I feed the result into the function where I converted the string back to byte[] and ran it through the decryption process. However, I can't get the desired result...any ideas?
提前致謝.
推薦答案
在這里我可以看到兩邊的問題.
Here I can see problems on both sides.
請記住，編碼時得到的不是字符串，而是字節數組.所以在 PHP 中你不需要對 cyphertext 進行 urlencode.
Please keep in mind that what you get when encoding is not string, but rather an array of bytes. So in PHP you don't need to urlencode cyphertext.
base64 編碼就是你所需要的.當您打開 base64_encode help 時，您會看到
base64 encoding is all you need. When you open base64_encode help you see
base64_encode 使用 base64 對給定數據進行編碼.這種編碼是旨在使二進制數據在傳輸過程中幸存
base64_encode Encodes the given data with base64. This encoding is designed to make binary data survive transport
還有一件事 - 要在 .net 中以正確的長度解碼您的消息，您必須手動附加填充字符.RijndaelManaged 的??默認填充模式是 PKCS7，讓我們堅持下去.您必須將源字符串擴展到字符代碼等于填充字節數的偶數塊.
One more thing - to have your message decoded in .net with a correct length, you have to manually append it with padding characters. Default padding mode for RijndaelManaged is PKCS7, lets' stick with it. You have to extend your source string to even blocks with characters code equal to number of padding bytes.
<?php
$iv = "45287112549354892144548565456541";
$key = "anjueolkdiwpoida";
$text = "This is my encrypted message";
// to append string with trailing characters as for PKCS7 padding scheme
$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, $key, $text, MCRYPT_MODE_CBC, $iv);
// this is not needed here
//$crypttext = urlencode($crypttext);
$crypttext64=base64_encode($crypttext);
print($crypttext64) . "
<br/>";
?>
在 C# 方面，您可以從 base64 到 byte[] 到 string 到 byte[] 的轉換.您只需要進行從 base64 到 byte[] 的第一次轉換.請記住，base64 保存的是二進制數據而不是字符串的加密文本.另請注意，RijndaelManaged 是 IDisposable，所以我將它包裝在 using() 構造中.如 MSDN 所述，調用 Close() 是必要的，但還不夠.
At C# side you have casting from base64 to byte[] to string to byte[]. You have to do the first conversion from base64 to byte[] only. Remember, base64 is holding the cyphered text that is binary data, not string. Also please note that RijndaelManaged is IDisposable, so I have wrapped it in using() construct. Calling Close() is necessary but not enough as stated in MSDN.
public byte[] Decode(string str)
{
var decbuff = Convert.FromBase64String(str);
return decbuff;
}
static public String DecryptRJ256(byte[] cypher, string KeyString, string IVString)
{
var sRet = "";
var encoding = new UTF8Encoding();
var Key = encoding.GetBytes(KeyString);
var IV = encoding.GetBytes(IVString);
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;
}
因此，以下 C# 代碼將返回初始字符串:
As a result, following code in C# will return you the initial string:
var iv = "45287112549354892144548565456541";
var key = "anjueolkdiwpoida";
var cypher = "u+rIlHB/2rrT/u/qFInnlEkg2unhizsNzGVb9O54sP8=";
var temp = DecryptRJ256(Decode(cypher), key, iv);
這篇關于使用 Rijndael 進行跨平臺(php 到 C# .NET)加密/解密的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！