.Net 和 PHP Rijndael 加密不匹配

Question

起初我以为这是填充，因为 mcrypt 使用零填充，但我更改了 php 以使用 PKCS7 并得到相同的精确结果

有人可以帮忙吗？我认为这与 .Net 的 php 测试输出中的填充有关

：

Key: d88f92e4fa27f6d45b49446c7fc76976
Text: Testing123
Encrypted: /DMkj7BL9Eu2LMxKhdGT+A==
Encrypted after base64 decode: ?3$??K?K?,?J???
Decrypted: Testing123

PHP 的测试输出：

Key: d88f92e4fa27f6d45b49446c7fc76976
Text: Testing123
Encrypted: K+ke5FNI5T6F6B/XvDF494+S8538Ze83cFz6v1FE89U=
Encrypted after base64 decode: +éäSHå>…è×¼1x÷’óüeï7p\ú¿QDóÕ
Decrypted: Testing123����������������������

PHP:

class rijndael{
var $mcrypt_cipher = MCRYPT_RIJNDAEL_256;
var $mcrypt_mode = MCRYPT_MODE_CBC;
function decrypt($pass, $encrypted)
{
    $encrypted = base64_decode($encrypted);
    $key = $this->getkey($pass);
    $iv = $this->getiv($pass);
    $decrypted = mcrypt_decrypt($this->mcrypt_cipher, $key, $encrypted, $this->mcrypt_mode, $iv);

    $block = mcrypt_get_block_size($this->mcrypt_cipher, $this->mcrypt_mode);
    $pad = ord($decrypted[($len = strlen($decrypted)) - 1]);
    return substr($decrypted, 0, strlen($decrypted) - $pad);

}
function encrypt($pass, $decrypted)
{
    $key = $this->getkey($pass);
    $iv = $this->getiv($pass);
    $block = mcrypt_get_block_size($this->mcrypt_cipher, $this->mcrypt_mode);
    $pad = $block - (strlen($str) % $block);
    $str .= str_repeat(chr($pad), $pad);
    $encrypted = mcrypt_encrypt($this->mcrypt_cipher, $key, $decrypted, $this->mcrypt_mode, $iv);
    return base64_encode($encrypted);
}
function getkey($passphrase)
{
    $L1 = base64_encode(hash("sha256", $passphrase, true));
    $L2 = $passphrase.$L1;
    return hash("sha256", $L2, true);
}
function getiv($passphrase)
{
    $L1 = base64_encode(md5($passphrase));
    $L2 = $passphrase.$L1;
    return md5($L2);
}
}

VB .Net:

Public Class RijnDael

    Public Shared Function Decrypt(ByVal sData As String, ByVal sKey As String)
        Dim bytData() As Byte = Encoding.UTF8.GetBytes(sData)
        Return Decrypt(bytData, sKey)
    End Function
    Public Shared Function Decrypt(ByVal bytData As Byte(), ByVal strPass As String) As Byte()
        Dim bytResult As Byte()
        Using oRM As New System.Security.Cryptography.RijndaelManaged
            oRM.KeySize = 256
            oRM.Key = GeKey(strPass)
            oRM.IV = GetIV(strPass)
            oRM.Mode = CipherMode.CBC
            oRM.Padding = PaddingMode.PKCS7
            Using oMS As New MemoryStream(bytData)
                Using oCS As New Cryptography.CryptoStream(oMS, oRM.CreateDecryptor, Security.Cryptography.CryptoStreamMode.Read)
                    Dim TempDecryptArr As Byte()
                    ReDim TempDecryptArr(bytData.Length)
                    Dim decryptedByteCount As Integer
                    decryptedByteCount = oCS.Read(TempDecryptArr, 0, bytData.Length)
                    '
                    ReDim bytResult(decryptedByteCount)
                    Array.Copy(TempDecryptArr, bytResult, decryptedByteCount)
                    '
                    oCS.Close()
                End Using
                oMS.Close()
            End Using
        End Using
        Return bytResult
    End Function

    Public Shared Function Encrypt(ByVal sData As String, ByVal sKey As String)
        Dim bytData() As Byte = Encoding.UTF8.GetBytes(sData)
        Return Encrypt(bytData, sKey)
    End Function
    Public Shared Function Encrypt(ByVal bytData As Byte(), ByVal strPass As String) As Byte()
        Dim bytResult As Byte()
        Using oRM As New Cryptography.RijndaelManaged
            oRM.KeySize = 256
            oRM.Key = GeKey(strPass)
            oRM.IV = GetIV(strPass)
            oRM.Mode = CipherMode.CBC
            oRM.Padding = PaddingMode.PKCS7
            Using oMS As New MemoryStream
                Using oCS As New Cryptography.CryptoStream(oMS, oRM.CreateEncryptor, Cryptography.CryptoStreamMode.Write)
                    oCS.Write(bytData, 0, bytData.Length)
                    oCS.FlushFinalBlock()
                    bytResult = oMS.ToArray()
                    oCS.Close()
                End Using
                oMS.Close()
            End Using
        End Using
        Return bytResult
    End Function

    Private Shared Function GeKey(ByVal strPass As String) As Byte()
        Dim bytResult As Byte()
        'Generate a byte array of required length as the encryption key.
        'A SHA256 hash of the passphrase has just the required length. It is used twice in a manner of self-salting.
        Using oSHA256 As New Cryptography.SHA256Managed
            Dim L1 As String = System.Convert.ToBase64String(oSHA256.ComputeHash(Encoding.UTF8.GetBytes(strPass)))
            Dim L2 As String = strPass & L1
            bytResult = oSHA256.ComputeHash(System.Text.Encoding.UTF8.GetBytes(L2))
            oSHA256.Clear()
        End Using
        Return bytResult
    End Function

    Private Shared Function GetIV(ByVal strPass As String) As Byte()
        Dim bytResult As Byte()
        'Generate a byte array of required length as the iv.
        'A MD5 hash of the passphrase has just the required length. It is used twice in a manner of self-salting.
        Using oMD5 As New Cryptography.MD5CryptoServiceProvider
            Dim L1 As String = System.Convert.ToBase64String(oMD5.ComputeHash(Encoding.UTF8.GetBytes(strPass)))
            Dim L2 As String = strPass & L1
            bytResult = oMD5.ComputeHash(System.Text.Encoding.UTF8.GetBytes(L2))
            oMD5.Clear()
        End Using
        Return bytResult
    End Function

End Class

Answer 1

两段代码中的问题是：

• 在 .NET 和 PHP 代码中使用密钥和块大小均为 16 字节/128 位的 Rijndael-128。对于 Rijndael-256，您的代码生成长度错误的 IV。我不知道如何在 PHP 中使用 AES-256（密钥长度为 32 字节/256 位，块大小为 16 字节/128 位）。

• MD5 的使用：在 PHP 代码中，将第二个参数 true 添加到 md5() 函数（在两个位置），以便结果是二进制数据，而不是十六进制字符串。

• 在 PHP 代码的 encrypt() 函数中，将变量 $str 替换为 $decrypted（在两个位置）。 $str 从未被赋值且从未使用过，因此填充不起作用。

如果你解决了这些问题，那么两个程序都会返回结果：

Encrypted: /DMkj7BL9Eu2LMxKhdGT+A==

我还没有尝试解密它。

Answer 2

对于初学者来说，2 位代码将创建不同的初始化向量（PHP 使用 sha256 和 .net md5）。并且您不会通过第一个空字符来截断 PHP 输出。代码中也存在几个潜在的字符集问题。