Question

我正在尝试使用PowerShell中的Aes进行简单的加密/解密，但在尝试解密输出时我一直遇到异常。

我得到例外：

使用“0”参数调用“ReadToEnd”的异常：“填充是无效且无法删除。“

有什么想法吗？

Function Aes-Encrypt( $plainTextBytes ){

    $key = "vqMcLYelBxefzIAMpO9Q/Q=="
    $plainText = [System.Text.Encoding]::UTF8.GetBytes($plainTextBytes)

    #Use the AES cipher and represent it as an object.
    $AES = New-Object "System.Security.Cryptography.AesManaged"
    $AES.Mode = [System.Security.Cryptography.CipherMode]::CBC
    $AES.Padding = [System.Security.Cryptography.PaddingMode]::PKCS7
    $AES.BlockSize = 128
    $AES.KeySize = 128
    $IV = $AES.IV
    #$AES.Key = $key

    # Creates a MemoryStream to do the encryption in 
    $ms = new-Object IO.MemoryStream 

    # Creates the new Cryptology Stream --> Outputs to $MS or Memory Stream 
    $cs = new-Object Security.Cryptography.CryptoStream $ms,$AES.CreateEncryptor(),"Write" 

    #Writes the string in the Cryptology Stream
    $cs.Write($IV, 0, 16)
    $cs.Write($plainText, 0, $plainText.Length);
    $cs.FlushFinalBlock();

    # Stops the Cryptology Stream
    $cs.Close()

    # Stops writing to Memory
    $ms.Close()

    # Clears the IV and HASH from memory to prevent memory read attacks
    $cs.Clear()

    # Takes the MemoryStream and puts it to an array
    [byte[]]$rmesult = $ms.ToArray()
    # return $ms.ToArray()
    # Converts the array from Base 64 to a string and returns
    return [Convert]::ToBase64String($rmesult)

}

Function Aes-Decrypt( $DecryptData ){

    $key = "vqMcLYelBxefzIAMpO9Q/Q=="
    #$plainText = [System.Text.Encoding]::UTF8.GetBytes($plainTextBytes)

    # Create a COM Object for RijndaelManaged Cryptography 
    #$r = new-Object System.Security.Cryptography.RijndaelManaged 

    #Use the AES cipher and represent it as an object.
    $AES = New-Object "System.Security.Cryptography.AesManaged"
    $AES.Mode = [System.Security.Cryptography.CipherMode]::CBC
    $AES.Padding = [System.Security.Cryptography.PaddingMode]::PKCS7
    $AES.BlockSize = 128
    $AES.KeySize = 128
    $IV = $AES.IV
    #$AES.Key = $key

    $cipherTextBytes = [Convert]::FromBase64String($DecryptData)

    # Creates a MemoryStream to do the encryption in 
    $ms = new-Object IO.MemoryStream @(,$cipherTextBytes)

    # Creates the new Cryptology Stream --> Outputs to $MS or Memory Stream 
    $cs = new-Object Security.Cryptography.CryptoStream $ms,$AES.CreateDecryptor(),"Read" 

    # Read the new decrypted stream 
    $sr = new-Object IO.StreamReader $cs 

    # Return from the function the stream 
    Write-Output $sr.ReadToEnd() 

    # Stops the stream     
    $sr.Close() 

    # Stops the crypology stream
    $cs.Close()

    # Stops writing to Memory
    $ms.Close()

    $cs.Clear()

    # Takes the MemoryStream and puts it to an array
    return $ms.ToArray()



}

Answer 1

消息：

“填充无效，无法删除。”

是加密无效的一般症状，如果您不在加密和加密时使用相同的密钥和IV，则可能会出现这种情况。解密，或者加密消息是否以某种方式被更改。

在您的代码中，您似乎没有设置密钥，并且您不会生成随机IV。此外，您似乎在加密流中加密IV，这不会产生您正常期望的效果。

您需要生成一个随机IV并将其与您的加密数据一起以未加密的形式传递（它不需要保密）。然后，您的解密器需要在开始解密之前读取IV并使用它初始化AES密码。

使用“0”参数调用“ReadToEnd”的异常：“填充无效且无法删除。”

1 个答案: