c# – 为我的AES方法创建一个字节数组的字符数是多少？

我在这里使用AES方法：http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndaelmanaged.aspx

我想要一个字符串值,我将转换为字节数组并将其传递给AES加密方法.字符串应该有多少个字符来生成方法所需的正确字节数组大小？

static byte[] encryptStringToBytes_AES(string plainText, byte[] Key, byte[] IV)
    {
        // Check arguments.
        if (plainText == null || plainText.Length <= 0)
            throw new ArgumentNullException("plainText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("Key");

        // Declare the stream used to encrypt to an in memory
        // array of bytes.
        MemoryStream msEncrypt = null;

        // Declare the RijndaelManaged object
        // used to encrypt the data.
        RijndaelManaged aesAlg = null;

        try
        {
            // Create a RijndaelManaged object
            // with the specified key and IV.
            aesAlg = new RijndaelManaged();
            aesAlg.Key = Key;
            aesAlg.IV = IV;

            // Create a decrytor to perform the stream transform.
            ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

            // Create the streams used for encryption.
            msEncrypt = new MemoryStream();
            using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
            {
                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                {

                    //Write all data to the stream.
                    swEncrypt.Write(plainText);
                }
            }

        }
        finally
        {

            // Clear the RijndaelManaged object.
            if (aesAlg != null)
                aesAlg.Clear();
        }

        // Return the encrypted bytes from the memory stream.
        return msEncrypt.ToArray();

    }

解决方法:

纯文本的大小无关紧要.只需确保在decryptStringFromBytes_AES(byte [] cipherText,byte [] Key,byte [] IV)方法中使用完全相同的IV和Key以及加密字节.这将返回给您输入的纯文本.

例如：

string plain_text = "Cool this works";
byte[] iv = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
                                           0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F};
byte[] key = new byte[] { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
                                           0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF };
byte[] encrytped_text = encryptStringToBytes_AES(plain_text, key, iv);
string plain_text_again = decryptStringFromBytes_AES(encrypted_text, key, iv);

在这里你应该看到纯文本和纯文本再次相同.现在继续将plain_text更改为你想要的任何东西,看看这个工作正常.

RijndaelManaged的默认值为：
BlockSize：128
KeySize：256
模式：CipherMode.CBC
填充：PaddingMode.PKCS7

有效的IV大小是：
128,192,256位(这是BlockSize,请确保将其设置为您正在使用的大小IV)
有效密钥大小为：
128,192,256位(这是KeySize,请确保将其设置为您正在使用的大小键)

这意味着byte [] iv可以是16,24或32个字节(在我上面的例子中是16个字节),而byte []键也可以是16,24或32个字节(在我上面的例子中它是16个字节) ).

希望有所帮助.

标签：c,asp-net,encryption,aes,rijndaelmanaged
来源： https://codeday.me/bug/20190607/1192722.html