Question

我使用以下代码加密和解密asp.net中的密码。加密工作完美，但解密时会引发此错误 Invalid length for a Base-64 char array.

我的密码是123，我使用它来加密：HttpUtility.UrlEncode(CryptorEngine.Encrypt(strpassword, true)); 并解密我正在使用它如下：

CryptorEngine.Decrypt(HttpUtility.UrlDecode(strpassword), true));

这是代码：

 public class CryptorEngine
    {
        /// <summary>
        /// Encrypt a string using dual encryption method. Return a encrypted cipher Text
        /// </summary>
        /// <param name="toEncrypt">string to be encrypted</param>
        /// <param name="useHashing">use hashing? send to for extra secirity</param>
        /// <returns></returns>
        public static string Encrypt(string toEncrypt, bool useHashing)
        {
            byte[] keyArray;
            byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

            System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
            // Get the key from config file
            string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
            //System.Windows.Forms.MessageBox.Show(key);
            if (useHashing)
            {
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                hashmd5.Clear();
            }
            else
                keyArray = UTF8Encoding.UTF8.GetBytes(key);

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            tdes.Key = keyArray;
            tdes.Mode = CipherMode.ECB;
            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateEncryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
            tdes.Clear();
            return Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }
        /// <summary>
        /// DeCrypt a string using dual encryption method. Return a DeCrypted clear string
        /// </summary>
        /// <param name="cipherString">encrypted string</param>
        /// <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
        /// <returns></returns>
        public static string Decrypt(string cipherString, bool useHashing)
        {
            byte[] keyArray;
            byte[] toEncryptArray = Convert.FromBase64String(cipherString);

            System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
            //Get your key from config file to open the lock!
            string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));

            if (useHashing)
            {
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                hashmd5.Clear();
            }
            else
                keyArray = UTF8Encoding.UTF8.GetBytes(key);

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            tdes.Key = keyArray;
            tdes.Mode = CipherMode.ECB;
            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateDecryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

            tdes.Clear();
            return UTF8Encoding.UTF8.GetString(resultArray);
        }
    }

Answer 1

在URL中出现与加密输出冲突的字符，至少在我的代码中，这就是导致问题的原因。所以我使用这两个函数来改变这些字符并避免这种情况。

public static string ChangeSPChart(string sTheInput)
{
    StringBuilder sRetMe = new StringBuilder(sTheInput);

    sRetMe.Replace('+', '-');
    sRetMe.Replace('/', '*');
    sRetMe.Replace('=', '!');

    return sRetMe.ToString();
}

public static string FixSPChart(string sTheInput)
{
    StringBuilder sRetMe = new StringBuilder(sTheInput);

    sRetMe.Replace('-', '+');
    sRetMe.Replace('*', '/');
    sRetMe.Replace('!', '=');

    return sRetMe.ToString();
}

，加密/解密代码为：

public static string Encrypt(string toEncrypt, bool useHashing)
{
    byte[] keyArray;
    byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

    System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
    // Get the key from config file
    string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
    //System.Windows.Forms.MessageBox.Show(key);
    if (useHashing)
    {
        MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
        keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
        hashmd5.Clear();
    }
    else
        keyArray = UTF8Encoding.UTF8.GetBytes(key);

    TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
    tdes.Key = keyArray;
    tdes.Mode = CipherMode.ECB;
    tdes.Padding = PaddingMode.PKCS7;

    ICryptoTransform cTransform = tdes.CreateEncryptor();
    byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

    tdes.Clear();
    var encrypted = Convert.ToBase64String(resultArray, 0, resultArray.Length);

    // here I change it
    return  ChangeSPChart(encrypted);
}
/// <summary>
/// DeCrypt a string using dual encryption method. Return a DeCrypted clear string
/// </summary>
/// <param name="cipherString">encrypted string</param>
/// <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
/// <returns></returns>
public static string Decrypt(string cipherString, bool useHashing)
{
    cipherString = FixSPChart(cipherString);

    byte[] keyArray;
    byte[] toEncryptArray = Convert.FromBase64String(cipherString);

    System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
    //Get your key from config file to open the lock!
    string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));

    if (useHashing)
    {
        MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
        keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
        hashmd5.Clear();
    }
    else
        keyArray = UTF8Encoding.UTF8.GetBytes(key);

    TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
    tdes.Key = keyArray;
    tdes.Mode = CipherMode.ECB;
    tdes.Padding = PaddingMode.PKCS7;

    ICryptoTransform cTransform = tdes.CreateDecryptor();
    byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

    tdes.Clear();
    return UTF8Encoding.UTF8.GetString(resultArray);
}

Answer 2

您提供的代码运行正常。我用这个小程序测试了它：

void Main()
{
    var cryptB64 =CryptorEngine.Encrypt("123", true);
    var encoded = HttpUtility.UrlEncode(cryptB64);
    var decoded = HttpUtility.UrlDecode(encoded);
    var decrypted = CryptorEngine.Decrypt(decoded, true);

    bool matches = (decrypted=="123");
    Console.WriteLine(matches);
}

它按预期返回。

问题可能是您在某个时刻破坏了加密值。我猜它是通过HTTP传输的，我猜这是问题发生的地方。

附加说明：

调用CryptorEngine.Decrypt(HttpUtility.UrlDecode(strpassword), true));时，您需要确保strpassword是加密形式的密码，而不是您要比较的纯文本密码。

Answer 3

hiii请使用此代码，这样做效果很好

//信用卡的加密方法

public string EncryptTripleDES(string Plaintext, string Key)
{

    System.Security.Cryptography.TripleDESCryptoServiceProvider DES =

    new System.Security.Cryptography.TripleDESCryptoServiceProvider();

    System.Security.Cryptography.MD5CryptoServiceProvider hashMD5 =

    new System.Security.Cryptography.MD5CryptoServiceProvider();

    DES.Key = hashMD5.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(Key));

    DES.Mode = System.Security.Cryptography.CipherMode.ECB;

    System.Security.Cryptography.ICryptoTransform DESEncrypt = DES.CreateEncryptor();

    Buffer = System.Text.ASCIIEncoding.ASCII.GetBytes(Plaintext);
   string TripleDES = Convert.ToBase64String(DESEncrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));

    return TripleDES;

}
//Decryption Method 

public string DecryptTripleDES(string base64Text, string Key)
{

    System.Security.Cryptography.TripleDESCryptoServiceProvider DES =

    new System.Security.Cryptography.TripleDESCryptoServiceProvider();

    System.Security.Cryptography.MD5CryptoServiceProvider hashMD5 =

    new System.Security.Cryptography.MD5CryptoServiceProvider();
    DES.Key = hashMD5.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(Key));
    DES.Mode = System.Security.Cryptography.CipherMode.ECB;
    System.Security.Cryptography.ICryptoTransform DESDecrypt = DES.CreateDecryptor();
    Buffer = Convert.FromBase64String(base64Text);

    string DecTripleDES = System.Text.ASCIIEncoding.ASCII.GetString(DESDecrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
   return DecTripleDES;

}

Answer 4

这里有点晚了，但问题可能是别的（这对我来说）。

Request.Querystring已经进行了一些解码。在我的情况下，我基本上解码了两次。添加第二个“HttpUtility.UrlEncode”就可以了（至少在20次不同的测试之后）。

我还没有找到微软关于这种行为的确切文档，旧书被存放起来（我尽量不要离开我的椅子），但这些链接很有帮助：

does Request.Querystring automatically url decode a string?

http://forums.asp.net/t/1354726.aspx?Request+Querystring+without+decoding+possible+

加密和解密密码

4 个答案: