加密解密遇到的问题（密钥）

在配置网站数据库时常常把Web.Config中appSettings的ConnectionString加密，要是明文那可太危险了，常用的加密方法是DES加密/解密。

今天在配置网站时总是报错,错误如下：



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期间上网找了很多资料，但没有想要的，后来发现加密和解密用的密钥不一样，郁闷了半天。

#region ========加密========

/// <summary>

/// 加密

/// </summary>

/// <param name="Text"></param>

/// <returns></returns>

public static string Encrypt(string Text)

{

return Encrypt(Text, Key);

}

/// <summary>

/// 加密数据

/// </summary>

/// <param name="Text"></param>

/// <param name="sKey"></param>

/// <returns></returns>

public static string Encrypt(string Text, string sKey)

{

DESCryptoServiceProvider des = new DESCryptoServiceProvider();

byte[] inputByteArray;

inputByteArray = Encoding.Default.GetBytes(Text);

des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));

des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));

System.IO.MemoryStream ms = new System.IO.MemoryStream();

CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

cs.Write(inputByteArray, 0, inputByteArray.Length);

cs.FlushFinalBlock();

StringBuilder ret = new StringBuilder();

foreach (byte b in ms.ToArray())

{

ret.AppendFormat("{0:X2}", b);

}

return ret.ToString();

}

#endregion

#region ========解密========

/// <summary>

/// 解密

/// </summary>

/// <param name="Text"></param>

/// <returns></returns>

public static string Decrypt(string Text)

{

return Decrypt(Text, Key);

}

/// <summary>

/// 解密数据

/// </summary>

/// <param name="Text"></param>

/// <param name="sKey"></param>

/// <returns></returns>

public static string Decrypt(string Text, string sKey)

{

DESCryptoServiceProvider des = new DESCryptoServiceProvider();

int len;

len = Text.Length / 2;

byte[] inputByteArray = new byte[len];

int x, i;

for (x = 0; x < len; x++)

{

i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);

inputByteArray[x] = (byte)i;

}

des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));

des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));

System.IO.MemoryStream ms = new System.IO.MemoryStream();

CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

cs.Write(inputByteArray, 0, inputByteArray.Length);

cs.FlushFinalBlock();

return Encoding.Default.GetString(ms.ToArray());

}

#endregion