一.System.Security.Cryptography 命名空間
System.Security.Cryptography 命名空間提供加密服務，包括安全編碼和解碼的數據，以及許多其他操作，如哈希、 隨機數字生成和消息身份驗證。
Microsoft官方網址：https://msdn.microsoft.com/zh-cn/library/system.security.cryptography(v=vs.110).aspx
其中提供了des加密解密算法、HMAC、HMACSHA1、MD5、RSA 、SHA1等算法基礎類。
二.部分算法代碼介紹
1.單向加密--只有加密，沒有解密。
1.1.MD5加密
參考代碼：
private string GetMD5(string text)
{
MD5 md5 = new MD5CryptoServiceProvider();
byte[] data = md5.ComputeHash(Encoding.UTF8.GetBytes(text));
md5.Clear();
StringBuilder str = new StringBuilder();
for (int i = 0; i < data.Length; i++)
{
str.Append(data[i].ToString("X").PadLeft(2, '0'));
}
return str.ToString();
}
2.雙向加密--既有加密又可以解密
2.1.對稱性加密算法--使用提前商定好的密鑰進行加密以及解密
2.1.1.DES加密
方法一：
/// <summary>
/// 加密數據
/// </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();
}
方法二：
/// <summary>
/// DES ECB模式加密
/// </summary>
/// <param name="key">密鑰</param>
/// <param name="iv">IV(當模式爲ECB時，IV無用)</param>
/// <param name="str">明文的byte數組</param>
/// <returns>密文的byte數組</returns>
private string DesEncodeECB(string skey, string sdata)
{
try
{
string encryptKey = "";
if (skey.Length >= 8)
{
encryptKey = skey.Substring(0, 8);
}
else
{
encryptKey = skey;
}
byte[] key = Encoding.Default.GetBytes(encryptKey);
byte[] data = Encoding.Default.GetBytes(sdata);
// Create a MemoryStream.
MemoryStream mStream = new MemoryStream();
DESCryptoServiceProvider tdsp = new DESCryptoServiceProvider();
tdsp.Mode = CipherMode.ECB;
tdsp.Padding = PaddingMode.PKCS7;
CryptoStream cStream = new CryptoStream(mStream,
tdsp.CreateEncryptor(key, key),
CryptoStreamMode.Write);
cStream.Write(data, 0, data.Length);
cStream.FlushFinalBlock();
StringBuilder ret = new StringBuilder();
foreach (byte b in mStream.ToArray())
{
ret.AppendFormat("{0:X2}", b);
}
cStream.Close();
mStream.Close();
return ret.ToString();
}
catch (CryptographicException e)
{
stCommon.Errors.Logs("皇包車接口中，des加密出現異常！----" + e.StackTrace + e.Message);
return null;
}
}
2.1.2.DES解密
方法一：
/// <summary>
/// 解密數據
/// </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());
}
方法二：
/// <summary>
/// DES ECB模式解密
/// </summary>
/// <param name="key">密鑰</param>
/// <param name="iv">IV(當模式爲ECB時，IV無用)</param>
/// <param name="str">密文的byte數組</param>
/// <returns>明文的byte數組</returns>
private string DesDecodeECB(string skey, string sdata)
{
try
{
string encryptKey = skey.Substring(0, 8);
byte[] key = Encoding.Default.GetBytes(encryptKey);
byte[] data = Encoding.Default.GetBytes(sdata);
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
int len;
len = sdata.Length / 2;
byte[] inputByteArray = new byte[len];
int x, i;
for (x = 0; x < len; x++)
{
i = Convert.ToInt32(sdata.Substring(x * 2, 2), 16);
inputByteArray[x] = (byte)i;
}
des.Mode = CipherMode.ECB;
des.Padding = PaddingMode.PKCS7;
System.IO.MemoryStream ms = new System.IO.MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(key, key), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
return Encoding.Default.GetString(ms.ToArray());
}
catch (CryptographicException e)
{
stCommon.Errors.Logs("皇包車接口中，des解密出現異常！----" + e.StackTrace + e.Message);
return null;
}
}
2.2非對稱性加密算法
發送雙方A,B事先均生成一堆密匙，然後A將自己的公有密匙發送給B，B將自己的公有密匙發送給A，如果A要給B發送消 息，則先需要用B的公有密匙進行消息加密，然後發送給B端，此時B端再用自己的私有密匙進行消息解密，B向A發送消息時爲同樣的道理。
加密算法有RSA,DSA,ECC
注：自己見解，如有錯誤請指出。如有補充，請寫在評論區，謝謝！