C# 常用加密方法收集 对称,非对称

1.用RSACryptoServiceProvider签名验签, 私钥加密,公钥验证

  //生成公钥私钥对
  byte[] messagebytes = Encoding.UTF8.GetBytes("luo罗");  
  RSACryptoServiceProvider oRSA = new RSACryptoServiceProvider();  
  string privatekey = oRSA.ToXmlString(true);  
  string publickey = oRSA.ToXmlString(false);  
    
  //私钥签名  
  RSACryptoServiceProvider oRSA3 = new RSACryptoServiceProvider();  
  oRSA3.FromXmlString(privatekey);  
  byte[] AOutput = oRSA3.SignData(messagebytes, "SHA1");  
  //公钥验证  
  RSACryptoServiceProvider oRSA4 = new RSACryptoServiceProvider();  
  oRSA4.FromXmlString(publickey);  
  bool bVerify = oRSA4.VerifyData(messagebytes, "SHA1", AOutput);  

　　

2.RSA 公钥加密, 私钥解密

using System;
using System.Security.Cryptography;
/// <summary> 
/// 生成公钥,私钥对
/// </summary> 
public static string[] GenerateKeys()
{
    string[] sKeys = new String[2];
    RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
    sKeys[0] = rsa.ToXmlString(true);//私钥
    sKeys[1] = rsa.ToXmlString(false);//公钥
    return sKeys;
}

/// <summary> 
/// RSA 加密
/// </summary> 
/// <param name="sSource" >明文</param> 
/// <param name="sPublicKey" >公钥</param> 
public static string EncryptString(string sSource, string sPublicKey)
{
    RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
    string plaintext = sSource;
    rsa.FromXmlString(sPublicKey);
    byte[] cipherbytes;
    byte[] byteEn = rsa.Encrypt(Encoding.UTF8.GetBytes("a"), false);
    cipherbytes = rsa.Encrypt(Encoding.UTF8.GetBytes(plaintext), false);

    StringBuilder sbString = new StringBuilder();
    for (int i = 0; i < cipherbytes.Length; i++)
    {
        sbString.Append(cipherbytes[i] + ",");
    }
    return sbString.ToString();
}


/// <summary> 
/// RSA 解密
/// </summary> 
/// <param name="sSource">密文</param> 
/// <param name="sPrivateKey">私钥</param> 
public static string DecryptString(String sSource, string sPrivateKey)
{
    RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
    rsa.FromXmlString(sPrivateKey);
    byte[] byteEn = rsa.Encrypt(Encoding.UTF8.GetBytes("a"), false);
    string[] sBytes = sSource.Split(',');

    for (int j = 0; j < sBytes.Length; j++)
    {
        if (sBytes[j] != "")
        {
            byteEn[j] = Byte.Parse(sBytes[j]);
        }
    }
    byte[] plaintbytes = rsa.Decrypt(byteEn, false);
    return Encoding.UTF8.GetString(plaintbytes);
}

　　

3.RSA 改进版, 私钥加密, 公钥解密

代码参考这里, 代码较多就不贴出来了:

http://www.cnblogs.com/hhh/archive/2011/06/03/2070692.html

相关链接：
[1]RSA私钥加密公钥解密算法。

http://blog.csdn.net/zhilunchen/archive/2008/09/17/2943158.aspx

[2]BigInteger大整数运算类。 

http://www.codeproject.com/KB/cs/biginteger.aspx

4.DES 加密

/// <summary>
///  DES算法描述简介：
///  DES是Data Encryption Standard（数据加密标准）的缩写。它是由IBM公司研制的一种加密算法，
/// 美国国家标准局于1977年公布把它作为非机要部门使用的数据加密标准；
/// 它是一个分组加密算法，他以64位为分组对数据加密。
/// 同时DES也是一个对称算法：加密和解密用的是同一个算法。
/// 它的密匙长度是56位（因为每个第8 位都用作奇偶校验），
/// 密匙可以是任意的56位的数，而且可以任意时候改变．
/// </summary>
private static byte[] IV = { 0x14, 0xFC, 0x29, 0xC8, 0x9A, 0xCB, 0xCA, 0xE7 };//加密IV向量
public static String Encrypt(String Key, String str)
{
    byte[] bKey = Encoding.UTF8.GetBytes(Key.Substring(0, 8));
    byte[] bIV = IV;
    byte[] bStr = Encoding.UTF8.GetBytes(str);
    try
    {
        DESCryptoServiceProvider desc = new DESCryptoServiceProvider();
        MemoryStream mStream = new MemoryStream();
        CryptoStream cStream = new CryptoStream(mStream, desc.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write);
        cStream.Write(bStr, 0, bStr.Length);
        cStream.FlushFinalBlock();
        return Convert.ToBase64String(mStream.ToArray());
    }
    catch
    {
        return string.Empty;
    }
}

public static String Decrypt(String Key, String DecryptStr)
{
    try
    {
        byte[] bKey = Encoding.UTF8.GetBytes(Key.Substring(0, 8));
        byte[] bIV = IV;
        byte[] bStr = Convert.FromBase64String(DecryptStr);
        DESCryptoServiceProvider desc = new DESCryptoServiceProvider();
        MemoryStream mStream = new MemoryStream();
        CryptoStream cStream = new CryptoStream(mStream, desc.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write);
        cStream.Write(bStr, 0, bStr.Length);
        cStream.FlushFinalBlock();
        return Encoding.UTF8.GetString(mStream.ToArray());
    }
    catch
    {
        return string.Empty;
    }
}

　　

5.常用SHA1, MD5

/// <summary>
/// MD5加密
/// </summary>
private static string GetMd5(string md5)
{
    System.Security.Cryptography.MD5CryptoServiceProvider md = new System.Security.Cryptography.MD5CryptoServiceProvider();
    byte[] value, hash;
    value = System.Text.Encoding.UTF8.GetBytes(md5);
    hash = md.ComputeHash(value);
    md.Clear();
    string temp = "";
    for (int i = 0, len = hash.Length; i < len; i++)
    {
        temp += hash[i].ToString("X").PadLeft(2, '0');
    }
    return temp;
}

/// <summary>
/// SHA1加密
/// </summary>
private static string Get_SHA1(string strSource)
{
    System.Security.Cryptography.SHA1 sha = new System.Security.Cryptography.SHA1CryptoServiceProvider();
    byte[] bytResult = sha.ComputeHash(System.Text.Encoding.Default.GetBytes(strSource));
    //转换成字符串，32位  
    string strResult = BitConverter.ToString(bytResult);
    //BitConverter转换出来的字符串会在每个字符中间产生一个分隔符，需要去除掉  
    strResult = strResult.Replace("-", "");
    return strResult;
}