c# 实现MD5,SHA1,SHA256,SHA512等常用加密算法源代码

using system;
using system.io;
using system.data;
using system.text;
using system.diagnostics;
using system.security;
using system.security.cryptography;
/**//*
* .net框架由于拥有clr提供的丰富库支持，只需很少的代码即可实现先前使用c等旧式语言很难实现的加密算法。本类实现一些常用机密算法，供参考。其中md5算法返回int的tostring字串。返回数字字母型结果的算法参见之前blog文章
*/
namespace 档案数字化加工
{
/**//// <summary>
/// 类名：hashencrypt
/// 作用：对传入的字符串进行hash运算，返回通过hash算法加密过的字串。
/// 属性：［无］
/// 构造函数额参数：
/// isreturnnum:是否返回为加密后字符的byte代码
/// iscasesensitive：是否区分大小写。
/// 方法：此类提供md5，sha1，sha256，sha512等四种算法，加密字串的长度依次增大。
/// </summary>
public class hashencrypt
{
//private string strin;
private bool isreturnnum;
private bool iscasesensitive;
/**//// <summary>
/// 类初始化，此类提供md5，sha1，sha256，sha512等四种算法，加密字串的长度依次增大。
/// </summary>
/// <param name="iscasesensitive">是否区分大小写</param>
/// <param name="isreturnnum">是否返回为加密后字符的byte代码</param>
public hashencrypt(bool iscasesensitive, bool isreturnnum)
{
this.isreturnnum = isreturnnum;
this.iscasesensitive = iscasesensitive;
}
private string getstrin(string strin)
{
//string strin = strin;
if (strin.length == 0)
{
strin = "~null~";
}
if (iscasesensitive == false)
{
strin = strin.toupper();
}
return strin;
}
public string md5encrypt(string strin)
{
//string strin = getstrin(strin);
byte[] tmpbyte;
md5 md5 = new md5cryptoserviceprovider();
tmpbyte = md5.computehash(getkeybytearray(getstrin(strin)));
md5.clear();
return getstringvalue(tmpbyte);
}
public string sha1encrypt(string strin)
{
//string strin = getstrin(strin);
byte[] tmpbyte;
sha1 sha1 = new sha1cryptoserviceprovider();
tmpbyte = sha1.computehash(getkeybytearray(strin));
sha1.clear();
return getstringvalue(tmpbyte);
}
public string sha256encrypt(string strin)
{
//string strin = getstrin(strin);
byte[] tmpbyte;
sha256 sha256 = new sha256managed();
tmpbyte = sha256.computehash(getkeybytearray(strin));
sha256.clear();
return getstringvalue(tmpbyte);
}
public string sha512encrypt(string strin)
{
//string strin = getstrin(strin);
byte[] tmpbyte;
sha512 sha512 = new sha512managed();
tmpbyte = sha512.computehash(getkeybytearray(strin));
sha512.clear();
return getstringvalue(tmpbyte);
}
/**//// <summary>
/// 使用des加密（added by niehl 2005-4-6）
/// </summary>
/// <param name="originalvalue">待加密的字符串</param>
/// <param name="key">密钥(最大长度8)</param>
/// <param name="iv">初始化向量(最大长度8)</param>
/// <returns>加密后的字符串</returns>
public string desencrypt(string originalvalue, string key, string iv)
{
//将key和iv处理成8个字符
key += "12345678";
iv += "12345678";
key = key.substring(0, 8);
iv = iv.substring(0, 8);
symmetricalgorithm sa;
icryptotransform ct;
memorystream ms;
cryptostream cs;
byte[] byt;
sa = new descryptoserviceprovider();
sa.key = encoding.utf8.getbytes(key);
sa.iv = encoding.utf8.getbytes(iv);
ct = sa.createencryptor();
byt = encoding.utf8.getbytes(originalvalue);
ms = new memorystream();
cs = new cryptostream(ms, ct, cryptostreammode.write);
cs.write(byt, 0, byt.length);
cs.flushfinalblock();
cs.close();
return convert.tobase64string(ms.toarray());
}
public string desencrypt(string originalvalue, string key)
{
return desencrypt(originalvalue, key, key);
}
/**//// <summary>
/// 使用des解密（added by niehl 2005-4-6）
/// </summary>
/// <param name="encryptedvalue">待解密的字符串</param>
/// <param name="key">密钥(最大长度8)</param>
/// <param name="iv">m初始化向量(最大长度8)</param>
/// <returns>解密后的字符串</returns>
public string desdecrypt(string encryptedvalue, string key, string iv)
{
//将key和iv处理成8个字符
key += "12345678";
iv += "12345678";
key = key.substring(0, 8);
iv = iv.substring(0, 8);
symmetricalgorithm sa;
icryptotransform ct;
memorystream ms;
cryptostream cs;
byte[] byt;
sa = new descryptoserviceprovider();
sa.key = encoding.utf8.getbytes(key);
sa.iv = encoding.utf8.getbytes(iv);
ct = sa.createdecryptor();
byt = convert.frombase64string(encryptedvalue);
ms = new memorystream();
cs = new cryptostream(ms, ct, cryptostreammode.write);
cs.write(byt, 0, byt.length);
cs.flushfinalblock();
cs.close();
return encoding.utf8.getstring(ms.toarray());
}
public string desdecrypt(string encryptedvalue, string key)
{
return desdecrypt(encryptedvalue, key, key);
}
private string getstringvalue(byte[] byte)
{
string tmpstring = "";
if (this.isreturnnum == false)
{
asciiencoding asc = new asciiencoding();
tmpstring = asc.getstring(byte);
}
else
{
int icounter;
for (icounter = 0; icounter < byte.length; icounter++)
{
tmpstring = tmpstring + byte[icounter].tostring();
}
}
return tmpstring;
}
private byte[] getkeybytearray(string strkey)
{
asciiencoding asc = new asciiencoding();
int tmpstrlen = strkey.length;
byte[] tmpbyte = new byte[tmpstrlen - 1];
tmpbyte = asc.getbytes(strkey);
return tmpbyte;
}
}
}