如何加密一个字符串。

[tztz520]

加密一个字符串，这个字符串有小数点，汉字，数字，什么都有，怎样加密呢，又怎样把加密的字符串解密呢，最好有源码。

[孟子E章]

http://dotnet.aspx.cc/ShowDetail.aspx?id=7AE7D20A-A5DA-4303-AC2D-32046BE4D086

[Dugu_Niu]

这是一个不可逆加密的例子
public static string Encrypt(string cleanString)
{
Byte[] clearBytes = new UnicodeEncoding().GetBytes(cleanString);
Byte[] hashedBytes = ((HashAlgorithm) CryptoConfig.CreateFromName("MD5")).ComputeHash(clearBytes);

return BitConverter.ToString(hashedBytes);
}

这是一个可逆加密的例子
static byte[] key = new Byte[32]
{
0x8D, 0xE0, 0xB9, 0xF4,
0xF5, 0x97, 0x90, 0xB0,
0x6B, 0x9F, 0xDC, 0x37,
0x75, 0x7C, 0x76, 0x1B,
0x30, 0x87, 0xB9, 0x29,
0x25, 0xD1, 0x0D, 0xC2,
0xFE, 0xB6, 0x8F, 0x63,
0xF0, 0x2D, 0x22, 0x9D
};
static byte[] iv = new Byte[16]
{
0x1D, 0x21, 0x9B, 0x79,
0xF7, 0x5B, 0x59, 0x88,
0xAD, 0xE4, 0x2E, 0x7D,
0x17, 0xEA, 0x23, 0x5A
};
private static string GetDatabaseConnectionString()
{
FileStream fin;
try
{
fin = new FileStream(System.Windows.Forms.Application.StartupPath + DeployFile,
FileMode.Open, FileAccess.Read);
}
catch
{
System.Diagnostics.Trace.Fail("严重错误: 打开安全配置文件错误，请与系统开发商联系!!!");
return string.Empty;
}

SymmetricAlgorithm rijn = SymmetricAlgorithm.Create();
CryptoStream encStream = new CryptoStream(fin, rijn.CreateDecryptor(key, iv), CryptoStreamMode.Read);

int len = encStream.ReadByte();
byte[] buffer = new byte[len];
encStream.Read(buffer, 0, len);
encStream.Close();
fin.Close();

System.Text.UTF8Encoding encoder = new System.Text.UTF8Encoding();
return encoder.GetString(buffer);
}

private static void SetDatabaseConnectionString(string str)
{
System.Text.UTF8Encoding encoder = new System.Text.UTF8Encoding();
FileStream fout;
try
{
fout = new FileStream(System.Windows.Forms.Application.StartupPath + DeployFile,
FileMode.Open, FileAccess.Write);
}
catch
{
System.Diagnostics.Trace.Fail("严重错误: 打开安全配置文件错误，请与系统开发商联系!!!");
return ;
}
fout.SetLength(0);
SymmetricAlgorithm rijn = SymmetricAlgorithm.Create();
CryptoStream encStream = new CryptoStream(fout, rijn.CreateEncryptor(key, iv), CryptoStreamMode.Write);

byte[] buffer = encoder.GetBytes(str);
encStream.WriteByte((byte)buffer.Length);
encStream.Write(buffer, 0, buffer.Length);
encStream.Close();
fout.Close();
}

[tztz520]

多谢帮忙!