加密字符串与图片保存于数据库,并显示读取显示

今天在回答CSDN上朋友的提问,如何把字符串与图片加密后保存与数据库,需要的时候再解密显示

于是做了个简单的测试DEMO

PS:这个DEMO主要的限制是图片大小不能超过4K

在窗体添加4个按钮,一个图片框

//加密字符串
private void button2_Click(object sender, EventArgs e)
{
AES samAES = new AES();

string strValue = samAES.Encrypt(samAES.GetBytes("My Name is sam!"),"SamTest");
string strSql = "Insert Into Test(name,Value) Values('String','"+strValue+"')";

using (System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection("server=.;uid=sa;pwd=**;database=SuperERP"))
{
conn.Open();
using (System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand(strSql, conn))
{
try
{
cmd.ExecuteNonQuery();

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}

}
//解密字符串
private void button3_Click(object sender, EventArgs e)
{
using (System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection("server=.;uid=sa;pwd=**;database=SuperERP"))
{
conn.Open();
DataSet ds = new DataSet();
using (System.Data.SqlClient.SqlDataAdapter adap = new System.Data.SqlClient.SqlDataAdapter("Select * From Test Where ID =1", conn))
{
try
{
adap.Fill(ds);

AES samAes = new AES();
object o = samAes.Decrypt(ds.Tables[0].Rows[0][2].ToString(), "SamTest", "String");
MessageBox.Show(o.ToString());
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}

}

//加密图片
private void button4_Click(object sender, EventArgs e)
{
AES samAES = new AES();

System.IO.FileStream fs = new System.IO.FileStream(@"c:\已收到.jpg", System.IO.FileMode.Open);
Image i = Image.FromStream(fs);

//System.IO.MemoryStream ms = new System.IO.MemoryStream();
//i.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
//byte[] btys = ms.ToArray();

string strValue = samAES.Encrypt(samAES.GetBytes(i), "SamTest");
string strSql = "Insert Into Test(name,Value) Values('Image','" + strValue + "')";

using (System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection("server=.;uid=sa;pwd=**;database=SuperERP"))
{
conn.Open();
using (System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand(strSql, conn))
{
try
{
cmd.ExecuteNonQuery();

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
}

//解密图片
private void button5_Click(object sender, EventArgs e)
{
using (System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection("server=.;uid=sa;pwd=**;database=SuperERP"))
{
conn.Open();
DataSet ds = new DataSet();
using (System.Data.SqlClient.SqlDataAdapter adap = new System.Data.SqlClient.SqlDataAdapter("Select * From Test Where ID =3", conn))
{
try
{
adap.Fill(ds);

AES samAes = new AES();
object o = samAes.Decrypt(ds.Tables[0].Rows[0][2].ToString(), "SamTest", "Image");
this.pictureBox1.Image = o as Image;
// MessageBox.Show(o.ToString());
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
}

}

public class AES
{
public string Encrypt(byte[] strEncrypt, string strKey)
{
byte[] keybytes = UTF8Encoding.UTF8.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(strKey,"md5"));
byte[] resultbytes = null;
using (RijndaelManaged rm = new RijndaelManaged())
{
rm.Key = keybytes;
rm.Mode = CipherMode.ECB;
rm.Padding = PaddingMode.PKCS7;
ICryptoTransform cTranf = rm.CreateEncryptor();
resultbytes = cTranf.TransformFinalBlock(strEncrypt, 0, strEncrypt.Length);
}
return Convert.ToBase64String(resultbytes);
}
public object Decrypt(string strDecrypt, string strKey,string strType)
{
byte[] keybytes = UTF8Encoding.UTF8.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(strKey,"md5"));
byte[] decryptbyte = Convert.FromBase64String(strDecrypt);
byte[] resultbytes = null;
using (RijndaelManaged rm = new RijndaelManaged())
{
rm.Key = keybytes;
rm.Mode = CipherMode.ECB;
rm.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransf = rm.CreateDecryptor();
resultbytes = cTransf.TransformFinalBlock(decryptbyte, 0, decryptbyte.Length);
}
if (strType == "String")
{
return UTF8Encoding.UTF8.GetString(resultbytes);
}
else
{
System.IO.MemoryStream ms = new System.IO.MemoryStream(resultbytes);
Image i = Image.FromStream(ms);
return i;
}

}

public byte[] GetBytes(object objTransfer)
{
byte[] _byts = null;
if (objTransfer.GetType()==typeof(System.String))
{
_byts = UTF8Encoding.UTF8.GetBytes(objTransfer.ToString());
}
else
{
Image i = objTransfer as Image;
System.IO.MemoryStream ms = new System.IO.MemoryStream();
i.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
_byts = ms.ToArray();
}

return _byts;
}
}