String encryption common to ASP

There are three types of encryption used in strings

1, MD5 encryption, this is often used for passwords, one-way encryption, non-decryption, some online decryption can be the majority of the solution, with code can not be achieved, if you do not want to decrypt, after the encryption of a random interception of a good;

2, Base64 bit encryption, usually encrypted after the end of the string will have two = =, can be decrypted;

3, SHA encryption, one-way encryption, security is not MD5 good.

The above non-decryption is relative, these encryption algorithms are cross-platform.

                Using System.Web.Security;        Using System.Security.Cryptography;        <summary>//MD5 functions///</summary>//<param name= "val" > Raw string </param> &LT;RETURNS&GT;MD5 results </returns> public static string Md5string (string val) {if (VA L.trim ().            Equals (String.Empty) = = true) return String.Empty;            Byte[] B = Encoding.UTF8.GetBytes (val); b = New MD5CryptoServiceProvider ().            ComputeHash (b);            string ret = String.Empty; for (int i = 0; i < b.length; i++) ret + = B[i]. ToString ("X").            PadLeft (2, ' 0 ');        return ret; }///<summary>//SHA1 string encryption///</summary>//<param name= "obj" ></para m>//<returns></returns> public static string SHA1 (String obj) {return F Ormsauthentication.hashpasswordforstoringinconfigfile (obJ, "SHA1"); }///<summary>//SHA256 string encryption///</summary>//<param name= "obj" ></pa ram>//<returns></returns> public static string SHA256 (String obj) {//re            Turn System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile (obj, "SHA256");            byte[] Bytvalue = System.Text.Encoding.UTF8.GetBytes (obj);            SHA256 sha256 = new sha256managed ();            byte[] RetVal = Sha256.computehash (Bytvalue);            StringBuilder sb = new StringBuilder (); for (int i = 0; i < retval.length; i++) {sb. Append (Retval[i].            ToString ("X2")); } return SB.        ToString (); }///<summary>//BASE64-bit encryption//</summary>//<param name= "Val" ></par         am>//<returns></returns> public static string EncryptBase64 (string val) {   Return Convert.tobase64string (Encoding.UTF8.GetBytes (Val)); }///<summary>//Base64 bit decryption///</summary>//<param name= "Val" ></para            m>//<returns></returns> public static string DecryptBase64 (string val) {        Return Encoding.Default.GetString (Convert.frombase64string (Val)); }//<summary>//BASE64 bit (MD5 encryption) [Standard, non-MD5 encryption and BASE64 bit encryption]///</summary>//<par Am Name= "val" > Original string </param>//&LT;RETURNS&GT;MD5 result </returns> public static string Encryptba Se64andmd5 (string val) {if (val. Trim ().            Equals (String.Empty) = = true) return String.Empty;            MD5CryptoServiceProvider MD5CSP = new MD5CryptoServiceProvider ();        Return convert.tobase64string (Md5csp.computehash (Encoding.UTF8.GetBytes (Val)));      }

You can also define a key, custom encryption algorithm

        <summary>//DES encrypted strings///</summary>//<param name= "encryptstring" > Pending Encrypted strings </param>///<param Name= "Encryptkey" > Encryption key, required for 8-bit </param>///<returns> encryption for successful return of encryption            After the string, the failure returns the source string </returns> public static string Encode (String encryptstring, String encryptkey) {            Encryptkey = utilsstring.substring (Encryptkey, 8);            Encryptkey = Encryptkey.padright (8, ");            byte[] RgbKey = Encoding.UTF8.GetBytes (encryptkey.substring (0, 8));            Byte[] Rgbiv = {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};            byte[] Inputbytearray = Encoding.UTF8.GetBytes (encryptstring);            DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider ();            MemoryStream mstream = new MemoryStream ();            CryptoStream cstream = new CryptoStream (Mstream, Dcsp.createencryptor (RgbKey, Rgbiv), cryptostreammode.write); Cstream.write (inputbytearray, 0, INputbytearray.length);            Cstream.flushfinalblock ();        Return convert.tobase64string (Mstream.toarray ()); }///<summary>//des decryption strings///</summary>//<param name= "decryptstring" > String to decrypt </param>///<param Name= "Decryptkey" > Decryption key, required for 8-bit, same as encryption key </param>//<returns&gt            Decryption succeeded in returning the decrypted string, failed to return to source string </returns> public static string Decode (String decryptstring, String decryptkey) {            Decryptkey = utilsstring.substring (Decryptkey, 8);            Decryptkey = Decryptkey.padright (8, ");            byte[] RgbKey = Encoding.UTF8.GetBytes (Decryptkey);            Byte[] Rgbiv = {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};            byte[] Inputbytearray = convert.frombase64string (decryptstring);            DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider ();            MemoryStream mstream = new MemoryStream (); CryptoStream cstream = new CryptoStream (Mstream, DCSP.            CreateDecryptor (RgbKey, Rgbiv), cryptostreammode.write);            Cstream.write (Inputbytearray, 0, inputbytearray.length);            Cstream.flushfinalblock ();        Return Encoding.UTF8.GetString (Mstream.toarray ()); }

　　

String encryption common to ASP