数据加密标准DES加密算法是一种对称加密算法,DES 使用一个 56 位的密钥以及附加的 8 位奇偶校验位,产生最大 64 位的分组大小。这是一个迭代的分组密码,使用称为 Feistel 的技术,其中将加密的文本块分成两半。使用子密钥对其中一半应用循环功能,然后将输出与另一半进行“异或”运算;接着交换这两半,这一过程会继续下去,但最后一个循环不交换。DES 使用 16 个循环,使用异或,置换,代换,移位操作四种基本运算。
特点:数据加密标准,速度较快,适用于加密大量数据的场合;
DES加密在C#中使用
class Program { public static void Main() { string text = "测试asdY^&*NN!__s some plaintext!"; Console.WriteLine("加密前的明文:" + text); string cyphertext = Encrypt("测试asdY^&*NN!__s some plaintext!", "19491001");//密码必须8位 Console.WriteLine("解密后的明文:" + Decrypt(cyphertext, "19491001")); Console.ReadLine(); } public static string Encrypt(string text, string key) { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); byte[] inputByteArray = Encoding.GetEncoding("UTF-8").GetBytes(text); byte[] a = ASCIIEncoding.ASCII.GetBytes(key); des.Key = ASCIIEncoding.ASCII.GetBytes(key); des.IV = ASCIIEncoding.ASCII.GetBytes(key); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); StringBuilder ret = new StringBuilder(); foreach (byte b in ms.ToArray()) { ret.AppendFormat("{0:X2}", b);//将第一个参数转换为十六进制数,长度为2,不足前面补0 } return ret.ToString(); } public static string Decrypt(string cyphertext, string key) { if (string.IsNullOrEmpty(cyphertext)) return string.Empty; DESCryptoServiceProvider des = new DESCryptoServiceProvider(); byte[] inputByteArray = new byte[cyphertext.Length / 2]; for (int x = 0; x < cyphertext.Length / 2; x++) { int i = (Convert.ToInt32(cyphertext.Substring(x * 2, 2), 16)); inputByteArray[x] = (byte)i; } des.Key = ASCIIEncoding.ASCII.GetBytes(key); des.IV = ASCIIEncoding.ASCII.GetBytes(key); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); StringBuilder ret = new StringBuilder(); return System.Text.Encoding.GetEncoding("UTF-8").GetString(ms.ToArray()); } }
java的DES加解密, 可以和C#互操作
package temptest; import java.io.IOException; import java.io.UnsupportedEncodingException; import javax.crypto.*; import javax.crypto.spec.*; import sun.misc.BASE64Decoder; public class desencryptiontest { public static void main(String[] args) { String text = "测试asdY^&*NN!__s some plaintext!"; System.out.println("加密前的明文:" + text); String cryperText = ""; try { cryperText = toHexString(encrypt(text)); System.out.println("加密前的明文:" + cryperText); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } try { System.out.println("解密后的明文:" + decrypt(cryperText)); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } try { System.in.read(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private static byte[] desKey; private static String key = "19491001"; public static String decrypt(String message) throws Exception { byte[] bytesrc = convertHexString(message); Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8")); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES"); SecretKey secretKey = keyFactory.generateSecret(desKeySpec); IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8")); cipher.init(Cipher.DECRYPT_MODE, secretKey, iv); byte[] retByte = cipher.doFinal(bytesrc); return new String(retByte); } public static byte[] encrypt(String message) throws Exception { Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8")); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES"); SecretKey secretKey = keyFactory.generateSecret(desKeySpec); IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8")); cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv); return cipher.doFinal(message.getBytes("UTF-8")); } public static byte[] convertHexString(String ss) { byte digest[] = new byte[ss.length() / 2]; for (int i = 0; i < digest.length; i++) { String byteString = ss.substring(2 * i, 2 * i + 2); int byteValue = Integer.parseInt(byteString, 16); digest[i] = (byte) byteValue; } return digest; } public static String toHexString(byte b[]) { StringBuffer hexString = new StringBuffer(); for (int i = 0; i < b.length; i++) { String plainText = Integer.toHexString(0xff & b[i]); if (plainText.length() < 2) plainText = "0" + plainText; hexString.append(plainText); } return hexString.toString(); } }
来源:https://www.cnblogs.com/haoxinyue/archive/2012/04/26/2470661.html