最簡單的DES密碼編譯演算法實現，des密碼編譯演算法

最簡單的DES密碼編譯演算法實現，des密碼編譯演算法

Base64.java

package com.mstf.des; import java.io.UnsupportedEncodingException; /** * base64編碼/解碼 * @author ceet * */public class Base64 { public static String encode(String data) {return new String(encode(data.getBytes()));} public static String decode(String data) {try {return new String(decode(data.toCharArray()),"utf-8");} catch (UnsupportedEncodingException e) {e.printStackTrace();return null;}} private static char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".toCharArray(); private static byte[] codes = new byte[256]; static {for (int i = 0; i < 256; i++) {codes[i] = -1;}for (int i = 'A'; i <= 'Z'; i++) {codes[i] = (byte) (i - 'A');} for (int i = 'a'; i <= 'z'; i++) {codes[i] = (byte) (26 + i - 'a');}for (int i = '0'; i <= '9'; i++) {codes[i] = (byte) (52 + i - '0');}codes['+'] = 62;codes['/'] = 63;} public static char[] encode(byte[] data) {char[] out = new char[((data.length + 2) / 3) * 4];for (int i = 0, index = 0; i < data.length; i += 3, index += 4) {boolean quad = false;boolean trip = false; int val = (0xFF & (int) data[i]);val <<= 8;if ((i + 1) < data.length) {val |= (0xFF & (int) data[i + 1]);trip = true;}val <<= 8;if ((i + 2) < data.length) {val |= (0xFF & (int) data[i + 2]);quad = true;}out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];val >>= 6;out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];val >>= 6;out[index + 1] = alphabet[val & 0x3F];val >>= 6;out[index + 0] = alphabet[val & 0x3F];}return out;} public static byte[] decode(char[] data) {int tempLen = data.length;for (int ix = 0; ix < data.length; ix++) {if ((data[ix] > 255) || codes[data[ix]] < 0) {--tempLen;}}int len = (tempLen / 4) * 3;if ((tempLen % 4) == 3) {len += 2;}if ((tempLen % 4) == 2) {len += 1; }byte[] out = new byte[len]; int shift = 0;int accum = 0;int index = 0; for (int ix = 0; ix < data.length; ix++) {int value = (data[ix] > 255) ? -1 : codes[data[ix]]; if (value >= 0) {accum <<= 6;shift += 6;accum |= value;if (shift >= 8) {shift -= 8;out[index++] = (byte) ((accum >> shift) & 0xff);}}} if (index != out.length) {throw new Error("Miscalculated data length (wrote " + index+ " instead of " + out.length + ")");} return out;}}

DESUtil.java

package com.mstf.des; import java.security.Key;import java.security.SecureRandom; import javax.crypto.Cipher;import javax.crypto.KeyGenerator; /** * DES對稱演算法(加密/解密) *  * @author ceet * */public class DESUtil { private Key key; public DESUtil(String strKey) {setKey(strKey);} public void setKey(String strKey) {try {KeyGenerator generator = KeyGenerator.getInstance("DES");generator.init(new SecureRandom(strKey.getBytes())); // 根據參數產生keythis.key = generator.generateKey();} catch (Exception e) {e.printStackTrace();}} public String encrypt(String source) {return encrypt(source, "utf-8");} public String decrypt(String encryptedData) {return decrypt(encryptedData, "utf-8");} public String encrypt(String source, String charSet) {String encrypt = null;try {byte[] ret = encrypt(source.getBytes(charSet));encrypt = new String(Base64.encode(ret));} catch (Exception e) {e.printStackTrace();encrypt = null;}return encrypt;} public String decrypt(String encryptedData, String charSet) {String descryptedData = null;try {byte[] ret = descrypt(Base64.decode(encryptedData.toCharArray()));descryptedData = new String(ret, charSet);} catch (Exception e) {e.printStackTrace();descryptedData = null;}return descryptedData;} private byte[] encrypt(byte[] primaryData) {try {Cipher cipher = Cipher.getInstance("DES"); // Cipher對象實際完成加密操作cipher.init(Cipher.ENCRYPT_MODE, this.key); // 用密鑰初始化Cipher對象(加密) return cipher.doFinal(primaryData);} catch (Exception e) {e.printStackTrace();return null;}} private byte[] descrypt(byte[] encryptedData) {try {Cipher cipher = Cipher.getInstance("DES"); // Cipher對象實際完成解密操作cipher.init(Cipher.DECRYPT_MODE, this.key); // 用密鑰初始化Cipher對象(解密) return cipher.doFinal(encryptedData);} catch (Exception e) {e.printStackTrace();return null;}} public static void main(String[] args) {String code = "ceet";DESUtil desUtil = new DESUtil("key");String encrypt = desUtil.encrypt(code);String decrypt = desUtil.decrypt(encrypt);System.out.println("原內容：" + code);System.out.println("加密：" + encrypt);System.out.println("解密：" + decrypt);}}