DES加密共有四種模式：電子密碼本模式（ECB）、加密分組鏈接模式（CBC）、加密反饋模式（CFB）和輸出反饋模式（OFB）。
CBC模式加密：
import java.security.Key;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import com.sun.org.apache.xml.internal.security.utils.Base64;
public class DesCbcUtil {
public static final String ALGORITHM_DES = "DES/CBC/PKCS5Padding";
/**
* 加密
* @param data 待加密字符串
* @param key 加密私鑰，長度不能夠小於8位
* @return 加密後的字節數組，一般結合Base64編碼使用
* @throws CryptException 異常
*/
public static String encode(String key, String data) throws Exception {
return encode(key, data.getBytes());
}
/**
* 加密
* @param data 待加密字符串
* @param key 加密私鑰，長度不能夠小於8位
* @return 加密後的字節數組，一般結合Base64編碼使用
* @throws CryptException 異常
*/
public static String encode(String key, byte[] data) throws Exception {
try {
byte[] ivbyte = { 1, 2, 3, 4, 5, 6, 7, 8 };
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
// key的長度不能夠小於8位字節
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
IvParameterSpec iv = new IvParameterSpec(ivbyte);
AlgorithmParameterSpec paramSpec = iv;
cipher.init(Cipher.ENCRYPT_MODE, secretKey, paramSpec);
byte[] bytes = cipher.doFinal(data);
return Base64.encode(bytes);
} catch (Exception e) {
throw new Exception(e);
}
}
/**
* 解密
* @param data 待解密字符串
* @param key 解密私鑰，長度不能夠小於8位
* @return 解密後的字節數組
* @throws Exception 異常
*/
public static byte[] decode(String key, byte[] data) throws Exception {
try {
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
// key的長度不能夠小於8位字節
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
IvParameterSpec iv = new IvParameterSpec("12345678".getBytes());
AlgorithmParameterSpec paramSpec = iv;
cipher.init(Cipher.DECRYPT_MODE, secretKey, paramSpec);
return cipher.doFinal(data);
} catch (Exception e) {
throw new Exception(e);
}
}
/**
* 獲取編碼後的值
*
* @param key
* @param data
* @return
* @throws Exception
*/
public static String decodeValue(String key, String data) {
byte[] datas;
String value = null;
try {
if (System.getProperty("os.name") != null
&& (System.getProperty("os.name").equalsIgnoreCase("sunos") || System
.getProperty("os.name").equalsIgnoreCase("linux"))) {
datas = decode(key, Base64.decode(data));
} else {
datas = decode(key, Base64.decode(data));
}
value = new String(datas);
} catch (Exception e) {
value = "";
}
return value;
}
}
ECB模式加密：
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import android.util.Base64;
public class DesEcbUtil {
public static final String ALGORITHM_DES = "DES/ECB/PKCS5Padding";
/**
* 加密
* @param data 待加密字符串
* @param key 加密私鑰，長度不能夠小於8位
* @return 加密後的字節數組，一般結合Base64編碼使用
* @throws CryptException 異常
*/
public static String encode(String key, String data) throws Exception {
return encode(key, data.getBytes());
}
/**
* 加密
* @param data 待加密字符串
* @param key 加密私鑰，長度不能夠小於8位
* @return 加密後的字節數組，一般結合Base64編碼使用
* @throws CryptException 異常
*/
public static String encode(String key, byte[] data) throws Exception {
try {
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
// key的長度不能夠小於8位字節
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
byte[] bytes = cipher.doFinal(data);
return Base64.encodeToString(bytes, 3);
} catch (Exception e) {
throw new Exception(e);
}
}
/**
* 解密
* @param data 待解密字符串
* @param key 解密私鑰，長度不能夠小於8位
* @return 解密後的字節數組
* @throws Exception 異常
*/
public static byte[] decode(String key, byte[] data) throws Exception {
try {
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
// key的長度不能夠小於8位字節
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
cipher.init(Cipher.DECRYPT_MODE, secretKey);
return cipher.doFinal(data);
} catch (Exception e) {
throw new Exception(e);
}
}
/**
* 獲取編碼後的值
*
* @param key
* @param data
* @return
* @throws Exception
*/
public static String decodeValue(String key, String data) {
byte[] datas;
String value = null;
try {
if (System.getProperty("os.name") != null
&& (System.getProperty("os.name").equalsIgnoreCase("sunos") || System
.getProperty("os.name").equalsIgnoreCase("linux"))) {
datas = decode(key, Base64.decode(data, 3));
} else {
datas = decode(key, Base64.decode(data, 3));
}
value = new String(datas);
} catch (Exception e) {
value = "";
}
return value;
}
}
測試（CBC模式的測試和ECB的一樣）：
try {
//待加密內容url
String str = "";
String pwdKey = "moshapp";
String pwdKeyMD5 = MD5Util.encode(pwdKey);
System.out.println("pwdKeyMD5：" + pwdKeyMD5);
String encodeStr = DesEcbUtil.encode(pwdKeyMD5, str);
String decodeStr = DesEcbUtil.decodeValue(pwdKeyMD5, encodeStr);
System.out.println("加密前的字符串：" + str);
System.out.println("加密後的字符串：" + encodeStr);
System.out.println("解密後的字符串：" + decodeStr);
// URL轉義
final String encodedURL = URLEncoder.encode(encodeStr, "UTF-8");
// URL urlStr = new URL(encodedURL);
System.out.println("轉義後的字符串：" + encodedURL);
} catch (Exception e) {
e.printStackTrace();
}