java 简单的des加密示例
1.加密结果
包含 ： 对int加密 、对string加密、对byte[]加密。
1 10-09 18:33:32.484 7617-7617/com.example.tt.downtest D/CipherUtil: init Cipher needs 18 ms 2 10-09 18:33:32.484 7617-7617/com.example.tt.downtest D/CipherUtil: -----=====-----------=========----- 3 10-09 18:33:32.484 7617-7617/com.example.tt.downtest D/CipherUtil: bytes data is [ �� 4 ] 5 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: encrypt ret is [ ����h�1 !m�7M��J�˝��� ] needs 5 ms 6 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: decrypt ret is [ �� 7 ] needs 0 ms 8 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: -----=====-----------=========----- 9 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: int data is [ 100 ] 10 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: encrypt ret is [ [�� sZ"� ] needs 0 ms 11 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: decrypt ret is [ 100 ] needs 0 ms 12 10-09 18:33:32.490 7617-7617/com.example.tt.downtest D/CipherUtil: -----=====-----------=========----- 13 10-09 18:33:32.491 7617-7617/com.example.tt.downtest D/CipherUtil: string data is [ hello world ] 14 10-09 18:33:32.491 7617-7617/com.example.tt.downtest D/CipherUtil: encrypt ret is [ ��́��|��@�y��y ] needs 0 ms 15 10-09 18:33:32.491 7617-7617/com.example.tt.downtest D/CipherUtil: decrypt ret is [ hello world ] needs 0 ms
2.完整示例
1 package com.example.tt.downtest; 2 3 4 import android.util.Log; 5 6 import java.security.InvalidKeyException; 7 import java.security.NoSuchAlgorithmException; 8 import java.security.spec.InvalidKeySpecException; 9 10 import javax.crypto.BadPaddingException; 11 import javax.crypto.Cipher; 12 import javax.crypto.IllegalBlockSizeException; 13 import javax.crypto.NoSuchPaddingException; 14 import javax.crypto.SecretKey; 15 import javax.crypto.SecretKeyFactory; 16 import javax.crypto.spec.DESKeySpec; 17 18 19 public class CipherUtil { 20 21 final String TAG = "CipherUtil"; 22 long begin,end; 23 24 25 String algorithm = "DES"; 26 Cipher cipher; 27 SecretKey secretKey; 28 byte key[] = new byte[]{'c','B','z',2,'b','y','d',8}; 29 30 void init(){ 31 begin = System.currentTimeMillis(); 32 try { 33 cipher = Cipher.getInstance(algorithm); 34 DESKeySpec keySpec = new DESKeySpec(key); 35 SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(algorithm); 36 secretKey = keyFactory.generateSecret(keySpec); 37 } catch (NoSuchAlgorithmException e) { 38 e.printStackTrace(); 39 } catch (NoSuchPaddingException e) { 40 e.printStackTrace(); 41 } catch (InvalidKeyException e) { 42 e.printStackTrace(); 43 } catch (InvalidKeySpecException e) { 44 e.printStackTrace(); 45 } 46 end = System.currentTimeMillis(); 47 Log.d(TAG, "init Cipher needs " + (end - begin) + " ms"); 48 } 49 50 byte[] des(int mode,byte data[]){ 51 52 byte[] ret = null; 53 //加密的内容存在并且密钥存在且长度为8个字节 54 if (data != null && data.length > 0) { 55 try { 56 //Cipher.DECRYPT_MODE 解密 57 //Cipher.ENCRYPT_MODE 加密 58 cipher.init(mode, secretKey); 59 ret = cipher.doFinal(data); 60 61 } catch (IllegalBlockSizeException e) { 62 e.printStackTrace(); 63 } catch (BadPaddingException e) { 64 e.printStackTrace(); 65 } catch (InvalidKeyException e) { 66 e.printStackTrace(); 67 } 68 } 69 return ret; 70 } 71 72 //DES 解密 73 public byte[] desDecrypt(byte data[]){ 74 return des(Cipher.DECRYPT_MODE,data); 75 } 76 //DES 加密 77 public byte[] desEncrypt(byte data[]){ 78 return des(Cipher.ENCRYPT_MODE,data); 79 } 80 81 //byte 数组与 int 的相互转换 82 public static int byteArrayToInt(byte[] b) { 83 return b[3] & 0xFF | 84 (b[2] & 0xFF) << 8 | 85 (b[1] & 0xFF) << 16 | 86 (b[0] & 0xFF) << 24 ; 87 } 88 89 public static byte[] intToByteArray(int a) { 90 return new byte[] { 91 (byte) ((a >> 24) & 0xFF), 92 (byte) ((a >> 16) & 0xFF), 93 (byte) ((a >> 8) & 0xFF), 94 (byte) (a & 0xFF) 95 }; 96 } 97 98 public CipherUtil(){ 99 init(); 100 } 101 102 void testEncryptBytes(){ 103 byte data[] = new byte[16]; 104 for (int i = 0;i < data.length;++i){ 105 data[i] = (byte) i; 106 } 107 Log.d(TAG, "bytes data is [ " + new String(data) + " ]"); 108 109 begin = System.currentTimeMillis(); 110 byte encrypt[] = desEncrypt(data); 111 end = System.currentTimeMillis(); 112 Log.d(TAG, "encrypt ret is [ " + new String(encrypt) + " ] needs " + (end - begin) + " ms"); 113 114 begin = System.currentTimeMillis(); 115 byte decrypt[] = desDecrypt(encrypt); 116 end = System.currentTimeMillis(); 117 118 Log.d(TAG, "decrypt ret is [ " + new String(decrypt) + " ] needs " + (end - begin) + " ms"); 119 120 } 121 void testEncryptInt(){ 122 int data = 100; 123 byte bytes[] = intToByteArray(data); 124 Log.d(TAG, "int data is [ " + data + " ]"); 125 126 begin = System.currentTimeMillis(); 127 byte encrypt[] = desEncrypt(bytes); 128 end = System.currentTimeMillis(); 129 Log.d(TAG, "encrypt ret is [ " + new String(encrypt) + " ] needs " + (end - begin) + " ms"); 130 131 begin = System.currentTimeMillis(); 132 byte decrypt[] = desDecrypt(encrypt); 133 end = System.currentTimeMillis(); 134 135 Log.d(TAG, "decrypt ret is [ " + byteArrayToInt(decrypt) + " ] needs " + (end - begin) + " ms"); 136 137 } 138 void testEncryptString(){ 139 String str = "hello world"; 140 byte data[] = str.getBytes(); 141 Log.d(TAG, "string data is [ " + str + " ]"); 142 143 begin = System.currentTimeMillis(); 144 byte encrypt[] = desEncrypt(data); 145 end = System.currentTimeMillis(); 146 Log.d(TAG, "encrypt ret is [ " + new String(encrypt) + " ] needs " + (end - begin) + " ms"); 147 148 149 begin = System.currentTimeMillis(); 150 byte decrypt[] = desDecrypt(encrypt); 151 end = System.currentTimeMillis(); 152 153 Log.d(TAG, "decrypt ret is [ " + new String(decrypt) + " ] needs " + (end - begin) + " ms"); 154 155 } 156 157 public void testMain(){ 158 159 Log.d(TAG, "-----=====-----------=========-----"); 160 testEncryptBytes(); 161 Log.d(TAG, "-----=====-----------=========-----"); 162 testEncryptInt(); 163 Log.d(TAG, "-----=====-----------=========-----"); 164 testEncryptString(); 165 } 166 }
