版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/muziby/article/details/79650440
常见编码加密解密的基础用法
- Base64编码
- URL编码
- GZIP
- AES加密
- DES加密
RSA加密
public class MainActivity extends AppCompatActivity { private EditText mTextContent; private TextView mTxtResult; private TextView mTxtPass; private byte [] mDecode; private byte [] mPriDecode; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mTextContent = (EditText) findViewById (R.id.txt_content); mTxtResult = (TextView) findViewById (R.id.txt_result); mTxtPass = (TextView) findViewById (R.id.txt_password); }编码
public void btnBase64Encode(View view) { String str = mTextContent.getText().toString().trim(); // Base64编码 no_wrap 代表编码的结果没有任何换行 String encoded = Base64.encodeToString(str.getBytes(), Base64.NO_WRAP); mTxtResult.setText(encoded); //Base64 解码， byte[] decode = Base64.decode(encoded, Base64.NO_WRAP); String ss = new String(decode); Log.d("Base64 ", "ss = " + ss); } public void btnURLEncode(View view) { String str = "%E5%8F%98%E5%BD%A2%E9%87%91%E5%88%9A"; try { String decode = URLDecoder.decode(str, "utf-8"); Log.d("UE", "URLENCODING: " + decode); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } //URLEncoder try { String encode = URLEncoder.encode("BY帅", "utf-8"); Log.d("UE", "URLENCODING: edncode: " + encode); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } /** * GZIP压缩，解压缩 * * @param view */ public void btnGzipTest(View view) { String str = mTextContent.getText().toString().trim(); // 1.压缩GZIP,GZIPOutPutStream ByteArrayOutputStream bout = new ByteArrayOutputStream(); try { GZIPOutputStream gzipout = new GZIPOutputStream(bout); gzipout.write(str.getBytes());//利用GZIPOutPutStream压缩，并输出结果 gzipout.finish();//必须调用生成实际的压缩数据 gzipout.close(); } catch (IOException e) { e.printStackTrace(); } byte[] bytes = bout.toByteArray(); mTxtResult.setText("内容长度：" + str.length() + "\n压缩大小：" + bytes.length); String s = Arrays.toString(bytes); Log.d("GZIP", s); //解压缩 GZIPInputStream ByteArrayInputStream bin = new ByteArrayInputStream(bytes); try { GZIPInputStream gzipIn = new GZIPInputStream(bin); ByteArrayOutputStream bo = new ByteArrayOutputStream(); byte[] buf = new byte[128]; int len; while (true) { len = gzipIn.read(buf); if (len == -1) { break; } bo.write(buf, 0, len); } byte[] bytes1 = bo.toByteArray(); String s1 = new String(bytes1); Log.d("GZIP", s1); } catch (IOException e) { e.printStackTrace(); } } public void btnDesTest(View view) { //DES TEST String str = mTextContent.getText().toString().trim(); String pwd = mTxtPass.getText().toString().trim(); // byte[] encrypt = CryptUtil.desEncrypt(str.getBytes(), pwd.getBytes()); byte[] iv = {23, 12, 3, 2, 4, 5, 7, 3, 4, 3, 34, 66, 6, 7, 93, 12}; byte[] encrypt = CryptUtil.aesEncryptWithIv(str.getBytes(), pwd.getBytes(), iv); String s = Base64.encodeToString(encrypt, Base64.NO_WRAP); mTxtResult.setText(s); //解密，把Base64还原，并且解密 byte[] ed = Base64.decode(s, Base64.NO_WRAP); byte[] data = CryptUtil.aesDecryptWithIv(ed, pwd.getBytes(), iv); String ss = new String(data); Log.d("DES", "btnDesTest : " + ss); } public void btnRsaTest(View view) { String state = Environment.getExternalStorageState(); File dir = getFilesDir(); if (state.equals(Environment.MEDIA_MOUNTED)) { dir = Environment.getExternalStorageDirectory(); } if (!dir.exists()) { dir.mkdirs(); } Log.d("KEY", "dir : " + dir.getAbsolutePath()); File target = new File(dir, "secret.txt"); try { if (!target.exists()) { // 1.加载或者生成密钥对 KeyPair keyPair = CryptUtil.generateRsaKey(1024); // 私钥 PrivateKey aPrivate = keyPair.getPrivate(); // 公钥 PublicKey aPublic = keyPair.getPublic(); // 私钥的数据格式 byte[] privEncoded = aPrivate.getEncoded(); byte[] pubEncoded = aPublic.getEncoded(); // String publicstr = aPublic.toString(); String pubkeyEncode = Base64.encodeToString(pubEncoded, Base64.NO_WRAP); String priKeyEncode = Base64.encodeToString(privEncoded, Base64.NO_WRAP); // Log.d("Key", publicstr); //TODO:把公钥，私钥使用BASE64编码，保存到文件中，下一次启动时，需要先加载，没有才创建 target.createNewFile(); BufferedWriter bw = new BufferedWriter(new FileWriter(target, true)); bw.write(pubkeyEncode); bw.newLine(); bw.write(priKeyEncode); bw.close(); BufferedReader bufferedReader = new BufferedReader(new FileReader(target)); String Pub = bufferedReader.readLine(); mDecode = Base64.decode(Pub, Base64.NO_WRAP); String Pri = bufferedReader.readLine(); mPriDecode = Base64.decode(Pri, Base64.NO_WRAP); bufferedReader.close(); // FileOutputStream fos = new FileOutputStream(target); // fos.write(pubencode); // fos.close(); }else if (target.exists()){ BufferedReader bufferedReader = new BufferedReader(new FileReader(target)); String Pub = bufferedReader.readLine(); mDecode = Base64.decode(Pub, Base64.NO_WRAP); String Pri = bufferedReader.readLine(); mPriDecode = Base64.decode(Pri, Base64.NO_WRAP); Log.d("key","public: " + Pub); Log.d("key","private: " + Pri); bufferedReader.close(); } } catch (IOException e) { e.printStackTrace(); } X509EncodedKeySpec keySpec = new X509EncodedKeySpec(mDecode); PKCS8EncodedKeySpec pkeySpec = new PKCS8EncodedKeySpec(mPriDecode); RSAPrivateKey privateKey = null; RSAPublicKey rsap = null; KeyFactory keyFactory; try { keyFactory = KeyFactory.getInstance("RSA"); rsap = (RSAPublicKey) keyFactory.generatePublic(keySpec); privateKey = (RSAPrivateKey) keyFactory.generatePrivate(pkeySpec); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (InvalidKeySpecException e) { e.printStackTrace(); } String str = mTextContent.getText().toString().trim(); byte[] encrypt = CryptUtil.rsaEncrypt(str.getBytes(), rsap); String es = Base64.encodeToString(encrypt, Base64.NO_WRAP); mTxtResult.setText(es); byte[] dd = Base64.decode(es, Base64.NO_WRAP); byte[] data = CryptUtil.rsaDecrypt(dd, privateKey); String s1 = new String(data); Log.d("RSA", "RSACry : " + s1); } }
加密工具类
public class CryptUtil {
private CryptUtil() {
}
/**
* DES 加密算法
*
* @param data 原始数据
* @param key 密码，必须是8个字节
* @return byte[] 经过加密之后的内容
*/
public static byte[] desEncrypt(byte[] data, byte[] key) {
byte[] ret = null;
if (data != null && key != null) {
if (data.length > 0 && key.length == 8) {
// 1.使用 Cipher引擎，来初始化加密，并且设置密码
try {
Cipher cipher = Cipher.getInstance("DES");
// 1.1 DESKEYSPEC用于描述 的事的密码
DESKeySpec spec = new DESKeySpec(key);
// 1.2使用SecretKeyFactory生成Key对象
SecretKeyFactory des = SecretKeyFactory.getInstance("DES");
SecretKey sk = des.generateSecret(spec);
// 1.3初始化Cipper 为加密I操作，并且制定密钥
cipher.init(Cipher.ENCRYPT_MODE, sk);
// 2.加密数据
ret = cipher.doFinal(data);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
}
return ret;
}
/**
* DES 解密算法
*
* @param data 原始数据
* @param key 密码，必须是8个字节
* @return byte[] 经过解密之后的内容
*/
public static byte[] desDecrypt(byte[] data, byte[] key) {
byte[] ret = null;
if (data != null && key != null) {
if (data.length > 0 && key.length == 8) {
// 1.使用 Cipher引擎，来初始化解密，并且设置密码
try {
Cipher cipher = Cipher.getInstance("DES");
// 1.1 DESKEYSPEC用于描述 的事的密码
DESKeySpec spec = new DESKeySpec(key);
// 1.2使用SecretKeyFactory生成Key对象
SecretKeyFactory des = SecretKeyFactory.getInstance("DES");
SecretKey sk = des.generateSecret(spec);
// 1.3初始化Cipper 为解密操作，并且制定密钥
cipher.init(Cipher.DECRYPT_MODE, sk);
// 2.解密数据
ret = cipher.doFinal(data);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
}
return ret;
}
///////////////////////////////////////////////////////////////////////////
// AES方式
///////////////////////////////////////////////////////////////////////////
public static byte[] aesEncrySimple(byte[] data, byte[] key) {
byte[] ret = null;
if (data != null && key != null) {
if (data.length > 0 && key.length == 16) {
// AES 128bit = 16nytes
try {
Cipher cipher = Cipher.getInstance("AES");
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
cipher.init(Cipher.ENCRYPT_MODE, keySpec);
ret = cipher.doFinal(data);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
}
return ret;
}
public static byte[] aesDecrySimple(byte[] data, byte[] key) {
byte[] ret = null;
if (data != null && key != null) {
if (data.length > 0 && key.length == 16) {
// AES 128bit = 16nytes
try {
Cipher cipher = Cipher.getInstance("AES");
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
cipher.init(Cipher.DECRYPT_MODE, keySpec);
ret = cipher.doFinal(data);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
}
return ret;
}
///////////////////////////////////////////////////////////////////////////
// AES 方式2 使用两套密码
///////////////////////////////////////////////////////////////////////////
/**
* 使用两套密码的加密，强度更高
*
* @param data 数据
* @param key 第一个密码
* @param ivData 第二个密码
* @return
*/
public static byte[] aesEncryptWithIv(byte[] data, byte[] key, byte[] ivData) {
byte[] ret = null;
if (data != null && key != null && ivData != null) {
if (data.length > 0 && key.length == 16 && ivData.length == 16) {
//使用两套密码的，算法需要写成AES/算法模式/填充模式
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//准备第一套
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
//准备第二套密码
IvParameterSpec iv = new IvParameterSpec(ivData);
cipher.init(Cipher.ENCRYPT_MODE, keySpec, iv);
// ret = cipher.doFinal(data);
cipher.update(data);
ret = cipher.doFinal();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
}
return ret;
}
public static byte[] aesDecryptWithIv(byte[] data, byte[] key, byte[] ivData) {
byte[] ret = null;
if (data != null && key != null && ivData != null) {
if (data.length > 0 && key.length == 16 && ivData.length == 16) {
//使用两套密码的，算法需要写成AES/算法模式/填充模式
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//准备第一套
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
//准备第二套密码
IvParameterSpec iv = new IvParameterSpec(ivData);
cipher.init(Cipher.DECRYPT_MODE, keySpec, iv);
// ret = cipher.doFinal(data);
cipher.update(data);
ret = cipher.doFinal();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
}
return ret;
}
///////////////////////////////////////////////////////////////////////////
// RSA
///////////////////////////////////////////////////////////////////////////
// 1.生成密钥对， 公钥和私钥
/**
* bits 位数必须在 1024 和 2048 之间
*
* @param bits
* @return
*/
public static KeyPair generateRsaKey(int bits) {
KeyPair ret = null;
try {
KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
kpg.initialize(bits);
ret = kpg.generateKeyPair();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return ret;
}
/**
* RSA 加密，使用公钥加密，那么必须使用私钥解密
* 使用私钥加密，必须使用公钥解密
*
* @param data
* @param key
* @return
*/
public static byte[] rsaEncrypt(byte[] data, Key key) {
byte[] ret = null;
if (data != null && data.length > 0 && key != null) {
try {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, key);
ret = cipher.doFinal(data);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
return ret;
}
//解密
public static byte[] rsaDecrypt(byte[] data, Key key) {
byte[] ret = null;
if (data != null && data.length > 0 && key != null) {
try {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, key);
ret = cipher.doFinal(data);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
}
return ret;
}
}