java数据的加解密(RSA与AES)

RSA为不对称的加密算法，用公钥加密、私钥解密，一般用于加密数据量不是很大的数据，比如加密密钥，比如数据签名、验证。

AES为对称加密，非对齐的加密数据长度亦要至少能被16整除，密码也至少16位，如果用128位CBC方式，还要提个一个初始向量iv，亦要是16位。

利用空档时间手写了一个cipher库
pom引用

  io.github.tiger822
  cipher
  1.0

	KeyPair keyPair= RSAUtil.buildKeyPair();
    String publicKeyStr= base64Utils.encode( keyPair.getPublic().getEncoded());
    String privateKeyStr= base64Utils.encode(keyPair.getPrivate().getEncoded());
    System.out.println("public key:"+publicKeyStr);
    System.out.println("private key:"+privateKeyStr);
    CipherUtil cipher1=new RSAUtil(publicKeyStr);
    cipher1.initCipher();
    String rawText="我是要加密的字符串，This is a string that needs to be encrypted";
    byte[] encrypted= cipher1.encrypt(rawText.getBytes());
    System.out.println("加密后的内容："+base64Utils.encode(encrypted));
    byte[] e2=cipher1.encrypt("String 2".getBytes());

    CipherUtil cipher2=new RSAUtil((RSAPrivateCrtKey) keyPair.getPrivate());
    cipher2.initCipher();
    String plaintext=new String(cipher2.decrypt(encrypted));
    System.out.println("解密后的明文:"+plaintext);
    System.out.println(new String(cipher2.decrypt(e2)));

	String test="this the string that need to protect";
    KeyPair keyPair= RSAUtil.buildKeyPair();
    CipherUtil cipherUtil=new RSAUtil((RSAPrivateKey) keyPair.getPrivate());

    byte[] signCode=cipherUtil.sign(test.getBytes());
    System.out.println("签名："+base64Utils.encode(signCode));

    CipherUtil cipherUtil2=new RSAUtil(keyPair.getPublic().getEncoded());
    if (cipherUtil2.verify(signCode,test.getBytes())){
      System.out.println("验证通过");
    }
    if (!cipherUtil2.verify(signCode,(test+".").getBytes())){
      System.out.println("验证失败");
    }

	String rawText="这是加密字符串， I need to encrypt.";
    String password="abcd@1234";
    String iv="123456";
    CipherUtil aes=new AESUtil(password,iv);
    aes.initCipher();
    byte[] secret=null;
    for (int i=0;i<3;i++){
      secret= aes.encrypt(rawText.getBytes());
      System.out.println("AES加密后:"+base64Utils.encode(secret));
    }

    CipherUtil aesDesc=new AESUtil(password,iv);
    aesDesc.initCipher();
    byte[] plaintContent=aesDesc.decrypt(secret);
    System.out.println("解密后："+new String(plaintContent));