Java 工具类之 AES 加解密

不念不忘少年蓝@ 2023-06-14 14:57 28阅读 0赞

import lombok.Setter;
    import lombok.extern.slf4j.Slf4j;
    
    import javax.crypto.Cipher;
    import javax.crypto.KeyGenerator;
    import javax.crypto.SecretKey;
    import java.nio.charset.StandardCharsets;
    import java.security.Key;
    import java.security.NoSuchAlgorithmException;
    import java.security.SecureRandom;
    
    /** * @author potoyang * Description: AES 加解密工具类 */
    @Slf4j
    class AESUtil { 
    
        private static final String DEFAULT_CIPHER_ALGORITHM = "AES";
    
        @Setter
        private String content;
    
        private String secret;
    
        AESUtil(String content) { 
            this.content = content;
            this.secret = "324iu23094u598ndsofhsiufhaf_+0wq-42q421jiosadiusadiasd";
        }
    
        /** * AES 加密 */
        String encrypt() { 
            try { 
                Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
                Key key = getKey();
                cipher.init(Cipher.ENCRYPT_MODE, key);
                byte[] result = cipher.doFinal(content.getBytes(StandardCharsets.UTF_8));
                return byte2hex(result);
            } catch (Exception e) { 
                log.error("AES 加密出错: [{}]", e.getMessage());
            }
            return null;
        }
    
        /** * AES 解密 */
        String decrypt() { 
            if (content.length() < 1) { 
                return null;
            }
    
            try { 
                Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
                Key key = getKey();
                cipher.init(Cipher.DECRYPT_MODE, key);
                byte[] original = cipher.doFinal(hex2byte(content));
                return new String(original, StandardCharsets.UTF_8);
            } catch (Exception e) { 
                log.error("AES 解密出错: [{}]", e.getMessage());
            }
            return null;
        }
    
        private Key getKey() { 
            SecretKey key = null;
            try { 
                KeyGenerator generator = KeyGenerator.getInstance("AES");
                SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
                random.setSeed(secret.getBytes());
                generator.init(128, random);
                key = generator.generateKey();
            } catch (NoSuchAlgorithmException e) { 
                e.printStackTrace();
            }
            return key;
        }
        
        private byte[] hex2byte(String strhex) { 
            if (strhex == null) { 
                return null;
            }
            int len = strhex.length();
            if (len % 2 == 1) { 
                return null;
            }
            byte[] b = new byte[len / 2];
            for (int i = 0; i != len / 2; i++) { 
                b[i] = (byte) Integer.parseInt(strhex.substring(i * 2, i * 2 + 2), 16);
            }
            return b;
        }
    
        private static String byte2hex(byte[] b) { 
            StringBuilder hs = new StringBuilder();
            String stmp;
            for (byte value : b) { 
                stmp = (Integer.toHexString(value & 0XFF));
                if (stmp.length() == 1) { 
                    hs.append("0").append(stmp);
                } else { 
                    hs.append(stmp);
                }
            }
            return hs.toString().toUpperCase();
        }
    }