android 应用AES技术加密/解密字符串

待我称王封你为后i 2022-06-17 07:46 195阅读 0赞

package common;
    
    import java.security.SecureRandom;   
    
    import javax.crypto.Cipher;   
    import javax.crypto.KeyGenerator;   
    import javax.crypto.SecretKey;   
    import javax.crypto.spec.SecretKeySpec;   
      
    /**  
     加密 – 
     1.String encryptingCode = SimpleCrypto.encrypt(masterPassword,originalText);
    
    
    解密 – 
     1.String originalText = SimpleCrypto.decrypt(masterpassword, encryptingCode);
    
    
     masterpassword: 密码。
     encryptingCode：加密后的字符串。
     originalText: 需要加密的字符串。
     */  
    public class AES {   
      
        public static String encrypt(String seed, String cleartext) throws Exception {   
            byte[] rawKey = getRawKey(seed.getBytes());   
            byte[] result = encrypt(rawKey, cleartext.getBytes());   
            return toHex(result);   
        }   
           
        public static String decrypt(String seed, String encrypted) throws Exception {   
            byte[] rawKey = getRawKey(seed.getBytes());   
            byte[] enc = toByte(encrypted);   
            byte[] result = decrypt(rawKey, enc);   
            return new String(result);   
        }   
      
        private static byte[] getRawKey(byte[] seed) throws Exception {   
            KeyGenerator kgen = KeyGenerator.getInstance("AES");   
            SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");   
            sr.setSeed(seed);   
            kgen.init(128, sr); // 192 and 256 bits may not be available   
            SecretKey skey = kgen.generateKey();   
            byte[] raw = skey.getEncoded();   
            return raw;   
        }   
      
           
        private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {   
            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");   
            Cipher cipher = Cipher.getInstance("AES");   
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec);   
            byte[] encrypted = cipher.doFinal(clear);   
            return encrypted;   
        }   
      
        private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {   
            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");   
            Cipher cipher = Cipher.getInstance("AES");   
            cipher.init(Cipher.DECRYPT_MODE, skeySpec);   
            byte[] decrypted = cipher.doFinal(encrypted);   
            return decrypted;   
        }   
      
        public static String toHex(String txt) {   
            return toHex(txt.getBytes());   
        }   
        public static String fromHex(String hex) {   
            return new String(toByte(hex));   
        }   
           
        public static byte[] toByte(String hexString) {   
            int len = hexString.length()/2;   
            byte[] result = new byte[len];   
            for (int i = 0; i < len; i++)   
                result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();   
            return result;   
        }   
      
        public static String toHex(byte[] buf) {   
            if (buf == null)   
                return "";   
            StringBuffer result = new StringBuffer(2*buf.length);   
            for (int i = 0; i < buf.length; i++) {   
                appendHex(result, buf[i]);   
            }   
            return result.toString();   
        }   
        private final static String HEX = "0123456789ABCDEF";   
        private static void appendHex(StringBuffer sb, byte b) {   
            sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));   
        }   
           
    }

原文地址:[http://hi.baidu.com/1018834925/blog/item/62a6c146b869ad24869473c1.html][http_hi.baidu.com_1018834925_blog_item_62a6c146b869ad24869473c1.html]

[http_hi.baidu.com_1018834925_blog_item_62a6c146b869ad24869473c1.html]: http://hi.baidu.com/1018834925/blog/item/62a6c146b869ad24869473c1.html