java实现的AES秘钥生成算法示例

 import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; public class Test { public static void main(String[] args) { getKey(); getKeyByPass(); } /** * 随机生成秘钥 */ public static void getKey() { try { KeyGenerator kg = KeyGenerator.getInstance("AES"); kg.init(128); //要生成多少位，只需要修改这里即可128, 192或256 SecretKey sk = kg.generateKey(); byte[] b = sk.getEncoded(); String s = byteToHexString(b); System.out.println(s); System.out.println("十六进制密钥长度为"+s.length()); System.out.println("二进制密钥的长度为"+s.length()*4); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); System.out.println("没有此算法。"); } } /** * 使用指定的字符串生成秘钥 */ public static void getKeyByPass() { //生成秘钥 String password="testkey"; try { KeyGenerator kg = KeyGenerator.getInstance("AES"); // kg.init(128);//要生成多少位，只需要修改这里即可128, 192或256 //SecureRandom是生成安全随机数序列，password.getBytes()是种子，只要种子相同，序列就一样，所以生成的秘钥就一样。 kg.init(128, new SecureRandom(password.getBytes())); SecretKey sk = kg.generateKey(); byte[] b = sk.getEncoded(); String s = byteToHexString(b); System.out.println(s); System.out.println("十六进制密钥长度为"+s.length()); System.out.println("二进制密钥的长度为"+s.length()*4); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); System.out.println("没有此算法。"); } } /** * byte数组转化为16进制字符串 * @param bytes * @return */ public static String byteToHexString(byte[] bytes) { StringBuffer sb = new StringBuffer(); for (int i = 0; i  3) { sb.append(strHex.substring(6)); } else { if(strHex.length() <2) { sb.append("0" + strHex); } else { sb.append(strHex); } } } return sb.toString(); } }