解决Linux操作系统下AES解密失败的问题
windows上加解密正常,linux上加密正常,解密时发生如下异常:
javax.crypto.BadPaddingException: Given final block not properly padded
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)
at javax.crypto.Cipher.doFinal(DashoA13*..)
at chb.test.crypto.AESUtils.crypt(AESUtils.java:386)
at chb.test.crypto.AESUtils.AesDecrypt(AESUtils.java:254)
at chb.test.crypto.AESUtils.main(AESUtils.java:40)
解决方法:
经过检查之后,定位在生成KEY的方法上,如下:
- public static SecretKey getKey (String strKey) {
- try {
- KeyGenerator _generator = KeyGenerator.getInstance( "AES" );
- _generator.init(128, new SecureRandom(strKey.getBytes()));
- return _generator.generateKey();
- } catch (Exception e) {
- throw new RuntimeException( " 初始化密钥出现异常 " );
- }
- }
修改到如下方式,问题解决:
- public static SecretKey getKey(String strKey) {
- try {
- KeyGenerator _generator = KeyGenerator.getInstance( "AES" );
- SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );
- secureRandom.setSeed(strKey.getBytes());
- _generator.init(128,secureRandom);
- return _generator.generateKey();
- } catch (Exception e) {
- throw new RuntimeException( " 初始化密钥出现异常 " );
- }
- }
原因分析
SecureRandom 实现完全隨操作系统本身的內部狀態,除非調用方在調用 getInstance 方法之後又調用了 setSeed 方法;该实现在 windows 上每次生成的 key 都相同,但是在 solaris 或部分 linux 系统上则不同。