RSA加密过程中出现很多问号

错误代码事例

 public static byte[] decryptByPublicKey(byte[] data, String key)   throws Exception {

// 对密钥解密

byte[] keyBytes =decryptBASE64(key);

// 取得公钥

X509EncodedKeySpec x509KeySpec =new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicKey = keyFactory.generatePublic(x509KeySpec);

// 对数据解密

 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

 cipher.init(Cipher.DECRYPT_MODE, publicKey);

return cipher.doFinal(data);

}

正确事例

private static StringRSAC ="RSA/ECB/PKCS1Padding";

 public static byte[] decryptByPublicKey(byte[] data, String key)   throws Exception {

// 对密钥解密

byte[] keyBytes =decryptBASE64(key);

// 取得公钥

 X509EncodedKeySpec x509KeySpec =new X509EncodedKeySpec(keyBytes);

KeyFactorykeyFactory= KeyFactory.getInstance(KEY_ALGORITHM);

Key publicKey =keyFactory.generatePublic(x509KeySpec);

// 对数据解密

Cipher cipher = Cipher.getInstance(RSAC);

cipher.init(Cipher.DECRYPT_MODE, publicKey);

return cipher.doFinal(data);

}