以下是網上普遍能收到的JAVA AES加密解密方法。

因為裏面用到了KeyGenerator 和 SecureRandom，但是.NET 裏面沒有這2個類。無法使用安全隨機數生成KEY。

我們在接收JAVA發送的AES加密字符串後，在.NET沒有對應的KeyGenerator 和 SecureRandom去生成AES 的 KEY值，導致無法直接解密。

 1 import java.security.SecureRandom;
 2 import java.util.Base64;
 3 
 4 import javax.crypto.Cipher;
 5 import javax.crypto.KeyGenerator;
 
 6 import javax.crypto.SecretKey;
 7 import javax.crypto.spec.SecretKeySpec;
 8 
 9 public class javaaes {
10     public static void main(String[] args) throws Exception{
11         byte[] a = AesEncrypt("123456".getBytes(),"abcd1234");
12         System.out.println(new String(Base64.getEncoder().encodeToString(a)));
 
13     }
14     //AES加密
15     public static byte[] AesEncrypt(byte[] byteContent, String password) throws Exception {
16         
17         KeyGenerator kgen = KeyGenerator.getInstance("AES");
18         SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
19         secureRandom.setSeed(password.getBytes());
 
20         kgen.init(128, secureRandom);
21 
22         SecretKey secretKey = kgen.generateKey();
23         byte[] enCodeFormat = secretKey.getEncoded();//AES加密實際的Key值        
24         //如果直接enCodeFormat=password.getBytes(),那.NET直接就可以解密
25 
26         SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
27 
28         Cipher cipher = Cipher.getInstance("AES");
29 
30         cipher.init(Cipher.ENCRYPT_MODE, key);
31         return cipher.doFinal(byteContent);
32     }
33     //AES解密
34     public static byte[] AesDecrypt(byte[] byteContent, String password) throws Exception {
35         KeyGenerator kgen = KeyGenerator.getInstance("AES");
36         SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
37         secureRandom.setSeed(password.getBytes());
38         kgen.init(128, secureRandom);
39         
40         SecretKey secretKey = kgen.generateKey();
41         byte[] enCodeFormat = secretKey.getEncoded();
42         
43         SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
44         Cipher cipher = Cipher.getInstance("AES");
45         cipher.init(Cipher.DECRYPT_MODE, key);
46         return cipher.doFinal(byteContent);
47     }
48 
49 }

第一種方法是，在JAVA中將AES的密鑰直接生成出實際的key值，在.NET中用這個實際的key去解密。

 1     public static void main(String[] args) throws Exception{
 2         String password = "1234567890";//AES的密鑰
 3         KeyGenerator kgen = KeyGenerator.getInstance("AES");
 4         SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
 5         secureRandom.setSeed(password.getBytes());
 6         kgen.init(128, secureRandom);
 7 
 8         SecretKey secretKey = kgen.generateKey();
 9         byte[] enCodeFormat = secretKey.getEncoded();//AES加密實際的Key值
10         System.out.println(new String(Base64.getEncoder().encodeToString(enCodeFormat)));
11     }

 1         /// <summary>
 2         /// AES解密
 3         /// </summary>
 4         /// <param name="data"></param>
 5         /// <param name="key"></param>
 6         /// <returns></returns>
 7         public static string DeAES(byte[] content, string key)
 8         {
 9             using (AesCryptoServiceProvider aesProvider = new AesCryptoServiceProvider())
10             {
11                 aesProvider.Key = Convert.FromBase64String(key);
12                 aesProvider.Mode = CipherMode.ECB;
13                 aesProvider.Padding = PaddingMode.PKCS7;
14                 using (ICryptoTransform cryptoTransform = aesProvider.CreateDecryptor())
15                 {
16                     byte[] inputBuffers = content;
17                     byte[] results = cryptoTransform.TransformFinalBlock(inputBuffers, 0, inputBuffers.Length);
18                     aesProvider.Clear();
19                     return Encoding.UTF8.GetString(results);
20                 }
21             }
22         }

第二種方法是，下載IKVM ，解壓縮後在VS的項目中引用bin目錄下的IKVM.OpenJDK.Core.dll、IKVM.OpenJDK.Security.dll

 1 using java.security;
 2 using javax.crypto;
 3 using System.Security.Cryptography;
 4 using System.Text;
 5 using System;
 6 
 7 public class Program
 8 {
 9     public static void Main()
10     {
11         byte[] a = Convert.FromBase64String("W0fSdgixanavXMiDdPXa/Q==");
12         string result = DeAES(a, "abcd1234");
13         Console.WriteLine(result);
14         Console.Read();
15     }
16     /// <summary>
17     /// AES解密
18     /// </summary>
19     /// <param name="data"></param>
20     /// <param name="key"></param>
21     /// <returns></returns>
22     public static string DeAES(byte[] content, string key)
23     {
24         KeyGenerator kgen = KeyGenerator.getInstance("AES");
25         SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
26         secureRandom.setSeed(Encoding.ASCII.GetBytes(key));
27         kgen.init(128, secureRandom);
28         SecretKey secretKey = kgen.generateKey();
29         byte[] enCodeFormat = secretKey.getEncoded();
30 
31         using (AesCryptoServiceProvider aesProvider = new AesCryptoServiceProvider())
32         {
33             aesProvider.Key = enCodeFormat;
34             aesProvider.Mode = CipherMode.ECB;
35             aesProvider.Padding = PaddingMode.PKCS7;
36             using (ICryptoTransform cryptoTransform = aesProvider.CreateDecryptor())
37             {
38                 byte[] inputBuffers = content;
39                 byte[] results = cryptoTransform.TransformFinalBlock(inputBuffers, 0, inputBuffers.Length);
40                 aesProvider.Clear();
41                 return Encoding.UTF8.GetString(results);
42             }
43         }
44     }
45 
46 }

C# 實現 JAVA AES加密解密[原創]