针对java代码的AES加密对象c计数器部分

Question

我想将下面的Java aes加密转换为目标c。任何在Java和Objective C都有知识的人请帮忙。任何帮助将不胜感激。任何人都可以通过提供使用的加密方法的细节来提供帮助

import java.io.IOException; 
    import java.security.InvalidAlgorithmParameterException; 
    import java.security.InvalidKeyException; 
    import java.security.MessageDigest; 
    import java.security.NoSuchAlgorithmException; 

    import javax.crypto.BadPaddingException; 
    import javax.crypto.Cipher; 
    import javax.crypto.IllegalBlockSizeException; 
    import javax.crypto.NoSuchPaddingException; 
    import javax.crypto.SecretKey; 
    import javax.crypto.spec.IvParameterSpec; 
import javax.crypto.spec.SecretKeySpec; 

public class Crypto { 
    public static final String TAG = Crypto.class.getSimpleName(); 
    // Replace me with a 16-byte key, share between Java and C# 
    private static Cipher aesCipher; 
    private static SecretKey secretKey; 
    private static IvParameterSpec ivParameterSpec; 
    private static String CIPHER_TRANSFORMATION = "AES/CBC/PKCS5Padding"; 
    private static String CIPHER_ALGORITHM = "AES"; 
    private static byte[] rawSecretKey = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 

    // private static String MESSAGEDIGEST_ALGORITHM = "MD5"; 
    private static String MESSAGEDIGEST_ALGORITHM = "SHA-256"; 

    public Crypto(String passphrase) { 
     byte[] passwordKey = encodeDigest(passphrase); 

     try { 
      aesCipher = Cipher.getInstance(CIPHER_TRANSFORMATION); 
     } catch (NoSuchAlgorithmException e) { 
      Log.e(TAG, "No such algorithm " + CIPHER_ALGORITHM, e); 
     } catch (NoSuchPaddingException e) { 
      Log.e(TAG, "No such padding PKCS5", e); 
     } 

     secretKey = new SecretKeySpec(passwordKey, CIPHER_ALGORITHM); 
     ivParameterSpec = new IvParameterSpec(rawSecretKey); 
    } 

    public byte[] decrypt(byte[] clearData) { 
     try { 
      aesCipher.init(Cipher.DECRYPT_MODE, secretKey); 
     } catch (InvalidKeyException e) { 
      e.printStackTrace(); 
     } 

     byte[] decryptedData; 

     try { 
      decryptedData = aesCipher.doFinal(clearData); 
     } catch (IllegalBlockSizeException e) { 
      e.printStackTrace(); 
      return null; 
     } catch (BadPaddingException e) { 
      e.printStackTrace(); 
      return null; 
     } 
     return decryptedData; 

    } 

    public String decryptAsBase64(byte[] clearData) throws IOException { 
     byte[] decryptedData = decrypt(clearData); 
     return new String(Base64New.decode(decryptedData)); 
    } 

    public String encryptAsBase64(byte[] clearData) { 
     byte[] encryptedData = encrypt(clearData); 
     return Base64New.encodeBytes(encryptedData); 
    } 

    public byte[] encrypt(byte[] clearData) { 
     try { 
      aesCipher.init(Cipher.ENCRYPT_MODE, secretKey, ivParameterSpec); 
     } catch (InvalidKeyException e) { 
      Log.e(TAG, "Invalid key", e); 
      return null; 
     } catch (InvalidAlgorithmParameterException e) { 
      Log.e(TAG, "Invalid algorithm " + CIPHER_ALGORITHM, e); 
      return null; 
     } 

     byte[] encryptedData; 
     try { 
      encryptedData = aesCipher.doFinal(clearData); 
     } catch (IllegalBlockSizeException e) { 
      Log.e(TAG, "Illegal block size", e); 
      return null; 
     } catch (BadPaddingException e) { 
      Log.e(TAG, "Bad padding", e); 
      return null; 
     } 
     return encryptedData; 
    } 

    private byte[] encodeDigest(String text) { 
     MessageDigest digest; 
     try { 
      digest = MessageDigest.getInstance(MESSAGEDIGEST_ALGORITHM); 
      return digest.digest(text.getBytes()); 
     } catch (NoSuchAlgorithmException e) { 
      Log.e(TAG, "No such algorithm " + MESSAGEDIGEST_ALGORITHM, e); 
     } 

     return null; 
    } 
} 

Answer 1

下面是加密方法中使用的细节：

加密是AES CBC模式与PKCS＃5填充（PKCS＃7填充是这里相同）。

CBC模式有一个iv作为输入，iv是rawSecretKey这是全0字节（不是最佳实践）。

加密passwordKey使用SHA-256（不是最佳实践）从secretKey派生而来。

此外还有一些方法可以添加和删除Base64编码。