Question

我的java和Objective c加密方法产生不同的输出 - AES128，CBC模式。

键：YnA+lracf9xaiJO1oA/bTQ==
iV：190Dt3MNeL32o9Kd37HZlQ==
纯文本：text to encrypt

Java输出：mHZpz52LOK2K76t3B/EUuA==
Obj C输出：Fb0D46H4tN+ukgI05x/Dbg==

Java代码：

public static String AESEncrypt(String text, String key, String iv) throws Exception {
     Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
     byte[] keyBytes = new byte[16];
     byte[] b = key.getBytes("UTF-8");
     int len = b.length;
     if (len > keyBytes.length)
         len = keyBytes.length;
     System.arraycopy(b, 0, keyBytes, 0, len);

     byte[] keyBytesiv = new byte[16];
     byte[] biv = iv.getBytes("UTF-8");
     int leniv = biv.length;
     if (leniv > keyBytesiv.length)
         leniv = keyBytesiv.length;
     System.arraycopy(biv, 0, keyBytes, 0, len);
     SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
     IvParameterSpec ivSpec = new IvParameterSpec(keyBytesiv);

     cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);

     byte[] results = cipher.doFinal(text.getBytes("UTF-8"));
     BASE64Encoder encoder = new BASE64Encoder();
     return encoder.encode(results);
 }

目标C代码

+ (NSData *)AESOperation:(CCOperation)operation OnData:(NSData *)data key:(NSData *)key iV:(NSData *) iv {

  NSUInteger dataLength = [data length];
  size_t bufferSize = dataLength + kCCBlockSizeAES128;
  void *buffer = malloc(bufferSize);

  size_t numBytesEncrypted = 0;
  CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                      kCCAlgorithmAES128,
                                      kCCOptionPKCS7Padding,
                                      [key bytes],
                                      kCCBlockSizeAES128,
                                      [iv bytes],
                                      [data bytes],
                                      dataLength,
                                      buffer,
                                      bufferSize,
                                      &numBytesEncrypted);
  if (cryptStatus == kCCSuccess) {
     return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
  }

  free(buffer);
  return nil;
}

Answer 1

这样的问题有两种方法可以合并：

作为完整性检查，请尝试使用两种语言解密加密文本并查看其是否与原始文本匹配。
尝试使用其他库（第三个库）并与前两个值进行比较。

所以我尝试使用在线工具解密密文，并且可以使用Objective C输出恢复原始文本（＆＃34;要加密的文本＆＃34;）。它表明Java代码存在问题。我怀疑它可能与输入（key，iv）是base64编码的事实有关，而它似乎只是被视为UTF-8编码（getBytes()调用）。

Answer 2

由于上面的建议，我能够解决java代码的问题。下面是Java代码，它可以帮助我在java和Objective c上实现AES128 CBC模式

public static String AESEncrypt(String text, String key, String iv) throws Exception {

     Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
     byte[] keyBytes = new byte[16];
     byte[] b = new BASE64Decoder().decodeBuffer(key);
     int len = b.length;
     if (len > keyBytes.length)
         len = keyBytes.length;
     System.arraycopy(b, 0, keyBytes, 0, len);

     byte[] keyBytesiv = new byte[16];
     byte[] biv = new BASE64Decoder().decodeBuffer(iv);
     int leniv = biv.length;
     if (leniv > keyBytesiv.length)
         leniv = keyBytesiv.length;
     System.arraycopy(biv, 0, keyBytesiv, 0, len);

     SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
     IvParameterSpec ivSpec = new IvParameterSpec(keyBytesiv);

     cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);

     byte[] results = cipher.doFinal(text.getBytes("UTF-8"));
     BASE64Encoder encoder = new BASE64Encoder();
     return encoder.encode(results);
 }

Java和Objective C中的AES128 CBC加密提供不同的输出

2 个答案: