AES256加密/解密错误+ IOS SDK 7 [英] AES256 Encryption/Decryption Error+ IOS SDK 7

问题描述

我正在使用AES256的安全性和存储数据的加密形式，这在IOS 6及更低版本中正常工作，但是当我在IOS 7中测试了我的应用程序时，我没有收到我之前存储的数据。调试之后，我发现解密不起作用是IOS 7并返回空白。

我的代码如下：

<$ （NSData *）AES256DecryptWithKey：（NSString *）键{
//'key'应为AES256的32个字节，否则为零填充

char keyPtr [kCCKeySizeAES256 + 1]; //终结者的空间（未使用）


bzero（keyPtr，sizeof（keyPtr））; //填充零（用于填充）
//获取密钥数据
[key getCString：keyPtr maxLength：sizeof（keyPtr）encoding：NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
//参见文档：对于块密码，输出大小始终小于或等于输入大小加上一个块的大小。
//这就是为什么我们需要在这里添加一个块的大小
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void * buffer = malloc（bufferSize）;
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt（kCCDecrypt，kCCAlgorithmAES128，kCCOptionPKCS7Padding，
keyPtr，kCCKeySizeAES256，
NULL / *初始化向量（可选）* /，
[self bytes]，dataLength， * input * /
buffer，bufferSize，/ * output * /
& numBytesDecrypted）;
if（cryptStatus == kCCSuccess）{
//返回的NSData取得缓冲区的所有权，并在释放后释放
return [NSData dataWithBytesNoCopy：buffer length：numBytesDecrypted];
}
free（buffer）; //释放缓冲区;
return nil;

}

在IOS 7中再次获取我的数据？

谢谢

解决方案

找到关于 Apple Devforums 上的此问题的解决方案。

   - （NSData *）encrypt：（NSString *）key {
 //'key'应该是32字节对于AES256，将以零填充方式
 char keyPtr [kCCKeySizeAES256 + 1]; //用于终结器的空间（未使用）
 bzero（keyPtr，sizeof（keyPtr））; //填充零（用于填充）
 
 BOOL patchNeeded =（[key length]> kCCKeySizeAES256）; 
 if（patchNeeded）{
 key = [key substringToIndex：kCCKeySizeAES256]; //确保该键不再长于需要的（kCCKeySizeAES256）
} 
 
 //获取密钥数据
 [key getCString：keyPtr maxLength：sizeof（keyPtr）encoding ：NSUTF8StringEncoding]; 
 
 if（patchNeeded）{
 keyPtr [0] ='\0'; //以前的iOS版本比iOS7设置第一个字符为'\0'，如果键长于kCCKeySizeAES256 
} 
 
 NSUInteger dataLength = [self length]; 
 
 //查看文档：对于块密码，输出大小始终小于或等于输入大小加上一个块的大小。 
 //这就是为什么我们需要在这里添加一个块的大小
 size_t bufferSize = dataLength + kCCBlockSizeAES128; 
 void * buffer = malloc（bufferSize）; 
 
 size_t numBytesEncrypted = 0; 
 CCCryptorStatus cryptStatus = CCCrypt（kCCEncrypt，kCCAlgorithmAES128，kCCOptionPKCS7Padding，
 keyPtr，kCCKeySizeAES256，
 NULL / *初始化向量（可选）* /，
 [self bytes]，dataLength， * input * / 
 buffer，bufferSize，/ * output * / 
& numBytesEncrypted）; 
 if（cryptStatus == kCCSuccess）{
 //返回的NSData获取缓冲区的所有权，并在释放后释放它
 return [NSData dataWithBytesNoCopy：buffer length：numBytesEncrypted]; 
} 
 
 free（buffer）; //释放缓冲区; 
 return nil; 
} 
  

当然，复制粘贴相同的修补程序用于解密方法。 >

I am using AES256 for security and store data in encryption form which is working fine in IOS 6 and below but when i have tested my app in IOS 7, I am not getting my data which was store previously. After debugs, i found decryption is not working is IOS 7 and return blank.

My Code as below:

- (NSData *)AES256DecryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise

char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)


bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
// fetch key data
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
 NSUInteger dataLength = [self length];
//See the doc: For block ciphers, the output size will always be less than or
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                                      keyPtr, kCCKeySizeAES256,
                                      NULL /* initialization vector (optional) */,
                                      [self bytes], dataLength, /* input */
                                      buffer, bufferSize, /* output */
                                      &numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
    //the returned NSData takes ownership of the buffer and will free it on deallocation
    return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer); //free the buffer;
return nil;

}

Can you please help to get my data again in IOS 7?

Thanks

解决方案

Found the solution on this problem on Apple Devforums.

- (NSData *)encrypt:(NSString *)key {
 // 'key' should be 32 bytes for AES256, will be null-padded otherwise
 char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
 bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

 BOOL patchNeeded = ([key length] > kCCKeySizeAES256);
 if (patchNeeded) {
      key = [key substringToIndex:kCCKeySizeAES256]; // Ensure that the key isn't longer than what's needed (kCCKeySizeAES256)
 }

 // fetch key data
 [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

 if (patchNeeded) {
      keyPtr[0] = '\0';  // Previous iOS version than iOS7 set the first char to '\0' if the key was longer than kCCKeySizeAES256
 }

 NSUInteger dataLength = [self length];

 //See the doc: For block ciphers, the output size will always be less than or
 //equal to the input size plus the size of one block.
 //That's why we need to add the size of one block here
 size_t bufferSize = dataLength + kCCBlockSizeAES128;
 void *buffer = malloc(bufferSize);

 size_t numBytesEncrypted = 0;
 CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                                                keyPtr, kCCKeySizeAES256,
                                                NULL /* initialization vector (optional) */,
                                                [self bytes], dataLength, /* input */
                                                buffer, bufferSize, /* output */
                                                &numBytesEncrypted);
 if (cryptStatus == kCCSuccess) {
      //the returned NSData takes ownership of the buffer and will free it on deallocation
      return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
 }

 free(buffer); //free the buffer;
 return nil;
}

Of course, copy paste the same patch for the decrypt method.

这篇关于AES256加密/解密错误+ IOS SDK 7的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！