2013-08-06 17 views
2

我嘗試使用CCCrypt方法上的Xcode 5的工作,但它已經從XCode4和XCode5CCCrypt不是IOS 7

- (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; 
} 

不同的結果,當我把這種方法與此線......不同的結果

NSString *password = @"E7VRcIXn8yb2Ab+t/in9UzRof6vOpOYebgKbpt1GOcfDF8rpc5nZXngx1G8QfbDqsVrwZw26609GVwruUBrOirCI/WUT8U87fbD6lSy/zPwFIYC113LgXIEylYgzIWO4"; 
    NSString *pwd = [password AES256DecryptWithKey: @"abcd"]; 
    if (pwd) { 
     NSString *checkKey = @"0sSBf7Ncyov+uzvDikOBiA=="; 
     NSString *uncryptChk = [checkKey AES256DecryptWithKey: pwd]; 

在XCode4中,結果是"abcd",而在XCode5中結果是""

+2

請注意,由於iOS 7仍處於NDA之下,因此您不得在官方Apple Developers論壇之外討論此問題。我建議你把它發佈在那裏,因爲你會有更多的運氣獲得真正的答案。 – rckoenes

+0

嗨,你找到它的任何解決方案....? – Hindu

回答

2

自己跑進這個問題。似乎他們修正了從iOS6到iOS7的一個錯誤:[NSString keyCString:maxLength:encoding] iOS6上的舊方法會切斷部分緩衝區以填充keyPtr。

一個簡單的辦法是增加keyPTr大小

char keyPtr = kCCKeySizeAES256 * 2 + 1; 

但是需要記住的是,當你升級應用形式6〜7,而它應該工作。 keyCString會截斷長度以匹配keyPtr的大小。並用0替換第一個字符。所以要確保它在兩個平臺上都能正常工作。添加上面的代碼,並設置keyPtr [0] = 0;