AES256Encryption 在 64 位设备上返回零数据

Question

我正在使用 AES256 使用密钥进行加密和解密。一切正常，我在 iPhone5 上得到了完美的结果，但是当我尝试在 iPhone6 上使用它时，6+ 模拟器返回给我 nil 数据。是64位的问题吗？不确定。

我正在使用这两种方法来加密和解密数据。

我的密钥长度是 44，我传递它来加密和解密数据。

- (NSData *)AES256EncryptWithKey:(NSString *)key {

BOOL LongKey = NO;
// '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 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;
}



- (NSData *)AES256DecryptWithKey:(NSString *)key {

BOOL LongKey = NO;
// '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;
}

我已经尝试通过修改这些方法如下。但没有成功。

- (NSData *)AES256EncryptWithKey:(NSString *)key {

BOOL LongKey = NO;
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
if (key.length>32)
{
    LongKey = YES;
    key = [key substringToIndex:32];
}
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];

if (LongKey) {
    keyPtr[0]= 0;
}
keyPtr[32]= 0;

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;
}


- (NSData *)AES256DecryptWithKey:(NSString *)key {

BOOL LongKey = NO;
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
if (key.length>32)
{
    LongKey = YES;
    key = [key substringToIndex:32];
}
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];

if (LongKey) {
    keyPtr[0]= 0;
}
keyPtr[32]= 0;

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;
}

您能否提出建议，这里可能是什么问题？ 谢谢。

Answer 1

您必须在真实设备上进行测试。这对我们来说在模拟器上也失败了（Xcode5/6）