在IOS上加密/解密图像
我们正在使用加密/解密和UIIMAGE。 如果我们加密和解密和UIIMAge没有保存到iphone库，它工作正常但是如果我们加密，保存到库中，加载（图像加密）到应用程序并解密它工作不好。
我们使用此function来加密/解密/保存/加载
//加密
UIImage *image = self.imageView.image; CGContextRef ctx; CGImageRef imageRef = [image CGImage]; NSUInteger width = CGImageGetWidth(imageRef); NSUInteger height = CGImageGetHeight(imageRef); CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); unsigned char *rawData = malloc(height * width * 4); int valor =(height * width * 4); NSUInteger bytesPerPixel = 4; NSUInteger bytesPerRow = bytesPerPixel * width; NSUInteger bitsPerComponent = 8; CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); CGColorSpaceRelease(colorSpace); CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef); CGContextRelease(context); NSData *data = [NSData dataWithBytes:(const void *)rawData length:sizeof(unsigned char)*valor]; NSData *encryptedData = [data AES256EncryptWithKey:@"\"thisIsASecre"]; rawData = [encryptedData bytes]; NSData *dataData2 = [NSData dataWithBytes:rawData length:sizeof(rawData)]; ctx = CGBitmapContextCreate(rawData, CGImageGetWidth( imageRef ), CGImageGetHeight( imageRef ), 8, CGImageGetBytesPerRow( imageRef ), CGImageGetColorSpace( imageRef ), kCGImageAlphaPremultipliedLast ); imageRef = CGBitmapContextCreateImage (ctx); UIImage *rawImage = [UIImage imageWithCGImage:imageRef]; self.imageView.image = rawImage; UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil); CGContextRelease(ctx); //解密
UIImage *image = self.imageView.image; CGContextRef ctx; CGImageRef imageRef = [image CGImage]; NSUInteger width = CGImageGetWidth(imageRef); NSUInteger height = CGImageGetHeight(imageRef); CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); unsigned char *rawData = malloc(height * width * 4); int valor =(height * width * 4); NSUInteger bytesPerPixel = 4; NSUInteger bytesPerRow = bytesPerPixel * width; NSUInteger bitsPerComponent = 8; CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); CGColorSpaceRelease(colorSpace); CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef); CGContextRelease(context); NSData *data = [NSData dataWithBytes:(const void *)rawData length:sizeof(unsigned char)*valor]; NSData *encryptedData = [data AES256DecryptWithKey:@"\"thisIsASecre"]; rawData = [encryptedData bytes]; ctx = CGBitmapContextCreate(rawData, CGImageGetWidth( imageRef ), CGImageGetHeight( imageRef ), 8, CGImageGetBytesPerRow( imageRef ), CGImageGetColorSpace( imageRef ), kCGImageAlphaPremultipliedLast ); imageRef = CGBitmapContextCreateImage (ctx); UIImage *rawImage = [UIImage imageWithCGImage:imageRef]; self.imageView.image = rawImage; image = rawImage; UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil); CGContextRelease(ctx);
//加载图片
UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker animated:YES completion:NULL]; - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { self.imageView.image = [info objectForKey:@"UIImagePickerControllerOriginalImage"]; [picker dismissViewControllerAnimated:YES completion:NULL]; }
//我用来加密/解密的clases
- (NSData *)AES256EncryptWithKey:(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 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 { // '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; }
有人知道这是什么问题吗？
Thxs！
如果将位图图像保存到照片库，则会将其存储为JPG。 JPG的有损格式将完全影响您的加密过程。 尝试将位图图像转换为PNG图像，然后保存：
UIImage* pngImage = [UIImage imageWithData:UIImagePNGRepresentation(rawImage)]; UIImageWriteToSavedPhotosAlbum(pngImage, nil, nil, NULL);