private async Task <DocumentFile> BuildFromFileAsync(IFormFile file)
{
// detect image dimensions
string dimensions = null;
try
{
using (Stream fileStream = file.OpenReadStream())
using (Image image = Image.FromStream(fileStream, false, true))
dimensions = $"{image.Width},{image.Height}";
}
catch { }
// copy file
FileInfo fileInfo = new FileInfo(_settings.BuildFilePath(GenerateUniqueFileName()));
// copy in resources folder
using (var stream = new FileStream(fileInfo.FullName, FileMode.Create))
await file.CopyToAsync(stream);
// encrypt file
string iv = Guid.NewGuid().ToString().AsSpan(0, 16).ToString();
byte[] cipher = _cryptographyService.Encrypt(await File.ReadAllBytesAsync(fileInfo.FullName), Encoding.UTF8.GetBytes(_settings.EncryptKey), Encoding.UTF8.GetBytes(iv));
await File.WriteAllBytesAsync(fileInfo.FullName, cipher);
// create document file
DocumentFile result = new DocumentFile
{
OriginalName = file.FileName,
Path = fileInfo.Name,
Encryption = _cryptographyService.Name,
IV = iv,
Size = fileInfo.Length,
Dimensions = dimensions,
MimeType = file.ContentType,
};
return(result);
}
public async Task <DownloadDocumentResponse> Handle(DownloadDocumentByIdQuery query, CancellationToken cancellationToken)
{
Document document = await _documentRepository.FindByIdWithFileAsync(query.Id);
if (document == null)
{
throw new ApiProblemDetailsException($"Record with id: {query.Id} does not exist.", StatusCodes.Status404NotFound);
}
if (document.CreatedBy != _authenticatedUser.UserId)
{
throw new ApiProblemDetailsException($"You are not authorized to access this resource.", StatusCodes.Status403Forbidden);
}
// data
DocumentFile documentFile = document.File;
FileInfo fileInfo = new FileInfo(_settings.BuildFilePath(documentFile.Path));
// check if document is still valid
if (documentFile == null || !fileInfo.Exists)
{
throw new ApiProblemDetailsException($"Record with id: {query.Id} does contain file.", StatusCodes.Status404NotFound);
}
// decrypt
string iv = documentFile.IV;
byte[] decrypted = _cryptographyService.Decrypt(await File.ReadAllBytesAsync(fileInfo.FullName), Encoding.UTF8.GetBytes(_settings.EncryptKey), Encoding.UTF8.GetBytes(iv));
// response
return(new DownloadDocumentResponse
{
Id = query.Id,
Name = documentFile.OriginalName,
ContentType = documentFile.MimeType,
FileContent = decrypted,
});
}
