public void ChangeUserPassword(string id, string password)
{
if (string.IsNullOrEmpty(id))
{
throw new ArgumentNullException(ExMessage.MustNotBeNullOrEmpty(nameof(id)));
}
if (string.IsNullOrEmpty(password))
{
throw new ArgumentNullException(ExMessage.MustNotBeNullOrEmpty(nameof(password)));
}
password = CryptographicHelper.Hash(password);
_repository.ModifyPassword(id, password);
}
public Tuple <bool, bool> CheckForAuthandInt(Guid id)
{
bool isDistinct = true;
bool isVerified = true;
SubmissionViewModel submission = _assignmentsService.GetSubmission(id);
var submissions = _assignmentsService.GetSubmissions(submission.Assignment.Id);
MemberViewModel teacher = _membersService.GetMember(submission.Member.TeacherEmail);
byte[] key = CryptographicHelper.AsymmetricDecrypt(
Convert.FromBase64String(submission.SymmetricKey), teacher.PrivateKey);
byte[] iv = CryptographicHelper.AsymmetricDecrypt(
Convert.FromBase64String(submission.SymmetricIV), teacher.PrivateKey);
foreach (SubmissionViewModel sub in submissions)
{
if (sub.FileHash == submission.FileHash && sub.Member.Email != submission.Member.Email)
{
TempData["warning"] += "Assignment is identical to " + sub.Member.Email + "'s assignment!\n";
isDistinct = false;
}
}
if (!CryptographicHelper.VerifySignature(
CryptographicHelper.SymmetricDecrypt(
Convert.FromBase64String(submission.Signature), key, iv),
CryptographicHelper.Hash(GetDecryptedAssignment(id)),
submission.Member.PublicKey))
{
isVerified = false;
}
return(new Tuple <bool, bool>(isDistinct, isVerified));
}
public string AddUser(OrgUser dto)
{
var user = _repository.FindByAccount(dto.Account);
if (user != null)
{
throw new NonUniqueException($"user account must be unique,account={dto.Account}");
}
user = _repository.FindByCode(dto.Code);
if (user != null)
{
throw new NonUniqueException($"user code must be unique,code={dto.Code}");
}
dto.Id = ConfigHelper.NewGuid;
dto.Password = CryptographicHelper.Hash(ConfigHelper.DefaultUserPwd);
dto.State = (int)UserState.Normal;
if (string.IsNullOrEmpty(dto.Code))
{
dto.Code = dto.Id;
}
_repository.Add(dto);
return(dto.Id);
}
public IActionResult SubmitAssignment(IFormFile file)
{
var assignment = _assignmentsService.GetAssignment(Guid.Parse(CryptographicHelper.SymmetricDecrypt(Request.Cookies["Assignment"])));
ViewBag.Assignment = assignment;
if (file != null)
{
Stream stream = file.OpenReadStream();
int firstByte = stream.ReadByte();
int secondByte = stream.ReadByte();
int thirdByte = stream.ReadByte();
int fourthByte = stream.ReadByte();
stream.Position = 0;
//If the file passes the following check, a submission is created with user credentials
if (firstByte == 37 && secondByte == 80 && thirdByte == 68 && fourthByte == 70 && Path.GetExtension(file.FileName) == ".pdf")
{
SubmissionViewModel submission = new SubmissionViewModel();
submission.Member = _membersService.GetMember(User.Identity.Name);
Tuple <byte[], byte[]> keys = CryptographicHelper.GenerateKeys();
MemberViewModel teacher = _membersService.GetMember(submission.Member.TeacherEmail);
string encryptedKey = Convert.ToBase64String(CryptographicHelper.AsymmetricEncrypt(keys.Item1, teacher.PublicKey));
string encryptedIv = Convert.ToBase64String(CryptographicHelper.AsymmetricEncrypt(keys.Item2, teacher.PublicKey));
submission.SymmetricKey = encryptedKey;
submission.SymmetricIV = encryptedIv;
submission.Assignment = _assignmentsService.GetAssignment(assignment.Id);
string absolutePath = _host.WebRootPath + @"\..\ProtectedFiles\";
string uniqueName = Guid.NewGuid().ToString() + Path.GetExtension(file.FileName);
using (MemoryStream ms = new MemoryStream())
{
stream.CopyTo(ms);
ms.Position = 0;
submission.FileHash = Convert.ToBase64String(CryptographicHelper.Hash(ms.ToArray()));
var signature = CryptographicHelper.GenerateSignature(Convert.FromBase64String(submission.FileHash), submission.Member.PrivateKey);
submission.Signature = Convert.ToBase64String(CryptographicHelper.SymmetricEncrypt(
signature,
keys.Item1, keys.Item2));
System.IO.File.WriteAllBytes(absolutePath + uniqueName,
CryptographicHelper.SymmetricEncrypt(
ms.ToArray(),
keys.Item1,
keys.Item2
)
);
}
submission.FilePath = absolutePath + uniqueName;
_assignmentsService.AddSubmission(submission);
TempData["info"] = "File accepted";
return(RedirectToAction("index"));
}
else
{
TempData["warning"] = "File is not valid, only PDF allowed";
return(View());
}
}
else
{
TempData["warning"] = "Please upload a file";
return(View());
}
}
