the following uses the System.Security.Cryptography namespace from c#
and implements the unprotect method from the ProtectedData class
byte[] output = ProtectedData.Unprotect(input, null, DataProtectionScope.LocalMachine);
I'm trying to access my pc's HKEY_LOCALMACHINE registry with python because theres a key somewhere in it that i need (to read), in order to decrypt a file.
I read the docs but I'm still just not sure what method I should use for that purpose
aReg = winreg.ConnectRegistry(None, HKEY_LOCAL_MACHINE)
I'm not quite sure what comes next so any help would be appreciated.
Turns out I needed this: https://learn.microsoft.com/en-us/windows/win32/api/dpapi/nf-dpapi-cryptunprotectdata
import win32crypt
#open binary file in readmode
filecontents = fileObject.read()
unecryptedFileContents = win32crypt.CryptUnprotectData(filecontents)
I'm currently working on a project where pdf's can be decrypted after a successful api call that returns the password.
I've browsed through SO and pdftron SDK but can't find a definitive solution on how to insert this password into the security handler.
Things I have tried:
None of the GetSecurityHandler() methods seem to handle password insertion:
SecurityHandler handler = m_PdfDocument.GetSecurityHandler();
Takes a password string but throws error:
m_PdfDocument.InitStdSecurityHandler(pwd);
error: Message: Not a standard security handler. The custom filter needs to be registered.
Judging from the message I assumed I needed m_PdfDocument.InitSecurityHandler() instead, but that method doesn't take a string, only int.
Anyone can bump me onto the right track ?
Thank you for sending the file. This file is encrypted using custom encryption. Your DRM. No PDF reader can open the file, but your own custom PDF reader.
To open the PDF with PDFNet, you need to find out how the file was encrypted in the first place, and essentially do the opposite. I assume the other team that did the encryption was also decrypting, for at least testing purposes?
It might as simple as following example 3 in our Encryption sample. In which case you just need to register under the filter name that the other team used. I think I know what that is, but won't post here, and will email you instead.
But for others, if the PDF was encrypted with a filter called "Frodo", then it would be
CreateDelegate frodo_del = new CreateDelegate(FrodoSecurityHandler.Create);
SecurityManagerSingleton.Instance().RegisterSecurityHandler("Frodo", new SecurityDescriptor("Frodo Security", frodo_del));
Well according to this page, GetSecurityHandler() is used after you initialize another handler, so since InitSecurityHandler() takes an int you could do this
string password = "9quali52ty3";
// Convert the string into a byte[].
byte[] asciiBytes = Encoding.ASCII.GetBytes(password);
string compiledBytes = System.Text.Encoding.ASCII.GetString(asciiBytes);
int convertedBytes = int.Parse(compiledBytes);
m_PdfDocument.InitSecurityHandler(convertedBytes);
m_PdfDocument.GetSecurityHandler();
A good rule of thumb for programming: There is always a way to get from one datatype to another.
Credit to: #Brig Lamoreaux, #Zanoni and #Brandon on the following pages.
Brig Zanoni Brandon
I have a program which saves a little .txt file with a highscore in it:
// Create a file to write to.
string createHighscore = _higscore + Environment.NewLine;
File.WriteAllText(path, createText);
// Open the file to read from.
string createHighscore = File.ReadAllText(path);
The problem is that the user can edit the file as simple as possible – with a texteditor. So I want to make the file unreadable / uneditable or encrypt it.
My thinking was that I could save the data in a resource file, but can I write in a resource file?
Or save it as .dll, encrypt/decrypt it or look for a MD5-sum/hash.
You can't prevent the user from modifying the file. It's their computer, so they can do whatever they want (that's why the whole DRM issue is… difficult).
Since you said you're using the file to save an high-score, you have a couple of alternatives. Do note that as previously said no method will stop a really determined attacker from tampering with the value: since your application is running on the user computer he can simply decompile it, look at how you're protecting the value (gaining access to any secret used in the process) and act accordingly. But if you're willing to decompile an application, find out the protection scheme used and come up with a script/patch to get around it only to change a number only you can see, well, go for it?
Obfuscate the content
This will prevent the user from editing the file directly, but it won't stop them as soon as the obfuscation algorithm is known.
var plaintext = Encoding.UTF8.GetBytes("Hello, world.");
var encodedtext = Convert.ToBase64String(plaintext);
Save the ciphertext to the file, and reverse the process when reading the file.
Sign the content
This will not prevent the user from editing the file or seeing its content (but you don't care, an high-score is not secret) but you'll be able to detect if the user tampered with it.
var key = Encoding.UTF8.GetBytes("My secret key");
using (var algorithm = new HMACSHA512(key))
{
var payload = Encoding.UTF8.GetBytes("Hello, world.");
var binaryHash = algorithm.ComputeHash(payload);
var stringHash = Convert.ToBase64String(binaryHash);
}
Save both the payload and the hash in the file, then when reading the file check if the saved hash matches a newly computed one. Your key must be kept secret.
Encrypt the content
Leverage .NET's cryptographic libraries to encrypt the content before saving it and decrypt it when reading the file.
Please take the following example with a grain of salt and spend due time to understand what everything does before implementing it (yes, you'll be using it for a trivial reason, but future you — or someone else — may not). Pay special attention on how you generate the IV and the key.
// The initialization vector MUST be changed every time a plaintext is encrypted.
// The initialization vector MUST NOT be reused a second time.
// The initialization vector CAN be saved along the ciphertext.
// See https://en.wikipedia.org/wiki/Initialization_vector for more information.
var iv = Convert.FromBase64String("9iAwvNddQvAAfLSJb+JG1A==");
// The encryption key CAN be the same for every encryption.
// The encryption key MUST NOT be saved along the ciphertext.
var key = Convert.FromBase64String("UN8/gxM+6fGD7CdAGLhgnrF0S35qQ88p+Sr9k1tzKpM=");
using (var algorithm = new AesManaged())
{
algorithm.IV = iv;
algorithm.Key = key;
byte[] ciphertext;
using (var memoryStream = new MemoryStream())
{
using (var encryptor = algorithm.CreateEncryptor())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
using (var streamWriter = new StreamWriter(cryptoStream))
{
streamWriter.Write("MySuperSecretHighScore");
}
}
}
ciphertext = memoryStream.ToArray();
}
// Now you can serialize the ciphertext however you like.
// Do remember to tag along the initialization vector,
// otherwise you'll never be able to decrypt it.
// In a real world implementation you should set algorithm.IV,
// algorithm.Key and ciphertext, since this is an example we're
// re-using the existing variables.
using (var memoryStream = new MemoryStream(ciphertext))
{
using (var decryptor = algorithm.CreateDecryptor())
{
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
using (var streamReader = new StreamReader(cryptoStream))
{
// You have your "MySuperSecretHighScore" back.
var plaintext = streamReader.ReadToEnd();
}
}
}
}
}
As you seem to look for relatively low security, I'd actually recommend going for a checksum. Some pseudo-code:
string toWrite = score + "|" + md5(score+"myKey") + Environment.NewLine
If the score would be 100, this would become
100|a6b6b0a8e56e42d8dac51a4812def434
To make sure the user didn't temper with the file, you can then use:
string[] split = readString().split("|");
if (split[1] != md5(split[0]+"myKey")){
alert("No messing with the scores!");
}else{
alert("Your score is "+split[0]);
}
Now of course as soon as someone gets to know your key they can mess with this whatever they want, but I'd consider that beyond the scope of this question. The same risk applies to any encryption/decryption mechanism.
One of the problems, as mentioned in the comments down below, is that once someone figures out your key (through brute-forcing), they could share it and everybody will be able to very easily change their files. A way to resolve this would be to add something computer-specific to the key. For instance, the name of the user who logged in, ran through md5.
string toWrite = score + "|" + md5(score+"myKey"+md5(System.username /**or so**/)) + Environment.NewLine
This will prevent the key from being "simply shared".
Probably your best bet is securing the whole file using standard NT security and programmatically change the access control list to protect the whole file from being edited by unwanted users (excepting the one impersonating your own application, of course).
Cryptography can't help here because the file could be still editable using a regular text editor (for example, notepad) and the end user can corrupt the file just adding an extra character (or dropping one too).
There's an alternate approach which doesn't involve programming effort...
Tell your users that once they've manually edited the whole text file they've lost your support. At the end of the day, if you're storing this data is because it's required by your application. Corrupting it or doing the risky task of manually editing it can make your application produce errors.
Another alternate approach which involves programming effort...
Whenever you change the file from your application, you can compute a MD5 or SHA hash and store in a separate file, and once you want to read or write it again, you're going to check that the whole file produces the same hash before writing on it again.
This way, the user can still edit your file manually, but you'll know when this unexpected behavior was done by the user (unless the user also manually computes the hash whenever the file is changed...).
Something I have not yet seen mentioned is storing the high score on an online leader board. Obviously this solution requires a lot more development, but since you are talking about a game, you could probably make use of a third party provider like Steam, Origin, Uplay, ... This has the added advantage of leader boards not just being for your machine.
You cannot save data in a dll, and both Resource file and txt file are editable. It sounds like encryption is the only way for you. You can encrypt the string before saving it to a txt file. Take a look at this thread:
Encrypt and decrypt a string
You can serialize it and deserialize with encryption with CryptoStream :
Serialize file :
Create and open FileStream in write mode
Create Cryptostream and pass your filestream
Write contents to Cryptostream (encrypt)
Deserialize file :
Create and open FileStream in read mode
Create Cryptostream and pass your filestream
Read from Cryptostream (decrypt)
You can find examples and more information here :
msdn.microsoft.com/en-us/library/system.security.cryptography.cryptostream.aspx
http://www.codeproject.com/Articles/6465/Using-CryptoStream-in-C
Example :
byte[] key = { 1, 2, 3, 4, 5, 6, 7, 8 }; // Where to store these keys is the tricky part,
byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };
string path = #"C:\path\to.file";
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
// Encryption and serialization
using (var fStream = new FileStream(path, FileMode.Create, FileAccess.Write))
using (var cryptoStream = new CryptoStream(fStream , des.CreateEncryptor(key, iv), CryptoStreamMode.Write))
{
BinaryFormatter serializer = new BinaryFormatter();
// This is where you serialize your data
serializer.Serialize(cryptoStream, yourData);
}
// Decryption
using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read))
using (var cryptoStream = new CryptoStream(fs, des.CreateDecryptor(key, iv), CryptoStreamMode.Read))
{
BinaryFormatter serializer = new BinaryFormatter();
// Deserialize your data from file
yourDataType yourData = (yourDataType)serializer.Deserialize(cryptoStream);
}
Simple solution:
To mitigate the hackish user ability to change the score, you can write it as a binary I guess.
Another solution:
Write the data in a SQLite DB?
You can name your file as something that doesn't suggest it has a score table in it (e.g. YourApp.dat) and encrypt the contents.
The accepted answer here contains the code for encryption and decryption of text.
Update
I also suggest using some Guid as a password for the encryption.
You can't write in Resources, more information exists in this answer
The reason that you can't change a resource string at runtime, is
because the resource is compiled into your executable. If you reverse
engineer the compiled *.exe or *.dll file, you can actually see your
string in the code. Editing an already compiled executable file is
never a good idea (unless you're trying to hack it), but when you try
to do it from the executables code, it just plain impossible, as the
file is locked during execution.
You can add Read Only or Hidden attributes to your files using
File.SetAttributes, But still user can remove the attributes
from windows and edit the file.
An example:
File.SetAttributes(path, File.GetAttributes(path) | FileAttributes.Hidden);
Another way I could suggest is to save the data in a file with some
weird extensions so that the user can't think of it as an editable or
important file. somthing like ghf.ytr (Can't think of somthing
more weird right now!)
I'd also suggest making a text file with .dll extension and saving it in one of windows folders like system32. This way user will have a really hard time trying to find out where does the score information go!
Here is a code to make an text file not editable. in the same way you use this technique to make it not readable etc.
string pathfile = #"C:\Users\Public\Documents\Filepath.txt";
if (File.Exists(pathfile))
{
File.Delete(pathfile);
}
if (!File.Exists(pathfile))
{
using (FileStream fs = File.Create(pathfile))
{
Byte[] info = new UTF8Encoding(true).GetBytes("your text to be written to the file place here");
FileSecurity fsec = File.GetAccessControl(pathfile);
fsec.AddAccessRule(new FileSystemAccessRule("Everyone",
FileSystemRights.WriteData, AccessControlType.Deny));
File.SetAccessControl(pathfile, fsec);
}
}
I am basically creating a xlsx file but I am getting an error while using that file like below.
System.IO.FileFormatException: Archive file cannot be size 0.
The way I tried.
string file = "c:\\DoneDone61.xlsx";
using(File.Create(file))
{
}
Also I cannot open excel file manually because it says the file is corrupted.
Thanks for answers in advance.
An Excel file which you consider to be "blank" is not just a file with no data in it (which is what you are creating). You can see this yourself by creating a document manually in Excel and then opening it in notepad. You'll notice that it actually has data inside of it. That data is used to store information regarding the three empty sheets named "Sheet1", "Sheet2" and "Sheet3". Also, there is some header information so that any program looking at the file knows that it is actually a compressed file (as per the Excel file format). So, as you can see, even a pretty empty excel file still contains SOME data.
If you want to create a blank excel document using C#, you have two good options:
Use a library that allows you to actually work with creating Excel documents that takes care of creating the file correctly. Check out something like the Microsoft OpenXML SDK or ExcelPackage.
Create an empty Excel document, store it somewhere, and when you want to "create" a new empty Excel document, just make a copy of this file.
This one ...
using(File.Create(filePath))
{
}
... creates an empty file. Read: really empty (=> 0 bytes) not an empty XLSX with an XLSX skeleton: ZIP container, file header, style definitions, ....
What exactly did you expect?
EDIT:
If you want to create an empty XLSX file (like "Right Click on Mouse > New > New Microsoft Excel"), you have to use such an template, ... and write it onto the disk.
To achieve that, you have to deploy this template file with your application, and then do a File.Copy(source, dest), or integrate it as a resource and write the resource content to the disk.
What you need to use is Interop.Excel namespace. Here's a guide from msdn
please use this...Its a bit hacky but couldn't get a better way to do this using InterOp
public static void CreateEmptyXLSXFile(string FilePath)
{
FileStream MyStream = new FileStream(FilePath, FileMode.CreateNew, FileAccess.ReadWrite);
MyStream.Write(ExcelDocumentsInterOps.GetEmptyXSLXFileBytes(), 0, ExcelDocumentsInterOps.GetEmptyXSLXFileBytes().Length);
MyStream.Flush();
MyStream.Close();
MyStream.Dispose();
MyStream = null;
}
/// <summary>
/// Returns the bytes for an empty xslx file
/// </summary>
/// <returns></returns>
public static byte[] GetEmptyXSLXFileBytes()
{
string TheSting = "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return Convert.FromBase64String(TheSting);
}
When dealing with spreadsheet related tasks in .NET, you can use this open source library called SpreadsheetLight to write an excel file (especially, if you want to write content at some point).
If you prefer adding it as package via Nuget, you can say:
Install-Package SpreadsheetLight
After that, going by GenerateReport() exmaple:
// this one creates an empty workbook
using (SLDocument sl = new SLDocument())
{
// sl.SetCellValue("B3", "I love ASP.NET MVC");
sl.SaveAs("c:\\DoneDone61.xlsx");
}
Also see their tutorial for more interesting stuff.
this is my first question on here, so bear with me.
What I'm aiming to do is just create a basic .zip archive in C#. I have tried using the built-in GZipStream class of .NET and have managed to accomplish this, but then I have the problem that I cannot name the file "usercode.zip" without the archived file losing it's extension. Due to constraints I cannot make my program create these files as "usercode.trf.zip", which is the only way I've found of leaving the filename's extension intact inside the archive.
I've tried using a number of other zipping libraries and I can't seem to manage getting them working properly or the way I want it to.
I came upon the SevenZipHelper library that provides some nifty functions to use the LZMA (or 7-zip) library to compress a file.
The code I'm using looks as follows:
//Take the BF file and zip it, using 7ZipHelper
BinaryReader bReader = new BinaryReader(File.Open(pFileName, FileMode.Open));
byte[] InBuf = new byte[Count];
bReader.Read(InBuf, 0, InBuf.Length);
Console.WriteLine("ZIP: read for buffer length:" + InBuf.Length.ToString());
byte[] OutBuf = SevenZip.Compression.LZMA.SevenZipHelper.Compress(InBuf);
FileStream BZipFile = new FileStream(pZipFileName, FileMode.OpenOrCreate, FileAccess.Write);
BZipFile.Seek(0, SeekOrigin.Begin);
BZipFile.Write(OutBuf, 0, OutBuf.Length);
BZipFile.Close();
This creates a compressed file neatly, using the 7-zip algorithm. Problem is I can't guarantee that the clients using this program will have access to 7-zip, so the file has to be in normal zip algorithm. I've gone through the helper- as well as the 7-zip libraries and it seems it is possible to use this library to compress a file with the normal "ZIP" algorithm. I just cannot seem to figure out how to do this. I've noticed properties settings in a few places, but I cannot find any documentation or googling to tell me where to set this.
I realize there's probably better ways to do this and that I'm just missing something, but I can't sit and struggle with such a supposedly easy task forever. Any help would be greatly appreciated.
If you want you can take a look at this library, I've used it before and it's preaty simple to use : dotnetzip
EDIT(example):
using (ZipFile zip = new ZipFile())
{
foreach (String filename in FilesList)
{
Console.WriteLine("Adding {0}...", filename);
ZipEntry e = zip.AddFile(filename,"");
e.Comment = "file " +filename+" added "+DateTime.Now;
}
Console.WriteLine("Done adding files to zip:" + zipName);
zip.Comment = String.Format("This zip archive was created by '{0}' on '{1}'",
System.Net.Dns.GetHostName(), DateTime.Now);
zip.Save(zipName);
Console.WriteLine("Zip made:" + zipName);
}