Documentation for File.Decrypt(String) Method is incorrect

[paul1956]

Issue description
Documentation says "If the file is not encrypted, Decrypt will return a nonzero value, which indicates success."

Decript is a Sub and does not return anything. It would be great if it worked as documented but that is a different issue.
Target framework

• .NET Core

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Issue Details

---

Issue description
Documentation says "If the file is not encrypted, Decrypt will return a nonzero value, which indicates success."

Decript is a Sub and does not return anything. It would be great if it worked as documented but that is a different issue.
Target framework

• .NET Core

Author:	paul1956
Assignees:	-
Labels:	untriaged, Pri3, area-System.IO, :watch: Not Triaged
Milestone:	-

[adamsitnik]

@paul1956 you are right, it's a bug. Would you like to send a PR with a fix?

[paul1956]

@adamsitnik I have been unable to get it or any of the encryption API examples to work. Some reference MemoryProtectionScope which does not exist, and others say the API is obsolete. I am very new to encryption and can't get anything to work, so I have no idea how to correct the documentation.

[wenz]

I'd recommend just removing the sentence, since there is no return value. Took a quick shot at it.

[adamsitnik]

I have been unable to get it or any of the encryption API examples to work.

I've just tried and I think that I've failed as well.

I've used following code:

Details

using System;
using System.IO;

namespace FileEncryptDecrypt
{
    internal class Program
    {
        static void Main(string[] args)
        {
#if NET7_0
            if (!OperatingSystem.IsWindows())
            {
                return;
            }
#endif

            string contents = new string('a', 100);
            string encryptedFilePath = "encryptedFile.txt";
            string nonEncryptedFilePath = "nonEncryptedFile.txt";

            File.WriteAllText(encryptedFilePath, contents);
            File.WriteAllText(nonEncryptedFilePath, contents);

            try
            {
                File.Decrypt(nonEncryptedFilePath);
                Console.WriteLine("Decrypting non-encrypted file has NOT thrown.");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Decrypting non-encrypted file has failed with: {ex.Message}.");
            }
            finally
            {
                File.Delete(nonEncryptedFilePath);
            }

            try
            {
                
                File.Encrypt(encryptedFilePath);

                string encrypted = File.ReadAllText(encryptedFilePath);

                if (encrypted == contents)
                {
                    Console.WriteLine("The file was not encrypted at all.");
                }
                else
                {
                    Console.WriteLine("The file got encrypted!");
                    Console.WriteLine($"Content before: {contents}");
                    Console.WriteLine($"Content  after: {encrypted}");
                }

                File.Decrypt(encryptedFilePath);
                string decrypted = File.ReadAllText(encryptedFilePath);

                if (encrypted == contents)
                {
                    Console.WriteLine("The file was succesfully decrypted.");
                }
                else
                {
                    Console.WriteLine("The file got decrypted, but contents differ!");
                    Console.WriteLine($"Content before: {contents}");
                    Console.WriteLine($"Content  after: {decrypted}");
                }
            }
            finally
            {
                File.Delete(encryptedFilePath);
            }
        }
    }
}

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFrameworks>net48;net7.0</TargetFrameworks>
  </PropertyGroup>

</Project>

And got:

PS C:\Users\adsitnik\source\repos\FileEncryptDecrypt> dotnet run -c Release -f net48
Decrypting non-encrypted file has NOT thrown.
The file was not encrypted at all.
The file was succesfully decrypted.
PS C:\Users\adsitnik\source\repos\FileEncryptDecrypt> dotnet run -c Release -f net7.0
Decrypting non-encrypted file has NOT thrown.
The file was not encrypted at all.
The file was succesfully decrypted.

I am using Windows 11 Enterprise, according to the docs:

This method is not available on all versions of Windows. For example, it is not available on Home editions.

So I would either expect it to work or throw.

@bartonjs @GrabYourPitchforks @krwq am I doing something wrong or my understanding of how the APIs should work is wrong?