Develop Reference

Can you check python code in csharp before pythonNet execution?

i have recently started using pythonNet for executing scripts from Csharp, on an algorithm i was doing in csharp up until now, it works pretty well:
using (Py.GIL())
{
PythonEngine.Initialize();
using (var scope = Py.CreateScope())
{
string code = File.ReadAllText(fileName);
var scriptCompiled = PythonEngine.Compile(code, "Analyze.py");
scope.Execute(scriptCompiled);
dynamic func = scope.Get("predictFromData");
PyList Pydata = new PyList(data.ToPython());
PyTuple rettp = new PyTuple(func(Pydata));
PyList pyIndexList = new PyList(rettp[0]);
foreach (PyObject intobj in pyIndexList)
{
indexList.Add(intobj.As<int>());
}
}
}
But i'd like to know if there is a way to check if the code can be executed before actually running it, since it works with compiled code, and since PythonNet does require an external python installation to see if every modules are here ect... And then switch back to my previous csharp algorithm if it is not possible in python.
For now i'm thinking about simply executing a python unit test importing modules and testing functions with dummy values and returning exceptions and units tests values to csharp code, but i'd prefer a cleaner way if anyone has an idea.
Cheers.

There are few things you can check here:
first is to see if Python code has correct syntax, it can be done with the code like this:
public static IReadOnlyList<ScriptCompilationDiagnostic> CheckErrors(ScriptEngine engine, string script, string fileName, RunFlagType mode)
{
try
{
PythonEngine.Compile(script, fileName, mode);
}
catch (PythonException e)
{
dynamic error = e.Value;
return new[]
{
new ScriptCompilationDiagnostic
{
Kind = ScriptCompilationDiagnosticKind.Error,
Line = error.lineno - 1,
Column = error.offset - 1,
Message = error.msg,
Code = error.text,
FileName = error.filename,
},
};
}
return new ScriptCompilationDiagnostic[0];
}
second is that you can check if Python is installed on a target machine, with the code like this:
var pythonHome = TryGetFullPathFromPathEnvironmentVariable("python.exe");
private static string? TryGetFullPathFromPathEnvironmentVariable(string fileName)
{
if (fileName.Length >= MAXPATH)
throw new ArgumentException($"The executable name '{fileName}' must have less than {MAXPATH} characters.", nameof(fileName));
var sb = new StringBuilder(fileName, MAXPATH);
return PathFindOnPath(sb, null) ? sb.ToString() : null;
}
[DllImport("shlwapi.dll", CharSet = CharSet.Unicode, SetLastError = false)]
private static extern bool PathFindOnPath([In, Out] StringBuilder pszFile, [In] string[]? ppszOtherDirs);
If your script is using third-party modules, you may check that they're installed as well:
public bool IsModuleInstalled(string module)
{
string moduleDir = Path.Combine(PythonHome, "Lib", "site-packages", module);
return Directory.Exists(moduleDir) && File.Exists(Path.Combine(moduleDir, "__init__.py"));
}
Please note that Python.NET does not officially support the latest Python version 3.9, so alternatively you can distribute and install embedded python with your application from here:
https://www.python.org/ftp/python/3.7.3/
alongside with all required third-party modules as wheels.
We use this approach in our AlterNET Studio product to check if Python is installed for our Python debugger based on Debug Adapter Protocol, and install embedded Python with wheels for our Python.NET based scripter/debugger.

System.Security.Cryptography.CryptographicException: Object already exists

It's weird. I had this method to encrypt a string:
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Assert, Unrestricted = true)]
public static string Encrypt(this string stringToEncrypt, string key) {
var cspp = new CspParameters {
KeyContainerName = key,
Flags = CspProviderFlags.UseMachineKeyStore
};
var rsa = new RSACryptoServiceProvider(cspp) {
PersistKeyInCsp = true
};
var bytes = rsa.Encrypt(System.Text.Encoding.UTF8.GetBytes(stringToEncrypt), true);
return BitConverter.ToString(bytes);
}
And this was my client:
private const string EncryptionKey = "pezhman";
static Random random = new Random();
public static int CreateSalt() {
return random.Next(1000, 9999);
}
public void EncryptSomething() {
var salt = CreateSalt();
var plainText = salt + "," + DateTime.Now;
var encryptionSaltKey = EncryptionKey + DateTime.Now.Date;
// here im calling encryptor:
var encryptedValue = plainText.Encrypt(encryptionSaltKey);
}
I was using this in an ASP.NET MVC 4 application. It was working perfectly; but suddenly it stopped working. Actually, in local, I have no problem and it works. But, when I publish my code to the server, I get this error:
System.Security.Cryptography.CryptographicException: Object already
exists.
Do you have any idea what's happening here? I know I can grant access to the key to everyone. What I'm asking is, what just happened at the server? What is changed? What kind of changes can cause the problem?

What I'm asking is, what just happened at the server? What is changed? What kind of changes can cause the problem?
One possibility is the recently released Windows secuirty update MS14-059, although I can't explain the error message you are getting.
Basically, that update completely uninstalls MVC 4.0.0.0 and replaces it with 4.0.0.1 on your server, and it has caused grief for many people with broken builds. Since cryptography might depend on something very specific to the version number of the DLL, you might want to start there. You can prove or disprove this theory by testing your application on a machine without the above security patch installed to see if it starts working again.

How to check if Windows user account name exists in domain?

What is the simplest and most efficient way in C# to check if a Windows user account name exists? This is in a domain environment.
Input: user name in [domain]/[user] format (e.g. "mycompany\bob")
Output: True if the user name exists, false if not.
I did find this article but the examples there are related to authenticating and manipulating user accounts, and they assume you already have a user distinguished name, whereas I am starting with the user account name.
I'm sure I can figure this out using AD, but before I do so I was wondering if there is a simple higher level API that does what I need.
* UPDATE *
There are probably many ways to do this, Russ posted one that could work but I couldn't figure out how to tweak it to work in my environment. I did find a different approach, using the WinNT provider that did the job for me:
public static bool UserInDomain(string username, string domain)
{
string path = String.Format("WinNT://{0}/{1},user", domain, username);
try
{
DirectoryEntry.Exists(path);
return true;
}
catch (Exception)
{
// For WinNT provider DirectoryEntry.Exists throws an exception
// instead of returning false so we need to trap it.
return false;
}
}
P.S.
For those who aren't familiar with the API used above: you need to add a reference to System.DirectoryServices to use it.
The link I found that helped me with this: How Can I Get User Information Using ADSI
The examples use ADSI but can be applied to .NET DirectoryServices as well. They also demonstrate other properties of the user object that may be useful.

The System.DirectoryServices namespace in the article is exactly what you need and intended for this purpose. If I recall correctly, it is a wrapper around the Active Directory Server Interfaces COM interfaces
EDIT:
Something like the following should do it (it could probably do with some checking and handling). It will use the domain of the current security context to find a domain controller, but this could easily be amended to pass in a named server.
public bool UserInDomain(string username, string domain)
{
string LDAPString = string.Empty;
string[] domainComponents = domain.Split('.');
StringBuilder builder = new StringBuilder();
for (int i = 0; i < domainComponents.Length; i++)
{
builder.AppendFormat(",dc={0}", domainComponents[i]);
}
if (builder.Length > 0)
LDAPString = builder.ToString(1, builder.Length - 1);
DirectoryEntry entry = new DirectoryEntry("LDAP://" + LDAPString);
DirectorySearcher searcher = new DirectorySearcher(entry);
searcher.Filter = "sAMAccountName=" + username;
SearchResult result = searcher.FindOne();
return result != null;
}
and tested with the following
Console.WriteLine(UserInDomain("username","MyDomain.com").ToString());

Found a simple way to do this if you're on a high enough framework version:
using System.DirectoryServices.AccountManagement;
bool UserExists(string userName, string domain) {
using (var pc = new PrincipalContext(ContextType.Domain, domain))
using (var p = Principal.FindByIdentity(pc, IdentityType.SamAccountName, userName)) {
return p != null;
}
}

Cannot find the Locked property in Active Directory (C#)

First off I know there have been many posts on this topic however all of the information that I have found does not help in my situation. What is happening is that I cannot find where the property is for locking out a user in AD. I have used
link text
for everything else with AD and it has all worked however, the bit map the userAccountControl does not change if an account is locked out. Trying to access the lockoutTime returns an exception saying that it cannot find the property. The only thing that remotely works is the
user.InvokeGet("IsAccountLocked")
call, but it always returns false no matter the if the account is locked or not.
If anybody has any ideas it would be very helpful or a link that might help me out.
Thanks

If you are using .NET 3.5 you should use the UserPrincipal class in the System.DirectoryServices.AccountManagement namespace. This class has an IsAccountLockedOut() method as well as a property to get the AccountLockOutTime.
using (var context = new PrincipalContext( ContextType.Domain ))
{
using (var user = UserPrincipal.FindByIdentity( context,
IdentityType.SamAccountName,
name ))
{
if (user.IsAccountLockedOut())
{
... your code here...
}
}
}

If you're on .NET 2.0/3.0, you can use the following code, assuming you have an instance of a DirectoryEntry called user:
// get the "userAccountControl" property
int uac = Convert.ToInt32(user.Properties["userAccountControl"][0]);
const int ADS_UF_ACCOUNTDISABLE = 0x00000002;
const int ADS_UF_LOCKOUT = 0x00000010;
bool accountIsDisabled = (uac & ADS_UF_ACCOUNTDISABLE) == ADS_UF_ACCOUNTDISABLE;
bool accountIsLockedOut = (uac & ADS_UF_LOCKOUT) == ADS_UF_LOCKOUT;
Marc

Get User Account Status (Locked/Unlocked) from Active Directory on C-Sharp / C#

I need to find a way to check if an Active Directory UserAccount has his account locked or not.
I've tried userAccountControl property in a Windows 2000 AD but that property does not change a byte when I force an account to get locked (by trying to log on to a workstation providing the wrong password for that specific user) And I can tell by using ADExplorer.exe utility made by semi-god -> Mr. Russinovich
I've seen that in the 3.5 Framework they use the method .InvokeGet("userLockedOut"); but I'm trying to do this in a Enterprise Application that was written in .Net Framework 1.1 and there's no chance of using newer ones (just if you thought of suggesting so).

Here is a link with all the info on Active Directory stuff...
http://www.codeproject.com/KB/system/everythingInAD.aspx

Found this, it is a little more than I have done in the past (can't find exact snippets) though the key is doing a directory search and limiting based on the lockouttime for your user(s) that are returned. Additionally for a particular user, you can limit your search further using additional properties. The codeproject link above has that particular logic (for search limiting) I believe.
class Lockout : IDisposable
{
DirectoryContext context;
DirectoryEntry root;
DomainPolicy policy;
public Lockout(string domainName)
{
this.context = new DirectoryContext(
DirectoryContextType.Domain,
domainName
);
//get our current domain policy
Domain domain = Domain.GetDomain(this.context);
this.root = domain.GetDirectoryEntry();
this.policy = new DomainPolicy(this.root);
}
public void FindLockedAccounts()
{
//default for when accounts stay locked indefinitely
string qry = "(lockoutTime>=1)";
TimeSpan duration = this.policy.LockoutDuration;
if (duration != TimeSpan.MaxValue)
{
DateTime lockoutThreshold =
DateTime.Now.Subtract(duration);
qry = String.Format(
"(lockoutTime>={0})",
lockoutThreshold.ToFileTime()
);
}
DirectorySearcher ds = new DirectorySearcher(
this.root,
qry
);
using (SearchResultCollection src = ds.FindAll())
{
foreach (SearchResult sr in src)
{
long ticks =
(long)sr.Properties["lockoutTime"][0];
Console.WriteLine(
"{0} locked out at {1}",
sr.Properties["name"][0],
DateTime.FromFileTime(ticks)
);
}
}
}
public void Dispose()
{
if (this.root != null)
{
this.root.Dispose();
}
}
}
Code was pulled from this post: http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/5e0fadc2-f27b-48f6-a6ac-644e12256c67/

After seeing the .NET 1.1, check this thread out: http://forums.asp.net/t/434077.aspx, using the lockouttime in the filter should still do the trick.
Specifically in the thread (after the larger code post which provides alot of the syntax):
(&(objectClass=user)(objectCategory=person)(lockoutTime>=1));
One other thing, it turns out that if you are using .NET v.1.1, then S.DS converts the Integer8 to the long integer correctly for you (does not work with 1.0) - which means you can do away with reflection code (in the post):
//use the filter from above
SearchResultCollection src = ds.FindAll();
foreach(SearchResult sr in src)
{
DateTime lockoutTime = DateTime.FromFileTime((long)sr.Properties["lockoutTime][0]);
Response.Output.Write("Locked Out on: {0}", lockoutTime.ToString());
}