I am trying to retrieve Sharepoint list data using Microsoft.Sharepoint.Client library using vb.net windows form.
Below is the vb.net code for reference.
Imports Microsoft.SharePoint.Client
Public Class sharepoint_list
Private client_context As ClientContext
Private Sub sharepoint_list_Load(sender As Object, e As EventArgs) Handles MyBase.Load
client_context = New ClientContext("siteurl#user.com")
Dim web_ As Web = client_context.Web
client_context.Credentials = New SharePointOnlineCredentials("user#user.com", GetPassword("user#user.com", "mypass#123"))
client_context.Load(web_)
client_context.ExecuteQuery()
MsgBox(web_.Title)
End Sub
Public Function GetPassword(username As String, password As String) As Security.SecureString
Dim keyinfo As ConsoleKeyInfo
Dim securePass As Security.SecureString
securePass = New Security.SecureString
For Each c As Char In password
securePass.AppendChar(keyinfo.KeyChar)
Next
Return securePass
End Function
End Class
Whenever I try to run this piece of code, It throws an error with the following message
'.', hexadecimal value 0x00, is an invalid character.
and the following message on the console
A first chance exception of type 'System.ArgumentException' occurred
in System.Xml.dll
Any help would be appreciable.
Thanks in advance.
Modify the GetPassword method as below:
Public Function GetPassword(password As String) As Security.SecureString
Dim securePass As Security.SecureString
securePass = New Security.SecureString
For Each c As Char In password
securePass.AppendChar(c)
Next
Return securePass
End Function
Change the line of code below
client_context.Credentials = New SharePointOnlineCredentials("user#user.com", GetPassword("user#user.com", "mypass#123"))
to
client_context.Credentials = New SharePointOnlineCredentials("user#user.com", GetPassword("mypass#123"))
Related
Summary
I am creating a VB project that requires a user to enter an API key. I do not want to store the API key in plaintext for security purposes, so I am attempting to encrypt it. When changing the source of the "password" from an InputBox to a earlier declared variable, I get an error of System.ArgumentNullException: 'String reference not set to an instance of a String. Parameter name: s', and the execution fails.
Context
For security reasons, I don't want the API key to be stored in Plaintext. Instead, I would like the user to enter it once during the application's initial launch, where it converts the plaintext API key into an encrypted file. To encrypt the file, I don't want the user to enter a password, instead, I have combined a few local variables (User name, MAC address, Install location and Host name.) to serve as a password instead. This means the user shouldn't need to enter it on launch (it will read the encrypted API key from the local file), but if any of the variables change (install location, local username, etc.) then it will error, and the user will need to re-enter the API key.
When I try to change the code from having to type in the password, to using the userKey variable, the program no longer launches correctly. Dim password As String = InputBox("Enter the password:") works fine, but Dim password As String = userKey leads to the above error, despite userKey being defined as a string, it refuses to accept it.
Outcome
I would like to have it so the user only needs to enter the API key once the application is first ever launched. It then takes the machine's data to essentially create a UUID, which is what is used to encrypt the plaintext API key entered by the user. I do not want the user to have to set or remember a password to decrypt the API key. It should be automated, and throw an error if they attempt to login where the automated data doesn't allow successful decryption. It'll wipe the API key and ask the user to re-enter it.
Currently, the code works, but the user has to enter their chosen password each time, which is what I am trying to avoid. I am wanting to fully automate this using the UUID I have generated as userKey which is generated when the form is loaded.
My Code
Please see the current code below. It should be in a working state, but I am unsure as to how I can have it so Dim password as String = userKey doesn't get an error when not having the user actualy typing it.
Conclusion
I am new to VB, so this is a new experiment for me to try and learn VB. Please be gentle - I'd appreciate any tips or tricks on how to best achieve this task and similar. Thanks!
Imports System.IO
Imports Newtonsoft.Json
Imports System.Security.Cryptography
Imports System.Net.NetworkInformation
Imports System.Management
Imports System.Text
Public Class Form1
Public userKey As String
Private posts As List(Of Post)
Public Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim sHostName As String
Dim sUserName As String
Dim mac As String
Dim exePath As String = Application.ExecutablePath()
mac = getMacAddress()
' Get Host Name / Get Computer Name
sHostName = Environ$("computername")
' Get Current User Name
sUserName = Environ$("username")
Dim userKey As String
userKey = sUserName & mac & exePath & sHostName
Label5.Text = userKey
End Sub
Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click
Dim plainText As String = InputBox("Enter the plain text:")
Dim password As String = InputBox("Enter the password:")
Dim wrapper As New Simple3Des(password)
Dim cipherText As String = wrapper.EncryptData(plainText)
MsgBox("The cipher text is: " & cipherText)
My.Computer.FileSystem.WriteAllText("cipherText.txt", cipherText, False)
End Sub
Private Sub Button6_Click(sender As Object, e As EventArgs) Handles Button6.Click
Dim cipherText As String = My.Computer.FileSystem.ReadAllText("cipherText.txt")
Dim password As String = InputBox("Enter the password:")
Dim wrapper As New Simple3Des(password)
' DecryptData throws if the wrong password is used.
Try
Dim plainText As String = wrapper.DecryptData(cipherText)
MsgBox("The plain text is: " & plainText)
Catch ex As System.Security.Cryptography.CryptographicException
MsgBox("The data could not be decrypted with the password.")
End Try
End Sub
Function getMacAddress()
Dim nics() As NetworkInterface = NetworkInterface.GetAllNetworkInterfaces()
Return nics(1).GetPhysicalAddress.ToString
End Function
End Class
Public NotInheritable Class Simple3Des
Private TripleDes As New TripleDESCryptoServiceProvider
Private Function TruncateHash(
ByVal key As String,
ByVal length As Integer) As Byte()
Dim sha1 As New SHA1CryptoServiceProvider
' Hash the key.
Dim keyBytes() As Byte =
System.Text.Encoding.Unicode.GetBytes(key)
Dim hash() As Byte = sha1.ComputeHash(keyBytes)
' Truncate or pad the hash.
ReDim Preserve hash(length - 1)
Return hash
End Function
Sub New(ByVal key As String)
' Initialize the crypto provider.
TripleDes.Key = TruncateHash(key, TripleDes.KeySize \ 8)
TripleDes.IV = TruncateHash("", TripleDes.BlockSize \ 8)
End Sub
Public Function EncryptData(
ByVal plaintext As String) As String
' Convert the plaintext string to a byte array.
Dim plaintextBytes() As Byte =
System.Text.Encoding.Unicode.GetBytes(plaintext)
' Create the stream.
Dim ms As New System.IO.MemoryStream
' Create the encoder to write to the stream.
Dim encStream As New CryptoStream(ms,
TripleDes.CreateEncryptor(),
System.Security.Cryptography.CryptoStreamMode.Write)
' Use the crypto stream to write the byte array to the stream.
encStream.Write(plaintextBytes, 0, plaintextBytes.Length)
encStream.FlushFinalBlock()
' Convert the encrypted stream to a printable string.
Return Convert.ToBase64String(ms.ToArray)
End Function
Public Function DecryptData(
ByVal encryptedtext As String) As String
' Convert the encrypted text string to a byte array.
Dim encryptedBytes() As Byte = Convert.FromBase64String(encryptedtext)
' Create the stream.
Dim ms As New System.IO.MemoryStream
' Create the decoder to write to the stream.
Dim decStream As New CryptoStream(ms,
TripleDes.CreateDecryptor(),
System.Security.Cryptography.CryptoStreamMode.Write)
' Use the crypto stream to write the byte array to the stream.
decStream.Write(encryptedBytes, 0, encryptedBytes.Length)
decStream.FlushFinalBlock()
' Convert the plaintext stream to a string.
Return System.Text.Encoding.Unicode.GetString(ms.ToArray)
End Function
End Class
I am working on coronavirus statistics dashboard as university project, and I have some problems with asynchronous source data download from sites with statistics.
Well, I failed to understand how to do it myself.
I tried to create my own class with function what will create multiple async web requests
and then wait until they all finished, then return results of all these requests.
Imports System.Net.WebClient
Imports System.Net
Public Class AsyncDownload
Private result As New Collection
Private Sub DownloadCompletedHander(ByVal sender As Object, ByVal e As System.Net.DownloadStringCompletedEventArgs)
If e.Cancelled = False AndAlso e.Error Is Nothing Then
Dim myString As String = CStr(e.Result)
result.Add(myString, sender.Headers.Item("source"))
End If
End Sub
Public Function Load(sources As Array, keys As Array) As Collection
Dim i = 0
Dim WebClients As New Collection
While (i < sources.Length)
Dim newClient As New WebClient
newClient.Headers.Add("source", keys(i))
newClient.Headers.Add("sourceURL", sources(i))
AddHandler newClient.DownloadStringCompleted, AddressOf DownloadCompletedHander
WebClients.Add(newClient)
i = i + 1
End While
i = 1
For Each client As WebClient In WebClients
Dim url As String = client.Headers.Item("sourceURL")
client.DownloadStringAsync(New Uri(url))
Next
While (result.Count < WebClients.Count)
End While
Return result
End Function
End Class
And it is used in:
Dim result As New Collection
Private Sub test() Handles Me.Load
Dim downloader As New CoronaStatisticsGetter.AsyncDownload
result = downloader.Load({"https://opendata.digilugu.ee/covid19/vaccination/v3/opendata_covid19_vaccination_total.json"}, {"Nationalwide Data"})
End Sub
It should work like:
I create a new instance of my class.
Calling function Load of this class
Funciton Load creates instances of System.Net.WebClient for each url and adds as handler DownloadCompletedHander
Function Load goes calls DownloadStringAsync of each client
Function Load waits in While loop until result collection items count is not as big as number of url on input
If item count in result is same as urls number that means what everything is downloaded, so it breaks loop and returns all requested data
The problem is that it doesn't work, it just endlessly remain in while loop, and as I see using debug collection result is not updated (its size is always 0)
Same time, when I try to asynchronously download it without using my class, everything works fine:
Private Sub Download() 'Handles Me.Load
Dim wc As New System.Net.WebClient
wc.Headers.Add("source", "VaccinationByAgeGroup")
AddHandler wc.DownloadStringCompleted, AddressOf DownloadCompletedHander
wc.DownloadStringAsync(New Uri("https://opendata.digilugu.ee/covid19/vaccination/v3/opendata_covid19_vaccination_agegroup.json"))
End Sub
Could somebody tell me please why it is not working and where is the problem?
The following shows how one can use System.Net.WebClient with Task to download a string (ie: data) from a URL.
Add a project reference (System.Net)
VS 2019:
In VS menu, click Project
Select Add reference...
Select Assemblies
Check System.Net
Click OK
Create a class (name: DownloadedData.vb)
Public Class DownloadedData
Public Property Data As String
Public Property Url As String
End Class
Create a class (name: HelperWebClient.vb)
Public Class HelperWebClient
Public Async Function DownloadDataAsync(urls As List(Of String)) As Task(Of List(Of DownloadedData))
Dim allTasks As List(Of Task) = New List(Of Task)
Dim downloadedDataList As List(Of DownloadedData) = New List(Of DownloadedData)
For i As Integer = 0 To urls.Count - 1
'set value
Dim url As String = urls(i)
Debug.WriteLine(String.Format("[{0}]: Adding {1}", i, url))
Dim t = Task.Run(Async Function()
'create new instance
Dim wc As WebClient = New WebClient()
'await download
Dim result = Await wc.DownloadStringTaskAsync(url)
Debug.WriteLine(url & " download complete")
'ToDo: add desired code
'add
downloadedDataList.Add(New DownloadedData() With {.Url = url, .Data = result})
End Function)
'add
allTasks.Add(t)
Next
For i As Integer = 0 To allTasks.Count - 1
'wait for a task to complete
Dim t = Await Task.WhenAny(allTasks)
'remove from List
allTasks.Remove(t)
'write data to file
'Note: The following is only for testing.
'The index in urls won't necessarily correspond to the filename below
Dim filename As String = System.IO.Path.Combine("C:\Temp", String.Format("CoronavirusData_{0:00}.txt", i))
System.IO.File.WriteAllText(filename, downloadedDataList(i).Data)
Debug.WriteLine($"[{i}]: Filename: {filename}")
Next
Debug.WriteLine("all tasks complete")
Return downloadedDataList
End Function
End Class
Usage:
Private Async Sub btnRun_Click(sender As Object, e As EventArgs) Handles btnRun.Click
Dim helper As HelperWebClient = New HelperWebClient()
Dim urls As List(Of String) = New List(Of String)
urls.Add("https://opendata.digilugu.ee/covid19/vaccination/v3/opendata_covid19_vaccination_total.json")
urls.Add("https://api.covidtracking.com/v2/states.json")
urls.Add("https://covidtrackerapi.bsg.ox.ac.uk/api/v2/stringency/date-range/2020-01-01/2022-03-01")
urls.Add("http://covidsurvey.mit.edu:5000/query?age=20-30&gender=all&country=US&signal=locations_would_attend")
Dim downloadedDataList = Await helper.DownloadDataAsync(urls)
Debug.WriteLine("Complete")
End Sub
Resources:
How do I wait for something to finish in C#?
How should Task.Run call an async method in VB.NET?
VB.net ContinueWith
I'm rewriting hash_hmac code I got on PHP to VB.Net.
I need same result generated both in PHP and VB.Net.
This is hash_hmac code on PHP:
$data = urlencode('2019-07-21T15:30:57.465Z');
$data = '_ts='.$data;
$signatureSecretKey = "secrete";
$hash = hash_hmac('sha256',$data,$signatureSecretKey,true);
$signature = base64_encode($hash);
echo $signature;
The result shows:
upLQYFI3pI2m9Pu5fyiobpvCRhTvRmEyxrVDrdJOYG4=
And here is my code on VB:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim _ts, data, signature, secrete, hash
secrete = "secret"
_ts = DateTime.Now.ToString("2019-07-21T15:30:57.465Z")
data = "_ts=" & HttpUtility.UrlEncode(_ts)
signature = Encrypt(data, secrete)
TextBox1.Text = signature
End Sub
Public Function Encrypt(Content As String, Secret As String) As String
Dim kode As New System.Text.ASCIIEncoding()
Dim getkode As Byte() = kode.GetBytes(Secret)
Dim cont As Byte() = kode.GetBytes(Content)
Dim hmcKu As New HMACSHA256(getkode)
Dim HashCode As Byte() = hmcKu.ComputeHash(cont)
Return Convert.ToBase64String(HashCode)
End Function
Result of my code is:
892q1ArPxIqrX48PQegliVql703V2fcipb5A08F053o=
You can see my VB code generates different result from PHP.
I have tried almost every method I got from internet but the result always different. So, what is equivalent hash_hmac of PHP on VB and what is the right way to make this same result?
Please help?
Use this:
dim hmac as HMACSHA256 = new HMACSHA256(key) ' key = Encoding.ASCII.GetBytes("<secret>")
dim hashValue as byte() = hmac.ComputeHash(Encoding.ASCII.GetBytes("<message>"))
dim result as string = BitConverter.ToString(hashValue).Replace("-", "").ToLower()
hmac.dispose()
I found solution from fb community.
This is exact solution for this cases:
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Imports System.Text.RegularExpressions
Public Class Form1
Private Shared DES As New TripleDESCryptoServiceProvider
Private Shared MD5 As New MD5CryptoServiceProvider
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim _ts, data, signature, secrete
secrete = "secret"
_ts = DateTime.Now.ToUniversalTime.ToString("yyyy-MM-dd\THH:mm:ss.fff\Z")
data = "_ts=" & HttpUtility.UrlEncode(_ts)
Dim reg = New Regex("%[a-f0-9]{2}")
data = reg.Replace(data, Function(m) m.Value.ToUpperInvariant())
signature = Encrypt(data, secrete)
TextBox1.Text = signature
End Sub
Public Function Encrypt(Content As String, Secret As String) As String
Try
Dim kode As New System.Text.ASCIIEncoding()
Dim getkode As Byte() = kode.GetBytes(Secret)
Dim cont As Byte() = kode.GetBytes(Content)
Dim hmcKu As New HMACSHA256(getkode)
Dim HashCode As Byte() = hmcKu.ComputeHash(cont)
Return Convert.ToBase64String(HashCode)
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Function
End Class
I am attempting to create a binary file that is not readable by notepad in windows. This file needs to contain text information. The current code I run is readable in notepad (with a few extra characters here and there, but still human readable). Any assistance is greatly appreciated.
Using writer As BinaryWriter = New BinaryWriter(File.Open("file.bin", FileMode.Create))
writer.Write(rtbWriter.Text)
End Using
All files can be read by notepad - whether it is binary or not. If you don't want the text to be readable (or to be more accurate - understandable), consider using encryption.
EDIT: For an introduction on how to use encryption, see the link below to see how to use the 3DES cryptographic service provider in VB.NET:
simple encrypting / decrypting in VB.Net
*A more sophisticated approach would chain together the File Stream and Crypto Stream...
...but here's a very simple example showing how to encrypt/decrypt individual strings so you have something to play with and learn from:
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Public Class Form1
Private Key As String = "SomeRandomKeyThatIsHardCoded"
Private data As New List(Of String)
Private DataFileName As String = System.IO.Path.Combine(My.Computer.FileSystem.SpecialDirectories.MyDocuments, "SomeFile.txt")
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
' Some data to play with:
data.Add("User X, Access Y")
data.Add("User Y, Access Z")
data.Add("User Z, Access A")
ListBox1.DataSource = data
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
' Write out each entry in encrypted form:
Using SW As New StreamWriter(DataFileName, False)
For Each entry As String In data
SW.WriteLine(Crypto.Encrypt(entry, Key))
Next
End Using
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
data.Clear()
ListBox1.DataSource = Nothing
' Read each encrypted line and decrypt it:
Using SR As New System.IO.StreamReader(DataFileName)
While Not SR.EndOfStream
data.Add(Crypto.Decrypt(SR.ReadLine, Key))
End While
End Using
ListBox1.DataSource = data
End Sub
End Class
Public Class Crypto
Private Shared DES As New TripleDESCryptoServiceProvider
Private Shared MD5 As New MD5CryptoServiceProvider
Public Shared Function MD5Hash(ByVal value As String) As Byte()
Return MD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(value))
End Function
Public Shared Function Encrypt(ByVal stringToEncrypt As String, ByVal key As String) As String
DES.Key = Crypto.MD5Hash(key)
DES.Mode = CipherMode.ECB
Dim Buffer As Byte() = ASCIIEncoding.ASCII.GetBytes(stringToEncrypt)
Return Convert.ToBase64String(DES.CreateEncryptor().TransformFinalBlock(Buffer, 0, Buffer.Length))
End Function
Public Shared Function Decrypt(ByVal encryptedString As String, ByVal key As String) As String
Try
DES.Key = Crypto.MD5Hash(key)
DES.Mode = CipherMode.ECB
Dim Buffer As Byte() = Convert.FromBase64String(encryptedString)
Return ASCIIEncoding.ASCII.GetString(DES.CreateDecryptor().TransformFinalBlock(Buffer, 0, Buffer.Length))
Catch ex As Exception
Return ""
End Try
End Function
End Class
Hey all, i have converted some C# PayPal API Code over to VB.net. I have added that code to a class within my project but i can not seem to access it:
Imports System
Imports com.paypal.sdk.services
Imports com.paypal.sdk.profiles
Imports com.paypal.sdk.util
Namespace GenerateCodeNVP
Public Class GetTransactionDetails
Public Sub New()
End Sub
Public Function GetTransactionDetailsCode(ByVal transactionID As String) As String
Dim caller As New NVPCallerServices()
Dim profile As IAPIProfile = ProfileFactory.createSignatureAPIProfile()
profile.APIUsername = "xxx"
profile.APIPassword = "xxx"
profile.APISignature = "xxx"
profile.Environment = "sandbox"
caller.APIProfile = profile
Dim encoder As New NVPCodec()
encoder("VERSION") = "51.0"
encoder("METHOD") = "GetTransactionDetails"
encoder("TRANSACTIONID") = transactionID
Dim pStrrequestforNvp As String = encoder.Encode()
Dim pStresponsenvp As String = caller.[Call](pStrrequestforNvp)
Dim decoder As New NVPCodec()
decoder.Decode(pStresponsenvp)
Return decoder("ACK")
End Function
End Class
End Namespace
I am using this to access that class:
Private Sub cmdGetTransDetail_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdGetTransDetail.Click
Dim thereturn As String
thereturn =GetTransactionDetailsCode("test51322")
End Sub
But it keeps telling me:
Error 2 Name 'GetTransactionDetailsCode' is not declared.
I'm new at calling classes in VB.net so any help would be great! :o)
David
Solved
Dim payPalAPI As New GenerateCodeNVP.GetTransactionDetails
Dim theReturn As String
theReturn = payPalAPI.GetTransactionDetailsCode("test51322")
You're probably getting that error because you need to call it like this:
Private Sub cmdGetTransDetail_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdGetTransDetail.Click
Dim thereturn As String
Dim myTransaction as new GetTransactionDetails
thereturn = myTransaction.GetTransactionDetailsCode("test51322")
End Sub
Or you can make the function be a public shared function and access it as if it were a static method
Your GetTransactionDetailsCode method is an instance method of the GetTransactionDetails class, which means that you need an instance of the GetTransactionDetails class in order to call the method.
You can do that like this:
Dim instance As New GetTransactionDetails()
thereturn = instance.GetTransactionDetailsCode("test51322")
However, your method doesn't actually use the class instance, so you should change your GetTransactionDetails class to a Module instead.