File Encryption By Using The Imports System.Security.Cryptography?
Feb 16, 2010
I'm working on a basic file encryption by using the Imports System.Security.Cryptography.I was thinking of putting a password as a final security measure.Would i have to store the password inside the file or how will this work?
I realize AesCryptoServiceProvider is part of .NET framework 3.5. I do have 3.5 installed. However, (I can't believe I don't know this), how can I utilized Framework 3.5 so I can access the AesCryptoServiceProvider? Currently, it points to 2.0.
Imports System.Security.Cryptography Imports System.IO Imports System.Text 'SymmCrypto is a wrapper of System.Security.Cryptography.SymmetricAlgorithm
[code]....
Most of the time this works as it should, but sometimes it encodes a string and the gives an error on decoding it. The error message is: Invalid length for a Base-64 char array.
I am trying to mimic the results of some C code that uses the OpenSSL library using the system.security.crytography library in the .net 3.5 world, and I can't seem to get it right. part of the issue is my understanding of crytography in general.
Here's what is supposed to happen:
I send a request for authentication to a device.It returns a challenge digest, which I then need to sign with a known key and return The device returns a "success" or "Fail" message.I have the following code snippet that I am trying to "copy":
What I've decided to start working on is pretty much a personal project but something I may use in my UNI course in due time. I'm creating a security program with a set of access codes (yes I am a bit of a star trek fan) - 4 in total to be exact. I want to be able to use an Encrypted key file in form of a simple notepad created text file to update the codes at any due time. All I'm looking to do is write the access codes to the text file (say for a friend to use the program), Encrypt the file through the program and be able to also decrypt to obtain the new access codes on demand also via the same program. Once decrypted the codes can be read and verified if the user has entered each one correctly. I could hard code the access codes into the program but would rather do it the way I've thought of.
Back in the days of the old VB6 there was a simple method but for some reason that doesnt work any more. What I guess I'm looking to do is have 4 text fields where 4 digit access codes are typed into, have the program take them and encrypt each one is then written to the text file. Hoping that will make it a bit clearer what I'm trying to achieve as I think I made it sound like I want to encrypt the text file after the info has been written to it, which is of course one option so wouldn't mind know how to do that too!
Public Class Form1 Imports System.Math Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load[code].....
For some reason, when i try to start the program im getting the following errors: Error1'Imports' statements must precede any declarations.C:Vb10sbschap05My Framework MathMy Framework MathForm1.vb25My Framework Math
Error2'Sqrt' is not declared. It may be inaccessible due to its protection level.C:Vb10sbschap05My Framework MathMy Framework MathForm1.vb1018My Framework Math
Im using Visual Basic Express 2010.This is from a tutorial in Microsoft Visual Basic 2010 Step by Step
Can anyone tell me if the Imports System.IO accepts all files types?? What I mean is, can I use it to access .csv, .xls or .doc files? And one other thing.Do I need to include the file location in the body of the procedure/function??
I am currently trying to create a DLL for use with a RESTful api. The only issue I have is that so that this DLL can be used in a service or a program without a GUI, so I can't use "Imports System.Drawing.Imaging" as this requires a form. I have looked around for examples to handle this without using this library but have had no luck.
When trying to compile my newly created ClassLibrary class 'Validator' that validates entries made into TextBoxs or MaskedTextBoxs, I get the following error:
Warning 1 Namespace or type specified in the Imports 'System.Windows.Forms' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases. C:Users erryDocumentsVisual Studio 2008ProjectsMillerClassLibMillerClassLibValidator.vb 1 9 MillerClassLib.
Following is the first part of code in the class:
Imports
System.Windows.Forms Public Class Validator
[code]....
What can I do to resolve this problem? The classes in this class library will be used to validate forms data input in a number of varied projects.
Alright I am trying to make a little login system with encryption. I am trying to see if the user entered in there encryption key, if they did then they can input there account. Same thing with the password textbox. If they already entered in there encryption key then let them type in there password. I am trying to make it so if there text in encryption key then let them type in there account or if they didn't then let them put it in then let them type in there account.
Dim AccountInfo As String Dim PasswordInfo As String Dim EncryptionKey As String 'account textbox [Code] .....
i am getting the error "System.security.permissions.securitypermission" when running the VB application in another machine. i have put the .exe file in the common path and i ran it my machine and it is working fine, but when i tried to run it in the different machine i am getting the error. Can anyone help me out in fixing this error.
I have made an simple application (.exe). When i run this program local on my machine it works fine. When i run it from an server i get the system.security.securityexception message.
my computer is running Windows7 ,installed .net framework 4.0.I know "system.windows.input" be supported by .net framework 3.5, but does windows7 already has that?
i want to manipulate complex numbers and i followed that link but when i typed Imports System.Numerics but it gives an error [URL] so how to overcome this problem?
I am trying trite code that will copy information from an infopath document to a word document that is being used as a template containing only a header and footer. The only reason for the code is becausthe footer (not optional) is too long to be handled by Infopath (which has a 255 character limit) and word can hold the full footer. Following the guidance on
Public Sub CTRL1_5_Clicked(ByVal sender As Object, ByVal e As ClickedEventArgs) Dim appWord As Word.Application Dim wrdDoc As Word.Document
I'm working with a vb.net 2005 project that i converted from vb 6.0 last year. It's working fine in windows xp, but on vista and windows 7 i get an error saying 'Insufficient security permissions to set the system time.' Can you think of any way to replicate this error on windows xp? I'm trying to get a windows 7 box setup at work but I was wondering if there was anything I could try with xp in the meantime.
I want to add a feature to my trial version of the application. After first activation, I want to make it limited to 90 days. But I am concerned about user's changing the date of system hence deceiving my application. Is there any possibility to make it fool proof in a way that even if user takes the calender back, application expires after 90 days of first activation? First activation date has been saved in the database.
Trying to read key "HKLMSOFTWAREPoliciesMicrosoftWindowsWindowsU pdateAU" value "AUOptions" and get the following : A first chance exception of type 'System.Security.SecurityException' occurred in mscorlib.dll Error occurs in ReadRegistry key SOFTWAREPoliciesMicrosoftWindowsWindowsUpdate AU : Requested registry access is not allowed. This occurs in my vb.net application when application is run under an account called OPER in the USERS group. The application :
1/is on my PC's hard drive, its not a web app or on a network share
2/is launched via a desktop click
3/ has a manifest specifying executionlevel "AsInvoker"
It does not occur when the Application is run as an Administrator. It does not occur if I read the value with a non .NET program when logged in as OPER whch makes me think it is a .NET problem not a registry permissions problem. Examining "Effective Permissions" shows that my OPER login has query value permission.I need the application to be able to read the key like the non .NET application while running at USERS level.
we are making our program in other computer it runs, without errors, but then when we transfer the program to another computer it has an error that says
An error occurred creating the form. See Exception.InnerException for details.The error is: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
I wrote a custom assembly for SSRS that returns a jpeg for the background image in a textbox on the report.I followed all instructions on msdn in regards to security but i still receive the same error.
ive been trying to use System.Security.Cryptography to encrypt and decrypt a file but its not working for me
this code
Private Sub EncryptFile(ByVal sInputFilename As String, ByVal sOutputFilename As String, ByVal sKey As String) Dim fsInput As New FileStream(sInputFilename, FileMode.Open, FileAccess.Read) Dim fsEncrypted As New FileStream(sOutputFilename, FileMode.Create, FileAccess.Write) Dim DES As New DESCryptoServiceProvider()