VS 2005 Encryption/Decryption With Crytography Classes?
Aug 25, 2009
I'm using the cryptography classes in .net to encrypt and decrypt files. When I encrypt a txt file, then decrypt in my code it works fine. But when I encrypt an xml file and try to decrypt it within my code I get an error saying "padding is invalid and cannot be removed." I am setting the padding during both the encryption and decryption as:
PaddingMode.PKCS7. Do you think the file being an xml file has something to do with the error that's occuring? Also, should I or should I not be setting the padding for both encryption and decryption?
modifying these functions to encrypt/decrypt byte arrays rather than strings. Also, to have the functions return the encrypted/decrypted byte array, rather than a string.
My purpose is to encrypt the database so that it cannot be open independently without using the application. my application should still be able to access it read/write.
At the moment I have a Form containing two text boxes and two buttons. I want the one textbox to be used to type a message (to be encrypted) and the second textbox will be for a key to decrypt the message. Button one will be for encryption and button 2 for decryption.
From desktop application I want to upload an image. Then want to pass that image to webservice which encrypt it and pass it to another webservice which will save the encrypted image in the Access database. And then using ASP.net want to decrypt the image.
I have a Problem to Decrypt my crypted files :e.g. if I encrypt this text:
B�AR B�LASDJASPDJAPSDJPASDJPASD asdj ...
And Decrypt it:
AB0_�-M3‚S�r�WPJAPSDJPASDJPASD asdj ...
The first chars are wrong! My Code to Encrypt and Decrypt :
Encrypt:
Public Shared Sub EncryptFile(ByVal sSource As String, ByVal sTarget As String, Optional ByVal BufferSize As Long = 4096) Dim ErrorHappened As Boolean = False Dim OldFileStream As FileStream Dim NewFileStream As FileStream
I need to encrypt a string using javascript and decrypt it using vb.net, is there a compatible encryption/decryption method between javascript and vb.net to be used?
[Code] I need to do a video encryption/decryption on p2p chat. The concept for my understanding is to capture the video, encode it then encrypt, on the receiver side is to decode and decrypt it.
I need to encrypt an XML file, send it to another location and decrypt it there. As you can see from the codes below, I am using the same key but it won't work (for now im simply using two local files).
The error I get is as follows:
Padding is invalid and cannot be removed.on this line in Decrypt.aspx: Dim xReader As XmlTextReader I am thinking it might be at the actual encryption stage causing errors e.g., file not saving correctly.
Encrypt.aspx Dim rijnAlg As RijndaelManaged rijnAlg = RijndaelManaged.Create()
I'm trying to find a simple and easy encryption/decryption method for strings. The strings will contain spaces, special characters, numbers, and letters. I just need to be able to encrypt/decrypt them.
I was board making web browsers and OS so, I tried making an Encryption/Decryption program. I surfed the net and found a source code. But, after doing everything, I debug it, click the encrypt btn and nothing happens. I though the encrypting is a slow process. The thing is the process should be immediate cause I downloaded this web browser called 'Areo Pack'. It comes with a few other program and one of them in an Encryption/Decryption program. I tried it and it was done in a few seconds. I tried opening the encrypted file with notepad and I see a text file with Chinese, Japaneses, Korean, etc.
Imports System.Security.Cryptography Imports System.Text Public Class Form1 Private Shared DES As New TripleDESCryptoServiceProvider Private Shared MD5 As New MD5CryptoServiceProvider [Code] .....
I am trying to make a key that will be used in file encryption/decryption for my application. However, there is no user data involved with this application (As i would usually use the user's password to generate the encryption key), so i have to turn to another method.
I am thinking that maybe it is possible to generate a completely random key the first time the program runs, then save this key inside the program so that it is inaccessible by the user. The user will not be shown this key, but the key MUST be randomly generated for each application, and it also must stay constant once it is created.
Is there a way to encrypt/decrypt text (string form) in VB.net using another string as a key? Meaning, if one user encrypts using this key, the other user needs to decrypt using the same key?I do NOT mean public and private key encryption or anything of the sort.If not, what is the second best way to encrypt/decrypt data without public/private keys?I want to make a simple way to send messages securely.
This is for a simple encryption / decryption program. However when I run this the program does nothing and doesnt respond. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim decryptedtext As String Dim encryptedtext As String Dim k As Int16
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!
I have (using some examples) created a program which reads from a file, encrypts the content and writes it to a new file. The file can then be reopened in the program and decrypted.Now I am trying to adapt the program to split the file into pieces as specified by the user whilst it is been written to the hard drive. This also works, but when the files are read and decrypted the original file seems to be corrupted. I have been testing it using a JPG which turns out viewable, but is distorted. However the filesize is the same as the orignal after the encryption/decryption process. [code]
I want it to do is that you input a string, then you select an algorithm (Theres only going to be one RijnDael) then you input a key, then the Initialization Vector comes from "txtIV.text" then you select the key bytes and the block bytes from the numeric up/down, then you either encrypt or decrypt.
I've got a site using .netCART. It's running fine in production with Windows Server 2003 and .NET 2.0. On the new server (Windows Server 2008) everything is working except for credit card decryption in the store admin. No errors are being sent, no exceptions thrown, just the encrypted string being output to the screen instead of a decrypted credit card number.
Dim strCCEncrypt As String strCCEncrypt = Trim(DataRow.Item("CreditCard")) strCCEncrypt = tools.Decrypt(strCCEncrypt) 'tools is a .netCART utility
Public Function EncryptString128Bit(ByVal vstrTextToBeEncrypted As String, _ByVal vstrEncryptionKey As String) As String Dim bytValue() As Byte = Encoding.ASCII.GetBytes(vstrTextToBeEncrypted.ToCharArray)
I'm making an application that will be available as both a Windows App and an ASP.Net App. The web app has a much scaled-down version of the functionality of the window app. I want to reference the classes contained with the windows app from my web app. The thing is, my classes in the windows app may have some modifications: if I reference them in my web app, will this pick up the changes made automatically? Also, referencing the project is for development work, when I go to deploy the web app, I will probably need to reference the classes as dll's. So the next questions are: 1. Is this the right way to go about doing this? 2. How do I make the Classes I have into self-contained dll files?
I have tried this question several times, sometimes a little in the face of MS VB teams but with no constructive answers. Perhaps with too much rant. I suspect that VB.NET does not allow me to do what I can easly do in VB5.0. The VB team should easily be able to supply the information I need, but have not yet answered the questions. I want to do a lot of work on very large bitmaps (20 Mp or more; 80Mb or more ARGB) using arrays for access. This I used to do in VB5.0 using the SAFEARRAY and BITMAP STRUCTURES. NOT the corresponding .NET CLASSES. But I now need to use an SDK requiring .NET. However, through lack of wisdom, the VB team dropped 5 critical resources on the move to VB.NET - VarPtr, VarPtrArray, the 2 structures and CopyMemory. The SAFEARRAY CLASS seems to lack a set method for array data and the BITMAP CLASS seems to lack both get and set methods for data. On building a .NET solution using VB.NET, c#.NET and C++.NET projects I could not locate the set and get methods. Interop could not upgrade my VB5.0 to VB2005 - presumably on account of these 5 problems. I was surprised that even C++ suffered too. .NET hurts. So, first off, two critcal simple questions: A) Bearing in mind that much of the .NET is tinsel-wrapped APIs, does a pointer to an array still point to a defining SAFEARRAY STRUCTURE of the original format (NOT of course to a first element of an array). If that is so, I am lucky for I can then fill and use (perhaps) my own SAFEARRAY STRUCTURE by memory manipulation in C++. B) If the same applies to a bitmap pointer I can then perhaps do the same with BITMAP STRUCTURES. If that can be done I can hopefully work in a .NET solution containing C++ (for the pointer and mmory work) and VB2005 (for the rest of the work). I can then 1) in VB define two empty byte-arrays GLOBAL in VB.NET- Pic1() and Pic2(). They do not need to be dimensioned. SAFE FROM GC 2) in VB define two GLOBAL SAFEARRAYS to match the arrays, one with one and another with 2 dims matching the bitmap in size. SAFE FROM GC 3) move ByRef the 4 objects to VC++. STILL SAFE FROM GC, LEFT EXACTLY WHERE THEY WERE. 3) copy the BITMAP data pointers to the data pointers of the SAFEARRAYS. DOES NOT MOVE ANYTHING. 4) copy the addresses of the SAFEARRAYS to the corresponding arrays STILL DOES NOT MOVE ANYTHING, BUT JOB DONE. And then I will be able to process the images in seconds rather than minutes after moving only 4 4-byte numbers. I would welcome alternative sequences, provided they DO NOT involve put and set pixels or array elements on the trivial side and do not involve moving 80Mb of image data between "safe" and "unsafe" memory on the Herculian side. Else, as the Pic() ans Safearrays MUST point somehow to structures, WHAT EXACTLY ARE THEY, AND WHERE? I want to access them. If I can't overcome these 5 silly MS blunders I'll just have to build two uncoupled projects - one in VB5.0 and the other in VB/VC++ .NET. I'm not going to get involved myself with tinsel and gladwrap workarounds.
I have set up a method in vb.net and in xcode for encrypting a string using as far as i can tell the same parameters for an AES encryption.I've looked all over the place but cannot find information on whether they use the same encryption algorithm and settings.
this is the vb.net code:
Dim encryptAES As New AesCryptoServiceProvider() Dim encoding As New UTF8Encoding() Dim encryptor As ICryptoTransform encryptAES.Key = encoding.GetBytes("12345678901234567890123456789032") encryptAES.IV = encoding.GetBytes("1234567890123416") encryptAES.Mode = CipherMode.CBC
I've read that modules are basically shared classes. For a module though, you can call a method directly without prefixing the module name. So I can do this: methodTest("abc", mod1Enum.enum2)But for a class with shared members I have to fully qualify the method call, and in this case fully qualify the enum:[code]In our conversion from VB6 to .NET the need to fully qualify all calls like this might be an argument for us to bring our VB6 modules over as modules instead of converting them to classes.
bare with me here ok I posted on here a while back, like month to 2 months ago about creating an array of data (user inputed data). But was suggested to go the class route. After weeks of lengthly reading came up with a list collection class.
