I have spent quite a while trying to solve this problem.I would like to be able to decrypt a file using an old password, then encrypt the file with a new password in memory. I could easily write the unencrypted file to disk then encrypt the file with a new password, BUT I was trying to keep the unencrypted file from being written to disk. Could someone point me in the right direction?
Private Function ReEncryptFile(ByVal PathToFile As String, ByVal OldPassword As String, ByVal NewPassword As String) As Boolean End Function I've been using a cryptostream to decrypt the file, but I cant seem to figure a way to encrypt the crytostream afterwards (or convert it to a memorystream and (re)encrypt the memorystream)
I've attempted using code snippets as a test to encrypt a string, save it to a file & the reload it back, decrypting it. I consistently get a "Padding is invalid and cannot be removed." error on decrypting the string.
I use the following Rijndael code to do encryption without fail for many times. But why it can not encrypt an ISO file with 4.2 GB? In fact my computer has 16GB memory and it should not be a memory problem. I use Windows 7 Ultimate. The code is compiled as winform (.Net 4) using Visual Studio 2010 (a VB.NET project).
I have checked that the ISO file is OK and can be mounted as virtual drive and even can be burnt to DVD rom. So it is not the ISO file problem.My question: Why the following code cannot encrypt an ISO file with size of 4.2GB? Is that caused by the limitation of Windows/.NET 4 implementation?
At first i thought it was the padding since mcrypt uses zero padding but i changed the php to use PKCS7 and get the same exact results.I think it has something to do with the padding in the php.Test output from .Net:
I'm trying out the Rijndael to generate an encrypted license string to use for our new software, so we know that our customers are using the same amount of apps that they paid for.[code]...
I want to know if I can directly read or write values in the current process in a Visual Basic 2005 Windows application. Like *(DWORD*)(0x123456) = 1; in C++ will write the value 1 at the address 0x123456. So anyway to do the same in VB using only built in functions and not using ReadProcessMemory and WriteProcessMemory?
how can i release a form from memory i am using public variables in my form , & the same variables are appearing on the form controls , like text box and datagridview values
We have an application that has a memory leak. The leak occurs when we run batch processes that utilize objects in a COM library (ArcObjects by ESRI). It's not real noticable when the batch is small, but when it gets into several hundred interations the memory leak gets into the hundreds of megs.
We've looked over everything and made sure we're doing Using... End Using where possible. We've made sure all our objects implement iDisposable and explicitly dispose of their COM references in the Dispose method. We've put in explicit calls to the garbage collector. My development lead has fretted and pulled his hair out on this one for two years. Still the leak remains.
Today I noticed something strange. I ran a large batch process and the app had grown to several hundred megs in size. I had the task manager up with the app - looking at them at the same time. I moused over the 'close' button on the app and suddenly the app dumped about two thirds of it's RAM. Mind you - I didn't actually press the close button, just moused over it.
So something happened inside the app that caused it to clean itself up, but I don't exactly know what. If we could find out what happened maybe we could plug this leak.
It's several years since I last used BitBlt and the like in VB6, and I'm just refreshing my memory with a little sample app before using it on the current project I'm working on in VB2005. I've come up with the following:
I am using a slightly modified version of this code. to create a mission critical application. That files that will be encrypted are very important. This has to be done from scratch because there are some other things that has to be done along with this. How secure is this? Its impossible to crack this encryption right? [Code]
My current approach of using Rijndael is to use a pair of static Key and Iv for all encryption operations (I mean I use this pair of Key and Iv for all protected files in my computer).
I heard that IV must be unique for each Rijndael encryption. Is that true? What is the problem (if any) for my current approach of using single static Key and Iv pair?
Im using Rijndael (as AES algorithm) for encrypting. I encrypt the values (objects properties) and serialize the object to xml an dsend the xml to the receiver via a web service. I want to pass along the encrypted symmetric key that I used to encrypt the data. But what key should I pass along?
My decryption algorithm looks like this (vb.net):
CODE:
If I want to decrypt the encrypted string I have to use both key and IV, but I think I have to pass along only a key value. Do I have to do this another way or what should I pass along? My specification says that the values have to be encrypted using AES and a 128 bits key.
I'm building SQL statements with a bunch of values from a dataset. Obviously that gives some really long names to put inline or even in parameter. addwithvalue code so beforehand I just declare a bunch of variables with really short names and assign them to the DS's exact fields like: [code] but this way I'm putting all the data in the dataset into memory twice by copying it into a new variable, right? So I was thinking, if it's just a string variable representing a field on the dataset, why not declare it by reference so the variable is basically a handy nickname pointing to that field in the dataset.Will it even work to have a string declared by reference and connected to one value inside of a dataset? And if so, will that stop duplicating everything in memory? I forgot how to declare a variable as a reference to another variable instead of the normal way in VB.
What's the difference? I'm going to create a password encrypting program, and I wanted to know what's the basic difference about the managed class and the "not managed" class.
how to avoid this error?"Insufficient memory to continue the execution of the program "i always got this error when i trying to execute or run my program.. it come to the point that time error will appear.
I've made a screen capture program, and I have a program to play back the captured clips (right now there's no sound). All of the data is stored like so:
I recently have been developing a app that uses the rijndael encrypt and decrypt function it stores dates in the registry (encrypted with a key using the algorithm)
for example Dim strOldDay As String = Key.GetValue("UserSettings", "").ToString the key was made using a private function called "createkeys"
example: dim current as currentdate Current.Day = DateTime.Now.Day.ToString Current.Day = Encrypt(pPassPhrase, Current.Day)
I am using Visual Studio 2005 with Service Pack1 installed. I am working on VB.Net project. However I am constantly choked up even I am in editing mode, i.e., I am NOT in debugging mode. Here is what bothers me:
I have a VB.net 2005 app using the Microsoft.Office.Interop.Excel.dll version 11, deployed on a number of XP machines with Office 2003 installed. On one and only one machine I get the following error:Error -2147467261 Attempted to read or write protected memory. This is often an indication that other memory is corrupt.The line which triggers the error is:
xlSheet.SaveAs(strPathXLS) xlSheet has been previously defined by Dim xlSheet As Microsoft.Office.Interop.Excel.Worksheet
This should save an Excel file in a folder on the desktop. I can save a file from Excel in that folder, and create a new Excel file in it from the right-click option. The app is working correctly on the development machine and at least 8 other XP boxes on site.All Office and dotNet 2 updates have been applied.Office and dotNet have been uninstalled and reinstalled to no effect.
I don't know whether it is simple or not because i am new to programming. my requirement is : In my vb.net winform application, the filenames of the files present in "D:Project" willbe displayed in DataGridView1 control. Now I want to load these files one after another into memory stream buffer and add the headers("ID","Name","Class") to the content in the file. Then I want to save these files in "C:" with "_de" as suufix to the filename i.e.,sample_de.csv.
In VB 2005, I am calling a C++ DLL function that returns the address in memory and size in bytes of a jpeg image. How can I load that jpeg image directly from memory into a picture box in my VB form? I cannot afford to save it to disk first.
Im getting a problem with one of my programs I have made in visual basic.NET where it gives me a memory error when i debug the program in the IDE. the exact error is this: "Attempted to read or write protected memory. This is often an indication that other memory is corrupt". My program basically has a few forms with text fields on that get their text values from an access database on the same hard drive. Im wondering if im doing something wrong because my program just seems to eat up memory whenever it does anything. For example I have one form that has a combobox on it and when you change the drop down list selection it retreives a few strings from the database and puts them into the relevant text boxes, if you keep changing the selection then the memory usage (in task manager) just keeps going up and up. occasionally I get the error mentioned above when debugging but in my built version of the program it throws an exception everytime the memory usage gets past 49K.
Also I noticed when debugging in the "immediate window" frame I get the following message often:A first chance exception of type 'System. Invalid OperationException' occurred in System.Data.dll...Do I need to somehow be "releasing" the memory that is used to gather data once it becomes redundant?
Attempted to read or write protected memory. This is often an indication that other memory is corrupt. Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
QuoteSystem.AccessViolationException was unhandled Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt." Source="System.Windows.Forms"
Im designing a web browser and i continue to receive this error after going to about 3 websites it crashes with that error.
I have a BackgroundWorker object that I instantiated to perform a DB process on a background thread ansynchronously. I have event handlers for DoWork and RunWorkerCompleted. I can tell that the BackgroundWorker is disposing of itself because I added a message box into the Disposed event handler.Is it necessary to detach the event handlers to ensure that the memory is cleaned up and that there are not memory leaks?
