Construct Byte Arrays That Will Be Guaranteed To Come Out Of Encryption At A Pre-determined Size?
Mar 31, 2011
Working with System.Cryptography, I'm noticing that data arrays up to a certain size will either conform to the size of the Initialization Vector (IV) or the size of the Key provided. So with a 48-byte Key and a 32-byte IV, up to around 42 bytes of data will encrypt to 32 bytes and 44+ will encrypt to 48 bytes of data. I've tested this with a variety of data arrays, and it seems to always come out the same... but I have a concern that higher byte values in the original array may result in longer encrypted arrays.
how or whether I can construct byte arrays that will be guaranteed to come out of Encryption at a pre-determined size?
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Oct 6, 2008
I am in need of encrypting a byte array, but my encryption method that I found strictly deals with strings.
Here are the two pieces of code that I am dealing with.:
The byte array (the bytes that need to be sent encrypted)
Code:
Dim outStream As Byte() = System.Text.Encoding.ASCII.GetBytes(TextBox2.Text + "$")
serverStream.Write(outStream, 0, outStream.Length)
serverStream.Flush()
[Code]....
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May 27, 2010
I have a need to construct a command Byte to send to another device using bit wise operations.There seem to be plenty of article on how to do this for indiviual bits using an OR'd constant but how do I do this for values that span multiple bits? eg "Bits 4-1" set the repeat count".so how to I inject a repeat count value of say 7 into my command byte?
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Apr 6, 2011
Objective: Combine byte arrays, read specific sections, and then cut byte array at specified point.
Private Sub DataArrival(ByRef aBot As xyzSocket, ByRef theData As Byte())
Dim RDLength As Int32
If aBot.ReceivedData Is Nothing Then[code]....
I'm not sure if I have this right to begin with because I can't test it without having it completed.
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Sep 20, 2011
I have 2 byte arrays. I want to merge these two byte array into 1 byte array.Usually, I just create a new byte array with length = byte array #1 + byte array #2. Then copy byte array #1 and #2 to the new byte array.do I have more efficient way to merge 2 byte array using VB.NET and .Net 4?
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Jul 16, 2009
when I click the Open button a file is opened and its items are sorted alphabetically. to do this I have doubled the size of my list. However, when I click the button again to reopen the same file, the items will ADD ON to the previous open-file event even though I have this piece of lstListboxTwo.Items.Clear()(the correct thing is to clear the previous items and add the new ones)So I think this has to do with the new size of my list..I think that I have to set the list size back to its normal size when re-clicking on the button.
Public Class frmForm
Dim List() As String = {""}
Dim count As Integer
[code]....
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Aug 7, 2009
I'm trying to combine 2 byte arrays and then create a new byte array that contains the contents of both but running into a problem. The error says 'Source Array was not long enough.' I'm trying to combine HeaderByteArray and bytBuffer into newByteArray. I don't understand what Source Array is not long enough means and how to correct this.[code]...
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Mar 9, 2009
I am trying to compare two long bytearrays in vb.net and have run into a snag. Comparing two 50 meg files takes almost two mins so I'm clearly doing something wrong. I'm on an x64 machine with tons of memory so there are no issues there. Here is the code that I'm using at the moment and would like to change.[code]...
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Jun 8, 2011
I think there is Copy.to function but i cant find it
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Jun 24, 2009
A project requires to allocate a varying number of byte arrays (buffers).
It would be ideal if the following definition would be possible:
Dim ArrayOfBuffers() as buffer(10000) as Byte
The byte arrays must be ordered sequentially because they have to be written to a file by efficient procedures destinationFile.Write(ArrayOfBuffer(3),1000,1000)
The number of buffers will change during program execution sometimes. Therefore it would be nice to be able to do a ReDim on the data structure when needed.
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May 16, 2012
am trying to pass a structure that contains 2D arrays as Byte from VB.net to a C++ dll. The dll returns the structure with the 1D arrays filled. I am using UnmanagedType.ByValArray to pass the arrays from VB.net to C++.
Sample :
----------------------------------------- Structure -------------------------------------------------------
<Serializable(), StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi, Pack:=1)> _
[Code].....
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Jun 11, 2010
I am having some major problems with byte arrays. First off the bigger array I have the more values go missing, I originally wanted to make a huge array and just dump like a 100mb chunk of memory in it but when I did that every byte in the array returned 0. So I experimented a bit and found 4kb to be the biggest chunk size to reliably not return 0.. ok I figured I'll just loop the 4kb and glue them back together later but no such luck, after being combined into the main array the bigger the number gets the more values that should be there just aren't.
Here's a code sample:
Dim retval(4095) As Byte
Dim combval(RLen) As Byte
For i = 0 To RLen - 4095 Step 4096
ReadProcessMemory(ProcAccess, i, retval, 4096, 0)
retval.CopyTo(combval, i)
Next i
WriteLine(combval(321603964))
WriteLine(ReadMemory(321603964, 1)(0))
So with the last 2 lines if I pull up some smaller number like 8 digits or so it reports back no problem but anything slightly bigger like the number i have written in there right now is just 0. After some additional research I discovered that the reason why 4kb is the max size I can reliably get is coz that's the size memory chunks are made of, "page" as they call it. Why the memory reading drops off at higher addresses alltho I suspect it has something to do with the way memory is structured and I am just not hitting the startpoint of a page anymore due to an offset or something somewhere.
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Jun 21, 2011
I have an aspx page which houses an iframe. When a button is clicked, a WCF is called to produce a PDF which is read into a byte array. I was storing the byte array in a Globals.vb file like this:
Public Shared PDF_Data as Byte()
The global was loaded from the parent aspx page like this:
PDF_Data = MyWCF.Create_PDF_File(SomeVariable)
After that, the iFrame's src was set to a blank aspx page, which had the following code in the page_load event:
'Write the PDF binary data to the screen (viewer)
Response.Clear()
Response.Buffer = True
Response.ContentType = "application/pdf"
Response.BinaryWrite(Globals.PDF_Data.ToArray)
However, realizing that this application will have several users who will get different PDF documents, I have learned that this is not the way to go. My shared variable would be accessible to all users, a big no-no.However, I am stumped as to how I'm going to store the byte array and make it available to a child aspx page from it's parent.
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Feb 10, 2011
The relevant code below is not achieving what I hoped it would. I intend for
1. SerialPortBufferTemp to be used as the container for each Serial Port Read.
2. _buffer should contain the resultant array from two separate Reads, the second appended directly after the first.
(E.g. 60 bytes read on the 2nd Read will be appended to the 168 bytes received on the first Read (228 total resultant byte length))
The problem with my code below is that _buffer has increase in size from 300 bytes to 600 bytes, skipped bytes 168 to 300 (leaving them all zeros) and added the remaining 60 bytes from the second read beginning at _buffer[300].
private List<byte> _buffer = new List<byte>();
byte[] SerialPortBufferTemp = new byte[300];
serialPort1.Read(SerialPortBufferTemp, 0, iBytesRead);
if (iValidRecordCtr == 0) {
_buffer.Clear();
[Code] .....
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Dec 31, 2009
I can open a file in a hex editor and know that each 2 digits is a byte, they are 8 digits in binary correct?
How are they stored in arrays in VB.NET?
So if I have:
Dim xx() as byte =
What would I put after the equals? The hex digits from the hex editor? (This is just a program I'm not going to save, basically I don't want to open files to get etc. I want to put in the bytes in the code.)
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Nov 28, 2011
As a continuation of my other thread, "Finding A Pattern without a string Array (http:[url]....)", I would like to continue asking questions about enhancing a scanner with a few things:
1. Here is my code for finding signatures in a file:
'First the Signature Class:
Interface Signature
End Interface[code]......
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Jun 12, 2009
My app is receiving data in blocks but I don't know what size data will be received until it is finished, unlike file reading. So my app loads the data in chunks of 1024 bytes and then stops when there is no data to read. My question is, is it possible to keep increasing the size of a byte array as the data is being received?
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Apr 12, 2010
being used to PHP and the easiness of creating arrays with no specific size... I'm hating arrays in VB.
Is there a way I can create an array who's size I won't know?
I'm pulling information out of an XML file and need the information available in another sub - so I'm stashing it in a public array I create at the beginning of the form.
[Code]...
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Sep 24, 2010
What's the best way to convert a varying size byte array to a string, and then to convert it back?
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Dec 16, 2010
I inherited a project that includes a dialog between two applications. One in native C++ the other in VB.NET. The protocol is such that the first 4 bytes (32 bits) of the message encodes the size. However the VB.NET side never sets these first four bytes, however it does use the .net method BeginSendTo, which accepts an argument for size. Does the BeginSendTo method automatically add the size to the beginning of the message in the form of a 4 byte int?
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Apr 20, 2011
In languages like C++ and Java, it is possible to declare an array of an arbitrary size and then give it a specific size later in the code.
[Code]....
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May 25, 2009
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?
[Code].....
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May 25, 2009
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?[code]...
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Oct 11, 2010
i am in the process of learning myself VB.net (2010 dotnet 4 )And am a litte confused in whats the best way to program what can be called an array.i want to have an array that looks like this,
{{"aap", 1}, {"noot", 2}, {"mies", 3, "boom"}, {"vuur", 4, 7}}
now i tried to declare
[code].....
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Jul 12, 2011
When the program starts, it checks for the amount of threads the user wants to use to download files with. The threads are then created. When the user chooses a file to download, the threads begin grabbing the file until it's fully downloaded.The problem is, some threads stall right from the start, & just sit there doing nothing.The global work variable is Sync-Locked, then quickly released by each instance, & to my eyes, there is nothing wrong.They are all instances of the same class, & do the exact same thing, so why is it that some run, & others don't?VB.NET is the programming language. They are looping Background workers.I would really like to know why some run, & others don't.btw... they have quick non-blocking sleeps, as well as blocking sleeps to allow others the chance to run (proprietary non-blocking DLL).So all i'm left to think on is that Microsoft's process queuing has some type of bug going on in there someplace....or is there a way to do multiple looping threads where they're guaranteed to run?
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Jan 18, 2009
Im looking for a method to parse incoming byte arrays. The code i use now for recieving is:
[Code]...
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Aug 7, 2010
Why does C# define Byte+Byte=Int32 instead of Byte+Byte=Byte like VB?
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Jun 21, 2011
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
[Code]...
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Feb 25, 2012
I'm Using Visual Basic 2010, and what I want know is how I can create different list on a single ComboBox. Practically I've 2 ComboBox... the first with a list of Items inside and I want to create a second ComboBox With Different types of list based on the choice of the first ComboBox..
Example: First Combobox with all the continents and the secondo ComboBox With all the Nations, I want that the Nations list of the Second ComboBox change according to the Country selected from the list of the first ComboBox...
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Mar 25, 2010
I have a form with a tabcontrol and 4 tabs. I want to open a form with showdialog in a predetermined tab.
I've tried
OptionsForm.OPTS_TabControl1.SelectTab(1)
OptionsForm.OPTS_TabControl1.ShowDialog()
but it didn't work.
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