I'm working on software which encrypts/decrypts files. I would like to be able to guess the length of the data after the encryption but I can't use CryptoStream.Length (It throws a NotSupportedException).
I'm using RijndaelManaged (.Net Framework 4.0)
I'm encrypting a file with AES using CryptoStream. I'm also creating a CRC32 hash of the original file data. Later I need to decrypt the file and create a CRC32 hash of the decrypted data, in order to check if the decrypted file is 100% the same as the original file.
This is a part of the encryption routine. I'm reading a file in chunks and writing them encrypted to a new file. At the same time I'm creating a CRC32 hash of the chunks of data, which will give me the CRC32 hash of the entire file in the end. This works fine.
vb.net
'// Create the CryptoStream
Dim Crypto_Stream As New CryptoStream(FS, crypto_transform, CryptoStreamMode.Write)
[code]....
I am starting to use cryptostream class. I may be wrong, if you encrypt something, close the app, and then try to decrypt it, it will not be able to because a different key will be generated. Because I do need this functionality, I am wondering if it's possible to save the key in application settings and whether this is the right way to go?
View 2 Repliesthis is not working?
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End WhileI am trying to read from the ": " to the end of the line. I keep getting this error: Index and length must refer to a location within the string. Parameter name: length
am getting the above exception while swaping Items in the list(lstRoutePriority).PFB my code
if (lstRoutePriority.SelectedIndex > 0)
{
//Swap the two items
[Code].....
I have a field displaying on a datagrid that the user has asked to be variable length based on the data that is returned. Is there an easy way to determine how many characters are returned for a field and then converting that to a pixel length so that I can change the length of the field in the code.
View 2 Replies"Index and length must refer to a location within the string. Parameter name: length" whenever I run this code
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If using the following in an if statement I get an error: If trg.Name.Substring(4, 6).ToUpper <> ("ABCDEF") Then I get the error: "Index and length must refer to a location within the string. Parameter name: length"
I assume this is because the string (trg.name) is too small for the 4, 6 substring. What would be the correct method of working around this problem? VB.net Studio 2008.
When I load in the file to my program.
GPRS: 232154,456464,546
IP Addr: 123.456.2.789,9001
Interval: 12.5422
It appear Length cannot be less than zero. Parameter name: length.
My program is...
Private Sub Loadbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Loadbtn.Click
'Dim strFileName As String
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Sorry this is a very simple question but i am just too new to this.I can't get the code correctly and don't know what is wrong. If i enter Apple, i keep on getting When the word is written twice, 5 letters are used when it should be saying twice as much.
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What could caused the length cannot be less than zero in the following code?
For i = 0 To stPDFText.GetUpperBound(0)
If InStr(stPDFText(i), ("Page ")) <> 0 And InStr(stPDFText(i), " of ") = (InStr(stPDFText(i), ("Page ")) + 6) Then
If stReportPage(0) = "" Then[code].....
I want to get the time that a GIF file take to complete animation
View 5 RepliesI need to write the song length to an access database.I have worked out how to get to an mp3 song length. However, I also need to be able to get to the songlength for the following file extension :.kar, .mid, .kfn.
View 3 Repliesis have an IF..THEN statment in a VBS script that uses the underscore as a continuation so that the conditions for the IF are on separate lines, for readability. eg:
IF srvname = "A" or _
srvname = "B" or _
etc.
question is: how long can this IF..THEN statement be?
I have been trying to get the length of MaskedTextBox and then have the code perform a function.
Just so I am clear, I know I can use the MaskedTextBox.Full or the MaskedTextBox.Completed.
However, I would really just love to get the length instead.
Example:
If MaskedTextBox1.Text.Length = 5 Or _
MaskedTextBox1.Text.Length = 10 Then
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Could there be any specific reason why one can choose UBound over Length? Here is the code and 1-dimension is passed as second parameter.
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If I dim an array to say, 5 elements, should it not fail if I go to add a 6th? I thought this used to require a redim. In .NET 2.0, I have a character array of length = 3. When I populate it from the db, one record had 4 characters in it and it successfully added all 4 characters to the array?
View 2 RepliesI have a datagridviee with 8 columns. all the columns are generated programmingly. What i want is that, i want to fix the length as 6 of the 4 cells of the datagridview, remaining 4 will be readonly.
View 6 RepliesHow can I count the length of a string and also how many special characters are in the strings.
For instance if I have this string: $how*
How can I count that string is 5 chars long and that there are 2 special characters in the string. (special characters are the $ and
I think that I am going to have to use the .length method to count the length of the string.
i had the code belowing workin fine before but all of a suden i have a error init
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My form length is currently 1040 which when run displays as 870 and I use the vertical scroll bar to access the the boxes not displayed. I need more however, let's just say 1140 in length, but when I type that number into the 'size height' it only goes to 1044. Is there a way for my form to be the length that I need?
View 2 Replieswhat I want to do is I want to list every possible combination with alphabet A-Z and number 0-9 That will be AAAA?
View 8 RepliesI have some songs in the resources of my application and want to get their time length so that I can set a timer to tick when the song ends. And then start the next song. I want to do that in my code, and get the time length of a song as an integer value.
View 6 RepliesI am using the following piece of code (where sId is a Unique Id in our system) to generate Unique Hash value of 16 characters Max in length
Dim oMD5Hash As System.Security.Cryptography.SHA1 = System.Security.Cryptography.SHA1.Create()
Dim sHash As String =
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I was trying to grab the string length of readData but when I try msgbox (readData.Length),
its giving me a large numeric digit instead.
Dim readData as string
serverStream.Read(inStream, 0, buffSize)
Dim returndata As String = _
System.Text.Encoding.ASCII.GetString(inStream)
readData = "" + returndata
msg()
Here is the code I am trying to get to work:[code]I have managed to check for null. it is just the length check that I am have difficulty with.
View 12 RepliesWhen I try this code, Content Length is always -1.
Dim Request As HttpWebRequest = DirectCast(WebRequest.Create("http://www.google.com"), HttpWebRequest)
Dim Response As HttpWebResponse = Request.GetResponse()
[Code]....
Is there a way to shrink the length of the prompting box within VB. I just want to obtain 1 value and would rather not have to create anotherform with a single text box and label.
View 1 RepliesI keep getting the error saying that index and length must refer to a location within the string. I am sure there is just something minor that I am missing but I am having a difficult time figuring it out.
CODE:
I have some code that is meant to check the length of the values in the text boxes, and if any of the boxes has no content the length of the string is 0 (or null). Here is the code:
If (Len(Form_MainScreen.Ctl48.Value) Or Len(Form_MainScreen.Ctl49.Value) Or _
Len(Form_MainScreen.Ctl50.Value) Or Len(Form_MainScreen.Ctl51.Value) Or _
[code]....
When one string is blank, the length check becomes "null" and so does the whole statement.But if the length checks are all not null, the if statement becomes a "1" and then procedes to execute the Do X procedure again.