Encrypting And Decryption A File
Sep 20, 2011
I am actually really new to VB and C#. From numerous tutorials that i found online i was able to create a small program that will encrypt a file. However I am having a really hard time decrying it back.[code]All I am trying to do is to create a program that will decrypte these file with an upload button. Our system encrypts the files to prevent operators from changing the results, we need to trend the data. However it will take way to long to use the online tool provided with the software. A desktop tool will save us much more time. The files generated are 70mb and up.
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May 18, 2009
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
[code].....
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Feb 28, 2011
I'm having trouble writing the code to encrypt a file->networkstream->Decrypt the file.. I've tried several ways, but I keep failing....
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Oct 24, 2009
Im trying to create an encrypted file using a secure string and the AES128bit managed class to encrypt some data to a file.I have read many variations on the forums on how to do this but everyone seems to do it slightly differently. Ive created the below function and just wanted to confirm that this is the correct way to go about it.
[Code]...
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Mar 6, 2009
I finally managed to encrypt the user settings in my app.config with the following
[code].....
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Sep 13, 2011
I have a program and I want to make it so you need a specific key to use it. I want to store keys in a text file and also use encrypt strings from my program to a text file.
I'm using Visual Studio 2010 Ultimate and programming in Visual Basic
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Feb 26, 2012
Here is my code for encrypting a file:
Public Shared Function AESFileEncrypt(inputFilename As String, outputFilename As String) As Boolean
'Create SymmetricAlgorithm object and specify the Key and IV.
Dim AES As RijndaelManaged = New RijndaelManaged
[CODE]...........
This happens with large files. I gather that I have to use a fixed size buffer and read the file in small chunks, copying those chunks from the input to the output stream, until I reach the end of the input file.
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Dec 22, 2010
i will like to know if it will be possible to decrypt and encrypted file in vb.net or any without knowing the form of encryption..any information on how to go by it... in that if you lose the form on encryption can it be decrypted?
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Jul 29, 2009
Ok so I've made an encrypting/decrypting program and I've found a small bug with it. It will encrypt plain text files fine, except for the last character ( does anyone know how to fix this by the way? ) But when it comes to enrypting PNG Images.. well here's is the before and after files:
[Code]...
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Mar 4, 2010
I am working on a program that uses AES encryption to encrypt a file. I fully understand AES encryption (after lots of research) and I am able to encrypt a big long string of binary numbers. How do you turn a file into a string of zeros and ones. Actually, a file will probably be represented using hexadecimal, so......How do you turn a file into a string of hex values? Is this even possible in vb?
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Oct 8, 2010
i am looking to decrypt my HEX code file for an ATTiny chip and programming it using the AVRDude command line interface. Problem being, i do not want the user to be able to see what the HEX file is at any given time.Can the VB.net Cryptography crypt the HEX file before i put it onto the server and then decrypt it after the program downloads it from the server and runs it through the program without seeing the decrypted HEX file?Obviously the HEX file can not stay encrypted while being programmed to the ATTiny chip so how can i go about it so that i can create the original HEX file to be programmed within the program without having to worry about it writing a temporary file to the hard drive and then deleting it afterwards? (Because they could close the program after it does that temp file and they would be able to navigate and open it and see the code)
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Oct 8, 2010
i am looking to decrypt my HEX code file for an ATTiny chip and programming it using the AVRDude command line interface. Problem being, i do not want the user to be able to see what the HEX file is at any given time.
Can the VB.net Cryptography crypt the HEX file before i put it onto the server and then decrypt it after the program downloads it from the server and runs it through the program without seeing the decrypted HEX file?
Obviously the HEX file can not stay encrypted while being programmed to the ATTiny chip so how can i go about it so that i can create the original HEX file to be programmed within the program without having to worry about it writing a temporary file to the hard drive and then deleting it afterwards? (Because they could close the program after it does that temp file and they would be able to navigate and open it and see the code)
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Oct 7, 2010
i am looking to decrypt my HEX code file for an ATTiny chip and programming it using the AVRDude command line interface. Problem being, i do not want the user to be able to see what the HEX file is at any given time.
Can the VB.net Cryptography crypt the HEX file before i put it onto the server and then decrypt it after the program downloads it from the server and runs it through the program without seeing the decrypted HEX file?
Obviously the HEX file can not stay encrypted while being programmed to the ATTiny chip so how can i go about it so that i can create the original HEX file to be programmed within the program without having to worry about it writing a temporary file to the hard drive and then deleting it afterwards? (Because they could close the program after it does that temp file and they would be able to navigate and open it and see the code)
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Jul 12, 2011
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.
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Oct 8, 2010
i am looking to decrypt my HEX code file for an ATTiny chip and programming it using the AVRDude command line interface. Problem being, i do not want the user to be able to see what the HEX file is at any given time. VB.net Cryptography crypt the HEX file before i put it onto the server and then decrypt it after the program downloads it from the server and runs it through the program without seeing the decrypted HEX file?
Obviously the HEX file can not stay encrypted while being programmed to the ATTiny chip so how can i go about it so that i can create the original HEX file to be programmed within the program without having to worry about it writing a temporary file to the hard drive and then deleting it afterwards? (Because they could close the program after it does that temp file and they would be able to navigate and open it and see the code)
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Sep 29, 2009
I'm reading a file into a buffer using the Space function. Then I'm using blowfish dll's to encrypt it, and want to write the encrypted data to a txt file. (I realize you can use .NET cryptography classes, but I need to use these old blowfish dll's for this project.) Anyway, when when I encrypt the data in the buffer, I can see all encrypted data, but when I write it out to a file, I get a few lines of encrypted data and the rest of plain text.
HTML
' BLOCK_SIZE is a const which = 2048
sBlock = Space(BLOCK_SIZE)
Using sr As StreamReader = New StreamReader(FileToEncrypt)
sBlock = sr.ReadToEnd()
End Using[Code] ....
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Feb 10, 2011
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!
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Jul 3, 2009
I recently made a program that will automatically log in a site and start a game. I have it so that you can save the Username and Password to a text file. I need the text file to be encrypted though, and then decrypted when you load it back up.
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Mar 29, 2010
I am new to .net classes and i would like to know how can i encrypt a text with AES256 algorithm.
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Apr 8, 2012
I have a DER file with sha1RSA as the Signature Algorithm. I have to encrypt some data using it.Can anyone tell me how do I load the DER file and use the RSA public key in it to encrypt my data in .NET?
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May 19, 2012
I'm using the .NET version of BouncyCastle, and I have to save a private RSA key to file, obviously encrypted with a password for security reasons.What I'm trying right now is this:
Dim rand As New SecureRandom
Dim arr As Byte() = New Byte(7) {}
rand.NextBytes(arr)
[code].....
But BouncyCastle is thwrowing a NullReferenceException on the last instruction. Since the method is totally undocumented >:( I wonder if any of you know how to use it correctly...
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May 11, 2011
I have a requirement where I have to pass some values into the next page via querystring.This querystring is coming from third party and they need to have it on the otherpage for some analysis. I just do a response.redirect and add the querystring that i recieve from them to the other page. My problem is that the .net environment is encoding/encrypting some of the special characters used by them which I dont want as it does not bring back the correct values in the new page.
[Code]...
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Dec 11, 2009
There are many algorithms for encryption in internet. But i found them more complex. I want simple and powerful algorithm for encryption and decrytion of text.
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Jul 18, 2009
how to encrypting strings with SHA1, but all of the code I have found does not work or it is to complex for my program. I have found a website that has a encrypting demo program. It worked well so I email the programmer and he gave me this code.
[Code]...
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Feb 26, 2012
I heared about an encrypting function that encrypt the texts with a password I don't know exactly how it
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Nov 22, 2011
Im a Uni student and im having probs with encrypting an image and also the contents of a folder. I have successfully encrypted and decrypted a text file using the following code below.
If anyone could take a look and advise on how to alter my code to perform the task of selecting an image or folder and encrypting it and decrypting it via a secret key that you input within a textbox,
[Code]...
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Jan 15, 2010
what the relation between Serialization and encrypting files, i wanna know that and i wanna a lessons for serialization and i want to ask about this code in VB6 if we can convert it to VB.net 2008
Dim a As String * 10
Dim b As String * 10
Dim c As String * 10
[code]....
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Aug 9, 2009
how I can encrypt .pdf files? I haven't been able to find something that will give me an idea of how to do it.
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Feb 1, 2012
Here is some code that works well for strings:
[Code]....
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.
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Aug 25, 2010
I managed encrypting an xml document by encrypting an element and then replacing the element with the encrypted data. A shown in the sample code below. Public Shared Sub Encrypt(ByVal textReader As TextReader, ByVal textWriter As TextWriter, ByVal certificateName As String)
[Code]...
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