VS 2010 - Creating Library To Encrypt / Decrypt Files With AES
Sep 20, 2011
I'm attempting to create a little library to encrypt and decrypt Files with AES. There are loads of examples of how to do this on the internet so coding is not a problem. There are however a few questions regarding cryptography and AES in general.
#1 Does the IV need to be kept a secret like the key ?
#2 Can I just hash a string with SHA512 to make a key for AES ? or do I need to use PasswordDeriveBytes ?
#3 In the case of me using PasswordDeriveBytes Do I need to keep the salt a secret ?(or do I need to keep it at all)
#4 Can I generate the IV from the same password that the Key is derived from ?(if so How ?)
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Dec 26, 2011
I'm designing a program to encrypt and decrypt files using TripleDes Encryption algorithms but am having issues decrypting an image file. The file encrypts in the correct manner, but when I go to decrypt the file and open as an image I get an error message. One example is when trying to open the file in paint a message appears stating 'c:New FolderDecrypted.jpg Paint cannot read this file. This is not a valid bitmap file, or its format is not currently supported. My coding for the form is shown below:
"Imports System.Windows.Forms
Imports System.Security.Cryptography
Imports System.Security
[Code]....
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Jan 12, 2009
Lets get down to it, Basically, I'm making a kind of "Anti-Hack" for a project I'm working on.The basis of the "Anti-Hack" is the check processes for names of known Memory Editors, For example, one memory editor I am scanning for is Cheat Engine.exe, I am using this code to scan for it, then I use the result to activate a different piece of code.
If Process.GetProcessesByName("Cheat Engine").Length = 0 The
'It's OK
Else
<Removed for obvious reasons>
End If
Basically, I don't want my code to look like a library of If statements when the only thing I am changing is the process name, what I want to do, is have an encrypted .dat file with an array or list of known tools. I want to then go through the array/list and keep checking for instances of them running.I know nothing of how to encrypt/decrypt .dat files through VB. (I'm not an expert at it atm )I am open to other ways (Easier ways) of doing this, like a Class with a list of names etc.
**NOTE** I would rather it be a separate file as the program features an Auto-Update feature, so it will be easier to update the list.
**IMPORTANT**Also, I would like to know how to hide my process, so it cant simply be ended, It may sound suspicious but people will be able to just close it and start hacking T_T, Unless there is another way, I would appreciate it (Like making it so it cant be ended etc.)**IMPORTANT.
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Jan 31, 2012
I am after some code to encrypt/decrypt a file, with a feature to display theencryption/decryption process percentage.The following code works well for strings, but when I tried to use it on byte arrays, I get an out of memory error.
Public Function AESEncrypt(ByVal PlainText As String, ByVal Password As String, ByVal salt As String)
Dim HashAlgorithm As String = "SHA1" 'Can be SHA1 or MD5
[code].....
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Jan 29, 2012
I have this code which works well:
Public Function AESEncrypt(ByVal PlainText As String, ByVal Password As String, ByVal salt As String)
Dim HashAlgorithm As String = "SHA1" 'Can be SHA1 or MD5
Dim PasswordIterations As String = 2
Dim InitialVector As String = "CanEncryption123" 'This should be a string of 16 ASCII characters.
Dim KeySize As Integer = 256 'Can be 128, 192, or 256.
[Code] .....
What I am after is this: Rather than having a string to encrypt/decrypt, I have a byte array.
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Jun 13, 2011
Need to design a program that can encrypt and decrypt messages stored in simple text files using a private key stored in a separate file. Software should also be able to allow the users to enter simple messages that either displays the encrypted or decrypted message. The encryption method should use a simple substitution method. It should be set out in the following format:
Example (the "@" is the separator):
@
The character The Code End of line
A @ 4gh EOL
B @ 84!9 EOL
Has to use the 256 ASCII character codes. The separator will be used to separate the character and its corresponding code.Here are the pseudocodes I have come up with:
� Read any private key file
separator = readline(file);
while not EOF(file) do
tempStr = readline(file);
[code].....
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Apr 1, 2009
I have a classic ASP page which constructed a querystring for a link to an ASP.NET page. Certain elements in the querystring are somewhat sensitive so I want to encrypt them. I've come across some techniques for doing this in ASP.NET and also in classic ASP but I'm not sure how to do it from classic ASP to ASP.NET. I'm using .NET 3.5.
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Jul 6, 2011
i got encrypt way so how can i decrypt it and the encrypt way is :
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Jan 2, 2010
i need a standard way of encrypting a string and decrypting it using AES. I am aware of the Cryptography class, however almost every example creates a class to do the encryption,If .Net already has this implemented and ready to use why would we create classes for encryption and decryption, isn't it as simple as calling the encrypt method of the class or decrpyt and passing in the text. Unless everyone is wanting to centralize the code. But even then i see so many different examples from File,Data Protection etc..
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Jun 22, 2011
I need some help on saving/reading xml from/to dataset. I would like to make that complete file is encrypted and not only some elements inside or part of file.Currently this is not working in any way at all.[code]
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Dec 23, 2011
I ended up getting this properly working, as far as encrypting a file goes:How to encrypt and decrypt a file by using Visual Basic .NET or Visual Basic 2005 However, the catch is I have to change the name of the output file. What I was hoping to do is overwrite the original with the encrypted file, but when I tried that on a large file, it ended up only getting about 8 bytes of it.
Does anybody have any suggestions or recommendations? The overall idea is that I want to keep a file encrypted until it needs to be unencrypted for use by a program, but I'm not sure if there are better tools out there or if there's a better way of accomplishing this.
Question 2: I would really, really like to encrypt an entire folder, which I'm guessing would be faster than file by file, but when I try I keep getting access denied errors, even with DOS Cipher. Is there a way to do this with a key?
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Jul 18, 2010
there is anyone know how to encrypt and decrypt app config in vb.net??i want encrypt connection string and appsettings .
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Aug 15, 2011
How to encrypt and decrypt database..
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Aug 21, 2011
How to encrypt and decrypt database
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Jan 10, 2009
I am using vb.net 2008 i want to Know how can i encrypt text in a text box save it to a file then read the file decrypt the text and finaly display it in text box .
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Jul 28, 2011
I am trying to encrypt a zip in VB.NET to send to an android device using Air. Then once its on the device, decrypt it using the key and IV.
Here is part of my VB.NET Code:
Private Sub EncryptBytes(ByVal fileIn As String, ByVal fileOut As String, ByVal pass As String, ByVal ivString As String)
Dim crypt As New RijndaelManaged
crypt.KeySize = 256
[Code]...
This is not working ... Note that I tried to write a PKCS7 class based on a Java class I found. The hurlant package I downloaded only had PKCS5. VB.NET did not provide any of the same padding classes as hurlant comes with. I wish I could using "None" but I couldn't get passed the error in VB.I think there may also be an issue with the way I am converting a string into a byte array in VB vs Air.
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Nov 2, 2011
how to encrypt / decrypt a string in VB.Net.I followed the example given here and wrote the following code (below). There's a text box, an "encrypt" button, and a "decrypt" button. The idea is to type something into the text box ("like 'hello world'"), click "encrypt", and see the encrypted version appear in the text box. Clicking "decrypt" should then take you back to the original string.
But when I try to encrypt I get an error when I try to "FlushFinalBlock". The error is: "Length of the data to encrypt is invalid".The "decrypt" part is a total shot in the dark, as the example quoted above only deals with encryption, not decryption. I'm sure it's wrong, but since I can't get "encrypt" to work I haven't tested it yet.
Imports System.Data.SqlClient
Imports System.IO
Imports System.Security.Cryptography
Public Class Form1
[code]....
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Feb 13, 2009
how to encrypt and decrypt strings.
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Aug 18, 2011
I just know it works. So as a personal project I'm trying to learn in VB/C# all about Cryptographic methods and how to use those techniques to encrypt and decrypt files. [code]
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Nov 12, 2009
i have found a few encrypt/decrypt tutorials online but either they dont work or they only work when the application is running so if i encrypt a string using some code i find and save it (in its encrypted form) and then restart the application and enter the saved encrypted string into a textbox and run the decrypt code it wont decrypt it. i don't understand why en/de-cryption is so hard or why there are so little working examples online. could someone be so kind and show me some code that can let me en/de-crypt a string even if i restart the application or use it on a different computer? and doesn't show the weak key errors all the time.
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Nov 12, 2009
I am interested in knowing if non-text files like .xls/.xlsx or .doc files can be encrypted... From the Devlopers Guide on MSDN, I found code snippets that allow encryption / decryption of .txt files. This works absolutely fine. However, I would like to know if similar procedure can be used to encrypt/decrypt file other than .txt file.
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Jun 7, 2012
I am looking for any good tutorial about like in subject of this topic, how to up more secure my application. What I need is to the solution to encrypt my queries in application. Is there any good tutorial or something you could propose me?
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Aug 23, 2011
What are the best way to encrypt and decrypt stream of data ?I would like that my program read a file.. and unencrypt it in memory then when it save it.. it encrpyt the stream and save it.
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Jun 21, 2010
I have created a encryptor/decryptor that allows you to encrypt/decrypt text in a textbox, or a file. The basis of the system is to allow a user to thoroughly protect data within their system. Is there anyone that would be willing to test the program?
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May 11, 2009
For my VB assignment I need to encrypt message and decrypt it again I managed to do it all pretty easily but the problem is the enter key. How can I turn it into ASCI and back again example
user entered - Hello
My Name is kurt
encrypted Message - Hello13My Name is kurt
Decrypted Messafe - Hello
My Name is kurt
The Space is no problem I managed to encrypted well but the enterkey is coming wrong (btw 13 because its the asci value for enter key).
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Jul 23, 2009
I save data from datagridview to text file . I also load the same data from text file into datagridview for edit and update the same thing to text file. Now i want to make my Drill layer header.txt in encrypted format to prevent anyone to open that file and modify out of program. They only can modify it through the program How can we do like this?
My Drill Layer Header.txt file is like this
T240C3.175F012S27H2000
T239C0.95F034S55H1000
T236C1.2F029S48H2000
[code]....
This code can encryp the text file. But accrding to this code EncryptFile("c:\Drill Layer Header.txt", _ "c:\Drill Layer Header original1.txt", _ sSecretKey) It ask for input and output file. So it take data from Drill Layer Header then encrypt the save in drill layer header original.txt. I want it to take data from drill layer header and encrypt and save in same file.
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Jun 6, 2011
Is anybody know what is the easiest way to encrypt and decrypt text from textbox?
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Apr 23, 2012
I use these code to encrypt any plain text in vb2008.I want decrypt and use generated file in my app in android.I know that put files in assets folder and i use it.this code use Cryptography to encryption.how i can decrypt generated files in my android app.and how i use them in my android app.
Imports System.Security.Cryptography
Public NotInheritable Class Simple3Des
Private TripleDes As New TripleDESCryptoServiceProvider
[code].....
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Aug 16, 2010
this code is in a VB 2008 program which I inherited. The below code compiles perfectly but I haven't been able to figure out how to execute it!What code goes in the EncryptDialog_Load which will execute the Encrypt and then the Decrypt functions, then how I send and collect the key() and IV() information using this new code?
Code:
Imports System
Imports System.IO
Imports System.Xml
[code]....
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Mar 25, 2012
I have two functions that are supposed to encrypt and decrypt a string but the encrypt function returns a different encrypted string for the same text everytime. What have I done wrong?
[Code]...
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