Encryption/Decryption - Code To Encrypt A File->networkstream->Decrypt The File
Feb 28, 2011I'm having trouble writing the code to encrypt a file->networkstream->Decrypt the file.. I've tried several ways, but I keep failing....
View 1 RepliesI'm having trouble writing the code to encrypt a file->networkstream->Decrypt the file.. I've tried several ways, but I keep failing....
View 1 RepliesI 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.
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]....
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)
View 3 Repliesi 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)
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)
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.
I would like to know if it is possible to be able to encrypt a file and have my application be able to decrypt it and ammed the file as necessary. and then when the program exits it will encrypt the file back up.
View 4 Repliesi 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)
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!
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]
View 14 RepliesI 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?
Has anyone used these methods? I tried File.Encrypt on a text file, and I did not get an exception, however the Encrypt method did not work (the file was unchanged afterwards).
View 3 RepliesI 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.
View 1 RepliesI 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?
View 4 RepliesI 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.
The same thing that happens when you compile a script it turns in a non-readable mode but when it's opened in the right editor it's back for editing like normal.But just so it encrypts and decrypts the textfiles just like I said before.
View 3 RepliesI 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].....
For example I got this part of a method which serializes a textfile with a password and then encrypts it using the rijndael encryption method[code]...
View 8 RepliesI want to save my connection string in XML file.How to do that?How to encrypt and decrypt that file using VB.Net
View 2 RepliesI 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. Let say this text file i called as Drill.txt. I have another text file called header.txt which need to match its value with the value of Drill.txt file then overwrite value from Drill.txt to header.txt. Now i want to make my Drill.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?
[Code]...
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.
View 3 RepliesNeed 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].....
I create my algorthm and its finished but there is a problem, it encrypte all text and all text in a file but after decryption when i open my file (a video file)the player show all information about file(duration,size and ect) currectly but it dont play that my program encrypt and decrypt byte by byte and place a asci code in bytes(0 to 255)
View 12 RepliesHere 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.
I tried with the following code. It encrypted the file but after I FTP'd the file to my vendor he was not able to decrypt it.Then realized that this code is not using my PGP Keys to encrypt the file. It's creating a new key automatically. That's the reason my vendor is not able to decrypt the file. How can I encrypt the file using my PGP keys? So that my vendor can decrypt the file using same PGP keys.
' Encrypt textfile with Rijndael encryption
Public
Shared
Sub Encrypt(ByVal[code].....
encrypt MS Access database and also decrypt it.
My purpose is to encrypt the database so that it cannot be open independently without using the application. my application should still be able to access it read/write.
At the moment I have a Form containing two text boxes and two buttons. I want the one textbox to be used to type a message (to be encrypted) and the second textbox will be for a key to decrypt the message. Button one will be for encryption and button 2 for decryption.
View 7 RepliesFrom desktop application I want to upload an image. Then want to pass that image to webservice which encrypt it and pass it to another webservice which will save the encrypted image in the Access database. And then using ASP.net want to decrypt the image.
View 2 RepliesI have a Problem to Decrypt my crypted files :e.g. if I encrypt this text:
B�AR B�LASDJASPDJAPSDJPASDJPASD
asdj
...
And Decrypt it:
AB0_�-M3‚S�r�WPJAPSDJPASDJPASD
asdj
...
The first chars are wrong! My Code to Encrypt and Decrypt :
Encrypt:
Public Shared Sub EncryptFile(ByVal sSource As String, ByVal sTarget As String, Optional ByVal BufferSize As Long = 4096)
Dim ErrorHappened As Boolean = False
Dim OldFileStream As FileStream
Dim NewFileStream As FileStream
[code].....