Introduction In this article, I’ll explain a way to encode and decode a file in ASP.NET using C# and VB.NET with an example. Recently, I required searching out an easy way to encode and decode a file of any kind (I actually required to encode images and text files) and any size. I found many examples online, several of them did not work, or threw errors on sure file varieties. Encryption - The process of changing data or information into a code, particularly to stop unauthorized access. Decryption - The method of taking encoded or encrypted text or alternative information and changing it back to text that you simply or the pc will browse and perceive. This term may be used to describe a way of un-encrypting the information manually or with un-encrypting the information using the right codes or keys. The files are uploaded for encoding and decoding of files.

Encrypt a file using AES encryption in C# There are several resources in the internet which give sample code for encrypting/ decrypting a PLAINTEXT using C#, which uses RijndaelManaged or AES encryption. A simple C# application that encrypts files with AES (Advanced Encryption Standard). As shown in the video, an encrypted file can only be decrypted with the same key (case sensitive).

The AES symmetric algorithm is used for encoding and decoding of the files. The encrypted and decrypted files may be saved within folders on disk or may be downloaded to shopper user. So, in this article, I’ll explain a way to encode and decode the file in ASP.NET with an example. HTML Code Markup The HyperText Markup Language consists of File Upload control and 2 buttons. • Imports System.IO • Imports System.Security.Cryptography AES algorithm encoding and decoding functions Below are the functions for encoding and decoding which are used for Encrypting or Decrypting Files. File encoding The following Button-click event handler encrypts the uploaded file.

Name, Content type, and therefore the File Bytes of the uploaded file, are fetched and therefore the file is saved in a folder on disk. The encrypted file is then sent for transfer by the shopper user. Once transferred, each of the files is deleted. • Protected Sub EncryptFile(sender As Object, e As EventArgs) • 'Get the Input File Name and Extension. • Dim fileName As String = Path.GetFileNameWithoutExtension(FileUpload1.PostedFile.FileName) • Dim fileExtension As String = Path.GetExtension(FileUpload1.PostedFile.FileName) • • 'Build the File Path for the original (input) and the encrypted (output) file. • Dim input As String = Convert.ToString(Server.MapPath( '~/Files/' ) & fileName) & fileExtension • Dim output As String = Convert.ToString((Server.MapPath( '~/Files/' ) & fileName) + '_enc' ) & fileExtension • • 'Save the Input File, Encrypt it and save the encrypted file in output path. • FileUpload1.SaveAs(input) • Me.Encrypt(input, output) • • 'Download the Encrypted File.

• Response.ContentType = FileUpload1.PostedFile.ContentType • Response.Clear() • Response.AppendHeader( 'Content-Disposition', 'attachment; filename=' + Path.GetFileName(output)) • Response.WriteFile(output) • Response.Flush() • • 'Delete the original (input) and the encrypted (output) file. • File.Delete(input) • File.Delete(output) • • Response.End() • End Sub •.

I'm encrypting a text (just a string) using OpenSSL's CMS library. I've implemented a cms encrypt method and when I call this in a C++ project (with the equal certificate and input string) it produces the following output: MIME-Version: 1.0 />Content-Disposition: attachment; filename='smime.p7m' />Content-Type: application/pkcs7-mime; smime-type=enveloped-data; name='smime.p7m' Content-Transfer-Encoding: base64 />MIAGCSqGSIb3DQEHA6CAMIACAQAxggG9MIIBuQIBADCBoDCBkjELMAkGA1UEBhMC />QVQxDzANBgNVBAgMBlN0eXJpYTENMAsGA1UEBwwER3JhejEKMAgGA1UECgwBLzEK />MAgGA1UECwwBLzEdMBsGA1UEAwwUQ2hyaXN0b2YgU3Ryb21iZXJnZXIxLDAqBgkq />hkiG9w0BCQEWHXN0cm9. I'm using DESede encryptation in Java and I want to make the same encryptation using the OpenSSL's API in C++. /> Java code: String secretKey = 'abcdefghijklmnopqrstuvwx'; byte[] bytes = secretKey.getBytes('UTF-8'); SecretKey key = new SecretKeySpec(bytes, 'DESede'); Cipher ecipher = Cipher.getInstance('DESede'); ecipher.init(Cipher.ENCRYPT_MODE, key); String input = 'holahola1'; byte[] utf8 = input.getBytes('UTF8'); byte[] enc = ecipher.doFinal(utf8); // Encrypt /> output: [94, -45, 64, -105, 99, -5. I'm encrypting a text (just a string) using OpenSSL's CMS library. I've implemented a cms encrypt method and when I call this in a C++ project (with the equal certificate and input string) it produces the following output: MIME-Version: 1.0 />Content-Disposition: attachment; filename='smime.p7m' />Content-Type: application/pkcs7-mime; smime-type=enveloped-data; name='smime.p7m' Content-Transfer-Encoding: base64 />MIAGCSqGSIb3DQEHA6CAMIACAQAxggG9MIIBuQIBADCBoDCBkjELMAkGA1UEBhMC />QVQxDzANBgNVBAgMBlN0eXJpYTENMAsGA1UEBwwER3JhejEKMAgGA1UECgwBLzEK />MAgGA1UECwwBLzEdMBsGA1UEAwwUQ2hyaXN0b2YgU3Ryb21iZXJnZXIxLDAqBgkq />hkiG9w0BCQEWHXN0cm9.