How to make file password protect using c#

Question

How to make file password protect using c# , after download the image , while opening the image should ask password to open

Rajkiran Swain · Answer

https://www.aspsnippets.com/Articles/Encrypt-and-Decrypt-Word-Excel-PDF-Text-or-Image-Files-using-C-and-VBNet-in-ASPNet.aspx

Mukil Vendhan · Answer

hi friend kindly check this following link:https://youtu.be/dZJ_xWgdLqg for encryption: private const int SaltSize = 8; public static void Encrypt( FileInfo targetFile, string password ) { var keyGenerator = new Rfc2898DeriveBytes( password, SaltSize ); var rijndael = Rijndael.Create(); // BlockSize, KeySize in bit --> divide by 8 rijndael.IV = keyGenerator.GetBytes( rijndael.BlockSize / 8 ); rijndael.Key = keyGenerator.GetBytes( rijndael.KeySize / 8 ); using ( var fileStream = targetFile.Create() ) { // write random salt fileStream.Write( keyGenerator.Salt, 0, SaltSize ); using ( var cryptoStream = new CryptoStream( fileStream, rijndael.CreateEncryptor(), CryptoStreamMode.Write ) ) { // write data } } } for decrypt: public static void Decrypt( FileInfo sourceFile, string password ) { // read salt var fileStream = sourceFile.OpenRead(); var salt = new byte [SaltSize]; fileStream.Read( salt, 0, SaltSize ); // initialize algorithm with salt var keyGenerator = new Rfc2898DeriveBytes( password, salt ); var rijndael = Rijndael.Create(); rijndael.IV = keyGenerator.GetBytes( rijndael.BlockSize / 8 ); rijndael.Key = keyGenerator.GetBytes( rijndael.KeySize / 8 ); // decrypt using ( var cryptoStream = new CryptoStream( fileStream, rijndael.CreateDecryptor(), CryptoStreamMode.Read ) ) { // read data } }

Manikandan Murugesan · Answer

Refer the following Link : https://www.codeproject.com/Articles/696528/Csharp-Password-Protected-File You can not protect a text file with a password out of the box. You would need to encapsulate it, with an other application to do so. The simplest way, would be to use a Zip File. As taken form this post by Cheeso using DotNetZip: using ( var zip = new ZipFile ()) { zip . Password = "VerySecret!!" ; zip . AddFile ( "test.txt" ); zip . Save ( "Archive.zip" ); } This results in 2 steps. Create your files Zip them and choose a password.

Gokhul Varman · Answer

If you rhttps://stackoverflow.com/questions/19090282/protecting-a-file-by-a-passwordefer the link you can get a clear solution about it:

How to make file password protect using c#

Answers (4)