Didisoft PGP Decrypt and Verify - vb.net

Question

I am trying to Decrypt using Didisoft pgp, and running into some issues. I can generate private and public key just fine. I can also Encrypt the file using SignAndEncryptFile function, and it returns the .pgp file just fine. The problem is when I tried to use the DecryptAndVerifyFile function. It returns an exception Wrong Private Key, I have checked so many times, that my public and private key are the same to the one that I use for Encrypting the file, the password that I used is all the same, because I'm just testing it. What did I do Wrong? :(
It only happens when I tried to use public key and private key to encrypt and decrypt it. I managed to do Encrypt and Decrypt before but it only uses the private key.
Public Function GetValue(ByVal FileData As String, ByVal email As String, ByVal password As String) As String
Dim idKey As String = Guid.NewGuid().ToString()
Dim ks As KeyStore = New KeyStore()
Dim keySize As Integer = 1024
'Dim password As String = "12345"
Dim FilePathKey As String
Dim FilePathPublicKey As String
Dim keys As KeyPairInformation() = ks.GetKeys()
' Generate DH/DSS OpenPGP key
ks.GenerateElgamalKeyPair(keySize, email, password)
'idKey = ks(0).KeyId
FilePathKey = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\", "Coba\" + idKey + ".key")
ks.ExportPrivateKey(FilePathKey, ks(0).KeyId)
Dim sql As New MySqlConnection()
Dim adapter As New MySqlDataAdapter
sql.ConnectionString = "server=localhost;userid=root;database=test"
Dim query As String = "Select public_key from public_key LIMIT 1"
Dim cmd As MySqlCommand
Dim dt As New DataSet()
cmd = New MySqlCommand(query, sql)
sql.Open()
adapter = New MySqlDataAdapter(cmd)
adapter.Fill(dt)
sql.Close()
FilePathPublicKey = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\PublicKey\", dt.Tables(0).Rows(0).Item(0).ToString + ".key")
If File.Exists(FileData) Then
'Encrypt Data
Dim pgp As New PGPLib()
Dim idData As String = Guid.NewGuid().ToString()
Dim asciiArmor As Boolean = True
Dim withIntegrityCheck As Boolean = True
Dim encryptedOutputFile As String = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\Coba\", idData + ".pgp")
'Dim encryptedOutputFile As String = Path.Combine(Directory.GetCurrentDirectory(), "Tes\" + idData + ".pgp")
'C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\Data\
Dim encryptedOutputFileTes As New FileInfo(encryptedOutputFile)
cmd = New MySqlCommand("INSERT INTO `tes`(`tesid`) VALUES ('" + idKey + "')", sql)
sql.Open()
cmd.ExecuteNonQuery()
sql.Close()
pgp.SignAndEncryptFile(FileData, FilePathKey, password, FilePathPublicKey, encryptedOutputFile, asciiArmor, withIntegrityCheck)
'pgp.SignAndEncryptFile(FileData, FilePathKey, password, FilePathPublicKey, encryptedOutputFile, asciiArmor)
'pgp.EncryptFilePBE(FileData, FilePathKey, password, encryptedOutputFile, asciiArmor, withIntegrityCheck)
Dim FullFile As New FullFile(idData + ".pgp", My.Computer.FileSystem.ReadAllText(encryptedOutputFile))
cmd = New MySqlCommand("INSERT INTO `enkripsi_data`(`data`, `key`) VALUES ('" + idData + "','" + idKey + "')", sql)
sql.Open()
cmd.ExecuteNonQuery()
sql.Close()
Dim serializer As New JavaScriptSerializer
serializer.MaxJsonLength = Int32.MaxValue
Dim fullFileJSON = serializer.Serialize(FullFile)
Return fullFileJSON
Else
'File Tidak ada
Return "0"
End If
'Dim FilePath = HttpContext.Current.Server.MapPath("~/" + idKey + ".asc")
End Function
Public Function GetValue(ByVal FileData As String, ByVal password As String) As String
Dim sql As New MySqlConnection()
Dim adapter As New MySqlDataAdapter
Dim FileName As String
FileName = Path.GetFileNameWithoutExtension(FileData)
Dim pgp As New PGPLib()
sql.ConnectionString = "server=localhost;userid=root;database=test"
Dim dt As New DataTable()
Dim cmd As New MySqlCommand("SELECT `key` FROM `enkripsi_data` WHERE `data`='" + FileName + "'", sql)
sql.Open()
adapter = New MySqlDataAdapter(cmd)
adapter.Fill(dt)
sql.Close()
Dim KeyName As String
KeyName = dt.Rows(0)(0).ToString
Dim FilePathKey As String
FilePathKey = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\", "Coba\" + KeyName + ".key")
Dim decryptedOutputFile As String = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\", "Coba\Decrypted" + DateTime.Now.ToString(" dd-MM-yyyy HH.mm.ss") + ".bat")
Dim query As String = "Select public_key from public_key LIMIT 1"
Dim ds As New DataSet
cmd = New MySqlCommand(query, sql)
sql.Open()
adapter = New MySqlDataAdapter(cmd)
adapter.Fill(ds)
sql.Close()
Dim FilePathPublicKey As New String(Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\PublicKey\", ds.Tables(0).Rows(0).Item(0).ToString + ".key"))
If File.Exists(FileData) Then
Dim originalFileName As SignatureCheckResult
Try
'pgp.DecryptAndVerifyFile(FileData, FilePathKey, password, FilePathPublicKey, decryptedOutputFile)
'originalFileName = pgp.DecryptFile(FileData, FilePathKey, password, decryptedOutputFile)
originalFileName = pgp.DecryptAndVerifyFile(FileData, FilePathKey, password, FilePathPublicKey, decryptedOutputFile)
'==================================================
Dim fullFile As New FullFile(originalFileName, My.Computer.FileSystem.ReadAllText(decryptedOutputFile))
Dim serializer As New JavaScriptSerializer
serializer.MaxJsonLength = Int32.MaxValue
Dim fullFileJSON = serializer.Serialize(fullFile)
Return fullFileJSON
Catch e As PGPException
If TypeOf e Is NonPGPDataException Then
Return "The input file is not an OpenPGP archive or is corrupted"
ElseIf TypeOf e Is WrongPublicKeyException Then
Return "The supplied public key is not an OpenPGP public key or is corrupted"
ElseIf TypeOf e Is WrongPrivateKeyException Then
' The message cannot be decrypted with this private key
' or the supplied private key is not an OpenPGP private key or is corrupted
Return e.Message
ElseIf TypeOf e Is WrongPasswordException Then
Return "The password for the private key is incorrect"
ElseIf TypeOf e Is FileIsPBEEncryptedException Then
Return "The input file is password encrypted."
Return "You have to use DecryptAndVeifyFilePBE or DecryptAndVerifyStreamPBE"
ElseIf TypeOf e Is IntegrityCheckException Then
Return "The encrypted data is corrupted"
Else
Return e.Message
End If
End Try
Else
'File gak ada
Return "0"
End If
End Function

Answer 1

Here is the problem:
PGPLib.SignAndEncryptFile(dataFIle, signingPrivateKey, signingPrivateKeyPassword, encryptingPublicKey, desitinationFile)
PGPLib.DecryptAndVerifyFile(dataFIle, decryptingPrivateKey, decryptingPrivateKeyPassword, signatureVerifyingPublicKey, desitinationFile)
You use in both cases the same publicKey and the same private key - but PGP cryptography (and the library which implements it) expects when Decrypting to use the private key corresponding to the encryption key used in SignAndEncrypt,
and the verification key to be the corresponding public key of the private key used in SignAndEncrypt.
In essence here is what you shall do:
Dim FilePathPublicKey As New String(Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\PublicKey\", ds.Tables(0).Rows(0).Item(0).ToString + ".key"))
-> FilePathPublicKey must be the signature verifying public key from
ks.GenerateElgamalKeyPair(keySize, email, password)
...
FilePathKey = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\", "Coba\" + KeyName + ".key")
-> FilePathKey mys be the private key corresponding to the key used for encrypting (the private key of FilePathPublicKey = Path.Combine("C:\Users\user\Desktop\Kuliah\Semester 8\Project\Tes\TES\WindowsApp1\bin\Debug\PublicKey\", dt.Tables(0).Rows(0).Item(0).ToString + ".key")
originalFileName = pgp.DecryptAndVerifyFile(FileData, FilePathKey, password, FilePathPublicKey, decryptedOutputFile)