PGP Decryption Using BouncyCastle

Here's a BR you can use for simple crypto that uses the .net framework crypto libraries.

Imports System
Imports System.Collections.Generic
Imports System.Data
Imports System.Data.Common
Imports System.Globalization
Imports System.IO
Imports System.Linq
Imports System.Windows.Forms
Imports Microsoft.VisualBasic
Imports OneStream.Finance.Database
Imports OneStream.Finance.Engine
Imports OneStream.Shared.Common
Imports OneStream.Shared.Database
Imports OneStream.Shared.Engine
Imports OneStream.Shared.Wcf
Imports OneStream.Stage.Database
Imports OneStream.Stage.Engine
Imports System.Runtime.InteropServices
Imports System.Security.Cryptography

Namespace OneStream.BusinessRule.Extender.Crypto
	Public Class MainClass
		Public Function Main(ByVal si As SessionInfo, ByVal globals As BRGlobals, ByVal api As Object, ByVal args As ExtenderArgs) As Object
			Try
				Dim crypto As New Crypto()
				Dim b64Key  As String = String.Empty 
                Dim b64Vect As String = String.Empty 
				Dim encrypted As String = crypto.AesEncrypt("RobbSalzmann", b64Key, b64Vect)
				Dim decrypted As String = crypto.AesDecrypt(encrypted, b64Key, b64Vect)
				
				BRApi.ErrorLog.LogMessage(si, $"RobbSalzmann: {encrypted}")
				BRApi.ErrorLog.LogMessage(si, $"{decrypted}: {encrypted}")
				Return Nothing
			Catch ex As Exception
				Throw ErrorHandler.LogWrite(si, New XFException(si, ex))
			End Try
		End Function
	End Class

	Public Class Crypto
		Public Function AesEncrypt(plainText As String, <Out> ByRef aesKey As String, <Out> ByRef aesInitVect As String) As String
			Using aes As Aes = Aes.Create()
				aesKey = Convert.ToBase64String(aes.Key)
				aesInitVect = Convert.ToBase64String(aes.IV)
				Dim cryptpoXform As ICryptoTransform = aes.CreateEncryptor()
				Dim cryptoBytes As Byte()

				Using memoryStream As MemoryStream = New MemoryStream()
					Using cryptoStream As CryptoStream = New CryptoStream(memoryStream, cryptpoXform, CryptoStreamMode.Write)
						Using streamWriter As StreamWriter = New StreamWriter(cryptoStream)
							streamWriter.Write(plainText)
						End Using
						cryptoBytes = memoryStream.ToArray()
					End Using
				End Using

				Return Convert.ToBase64String(cryptoBytes)
			End Using
		End Function
		
		Public Function AesDecrypt(encrypted As String, b64Key As String, b64Vect As String) As String
		    Using aes As Aes = Aes.Create()
		        aes.Key = Convert.FromBase64String(b64Key)
		        aes.IV = Convert.FromBase64String(b64Vect)
		        Dim cryptoXform As ICryptoTransform = aes.CreateDecryptor()
		        Dim cipherBytes As Byte() = Convert.FromBase64String(encrypted)

		        Using memoryStream As MemoryStream = New MemoryStream(cipherBytes)
		            Using cryptoStream As CryptoStream = New CryptoStream(memoryStream, cryptoXform, CryptoStreamMode.Read)
		                Using streamReader As StreamReader = New StreamReader(cryptoStream)
		                    Return streamReader.ReadToEnd()
		                End Using
		            End Using
		        End Using
		    End Using
		End Function
	End Class
End Namespace

I only used it in Java contexts, unfortunately, but I think Stack Overflow will have (as usual) some interesting stuff: https://stackoverflow.com/questions/6987699/pgp-encryption-and-decryption-using-bouncycastle-c-sharp