using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
using System.Text;

namespace EncryptPublicKey
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));

                var readPassword = Encoding.UTF8.GetBytes("123");//it can be null.
                var editPassword = Encoding.UTF8.GetBytes("456");
                int permissions = PdfWriter.ALLOW_PRINTING | PdfWriter.ALLOW_COPY;
                pdfWriter.SetEncryption(readPassword, editPassword, permissions, PdfWriter.STRENGTH128BITS);

                pdfDoc.Open();

                pdfDoc.Add(new Phrase("tst 0"));
                pdfDoc.NewPage();
                pdfDoc.Add(new Phrase("tst 1"));
            }

            Process.Start("TestEnc.pdf");
        }
    }
}

using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.X509;

namespace EncryptPublicKey
{
    /// <summary>
    /// A Personal Information Exchange File Info
    /// </summary>
    public class PfxData
    {
        /// <summary>
        /// Represents an X509 certificate
        /// </summary>
        public X509Certificate[] X509PrivateKeys { set; get; }

        /// <summary>
        /// Certificate's public key
        /// </summary>
        public ICipherParameters PublicKey { set; get; }
    }
}

using System;
using System.IO;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Pkcs;
using Org.BouncyCastle.X509;

namespace EncryptPublicKey
{
    /// <summary>
    /// A Personal Information Exchange File Reader
    /// </summary>
    public class PfxReader
    {
        X509Certificate[] _chain;
        AsymmetricKeyParameter _asymmetricKeyParameter;
       
        /// <summary>
        /// Reads A Personal Information Exchange File.
        /// </summary>
        /// <param name="pfxPath">Certificate file's path</param>
        /// <param name="pfxPassword">Certificate file's password</param>
        public PfxData ReadCertificate(string pfxPath, string pfxPassword)
        {
            using (var stream = new FileStream(pfxPath, FileMode.Open, FileAccess.Read))
            {
                var pkcs12Store = new Pkcs12Store(stream, pfxPassword.ToCharArray());
                var alias = findThePublicKey(pkcs12Store);
                _asymmetricKeyParameter = pkcs12Store.GetKey(alias).Key;
                constructChain(pkcs12Store, alias);
                return new PfxData { X509PrivateKeys = _chain, PublicKey = _asymmetricKeyParameter };
            }
        }

        private void constructChain(Pkcs12Store pkcs12Store, string alias)
        {
            var certificateChains = pkcs12Store.GetCertificateChain(alias);
            _chain = new X509Certificate[certificateChains.Length];

            for (int k = 0; k < certificateChains.Length; ++k)
                _chain[k] = certificateChains[k].Certificate;
        }

        private static string findThePublicKey(Pkcs12Store pkcs12Store)
        {
            string alias = string.Empty;
            foreach (string entry in pkcs12Store.Aliases)
            {
                if (pkcs12Store.IsKeyEntry(entry) && pkcs12Store.GetKey(entry).Key.IsPrivate)
                {
                    alias = entry;
                    break;
                }
            }

            if (string.IsNullOrEmpty(alias))
                throw new NullReferenceException("Provided certificate is invalid.");

            return alias;
        }
    }
}

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace EncryptPublicKey
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));

                var certs = new PfxReader().ReadCertificate(@"D:\path\cert.pfx", "123");
                pdfWriter.SetEncryption(
                          certs: certs.X509PrivateKeys,
                          permissions: new int[] { PdfWriter.ALLOW_PRINTING, PdfWriter.ALLOW_COPY },
                          encryptionType: PdfWriter.ENCRYPTION_AES_128);

                pdfDoc.Open();

                pdfDoc.Add(new Phrase("tst 0"));
                pdfDoc.NewPage();
                pdfDoc.Add(new Phrase("tst 1"));
            }

            Process.Start("Test.pdf");
        }
    }
}

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace EncryptPublicKey
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfReader reader = new PdfReader("TestDec.pdf");
            using (var stamper = new PdfStamper(reader, new FileStream("TestEnc.pdf", FileMode.Create)))
            {
                var certs = new PfxReader().ReadCertificate(@"D:\path\cert.pfx", "123");
                stamper.SetEncryption(
                         certs: certs.X509PrivateKeys,
                         permissions: new int[] { PdfWriter.ALLOW_PRINTING, PdfWriter.ALLOW_COPY },
                         encryptionType: PdfWriter.ENCRYPTION_AES_128);
                stamper.Close();
            }

            Process.Start("TestEnc.pdf");
        }
    }
}

using System.Security.Cryptography.X509Certificates;

namespace InstallPfx
{
    class Program
    {
        private static void InstallCertificate(string cerFileName, string password)
        {
            var certificate = new X509Certificate2(cerFileName, password, X509KeyStorageFlags.PersistKeySet);
            var store = new X509Store(StoreName.My);
            store.Open(OpenFlags.ReadWrite);
            store.Add(certificate);
            store.Close();
        }

        static void Main(string[] args)
        {
            InstallCertificate(@"D:\forTest\file.pfx", "123456");
        }
    }
}

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PDFAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));                
                pdfDoc.Open();

                pdfDoc.Add(new Phrase("Test"));

                var fs = PdfFileSpecification.FileEmbedded(pdfWriter, @"C:\path\logo.png", "logo.png", null);
                pdfWriter.AddFileAttachment("توضیحات",fs);
            }

            Process.Start("Test.pdf");
        }
    }
}

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PDFAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));                
                pdfDoc.Open();

                pdfDoc.Add(new Phrase("Test"));

                var filePath = @"C:\path\logo.png";
                var fileInfo = new FileInfo(filePath);
                var pdfDictionary = new PdfDictionary();
                pdfDictionary.Put(PdfName.MODDATE, new PdfDate(fileInfo.LastWriteTime));
                var fs = PdfFileSpecification.FileEmbedded(pdfWriter, filePath, fileInfo.Name, null, true, null, pdfDictionary);
                pdfWriter.AddFileAttachment("توضیحات", fs);
            }

            Process.Start("Test.pdf");
        }
    }
}

pdfWriter.ViewerPreferences = PdfWriter.PageModeUseAttachments;

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PDFAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
            var reader = new PdfReader("Test.pdf");
            using (var stamper = new PdfStamper(reader, new FileStream("newTest.pdf", FileMode.Create)))
            {
                var filePath = @"C:\path\logo.png";
                addAttachment(stamper, filePath, "توضیحات");
                stamper.Close();
            }

            Process.Start("newTest.pdf");
        }

        private static void addAttachment(PdfStamper stamper, string filePath, string description)
        {
            var fileInfo = new FileInfo(filePath);
            var pdfDictionary = new PdfDictionary();
            pdfDictionary.Put(PdfName.MODDATE, new PdfDate(fileInfo.LastWriteTime));
            var pdfWriter = stamper.Writer;
            var fs = PdfFileSpecification.FileEmbedded(pdfWriter, filePath, fileInfo.Name, null, true, null, pdfDictionary);
            stamper.AddFileAttachment(description, fs);
        }
    }
}

using System;
using System.IO;

namespace NHibernate.Helper.DbSpecific
{
    public class SqlCEDbHelper
    {
        const string engineTypeName = "System.Data.SqlServerCe.SqlCeEngine, System.Data.SqlServerCe";

        /// <summary>
        /// note: this method will delete existing db and then creates a new one.
        /// </summary>
        /// <param name="filename"></param>
        /// <param name="password"></param>
        public static void CreateEmptyDatabaseFile(string filename, string password = "")
        {
            if (File.Exists(filename))
                File.Delete(filename);

            var type = System.Type.GetType(engineTypeName);
            var localConnectionString = type.GetProperty("LocalConnectionString");
            var createDatabase = type.GetMethod("CreateDatabase");

            var engine = Activator.CreateInstance(type);

            string connectionStr = string.Format("Data Source='{0}';Password={1};Encrypt Database=True", filename, password);
            if (string.IsNullOrWhiteSpace(password))
                connectionStr = string.Format("Data Source='{0}'", filename);

            localConnectionString.SetValue(
                obj: engine,
                value: connectionStr,
                index: null);
            createDatabase.Invoke(engine, new object[0]);
        }

        /// <summary>
        /// use this method to compact or encrypt existing db or decrypt it to a new db with all records
        /// </summary>
        /// <param name="sourceConnection"></param>
        /// <param name="destConnection"></param>
        public static void CompactDatabase(string sourceConnection, string destConnection)
        {
            var type = System.Type.GetType(engineTypeName);
            var engine = Activator.CreateInstance(type);

            var localConnectionString = type.GetProperty("LocalConnectionString");
            localConnectionString.SetValue(
                obj: engine,
                value: sourceConnection,
                index: null);

            var compactDatabase = type.GetMethod("Compact");
            compactDatabase.Invoke(engine, new object[] { destConnection });
        }
    }
}

Data Source=c:\path\db.sdf;Password=1234;Encrypt Database=True

private Configuration getConfig()
{
            var configure = new Configuration();
            configure.SessionFactoryName("BuildIt");

            configure.DataBaseIntegration(db =>
            {
                db.ConnectionProvider<DriverConnectionProvider>();
                db.Dialect<MsSqlCe40Dialect>();
                db.Driver<SqlServerCeDriver>();
                db.KeywordsAutoImport = Hbm2DDLKeyWords.AutoQuote;
                db.IsolationLevel = IsolationLevel.ReadCommitted;
                db.ConnectionString = ConnectionString;
                db.Timeout = 10;

                //for testing ...
                db.LogFormattedSql = true;
                db.LogSqlInConsole = true;
            });

            return configure;
}