CustomTextMessageEncoder.cs

using System;
using System.Text;
using System.ServiceModel.Channels;
using System.Xml;
using System.IO;
using System.Security.Cryptography;
using System.Resources;
using System.Security.Cryptography.X509Certificates;

namespace eMedNySOAPClient
{
    public class CustomTextMessageEncoder : MessageEncoder
    {
        private string contentType;
        private MessageVersion msgVersion;

        public CustomTextMessageEncoder(string contentType, MessageVersion msgVersion)
        {
            this.contentType = contentType;
            this.msgVersion = msgVersion;
        }

        public override string ContentType
        {
            get
            {
                return contentType;
            }
        }

        public override string MediaType
        {
            get
            {
                return string.Empty;
            }
        }

        public override MessageVersion MessageVersion
        {
            get
            {
                return msgVersion;
            }
        }

        public override Message ReadMessage(ArraySegment<byte> buffer, BufferManager bufferManager, string contentType)
        {
            byte[] msgContents = new byte[buffer.Count];
            Array.Copy(buffer.Array, buffer.Offset, msgContents, 0, msgContents.Length);
            bufferManager.ReturnBuffer(buffer.Array);

            MemoryStream stream = new MemoryStream(msgContents);

            var doc = new XmlDocument();
            doc.PreserveWhitespace = true;
            doc.Load(stream);

            var encryptedKey = doc.GetElementsByTagName( "xenc:EncryptedKey" )[0].InnerText;
            var cipherText = doc.GetElementsByTagName( "xenc:CipherValue" )[1].InnerText;
            var cipher = Convert.FromBase64String( cipherText );

            var clientCert = new X509Certificate2( //PULL IN YOUR CLIENT CERTIFICATE HERE );
            var rsa = (RSACryptoServiceProvider)clientCert.PrivateKey;
            byte [] key = rsa.Decrypt(Convert.FromBase64String(encryptedKey), false);

            SymmetricAlgorithm alg = new TripleDESCryptoServiceProvider();
            alg.KeySize = 192;
            alg.Mode = CipherMode.CBC;
            alg.Padding = PaddingMode.ISO10126;
            
            byte[] IV = new byte[8];
            Array.Copy(cipher, IV, 8);
            MemoryStream ms = new MemoryStream( cipher , IV.Length, cipher.Length-IV.Length);
            CryptoStream csDecrypt = new CryptoStream( ms, alg.CreateDecryptor(key, IV ), CryptoStreamMode.Read);
            byte [] fromEnc = new byte[cipher.Length];
            csDecrypt.Read(fromEnc, 0, fromEnc.Length);

            string messageBody = UTF8Encoding.UTF8.GetString(fromEnc);
            XmlDocumentFragment bodyElement = doc.CreateDocumentFragment();
            bodyElement.InnerXml = messageBody;

            var body = (XmlNode)doc.GetElementsByTagName("soapenv:Body")[0];
            body.ReplaceChild( bodyElement, body.FirstChild );

            doc.DocumentElement.RemoveChild( doc.GetElementsByTagName( "soapenv:Header" )[0] );

            stream = new MemoryStream();
            doc.Save(stream);

            stream.Position = 0;
            return Message.CreateMessage(XmlReader.Create(stream), int.MaxValue, this.MessageVersion);
        }

        public override Message ReadMessage(Stream stream, int maxSizeOfHeaders, string contentType)
        {
            XmlReader reader = XmlReader.Create(stream);
            var message = Message.CreateMessage(reader, maxSizeOfHeaders, this.MessageVersion);
            return message;
        }
        
        public override ArraySegment<byte> WriteMessage(Message message, int maxMessageSize, BufferManager bufferManager, int messageOffset)
        {
            MemoryStream stream = new MemoryStream();
            XmlWriter writer = XmlWriter.Create(stream);
            message.WriteMessage(writer);
            writer.Close();
           
            byte[] messageBytes = stream.GetBuffer();
            int messageLength = (int)stream.Position;

            int totalLength = messageLength + messageOffset;
            byte[] totalBytes = bufferManager.TakeBuffer(totalLength);
            Array.Copy(messageBytes, 0, totalBytes, messageOffset, messageLength);

            ArraySegment<byte> byteArray = new ArraySegment<byte>(totalBytes, messageOffset, messageLength);
            return byteArray;
        }

        public override void WriteMessage(Message message, Stream stream)
        {
            XmlWriter writer = XmlWriter.Create(stream);
            message.WriteMessage(writer);
            writer.Close();
        }
    }
}