/// <summary> /// Calculates sha1 mic based on the MIME body part. /// </summary> /// <param name="bodyPart"></param> /// <param name="digestMethod"></param> /// <returns></returns> public static Digest CalculateMic(MimeEntity bodyPart, SMimeDigestMethod digestMethod) { try { byte[] digest; using (var m = new MemoryStream()) { bodyPart.WriteTo(m); m.Seek(0, SeekOrigin.Begin); digest = BcHelper.Hash(m.ToArray(), digestMethod.GetAlgorithm()); } return(Digest.Of(digestMethod.GetDigestMethod(), digest)); } catch (IOException e) { throw new InvalidOperationException("Unable to read data from digest input. " + e.Message, e); } catch (Exception e) { throw new InvalidOperationException("Unable to handle mime body part. " + e.Message, e); } }
/// <summary> /// Receives an AS2 Message in the form of a map of headers together with the payload, /// which is made available in an input stream /// <p>If persisting message to the Message Repository fails, we have to return negative MDN.</p> /// </summary> /// <param name="httpHeaders">the http headers received</param> /// <param name="mimeMessage">supplies the MIME message</param> /// <returns>MDN object to signal if everything is ok or if some error occurred while receiving</returns> public MimeMessage Receive(IHeaderDictionary httpHeaders, MimeMessage mimeMessage) { Logger.Debug("Receiving message .."); SMimeReader sMimeReader = new SMimeReader(mimeMessage); // Get timestamp using signature as input Timestamp t2 = this.timestampProvider.Generate(sMimeReader.GetSignature(), Direction.IN); // Initiate MDN MdnBuilder mdnBuilder = MdnBuilder.NewInstance(mimeMessage); mdnBuilder.AddHeader(MdnHeader.Date, t2.GetDate()); // Extract Message-ID TransmissionIdentifier transmissionIdentifier = TransmissionIdentifier.FromHeader(httpHeaders[As2Header.MessageId]); mdnBuilder.AddHeader(MdnHeader.OriginalMessageId, httpHeaders[As2Header.MessageId]); // Extract signed digest and digest algorithm SMimeDigestMethod digestMethod = sMimeReader.GetDigestMethod(); // Extract content headers byte[] headerBytes = sMimeReader.GetBodyHeader(); Stream bodyStream = sMimeReader.GetBodyInputStream(); byte[] bodyBytes = bodyStream.ToBuffer(); mdnBuilder.AddHeader(MdnHeader.OriginalContentHeader, headerBytes); // Extract SBDH Mx.Peppol.Common.Model.Header header; bodyStream.Seek(0, SeekOrigin.Begin); using (var sbdReader = SbdReader.NewInstance(bodyStream)) { header = sbdReader.Header; // Perform validation of SBDH this.transmissionVerifier.Verify(header, Direction.IN); // Extract "fresh" InputStream using (Stream payloadInputStream = sMimeReader.GetBodyInputStream()) { // Persist content this.persisterHandler.Persist( transmissionIdentifier, header, new UnclosableInputStream(payloadInputStream)); } // Fetch calculated digest var s = SHA1.Create(); var hash = s.ComputeHash(headerBytes.Concat(bodyBytes).ToArray()); Digest calculatedDigest = Digest.Of(DigestMethod.Sha1, hash); mdnBuilder.AddHeader(MdnHeader.ReceivedContentMic, new Mic(calculatedDigest)); var check = this.VerifySignature(mimeMessage.Body as MultipartSigned, out var signatures); if (!check || signatures.Count != 1) { throw new NotSupportedException("Firma non valida"); } var signature = signatures[0]; var certificate = signature.SignerCertificate as SecureMimeDigitalCertificate; Debug.Assert(certificate != null, nameof(certificate) + " != null"); this.certificateValidator.Validate(Service.Ap, certificate.Certificate); // Create receipt (MDN) mdnBuilder.AddHeader(MdnHeader.Disposition, Disposition.Processed); MimeMessage mdn = this.sMimeMessageFactory.CreateSignedMimeMessage(mdnBuilder.Build(), digestMethod); mdn.Headers.Add(As2Header.As2Version, As2Header.Version); mdn.Headers.Add(As2Header.As2From, httpHeaders[As2Header.As2To]); mdn.Headers.Add(As2Header.As2To, httpHeaders[As2Header.As2From]); return(mdn); } }