public static DOCXField[] GetSignatureFields(string DocxFile) { int rc; int NumOfFields = 0; SAPIContext ctxSigField = new SAPIContextClass(); rc = SAPI.SignatureFieldEnumInit( hSession, ctxSigField, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_OFFICE_XML_PACKAGE, DocxFile, 0, ref NumOfFields); if (rc != 0) { throw new Exception("Failed in SAPISignatureFieldEnumInit (" + rc.ToString("X") + ")"); } //There are no signature fields if (NumOfFields == 0) { return(null); } DOCXField[] Fields = new DOCXField[NumOfFields]; for (int i = 0; i < NumOfFields; i++) { Fields[i] = new DOCXField(); //Get Signature Field Handle rc = SAPI.SignatureFieldEnumCont(hSession, ctxSigField, out Fields[i].hSigField); if (rc != 0) { throw new Exception("Failed in SignatureFieldEnumCont (" + rc.ToString("X") + ")"); } //Get Signature Field Details rc = SAPI.SignatureFieldInfoGet( hSession, Fields[i].hSigField, Fields[i].sSettings, Fields[i].sInfo); if (rc != 0) { throw new Exception("Failed in SignatureFieldInfoGet (" + rc.ToString("X") + ")"); } } SAPI.ContextRelease(ctxSigField); return(Fields); }
// This function is thread-safe and could be called by a few threads simoltaneously. // If FieldName parameter is NULL, a new field will be created, otherwise existing field will be signed // and all field-related parameters will be ignored public static void SAPI_sign_file(string FileName, string FieldName, string User, string Password, string SignPassword, int page, int x, int y, int height, int width, bool Invisible, string Reason, int AppearanceMask, string NewFieldName, string GraphImgName) { int rc; SESHandle SesHandle; SigFieldHandle sf = null; SAPICrypt SAPI = new SAPICrypt(); if ((rc = SAPI.HandleAcquire(out SesHandle)) != 0) { throw new Exception("Failed in SAPIHandleAcquire() with rc = " + rc.ToString("X")); } //Logon if ((rc = SAPI.Logon(SesHandle, User, null, Password)) != 0) { SAPI.HandleRelease(SesHandle); throw new Exception("Failed to authenticate user with rc = " + rc.ToString("X")); } //Set Graphical Image if required if (GraphImgName != null && GraphImgName.Length > 1) { SAPIContext ctxGraphImg = new SAPIContext(); //Start Graphical Images Enumeration if ((rc = SAPI.GraphicSigImageEnumInit(SesHandle, ctxGraphImg, AR_GR_SIG_DATA_FORMAT_ALL, 0)) != 0) { SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to enumerate graphical signatures with rc = " + rc.ToString()); } GraphicImageHandle hGrImg = null; bool isFound = false; while (((uint)(rc = SAPI.GraphicSigImageEnumCont(SesHandle, ctxGraphImg, out hGrImg))) != SAPI_ERROR_NO_MORE_ITEMS) { if (rc != 0) { SAPI.ContextRelease(ctxGraphImg); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to retrieve next graphical signature with rc = " + rc.ToString()); } //Get Graphical Signature Info GraphicImageInfo giInfo = null; if ((rc = SAPI.GraphicSigImageInfoGet(SesHandle, hGrImg, out giInfo, SAPI_ENUM_GRAPHIC_IMAGE_FORMAT.SAPI_ENUM_GRAPHIC_IMAGE_NONE, 0)) != 0) { SAPI.ContextRelease(ctxGraphImg); SAPI.HandleRelease(hGrImg); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to retrieve graphical signature info with rc = " + rc.ToString()); } //Check if required Graphical image has been found if (giInfo.Name.Trim().ToLower() == GraphImgName.Trim().ToLower()) { //If found - set is as default Graph. Image if ((rc = SAPI.GraphicSigImageSetDefault(SesHandle, hGrImg)) != 0) { SAPI.ContextRelease(ctxGraphImg); SAPI.HandleRelease(hGrImg); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to define default graphical signature with rc = " + rc.ToString()); } isFound = true; SAPI.ContextRelease(ctxGraphImg); SAPI.HandleRelease(hGrImg); break; } SAPI.HandleRelease(hGrImg); } SAPI.ContextRelease(ctxGraphImg); //If required Graph Image wasn't found... if (!isFound) { SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to find Graphical Image with name: " + GraphImgName); } } //Create new signature field if (FieldName == null) { SigFieldSettings SFS = new SigFieldSettings(); TimeFormat TF = new TimeFormat(); int Flags = 0; //Define name of the new signature field if (NewFieldName.Length > 0) { SFS.Name = NewFieldName; Flags |= AR_PDF_FLAG_FIELD_NAME_SET; } if (Invisible) { SFS.Invisible = 1; SFS.Page = -1; } else { // VISIBLE: SFS.Invisible = 0; // location: SFS.Page = page; SFS.X = x; SFS.Y = y; SFS.Height = height; SFS.Width = width; // appearance: SFS.AppearanceMask = AppearanceMask; SFS.LabelsMask = AppearanceMask; SFS.DependencyMode = SAPI_ENUM_DEPENDENCY_MODE.SAPI_ENUM_DEPENDENCY_MODE_INDEPENDENT; SFS.SignatureType = SAPI_ENUM_SIGNATURE_TYPE.SAPI_ENUM_SIGNATURE_DIGITAL; SFS.Flags = 0; // time: TF.DateFormat = "dd MMM yyyy"; TF.TimeFormat = "hh:mm:ss"; TF.ExtTimeFormat = SAPI_ENUM_EXTENDED_TIME_FORMAT.SAPI_ENUM_EXTENDED_TIME_FORMAT_NONE; SFS.TimeFormat = TF; } //Create the Field if ((rc = SAPI.SignatureFieldCreate(SesHandle, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_ADOBE, FileName, SFS, Flags, out sf)) != 0) { SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to create new signature field with rc = " + rc.ToString("X")); } } //Find an existing signature field by name else { SAPIContext ctxField = new SAPIContext(); int NumOfFields = 0; //Initiate the Signature Fields enumeration process if ((rc = SAPI.SignatureFieldEnumInit(SesHandle, ctxField, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_ADOBE, FileName, 0, ref NumOfFields)) != 0) { SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to start signature field enumeration with rc = " + rc.ToString("X")); } bool isFound = false; for (int i = 0; i < NumOfFields; i++) { //Get Next field's handle if ((rc = SAPI.SignatureFieldEnumCont(SesHandle, ctxField, out sf)) != 0) { SAPI.ContextRelease(ctxField); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed in signature fields enumeration with rc = " + rc.ToString("X")); } //Retrieve Signature Field's info SigFieldSettings sfs = new SigFieldSettings(); SigFieldInfo sfi = new SigFieldInfo(); if ((rc = SAPI.SignatureFieldInfoGet(SesHandle, sf, sfs, sfi)) != 0) { SAPI.HandleRelease(sf); SAPI.ContextRelease(ctxField); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to retrieve signature field details with rc = " + rc.ToString("X")); } //Check that the field we've found is not signed. If Signed - just skip it. if (sfi.IsSigned != 0) { continue; } if (sfs.Name == FieldName) { SAPI.ContextRelease(ctxField); isFound = true; break; } //Release handle of irrelevant signature field SAPI.HandleRelease(sf); } if (!isFound) { SAPI.ContextRelease(ctxField); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("The file doesn't contain any signature field named: " + FieldName); } } //Define the Reason if ((rc = SAPI.ConfigurationValueSet(SesHandle, SAPI_ENUM_CONF_ID.SAPI_ENUM_CONF_ID_REASON, SAPI_ENUM_DATA_TYPE.SAPI_ENUM_DATA_TYPE_STR, Reason, 1)) != 0) { SAPI.HandleRelease(sf); SAPI.Logoff(SesHandle); SAPI.HandleRelease(SesHandle); throw new Exception("Failed in SAPIConfigurationValueSet with rc = " + rc.ToString("X")); } if (string.IsNullOrEmpty(SignPassword)) { //Prompt-for-sign mode is disabled rc = SAPI.SignatureFieldSign(SesHandle, sf, 0); } else { //Prompt-for-sign mode is enabled rc = SAPI.SignatureFieldSignEx(SesHandle, sf, 0, SignPassword); } if (rc != 0) { SAPI.Logoff(SesHandle); SAPI.HandleRelease(sf); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to Sign signature field with rc = " + rc.ToString("X")); } SAPI.Logoff(SesHandle); SAPI.HandleRelease(sf); SAPI.HandleRelease(SesHandle); return; }
static void Main(string[] args) { string InFileName = "C:\\temp\\tag-sample.pdf"; string OutFileName = "C:\\temp\\tag-sample-signed.pdf"; string startDelim = "<<"; string endDelim = ">>"; int rc; SESHandle SesHandle; SigFieldSettings SFS = new SigFieldSettings(); TimeFormat TF = new TimeFormat(); int Flags = AR_PDF_FLAG_FIELD_NAME_SET; int LocNumber; SAPICrypt SAPI = new SAPICrypt(); // SAPIInit() should be called once per process if ((rc = SAPI.Init()) != 0) { throw new Exception("Failed to initialize SAPI! (" + rc.ToString("X") + ")"); } // Open a new SAPI context if ((rc = SAPI.HandleAcquire(out SesHandle)) != 0) { throw new Exception("Failed in SAPIHandleAcquire() with rc = " + rc.ToString("X")); } if ((rc = SAPI.Logon(SesHandle, "{DSA User}", null, "{DSA User password}")) != 0) { SAPI.HandleRelease(SesHandle); throw new Exception("Failed in SAPILogon() with rc = " + rc.ToString("X")); } // // Locate all field tags in the PDF // The PDF filename to be used is defined above. // The format of each field locator in the PDF should be: // << w={width}; h={height}; n={field name}; a={appearance mask} >> // // For example: // << w=120; h=80; n=Signer1; a=15; >> // SAPIContext SigLocatorCtx = new SAPIContext(); Array fileBytes = File.ReadAllBytes(InFileName); SAPIByteArray doc = new SAPIByteArray(); doc.FromArray(ref fileBytes); FileHandle fh; if ((rc = SAPI.CreateFileHandleByMem(out fh, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_ADOBE, 0, doc)) != 0) { SAPI.HandleRelease(SesHandle); throw new Exception("Failed to create file handle with rc = " + rc.ToString("X")); } // Initiate a new Field Locator enumerator. // The argument LocNumber will contain the number of signature tags found in the PDF document. // if ((rc = SAPI.SignatureFieldLocatorEnumInit(SesHandle, SigLocatorCtx, fh, startDelim, endDelim, 0, out LocNumber)) != 0) { SAPI.HandleRelease(fh); SAPI.HandleRelease(SesHandle); throw new Exception("LocatorEnumInit failed with rc = " + rc.ToString("X")); } // Do for all tags in the document string strEncMsg; for (int i = 0; i < LocNumber; i++) { // Get settings for the next field locator. // (Use strEncMsg string to parse the field locator content if a custom string format has been used) if ((rc = SAPI.SignatureFieldLocatorEnumCont(SesHandle, SigLocatorCtx, SFS, out strEncMsg)) != 0) { SAPI.ContextRelease(SigLocatorCtx); SAPI.HandleRelease(fh); SAPI.HandleRelease(SesHandle); throw new Exception("LocatorEnumCont failed with rc = " + rc.ToString("X")); } // The following values of the SignatureFieldSettings will be automatically set by SAPI: // X/Y Location (including page number) // Width // Height // Field Name // Appearance Mask // SFS.LabelsMask = 0; SFS.DependencyMode = SAPI_ENUM_DEPENDENCY_MODE.SAPI_ENUM_DEPENDENCY_MODE_INDEPENDENT; SFS.SignatureType = SAPI_ENUM_SIGNATURE_TYPE.SAPI_ENUM_SIGNATURE_DIGITAL; SFS.Flags = 0; // time: TF.DateFormat = "dd MMM yyyy"; TF.TimeFormat = "hh:mm:ss"; TF.ExtTimeFormat = SAPI_ENUM_EXTENDED_TIME_FORMAT.SAPI_ENUM_EXTENDED_TIME_FORMAT_NONE; SFS.TimeFormat = TF; // Now create the signature field on the PDF // We make use of SignatureFieldCreateEx function in order to pass the FileHandle for the in-memory // file rather than a UNC file path. if ((rc = SAPI.SignatureFieldCreateSignEx2(SesHandle, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_ADOBE, "", fh, SFS, Flags, null)) != 0) { SAPI.ContextRelease(SigLocatorCtx); SAPI.HandleRelease(fh); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to create new signature field with rc = " + rc.ToString("X")); } } // Write the PDF to an output file if ((rc = SAPI.GetFileMemData(fh, 0, doc)) != 0) { SAPI.ContextRelease(SigLocatorCtx); SAPI.HandleRelease(fh); SAPI.HandleRelease(SesHandle); throw new Exception("Failed to GetFileMem with rc = " + rc.ToString("X")); } File.WriteAllBytes(OutFileName, (byte[])doc.ToArray()); // Finalize work with SAPI SAPI.ContextRelease(SigLocatorCtx); SAPI.HandleRelease(fh); SAPI.HandleRelease(SesHandle); }
public static SignatureDetails ValidateXMLSignature(string SignedXML) { if (SignedXML == null) { throw new ArgumentNullException("SignedXML"); } //Make sure the SAPI Library is loaded SAPIInit(); SignatureDetails SigDetails = new SignatureDetails(); SigFieldSettings SigFieldSettings = new SigFieldSettings(); SigFieldInfo SignatureFieldInfo = new SigFieldInfo(); SAPICrypt SAPI = new SAPICrypt(); SigFieldHandle hField = null; int rc; SESHandle hSession = new SESHandle(); if ((rc = SAPI.HandleAcquire(out hSession)) != 0) { throw new Exception(string.Format( "Memory allocation error (#{0})", rc.ToString("X"))); } SAPIContext ctxValidateSignature = new SAPIContext(); int num = 0; if ((rc = SAPI.SignatureFieldEnumInit(hSession, ctxValidateSignature, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_XML, SignedXML, 0, ref num)) != 0) { SAPI.HandleRelease(hSession); throw new Exception(string.Format( "An error occured while initializing the signature validation process (#{0})", rc.ToString("X"))); } if (num < 1) { throw new Exception("The XML file is not signed!"); } if (num > 1) { throw new Exception("SAPI only supports a single signature per XML file!"); } if ((rc = SAPI.SignatureFieldEnumCont(hSession, ctxValidateSignature, out hField)) != 0) { SAPI.ContextRelease(ctxValidateSignature); SAPI.HandleRelease(hSession); throw new Exception(string.Format( "Failed to retrieve signature (#{0})", rc.ToString("X"))); } if ((rc = SAPI.SignatureFieldInfoGet(hSession, hField, SigFieldSettings, SignatureFieldInfo)) != 0) { SAPI.ContextRelease(ctxValidateSignature); SAPI.HandleRelease(hSession); throw new Exception(string.Format( "Failed to parse signature details (#{0})", rc.ToString("X"))); } CertStatus not_used = new CertStatus(); SigDetails.isValid = SAPI.SignatureFieldVerify(hSession, hField, not_used, 0) == 0; SigDetails.SignerCertificate = new X509Certificate2( (byte[])(((SAPIByteArray)SignatureFieldInfo.Certificate).ToArray())); SigDetails.SignerName = SignatureFieldInfo.SignerName; //Convert FILE_TIME to ticks ulong filetime = SignatureFieldInfo.SignatureTime.HighDateTime; filetime <<= 32; filetime += SignatureFieldInfo.SignatureTime.LowDateTime; SigDetails.SignatureTimeTicks = DateTime.FromFileTimeUtc((long)filetime).Ticks; //Cleanup memory SAPI.ContextRelease(ctxValidateSignature); SAPI.HandleRelease(hSession); return(SigDetails); }
public static void SignStream( string Username, string Domain, string Password, Stream DataToSign, //The stream to read the data to be signed from Stream SignatureData //The stream to write the signature data to ) { if (string.IsNullOrEmpty(Username)) { throw new ArgumentNullException("Username"); } if (string.IsNullOrEmpty(Password)) { throw new ArgumentNullException("Password"); } if (DataToSign == null) { throw new ArgumentNullException("DataToSign"); } if (SignatureData == null) { throw new ArgumentNullException("SignatureData"); } //Make sure the SAPI library is loaded into the current process SAPIInit(); //Instantiate SAPI object SAPICrypt SAPI = new SAPICrypt(); SESHandle hSes = null; int rc = 0; if ((rc = SAPI.HandleAcquire(out hSes)) != 0) { throw new Exception(string.Format( "Memory allocation error (#{0})", rc.ToString("X"))); } if ((rc = SAPI.Logon(hSes, Username, Domain, Password)) != 0) { SAPI.HandleRelease(hSes); throw new Exception(string.Format( "Failed to authenticate the user(#{0})", rc.ToString("X"))); } //Allocate new signing context SAPIContext ctxBuffSign = new SAPIContext(); if ((rc = SAPI.BufferSignInit(hSes, ctxBuffSign, 0)) != 0) { SAPI.Logoff(hSes); SAPI.HandleRelease(hSes); throw new Exception(string.Format( "Failed to initialize buffer signing process(#{0})", rc.ToString("X"))); } int remaining = (int)DataToSign.Length; //Check that the stream is not empty if ((int)DataToSign.Length < 1) { SAPI.Logoff(hSes); SAPI.HandleRelease(hSes); throw new Exception("Cannot sign empty stream!"); } int chunkMaxSize = 1 << 20; //1MB //Calculate first chunk size int chunkSize = remaining < chunkMaxSize ? remaining : chunkMaxSize; while (remaining > 0) { Array chunk = new byte[chunkSize]; //Read in chunks of 1MB int read = DataToSign.Read((byte[])chunk, 0, chunkSize); if (read <= 0) { throw new EndOfStreamException(String.Format("End of stream reached with {0} bytes left to read", remaining)); } //Build SAPI-Compatible bytes array SAPIByteArray tmpBuff = new SAPIByteArray(); tmpBuff.FromArray(ref chunk); //Add read buffer to the signature calculation if ((rc = SAPI.BufferSignCont(hSes, ctxBuffSign, tmpBuff)) != 0) { SAPI.ContextRelease(ctxBuffSign); SAPI.Logoff(hSes); SAPI.HandleRelease(hSes); throw new Exception(string.Format( "An error occured while calculating the digital signature (#{0})", rc.ToString("X"))); } remaining -= read; chunkSize = Math.Min(remaining, chunkSize); } SAPIByteArray signature = new SAPIByteArray(); //Get the final signature if ((rc = SAPI.BufferSignEnd(hSes, ctxBuffSign, signature)) != 0) { SAPI.ContextRelease(ctxBuffSign); SAPI.Logoff(hSes); SAPI.HandleRelease(hSes); throw new Exception(string.Format( "Failed to sign the data (#{0})", rc.ToString("X"))); } //Write signature data to the stream byte[] tmpSig = (byte[])signature.ToArray(); SignatureData.Write(tmpSig, 0, tmpSig.Length); //Cleanup memory SAPI.ContextRelease(ctxBuffSign); SAPI.Logoff(hSes); SAPI.HandleRelease(hSes); }
public static SignatureDetails ValidateSignature(Stream SignedData, Stream Signature) { if (SignedData == null) { throw new ArgumentNullException("SignedData"); } if (Signature == null) { throw new ArgumentNullException("Signature"); } //Make sure the SAPI Library is loaded SAPIInit(); SignatureDetails SigDetails = new SignatureDetails(); int rc; SAPICrypt SAPI = new SAPICrypt(); SESHandle hSession = new SESHandle(); if ((rc = SAPI.HandleAcquire(out hSession)) != 0) { throw new Exception(string.Format( "Memory allocation error (#{0})", rc.ToString("X"))); } //Extract Signer Data from the Signature stream //Read Signature content from stream to the SAPI bytes array Array baSignature = new byte[(int)Signature.Length]; Signature.Read((byte[])baSignature, 0, (int)Signature.Length); SAPIByteArray sSignature = new SAPIByteArray(); sSignature.FromArray(ref baSignature); //SAPIByteArray sSignedData = new SAPIByteArray(); //Array t1 = (Array)SignedData; sSignedData.FromArray(ref t1); object Certificate; // Extract the signer's certificate from signature SAPI_ENUM_DATA_TYPE SAPIType = SAPI_ENUM_DATA_TYPE.SAPI_ENUM_DATA_TYPE_NONE; if ((rc = SAPI.PKCS7BlobGetValue(hSession, sSignature, SAPI_ENUM_PKCS7_FIELD.SAPI_ENUM_PKCS7_FIELD_CERT, out Certificate, ref SAPIType)) != 0) { SAPI.HandleRelease(hSession); throw new Exception(string.Format( "An error occured while extracting the signer's certificate from the signature stream (#{0})", rc.ToString("X"))); } SigDetails.SignerCertificate = new X509Certificate2((byte[])(((SAPIByteArray)Certificate).ToArray())); SigDetails.SignerName = SigDetails.SignerCertificate.GetNameInfo(X509NameType.SimpleName, false); SigDetails.SignerEmail = SigDetails.SignerCertificate.GetNameInfo(X509NameType.EmailName, false); //Run the signature validation process SAPIContext ctxValidateSignature = new SAPIContext(); if ((rc = SAPI.BufferVerifySignatureInit(hSession, ctxValidateSignature, sSignature, 0)) != 0) { SAPI.HandleRelease(hSession); throw new Exception(string.Format( "An error occured while initializing the signature validation process (#{0})", rc.ToString("X"))); } int remaining = (int)SignedData.Length; int chunkMaxSize = 1 << 20; //1MB //Calculate first chunk size int chunkSize = remaining < chunkMaxSize ? remaining : chunkMaxSize; while (remaining > 0) { Array chunk = new byte[chunkSize]; //Read in chunks of 1MB int read = SignedData.Read((byte[])chunk, 0, chunkSize); if (read <= 0) { throw new EndOfStreamException(String.Format("End of stream reached with {0} bytes left to read", remaining)); } //Build SAPI-Compatible byte array SAPIByteArray tmpBuff = new SAPIByteArray(); tmpBuff.FromArray(ref chunk); //Add read buffer to the validation calculation if ((rc = SAPI.BufferVerifySignatureCont(hSession, ctxValidateSignature, tmpBuff)) != 0) { SAPI.ContextRelease(ctxValidateSignature); SAPI.HandleRelease(hSession); throw new Exception(string.Format( "An error occured while validating the digital signature (#{0})", rc.ToString("X"))); } remaining -= read; chunkSize = Math.Min(remaining, chunkSize); } //Get the final validation result SAPIFileTime signingTime = new SAPIFileTime(); rc = SAPI.BufferVerifySignatureEnd(hSession, ctxValidateSignature, signingTime, new CertStatus()); if ((uint)rc == 0x90030360) //SAPI_SIGNATURE_NOT_VALID { SigDetails.isValid = false; SigDetails.SignatureTimeTicks = 0; } else if (rc == 0) { SigDetails.isValid = true; //Convert FILE_TIME to ticks ulong filetime = signingTime.HighDateTime; filetime <<= 32; filetime += signingTime.LowDateTime; SigDetails.SignatureTimeTicks = DateTime.FromFileTimeUtc((long)filetime).Ticks; } else { SAPI.ContextRelease(ctxValidateSignature); SAPI.HandleRelease(hSession); throw new Exception(string.Format( "Failed to validate Digital Signature (#{0})", rc.ToString("X"))); } //Cleanup memory SAPI.ContextRelease(ctxValidateSignature); SAPI.HandleRelease(hSession); return(SigDetails); }