DocumentSigner.Sign(Stream, Stream, SignatureOptions, SignatureInfo) Method

Signs a file with the specified signature and signature options.

Namespace: DevExpress.Office.DigitalSignatures

Assembly: DevExpress.Docs.v24.1.dll

NuGet Package: DevExpress.Document.Processor

Declaration

C#

public void Sign(
    Stream inputStream,
    Stream outputStream,
    SignatureOptions options,
    SignatureInfo signatureInfo
)

VB.NET

Public Sub Sign(
    inputStream As Stream,
    outputStream As Stream,
    options As SignatureOptions,
    signatureInfo As SignatureInfo
)

Parameters

Name	Type	Description
inputStream	Stream	The stream that contains a file to sign.
outputStream	Stream	The stream to which to save the file.
options	SignatureOptions	An object that contains signature options.
signatureInfo	SignatureInfo	An object that contains the signature information.

Remarks

Use the Sign method to sign documents and save the result. You can use XAdES-BES and XAdES-T signatures with X.509 certificates. Office File API supports signatures in the following document formats:

• Microsoft Word
  • Open XML (DOCX, DOTX, DOTM, DOCM)
  • 97-2003 (DOC, DOT)
• Microsoft Excel
  • Open XML (XLSX, XLTX, XLSM)
  • 97-2003 binary file (XLS, XLT)
• Microsoft PowerPoint
  • PPTX, PPT

The SignatureOptions class object allows you to specify validation data (certificate, hash algorithm, timestamp, etc.). Pass the SignatureInfo object to define the signer information.

The options and signatureInfo parameters cannot be null.

The code sample below signs and saves a Word and Excel document:

C#

using DevExpress.Office.DigitalSignatures;
using System;
using System.Diagnostics;
using System.Security.Cryptography.X509Certificates;

static void Main(string[] args)
{
    //Sign a workbook:
    using (Stream stream = new FileStream("Template.xlsx", FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
    {
        using (Stream outputStream = new FileStream("Workbook_signed.xlsx", FileMode.Create, FileAccess.Write, FileShare.Read))
        {
            SignDocument(stream, outputStream);
        }
    }

    //Sign a document:
    using (Stream stream = new FileStream("Template.docx", FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
    {
        using (Stream outputStream = new FileStream("Template_signed.docx", FileMode.Create, FileAccess.Write, FileShare.Read))
        {
            SignDocument(stream, outputStream);
        }
    }
}
static void SignDocument(Stream path, Stream output)
{
    DocumentSigner documentSigner = new DocumentSigner();
    documentSigner.Sign(path, output,
     CreateSignatureOptions(), CreateSignatureInfo());
}

//Specify a signature certificate and digest method:
static SignatureOptions CreateSignatureOptions()
{
    X509Certificate2 certificate = new X509Certificate2("Certificate/SignDemo.pfx", "dxdemo");
    Uri tsaServer = new Uri("https://freetsa.org/tsr");
    SignatureOptions options = new SignatureOptions();
    options.Certificate = certificate;
    if (tsaServer != null)
        options.TsaClient = new TsaClient(tsaServer, HashAlgorithmType.SHA256);

    //In this example, certificate validation is skipped
    options.SignatureFlags &= ~SignatureFlags.ValidateCertificate;
    options.CertificateKeyUsageFlags = X509KeyUsageFlags.None;
    options.DigestMethod = HashAlgorithmType.SHA256;

    X509ChainPolicy policy = new X509ChainPolicy();
    policy.RevocationMode = X509RevocationMode.NoCheck;
    policy.RevocationFlag = X509RevocationFlag.ExcludeRoot;
    policy.VerificationFlags |= X509VerificationFlags.AllowUnknownCertificateAuthority |
        X509VerificationFlags.IgnoreCertificateAuthorityRevocationUnknown;
    options.CertificatePolicy = policy;
    options.TimestampCertificatePolicy = policy;
    return options;
}

//Specify signer information:
static SignatureInfo CreateSignatureInfo()
{
    SignatureInfo signatureInfo = new SignatureInfo();
    signatureInfo.CommitmentType = CommitmentType.ProofOfApproval;
    signatureInfo.Time = DateTime.UtcNow;
    signatureInfo.ClaimedRoles.Clear();
    signatureInfo.ClaimedRoles.Add("Sales Representative");
    signatureInfo.Comments = "Demo Digital Signature";

    return signatureInfo;
}

VB.NET

Imports DevExpress.Office.DigitalSignatures
Imports System
Imports System.Diagnostics
Imports System.Security.Cryptography.X509Certificates

Shared Sub Main(ByVal args() As String)
    'Sign a workbook:
    Dim workbookOutput As String = "Workbook_signed.xlsx"
    SignDocument("Template.xlsx", workbookOutput)

    'Sign a document:
    Dim documentOutput As String = "Document_signed.docx"
    SignDocument("Template.docx", documentOutput)
End Sub

Shared Sub SignDocument(ByVal path As String, ByVal output As String)
    Dim documentSigner As New DocumentSigner()
    documentSigner.Sign(path, output,
     CreateSignatureOptions(), CreateSignatureInfo())
    Process.Start(output)
End Sub

' Specify a signature certificate and digest method:
Private Shared Function CreateSignatureOptions() As SignatureOptions
    Dim certificate As New X509Certificate2("Certificate/SignDemo.pfx", "dxdemo")
    Dim tsaServer As New Uri("https://freetsa.org/tsr")
    Dim options As New SignatureOptions()
    options.Certificate = certificate
    If tsaServer IsNot Nothing Then
        options.TsaClient = New TsaClient(tsaServer, HashAlgorithmType.SHA256)
    End If

    'In this example, certificate validation is skipped
    options.SignatureFlags = options.SignatureFlags And Not SignatureFlags.ValidateCertificate
    options.CertificateKeyUsageFlags = X509KeyUsageFlags.None
    options.DigestMethod = HashAlgorithmType.SHA256

    Dim policy As New X509ChainPolicy()
    policy.RevocationMode = X509RevocationMode.NoCheck
    policy.RevocationFlag = X509RevocationFlag.ExcludeRoot
    policy.VerificationFlags = policy.VerificationFlags Or X509VerificationFlags.AllowUnknownCertificateAuthority Or X509VerificationFlags.IgnoreCertificateAuthorityRevocationUnknown
    options.CertificatePolicy = policy
    options.TimestampCertificatePolicy = policy
    Return options
End Function

' Specify signer information:
Shared Function CreateSignatureInfo() As SignatureInfo
    Dim signatureInfo As New SignatureInfo()
    signatureInfo.CommitmentType = CommitmentType.ProofOfApproval
    signatureInfo.Time = Date.UtcNow
    signatureInfo.ClaimedRoles.Clear()
    signatureInfo.ClaimedRoles.Add("Sales Representative")
    signatureInfo.Comments = "Demo Digital Signature"

    Return signatureInfo
End Function