DocumentSigner.Validate(String, SignatureValidationOptions) Method

Validates a signature in the specified file with the specified options.

Namespace: DevExpress.Office.DigitalSignatures

Assembly: DevExpress.Docs.v24.1.dll

NuGet Package: DevExpress.Document.Processor

Declaration

C#

public PackageSignatureValidation Validate(
    string inputFileName,
    SignatureValidationOptions options
)

VB.NET

Public Function Validate(
    inputFileName As String,
    options As SignatureValidationOptions
) As PackageSignatureValidation

Parameters

Name	Type	Description
inputFileName	String	A name of a file with a signature (including the full path).
options	SignatureValidationOptions	An object that contains validation options.

Returns

Type	Description
PackageSignatureValidation	An object that contains validation information.

Remarks

Validation Options

The SignatureValidationOptions object allows you to specify signature validation options. Use the SignatureValidationOptions.ValidationFlags property to exclude validation steps.

C#

private static void ValidateSignature(string path)
{
    DocumentSigner validator = new DocumentSigner();

    //Specify validation options
    //In this example, certificate validation is skipped
    SignatureValidationOptions validationOptions = new SignatureValidationOptions();
    validationOptions.ValidationFlags = ~ValidationFlags.ValidateSignatureCertificate & ~ValidationFlags.ValidateTimestampCertificate;

    //Validate the signature:
    PackageSignatureValidation signatureValidation = validator.Validate(path, validationOptions);
    AnalyzeValidationResult(signatureValidation);

}

VB.NET

Private Shared Sub ValidateSignature(ByVal path As String)
  Dim validator As New DocumentSigner()

  'Specify validation options
  'In this example, certificate validation is skipped
  Dim validationOptions As New SignatureValidationOptions()
  validationOptions.ValidationFlags = (Not ValidationFlags.ValidateSignatureCertificate) And Not ValidationFlags.ValidateTimestampCertificate

  'Validate the signature:
  Dim signatureValidation As PackageSignatureValidation = validator.Validate(path, validationOptions)
  AnalyzeValidationResult(signatureValidation)
End Sub

Validation Process

The Validate method returns the PackageSignatureValidation instance that contains validation information. Check the PackageSignatureValidation.Result and PackageSignatureValidation.ResultMessage properties to determine whether the signature is valid.

Note

Make sure that the signature certificate is registered on your machine. Otherwise, the signature is invalid.

If the document is not signed, the PackageSignatureValidation.Result property returns SignaturesNotFound.

If the document to be validated is encrypted, specify the SignatureValidationOptions.DecryptionPassword property to decrypt the document. Otherwise, the Result property returns PackageSignatureValidationResult.PackageOpenFailed.

If the PackageSignatureValidation.Result property returns Invalid or PartiallyValid, check the PackageSignatureValidation.Items property to obtain a list of items with validation information. The number of SignatureValidationInfo objects in the list is equal to the number of signatures.

The table below lists API used to obtain information:

Property	Description
SignatureValidationInfo.PassedChecks	Returns verification types the signature passed.
SignatureValidationInfo.PassedCheckDetails	Obtains information about passed verifications.
SignatureValidationInfo.FailedChecks	Returns verification types the signature did not pass.
SignatureValidationInfo.FailedCheckDetails	Retrieves information about failed verifications.
SignatureValidationInfo.CheckDetails	Gets information about all verifications.

The code sample below analyzes the validation result and shows information in the console:

C#

private static void AnalyzeValidationResult(PackageSignatureValidation signatureValidation)
{
    string validationMessage = signatureValidation.ResultMessage;

    //Check validation result and show information in the console:
    switch (signatureValidation.Result)
    {
        case PackageSignatureValidationResult.Valid:
            Console.WriteLine(validationMessage); Console.ReadKey();
            Process.Start(output);
            break;

        case PackageSignatureValidationResult.SignaturesNotFound:
            Console.WriteLine(validationMessage);
            break;

        case PackageSignatureValidationResult.Invalid:
        case PackageSignatureValidationResult.PartiallyValid:
            var failedCheckDetails = signatureValidation.Items[0].FailedCheckDetails;
            Console.WriteLine(validationMessage);
            int i = 1;
            foreach (SignatureCheckResult checkResult in failedCheckDetails)
            {
                Console.WriteLine(String.Format("Validation details {0}: \r\n" +
                    "{1} failed, Info: {2} \r\n", i, checkResult.CheckType, checkResult.Info));
                i++;
            }
            Console.ReadKey();
            break;
    }
}

VB.NET

Private Shared Sub AnalyzeValidationResult(ByVal signatureValidation As PackageSignatureValidation)
  Dim validationMessage As String = signatureValidation.ResultMessage

  'Check validation result and show information in the console:
  Select Case signatureValidation.Result
    Case PackageSignatureValidationResult.Valid
      Console.WriteLine(validationMessage)
      Console.ReadKey()
      Process.Start(output)

    Case PackageSignatureValidationResult.SignaturesNotFound
      Console.WriteLine(validationMessage)

    Case PackageSignatureValidationResult.Invalid, PackageSignatureValidationResult.PartiallyValid
      Dim failedCheckDetails = signatureValidation.Items(0).FailedCheckDetails
      Console.WriteLine(validationMessage)
      Dim i As Integer = 1
      For Each checkResult As SignatureCheckResult In failedCheckDetails
        Console.WriteLine(String.Format("Validation details {0}: " & ControlChars.CrLf & "{1} failed, Info: {2} " & ControlChars.CrLf, i, checkResult.CheckType, checkResult.Info))
        i += 1
      Next checkResult
      Console.ReadKey()
  End Select
End Sub 

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the Validate(String, SignatureValidationOptions) method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

word-document-api-sign-document-and-validate-signature/CS/WordDocumentDigitalSignatureSample/Program.cs#L82

//Validate the signature:
PackageSignatureValidation signatureValidation = validator.Validate(path, validationOptions);
string validationMessage = signatureValidation.ResultMessage;

spreadsheet-document-api-sign-workbook-and-validate-signature/CS/WorkbookDigitalSignatureSample/Program.cs#L84

//Validate the signature:
PackageSignatureValidation signatureValidation = validator.Validate(path, validationOptions);
string validationMessage = signatureValidation.ResultMessage;

VB.NET

word-document-api-sign-document-and-validate-signature/VB/WordDocumentDigitalSignatureSample/Program.vb#L72

'Validate the signature:
Dim signatureValidation As PackageSignatureValidation = validator.Validate(path, validationOptions)
Dim validationMessage As String = signatureValidation.ResultMessage

spreadsheet-document-api-sign-workbook-and-validate-signature/VB/WorkbookDigitalSignatureSample/Program.vb#L77

'Validate the signature:
Dim signatureValidation As PackageSignatureValidation = validator.Validate(path, validationOptions)
Dim validationMessage As String = signatureValidation.ResultMessage