GroupDocs.Signature for .NET 20.6 Release Notes

Major Features

There are about ten new features, improvements and fixes in this release. New features implement ability to add native Word processing Watermark signature, obtain with document common information the list of electronic digital signatures in it. Also in this release we implemented additional encryption algorithm for Net Standard platform AES, fixed few bugs and issues. Below the list of most notable changes in release of GroupDocs.Signature for .NET 20.6:

  • Added ability to add native Watermark signature for Word Processing documents.
  • Implemented AES encryption algorithm for Net Standard platform
  • Improved modification of Watermark object for Word processing document files
  • Introduced ability to obtain information about electronic digital signatures in the document over one method to retrieve all document information
  • Improved validation for various text implementation signatures
  • Added ability to rotate signature on the image document with free angle
  • Fixed few bugs with processing QR-code signatures

Full List of Issues Covering all Changes in this Release

KeySummaryIssue Type
SIGNATURENET-2881Implement native Watermark signature for Word Processing documentsFeature
SIGNATURENET-2879Implement AES encryption algorithm for Net Standard platformFeature
SIGNATURENET-2878Implement modification of native Watermark sugantures for Word processing documentsFeature
SIGNATURENET-2637Implement ability to keep digital signature meta info layer for Document InfoFeature
SIGNATURENET-2443Improve Validation for unsupported text implementation scenariosImprovement
SIGNATURENET-2315Update implementation of signature rotation for Image documentsImprovement
SIGNATURENET-2906Unexpected recognition of QR-code on some imagesBug
SIGNATURENET-2882Exception on Word Processing document with obtaining watermark properties.Bug
SIGNATURENET-2837Document content is changed after saving for OTT filesBug

Public Developer Guide examples changes

Following topics from Developer Guide were added

Public API and Backward Incompatible Changes

Public enum SymmetricAlgorithmType was updated with new enumeration value for Net Standard 2.0.

Public class SymmetricAlgorithmType was updated with new enumeration .

  • new enumeration options AES was added to specify AES encryption algorithm..

New properties of TextSignOptions

    public enum SymmetricAlgorithmType
         . . .
        /// <summary>
        /// Represents AES encryption algorithm.
        /// </summary>

Following example demonstrates how to sign document with QR-code signature and encrypt EPC object into signature.

Sign document with AES encrypted EPC object data

using (Signature signature = new Signature("sample.pdf"))
    // setup key and passphrase
    string key = "1234567890";
    string salt = "1234567890";
    // create EPC object
    EPC epc = new EPC()
        Name = "Sherlock",
        BIC = "MrSherlockH",
        IBAN = "BE72000000001616",
        Amount = 123456.78D,
        Code = "SHRL",
        Reference = "Private service",
        Information = "Thanks for help"
    // create data encryption
    IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.AES, key, salt);
    // create options
    QrCodeSignOptions options = new QrCodeSignOptions
        EncodeType = QrCodeTypes.QR,
        // setup encryption
        DataEncryption = encryption,
        // setup Data property to EPC instance
        Data = epc,
        // set right bottom corner
        HorizontalAlignment = HorizontalAlignment.Right,
        VerticalAlignment = VerticalAlignment.Bottom,
        Width = 100,
        Height = 100,
        Margin = new Padding(10)
    // sign document to file
    SignResult result = signature.Sign(outputFilePath, options);

Public class TextSignOptions was updated with new property for document specific signatures. Supported only for text watermarks for WordProcessing documents yet.

Public class TextSignOptions was updated with new property.

  • new property Native of type bool was added to specify document specific signatures implementations. Now it influences only text watermarks for WordProcessing, but it’s application area could be widened soon.

New properties of TextSignOptions

    /// <summary>
    /// Represents the Text signature options.
    /// </summary>
    /// <remarks>
    public class TextSignOptions
        /// <summary>
        /// Gets or sets the native attribute. If it is set document specific signatures could be used.
        /// Native text watermark for WordProcessing documents is different than regular, for example.
        /// </summary>
        public bool Native { get; set; }

Following example demonstrates how to sign document with document specific signatures implementation of text watermark.

Sign WordProcessing document with native Watermark

using (Signature signature = new Signature("sample.docx"))
    TextSignOptions options = new TextSignOptions("John Smith Watermark")
        // set attribute of using document specific implementation
        Native = true,
        //Watermark will be the same for each page
        SignatureImplementation = TextSignatureImplementation.Watermark,
        // set text color and Font
        ForeColor = Color.Red,
        Font = new SignatureFont { Size = 72, FamilyName = "Comic Sans MS" },
        // set rotation
        // If rotation angle is not 0 it will be converted to 315.
        RotationAngle = 45,
        // set transparency
        // If transparency is not 0 it will be converted to 50%.
        Transparency = 0.9
    // sign document to file
    SignResult signResult = signature.Sign(outputFilePath, options);
    Console.WriteLine($"\nSource document signed successfully with {signResult.Succeeded.Count} signature(s).\nFile saved at {outputFilePath}.");
    Console.WriteLine("\nList of newly created signatures:");
    int number = 1;
    foreach (TextSignature temp in signResult.Succeeded)
        Console.WriteLine($"Signature #{number++}: Type: {temp.SignatureType} Id:{temp.SignatureId}, isNative: {temp.Native}");