GroupDocs.Signature for .NET 19.5 Release Notes

This page contains release notes for GroupDocs.Signature for .NET 19.5

Major Features

There are few new features, improvements and bug fixes in this regular release. Most features are related to support of djvu format for most service methods, implementation of serialization and encryption of custom data objects into Metadata signatures with ability to extract them back and specify custom serialization and data encryption. Also this release contains some internal security and licensing improvements.

Introduced ability to embed custom objects to Metadata Signature for Cells and Words Documents
Implemented support to embed custom objects to Metadata Signature for Slides Presentation Documents
Added support of custom serialization for Pdf Metadata Signature object
Implemented ability of custom data encryption and decryption for embedded objects into Metadata Signature for Pdf Documents
Internal improvements of error handling and code updates
Fixed data serialization issues with simple data type for QR and Metadata signature

Full List of Issues Covering all Changes in this Release

Key	Summary	Issue Type
SIGNATURENET-2020	Fix exception for de-serialization of encrypted string values in Metadata Signatures	Bug
SIGNATURENET-2012	SaveOptions.OutputFileName doesn’t affect on result name of signed document	Bug
SIGNATURENET-2008	PdfQRCodeSignature.GetData() throws exception	Bug
SIGNATURENET-2024	Implement ability to embed custom object to Slides Metadata Signature	New Feature
SIGNATURENET-1842	Implement ability to embed custom object to Words Metadata Signature	New Feature
SIGNATURENET-1838	Implement ability to embed custom object to Cells Metadata Signature	New Feature
SIGNATURENET-2014	Implement support of .djvu file format for verification process	Improvement
SIGNATURENET-2013	Implement ability to search files with .djvu format as image documents	Improvement
SIGNATURENET-2007	Implement ability to sign files with .djvu format as image documents	Improvement
SIGNATURENET-1980	Implement new method AddSignature for MetadataOptions	Improvement

Public API and Backward Incompatible Changes

This section lists public API changes that were introduced in GroupDocs.Signature for .NET 19.5. It includes not only new and obsoleted public methods, but also a description of any changes in the behavior behind the scenes in GroupDocs.Signature which may affect existing code. Any behavior introduced that could be seen as a regression and modifies existing behavior is especially important and is documented here.

GroupDocs.Signature.Options.WordsMetadataSignOptions
Public class WordsMetadataSignOptions was extended with new public method AddSignature. Method creates new Words Metadata Signature with passed arguments (name and value), adds signature to list of metadata signatures and returns newly created object as result.

AddSignature method

/// <summary>
/// Creates new WordsMetadataSignature with passed arguments and adds it to collection.
/// </summary>
/// <param name="name">The name of new metadata signature</param>
/// <param name="value">The value of new metadata signature</param>
/// <returns>Newly created signature that was added to MetadataSignatures collection</returns>
public WordsMetadataSignature AddSignature(string name, object value)

Following example demonstrates signing Words document with Metadata signature using this new method:

Sign Document with metadata signatures

// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
WordsMetadataSignOptions signOptions = new WordsMetadataSignOptions();
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property with encryption
var msAuth = signOptions.AddSignature("Author", "Mr.Scherlock Holmes");
msAuth.DataEncryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, "12345", "12345");
// setup data of document id
signOptions.AddSignature("DocumentId", Guid.NewGuid().ToString());
// setup data of sign date
var msDate = signOptions.AddSignature("SignDate", DateTime.Now);
msDate.Value = DateTime.Now.Date;
// setup some integer value
signOptions.AddSignature("DocDays", 12345);
// setup data of sign date
signOptions.AddSignature("SignKoeff", 2.345M);
// sign document
string signedPath = handler.Sign<string>("test.docx", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMetadata" });
Console.WriteLine("Signed file path is: " + signedPath);

GroupDocs.Signature.Options.SlidesMetadataSignOptions
Public class SlidesMetadataSignOptions was extended with new public method AddSignature. Method creates new Slides Metadata Signature with passed arguments (name and value), adds signature to list of metadata signatures and returns newly created object as result.

AddSignature method

/// <summary>
/// Creates new SlidesMetadataSignature with passed arguments and adds it to collection.
/// </summary>
/// <param name="name">The name of new metadata signature</param>
/// <param name="value">The value of new metadata signature</param>
/// <returns>Newly created signature that was added to MetadataSignatures collection</returns>
public SlidesMetadataSignature AddSignature(string name, object value)

Following example demonstrates signing Slides document with Metadata signature using this new method:

// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
SlidesMetadataSignOptions signOptions = new SlidesMetadataSignOptions();
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property with encryption
var msAuth = signOptions.AddSignature("Author", "Mr.Scherlock Holmes");
msAuth.DataEncryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, "12345", "12345");
// setup data of document id
signOptions.AddSignature("DocumentId", Guid.NewGuid().ToString());
// setup data of sign date
var msDate = signOptions.AddSignature("SignDate", DateTime.Now);
msDate.Value = DateTime.Now.Date;
// setup some integer value
signOptions.AddSignature("DocDays", 12345);
// setup data of sign date
signOptions.AddSignature("SignKoeff", 2.345M);
// sign document
string signedPath = handler.Sign<string>("test.pptx", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMetadata" });
Console.WriteLine("Signed file path is: " + signedPath);

GroupDocs.Signature.Options.PdfMetadataSignOptions
Public class PdfMetadataSignOptions was extended with new public method AddSignature. Method creates new Pdf Metadata Signature with passed arguments (name and value), adds signature to list of metadata signatures and returns newly created object as result.

AddSignature method

/// <summary>
/// Creates new PdfMetadataSignature with passed arguments and adds it to collection.
/// </summary>
/// <param name="name">The name of new metadata signature</param>
/// <param name="value">The value of new metadata signature</param>
/// <returns>Newly created signature that was added to MetadataSignatures collection</returns>
public PdfMetadataSignature AddSignature(string name, object value)

Following example demonstrates signing Pdf document with Metadata signature using this new method:

// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
PdfMetadataSignOptions signOptions = new PdfMetadataSignOptions();
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property with encryption
var msAuth = signOptions.AddSignature("Author", "Mr.Scherlock Holmes");
msAuth.DataEncryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, "12345", "12345");
// setup data of document id
signOptions.AddSignature("DocumentId", Guid.NewGuid().ToString());
// setup data of sign date
var msDate = signOptions.AddSignature("SignDate", DateTime.Now);
msDate.Value = DateTime.Now.Date;
// setup some integer value
signOptions.AddSignature("DocDays", 12345);
// setup data of sign date
signOptions.AddSignature("SignKoeff", 2.345M);
// sign document
string signedPath = handler.Sign<string>("test.pdf", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMetadata" });
Console.WriteLine("Signed file path is: " + signedPath);

GroupDocs.Signature.Options.CellsMetadataSignOptions
Public class CellsMetadataSignOptions was extended with new public method AddSignature. Method creates new Cells Metadata Signature with passed arguments (name and value), adds signature to list of metadata signatures and returns newly created object as result.

AddSignature method

/// <summary>
/// Creates new CellsMetadataSignature with passed arguments and adds it to collection.
/// </summary>
/// <param name="name">The name of new metadata signature</param>
/// <param name="value">The value of new metadata signature</param>
/// <returns>Newly created signature that was added to MetadataSignatures collection</returns>
public CellsMetadataSignature AddSignature(string name, object value)

Following example demonstrates signing Cells document with Metadata signature using this new method:

// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
CellsMetadataSignOptions signOptions = new CellsMetadataSignOptions();
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property with encryption
var msAuth = signOptions.AddSignature("Author", "Mr.Scherlock Holmes");
msAuth.DataEncryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, "12345", "12345");
// setup data of document id
signOptions.AddSignature("DocumentId", Guid.NewGuid().ToString());
// setup data of sign date
var msDate = signOptions.AddSignature("SignDate", DateTime.Now);
msDate.Value = DateTime.Now.Date;
// setup some integer value
signOptions.AddSignature("DocDays", 12345);
// setup data of sign date
signOptions.AddSignature("SignKoeff", 2.345M);
// sign document
string signedPath = handler.Sign<string>("test.xlsx", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMetadata" });
Console.WriteLine("Signed file path is: " + signedPath);

Public classes CellsMetadataSignature, SlidesMetadataSignature, WordsMetadataSignature were extended with new public property DataEncryption of type IDataEncryption

DataEncryption property

/// <summary>
/// Gets or sets implementation of <see cref="IDataEncryption"/> interface to encode and decode signature Value property.
/// </summary>
public IDataEncryption DataEncryption { get; set; }

and overloaded method public T GetData(). These methods return object of type T over de-serialization and decryption from Metadata Value.

GetData() method

/// <summary>
/// Obtain object from Metadata Signature Value over de-serialization and decryption
/// </summary>
/// <typeparam name="T">Type of object to deserialize from Metadata value</typeparam>
/// <returns></returns>
public T GetData<T>() where T : class

/// <summary>
/// Obtain object from Metadata Signature Value over deserialization.
/// </summary>
/// <typeparam name="T">Type of object to deserialize from Metadata Value</typeparam>
/// <param name="dataEncryption">Set custom data encryption implementation</param>
/// <returns></returns>
public T GetData<T>(IDataEncryption dataEncryption) where T : class

Custom data class DocumentSignature

Example of custom class

public class DocumentSignature
{
    // specify SkipSerialization attribute to skip this field on serialization
    [SkipSerialization]
    public string Version { get; set; }
    // specify SkipSerialization attribute to skip this field on serialization
    [SkipSerialization]
    public bool IsProcessed { get; set; }
    [Format("SignatureID")]
    public string ID { get; set; }
    [Format("Author")]
    public string Author { get; set; }
    [Format("SignatureDate","yyyy-MM-dd")]
    public DateTime Signed { get; set; }
    [Format("Factor", "N2")]
    public decimal DataFactor { get; set; }
}

Following example demonstrates signing Words document with Metadata signature with value of custom class DocumentSignature object:

Sign Words Document with custom objects in Metadata

// setup key and passphrase
string key = "1234567890";
string salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
WordsMetadataSignOptions signOptions = new WordsMetadataSignOptions();
// create custom object
DocumentSignature signature = new DocumentSignature()
{
    ID = Guid.NewGuid().ToString(),
    Author = Environment.UserName,
    Signed = DateTime.Now,
    DataFactor = 11.22M
};
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property
WordsMetadataSignature mdDocument = signOptions.AddSignature("DocumentSignature", signature);
// set encryption
mdDocument.DataEncryption = encryption;
// sign document
string signedPath = handler.Sign<string>("test.docx", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMedataDataEncrypted.docx" });
Console.WriteLine("Signed file path is: " + signedPath);

Example how to retrieve signed Words document file with DocumentSignature Metadata Value (see examples above how to sign Document with custom data objects)

Search custom object in Metadata

// setup key and pasphrase
string key = "1234567890";
string salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup search options
WordsSearchMetadataOptions searchOptions = new WordsSearchMetadataOptions();
// search document
SearchResult result = handler.Search("SignedMedataDataEncrypted.docx", searchOptions);
// output signatures
List<WordsMetadataSignature> signatures = result.ToList<WordsMetadataSignature>();
foreach (WordsMetadataSignature signature in signatures)
{
    if (signature != null && signature.Name.Equals("DocumentSignature"))
    {
        DocumentSignature docSignature = signature.GetData<DocumentSignature>(encryption);
        if (docSignature != null)
        {
            Console.WriteLine("Found DocumentSignature signature: #{0}. Author {1} from {2}. Factor: {3}", 
                   docSignature.ID, docSignature.Author, docSignature.DataFactor, docSignature.DataFactor);
        }
    }
}

Following example demonstrates signing Cells document with Metadata signature with value of DocumentSignature object:

Sign Cells Document with custom objects in Metadata

// setup key and passphrase
string key = "1234567890";
string salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
CellsMetadataSignOptions signOptions = new CellsMetadataSignOptions();
// create custom object
DocumentSignature signature = new DocumentSignature()
{
    ID = Guid.NewGuid().ToString(),
    Author = Environment.UserName,
    Signed = DateTime.Now,
    DataFactor = 11.22M
};
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property
CellsMetadataSignature mdDocument = signOptions.AddSignature("DocumentSignature", signature);
// set encryption
mdDocument.DataEncryption = encryption;

// sign document
string signedPath = handler.Sign<string>("test.xlsx", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMedataDataEncrypted.xlsx" });
Console.WriteLine("Signed file path is: " + signedPath);

Example how to retrieve signed Cells document file with DocumentSignature Metadata Value (see examples above how to sign Document with custom data objects)

Search custom object in Metadata

// setup key and pasphrase
string key = "1234567890";
string salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup search options
CellsSearchMetadataOptions searchOptions = new CellsSearchMetadataOptions();
// search document
SearchResult result = handler.Search("SignedMedataDataEncrypted.xlsx", searchOptions);
// output signatures
List<CellsMetadataSignature> signatures = result.ToList<CellsMetadataSignature>();
foreach (CellsMetadataSignature signature in signatures)
{
    if (signature != null && signature.Name.Equals("DocumentSignature"))
    {
        DocumentSignature docSignature = signature.GetData<DocumentSignature>(encryption);
        if (docSignature != null)
        {
            Console.WriteLine("Found DocumentSignature signature: #{0}. Author {1} from {2}. Factor: {3}",
                docSignature.ID, docSignature.Author, docSignature.DataFactor, docSignature.DataFactor);
        }
    }
}

Following example demonstrates signing Slides document with Metadata signature with value of DocumentSignature object:

Sign Cells Document with custom objects in Metadata

// setup key and passphrase
string key = "1234567890";
string salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup options with text of signature
SlidesMetadataSignOptions signOptions = new SlidesMetadataSignOptions();
// create custom object
DocumentSignature signature = new DocumentSignature()
{
    ID = Guid.NewGuid().ToString(),
    Author = Environment.UserName,
    Signed = DateTime.Now,
    DataFactor = 11.22M
};
// Specify different Metadata Signatures and add them to options sigature collection
// setup Author property
SlidesMetadataSignature mdDocument = signOptions.AddSignature("DocumentSignature", signature);
// set encryption
mdDocument.DataEncryption = encryption;

// sign document
string signedPath = handler.Sign<string>("test.pptx", signOptions,
    new SaveOptions { OutputType = OutputType.String, OutputFileName = "SignedMedataDataEncrypted.pptx" });
Console.WriteLine("Signed file path is: " + signedPath);

Example how to retrieve signed Slides document file with DocumentSignature Metadata Value (see examples above how to sign Document with custom data objects)

Search custom object in Metadata

// setup key and pasphrase
string key = "1234567890";
string salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
// setup Signature configuration
SignatureConfig signConfig = new SignatureConfig
{
    StoragePath = @"c:\Aspose\Test\Storage",
    OutputPath = @"c:\Aspose\Test\Output"
};
// instantiating the signature handler
SignatureHandler handler = new SignatureHandler(signConfig);
// setup search options
SlidesSearchMetadataOptions searchOptions = new SlidesSearchMetadataOptions();
// search document
SearchResult result = handler.Search("SignedMedataDataEncrypted.pptx", searchOptions);
// output signatures
List<SlidesMetadataSignature> signatures = result.ToList<SlidesMetadataSignature>();
foreach (SlidesMetadataSignature signature in signatures)
{
    if (signature != null && signature.Name.Equals("DocumentSignature"))
    {
        DocumentSignature docSignature = signature.GetData<DocumentSignature>(encryption);
        if (docSignature != null)
        {
            Console.WriteLine("Found DocumentSignature signature: #{0}. Author {1} from {2}. Factor: {3}",
                docSignature.ID, docSignature.Author, docSignature.DataFactor, docSignature.DataFactor);
        }
    }
}