Aspose.PDF for .NET 25.2

Improvements and Changes

Features and Enhancements

Aspose.PDF for .NET enables you to convert a PDF file to a PDF/X-compliant PDF file. PDF/X is a subset of the PDF standard that facilitates graphics exchange and has a series of printing-related requirements that do not apply to standard PDF files. Starting from version 25.2, we support the PDF/X-4 standard. This feature was made according to the User’s request PDFNET-56954.

The following code snippet shows how to convert PDF files to PDF/X-4 compliant PDF and provide an external ICC profile to ensure the proper color rendition.

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ConvertPdfToPdfX()
{
    // The path to the documents directory
    string dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "PDFToPDFX.pdf"))
    {
        // Set up the desired PDF/X format with PdfFormatConversionOptions
        Aspose.Pdf.PdfFormatConversionOptions options = new Aspose.Pdf.PdfFormatConversionOptions(Aspose.Pdf.PdfFormat.PDF_X_4, Aspose.Pdf.ConvertErrorAction.Delete);

        // Provide the name of the external ICC profile file (optional)
        options.IccProfileFileName = dataDir + "ISOcoated_v2_eci.icc";

        // Provide an output condition identifier and other necessary OutputIntent properties (optional)
        options.OutputIntent = new Aspose.Pdf.OutputIntent("FOGRA39");

        // Convert to PDF/X compliant document
        document.Convert(options);

        // Save PDF document
        document.Save(dataDir + "PDFToPDFX4_out.pdf");
    }
}

We’ve added an option to avoid twice calls from the CustomSignHash delegate during signing. This was made at the User’s request PDFNET-56058 which was originally reported as a bug. If you use SignHash to create a digital signature, you may find that the delegate is called twice during the document-saving process. Suppose for some reason you cannot afford two calls, for example. If a PIN code request occurs during the call, you can use the AvoidEstimatingSignatureLength option for the PKCS1, PKCS7, PKCS7Detached, and ExternalSignature classes.

The following code shows the use of the new options:

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SignWithCertificate(string pfxFilePath, string password)
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

    using (var sign = new Aspose.Pdf.Facades.PdfFileSignature())
    {   
        // Bind PDF document
        sign.BindPdf(dataDir + "input.pdf");
        // Create PKCS#7 object to sign
        var pkcs7 = new Aspose.Pdf.Forms.PKCS7(pfxFilePath, password);// You can use PKCS7Detached with digest algorithm argument
        // Set the delegate to external sign
        pkcs7.CustomSignHash = CustomSignHash;
        // Set an option to avoiding twice SignHash calling.
        pkcs7.AvoidEstimatingSignatureLength = true;
        // Sign the file
        sign.Sign(1, "reason", "cont", "loc", false, new System.Drawing.Rectangle(0, 0, 500, 500), pkcs7);
        // Save PDF document
        sign.Save(dataDir + "SignWithCertificate_out.pdf");
    }

    // Custom hash signing function to generate a digital signature
    byte[] CustomSignHash(byte[] signableHash, Aspose.Pdf.DigestHashAlgorithm digestHashAlgorithm)
    {
        var inputP12 = "111.p12";
        var inputPfxPassword = "123456";
        X509Certificate2 signerCert = new X509Certificate2(inputP12, inputPfxPassword, X509KeyStorageFlags.Exportable);
        RSACryptoServiceProvider rsaCSP = new RSACryptoServiceProvider();
        var xmlString = signerCert.PrivateKey.ToXmlString(true);
        rsaCSP.FromXmlString(xmlString);
        byte[] signedData = rsaCSP.SignData(signableHash, CryptoConfig.MapNameToOID("SHA1"));
        return signedData;
    }
}

Detailed information on the enhancement has already been added to the documentation.

In Aspose.PDF 25.2, we have added a new GetSignatureNames() method to obtain information about PDF digital signatures. This method returns a list of SignatureName objects, which prevents collisions when verifying signatures with the same names. Methods that accept the SignatureName type instead of a string signature name have also been added. The old PdfFileSignature.VerifySigned() method is deprecated. This improvement is logged as PDFNET-58918 in our issue tracker.

Thus, the recommended code for verifying signatures changes to the following:

// For complete examples and data files, check for https://github.com/aspose-pdf/Aspose.PDF-for-.NET  
private static void Verify()
{
    // The path to the documents directory
    string dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();
    
    // Open the document
    using (var document = new Aspose.Pdf.Document(dataDir + "signed_rsa.pdf"))
    {
        // Create an instance of PdfFileSignature for working with signatures in the document
        using (var signature = new Aspose.Pdf.Facades.PdfFileSignature(document))
        {         
            // Get a list of signature names in the document
            var sigNames = signature.GetSignatureNames();

            // Loop through all signature names to verify each one
            foreach (var sigName in sigNames)
            {
                // Verify that the signature with the given name is valid
                if (!signature.VerifySignature(sigName))
                {
                    throw new Exception("Not verified");
                }
            }
        }
    }
}

The possibility of adding a TextBoxField with several widget annotations has been added. This enhancement was made according to the User’s request PDFNET-58251.

Below is an example of the code used:

// For complete examples and data files, please visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void AddTextBoxFieldToPdf()
{
    // The path to the documents directory
    string dataDir = RunExamples.GetDataDir_AsposePdf_Forms();

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add a new page in the created document
        var page = document.Pages.Add();

        // Defining an array with rectangle data for widget annotations. 
        // The number of elements in the array determines the number of widget annotations to add.
        var rects = new Rectangle[]
        {
            new Rectangle(10, 600, 110, 620),
            new Rectangle(10, 630, 110, 650),
            new Rectangle(10, 660, 110, 680)
        };

        // Defining an array with DefaultAppearance used to specify how widget annotations are displayed in the added field.
        var defaultAppearances = new DefaultAppearance[]
        {
            new DefaultAppearance("Arial", 10, System.Drawing.Color.DarkBlue),
            new DefaultAppearance("Helvetica", 12, System.Drawing.Color.DarkGreen),
            new DefaultAppearance(FontRepository.FindFont("TimesNewRoman"), 14, System.Drawing.Color.DarkMagenta)
        };

        // Create a field
        var textBoxField = new TextBoxField(page, rects);

        // Setting the appearances of widget annotations
        short i = 0;
        foreach (WidgetAnnotation wa in textBoxField)
        {
            wa.DefaultAppearance = defaultAppearances[i++];
        }
        textBoxField.Value = "Text";

        // Add field to the document
        document.Form.Add(textBoxField);

        // Save PDF document
        document.Save(dataDir + "TextBox_out.pdf");
    }
}

Other notable enhancements

Bug Fixing and Other Changes

Public API and Backward Incompatible Changes

Added APIs

• Type: Aspose.Pdf.DataEditor.CosPdfDictionary
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.#ctor(Aspose.Pdf.Resources) System.Void
• Property: Aspose.Pdf.DataEditor.CosPdfDictionary.AllKeys System.Collections.Generic.ICollection`1[System.String]
• Property: Aspose.Pdf.DataEditor.CosPdfDictionary.Keys System.Collections.Generic.ICollection`1[System.String]
• Property: Aspose.Pdf.DataEditor.CosPdfDictionary.Values System.Collections.Generic.ICollection`1[Aspose.Pdf.DataEditor.ICosPdfPrimitive]
• Property: Aspose.Pdf.DataEditor.CosPdfDictionary.Count System.Int32
• Property: Aspose.Pdf.DataEditor.CosPdfDictionary.IsReadOnly System.Boolean
• Property: Aspose.Pdf.DataEditor.CosPdfDictionary.Item(System.String) Aspose.Pdf.DataEditor.ICosPdfPrimitive
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.CreateEmptyDictionary(Aspose.Pdf.Page) Aspose.Pdf.DataEditor.CosPdfDictionary
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.CreateEmptyDictionary(Aspose.Pdf.Document) Aspose.Pdf.DataEditor.CosPdfDictionary
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.ContainsKey(System.String) System.Boolean
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.Remove(System.String) System.Boolean
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.TryGetValue(System.String,Aspose.Pdf.DataEditor.ICosPdfPrimitive@) System.Boolean
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.Add(System.String,Aspose.Pdf.DataEditor.ICosPdfPrimitive) System.Void
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.Add(System.Collections.Generic.KeyValuePair{System.String,Aspose.Pdf.DataEditor.ICosPdfPrimitive}) System.Void
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.Clear System.Void
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.Contains(System.Collections.Generic.KeyValuePair{System.String,Aspose.Pdf.DataEditor.ICosPdfPrimitive}) System.Boolean
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.CopyTo(System.Collections.Generic.KeyValuePair,System.Int32) System.Void
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.Remove(System.Collections.Generic.KeyValuePair{System.String,Aspose.Pdf.DataEditor.ICosPdfPrimitive}) System.Boolean
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.GetEnumerator System.Collections.Generic.IEnumerator1[System.Collections.Generic.KeyValuePair2[System.String,Aspose.Pdf.DataEditor.ICosPdfPrimitive]]
• Method: Aspose.Pdf.DataEditor.CosPdfDictionary.ToCosPdfDictionary Aspose.Pdf.DataEditor.CosPdfDictionary
• Method: Aspose.Pdf.DataEditor.CosPdfPrimitive.ToCosPdfDictionary Aspose.Pdf.DataEditor.CosPdfDictionary
• Method: Aspose.Pdf.DataEditor.DictionaryEditor.#ctor(Aspose.Pdf.Resources) System.Void
• Method: Aspose.Pdf.DataEditor.ICosPdfPrimitive.ToCosPdfDictionary Aspose.Pdf.DataEditor.CosPdfDictionary
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetSignatureNames(System.Boolean) System.Collections.Generic.IList`1[Aspose.Pdf.Facades.SignatureName]
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetSignatureNames(System.Boolean) System.Collections.Generic.IList`1[Aspose.Pdf.Facades.SignatureName]
• Method: Aspose.Pdf.Facades.PdfFileSignature.CoversWholeDocument(Aspose.Pdf.Facades.SignatureName) System.Boolean
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetRevision(Aspose.Pdf.Facades.SignatureName) System.Int32
• Method: Aspose.Pdf.Facades.PdfFileSignature.RemoveSignature(Aspose.Pdf.Facades.SignatureName) System.Void
• Method: Aspose.Pdf.Facades.PdfFileSignature.RemoveSignature(Aspose.Pdf.Facades.SignatureName,System.Boolean) System.Void
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetSignerName(Aspose.Pdf.Facades.SignatureName) System.String
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetDateTime(Aspose.Pdf.Facades.SignatureName) System.DateTime
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetReason(Aspose.Pdf.Facades.SignatureName) System.String
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetLocation(Aspose.Pdf.Facades.SignatureName) System.String
• Method: Aspose.Pdf.Facades.PdfFileSignature.GetContactInfo(Aspose.Pdf.Facades.SignatureName) System.String
• Method: Aspose.Pdf.Facades.PdfFileSignature.VerifySignature(Aspose.Pdf.Facades.SignatureName) System.Boolean
• Method: Aspose.Pdf.Facades.PdfFileSignature.VerifySignature(Aspose.Pdf.Facades.SignatureName,Aspose.Pdf.Security.ValidationOptions,Aspose.Pdf.Security.ValidationResult@) System.Boolean
• Method: Aspose.Pdf.Facades.PdfFileSignature.ExtractImage(Aspose.Pdf.Facades.SignatureName) System.IO.Stream
• Method: Aspose.Pdf.Facades.PdfFileSignature.ExtractCertificate(Aspose.Pdf.Facades.SignatureName) System.IO.Stream
• Type: Aspose.Pdf.Facades.SignatureName
• Property: Aspose.Pdf.Facades.SignatureName.HasSignature System.Boolean
• Method: Aspose.Pdf.Facades.SignatureName.ToString System.String
• Field: Aspose.Pdf.Facades.SignatureName.Name System.String
• Field: Aspose.Pdf.Facades.SignatureName.FullName System.String
• Property: Aspose.Pdf.Forms.Signature.AvoidEstimatingSignatureLength System.Boolean
• Property: Aspose.Pdf.Forms.Signature.DefaultSignatureLength System.Int32
• Method: Aspose.Pdf.Forms.TextBoxField.#ctor(Aspose.Pdf.Page,Aspose.Pdf.Rectangle[]) System.Void
• Property: Aspose.Pdf.ImageStamp.XIndent System.Double
• Property: Aspose.Pdf.ImageStamp.YIndent System.Double
• Field: Aspose.Pdf.PdfFormat.PDF_X_4
• Type: Aspose.Pdf.Security.SignatureLengthMismatchException

Removed APIs

No removings.

For Aspose.PDF 25.2 we have completed work on the namespaces for APIs to make the structure simpler and more convenient.

Moved:

Other changes:

The following Fields are changed to the Properties:

• Aspose.Pdf.HtmlSaveOptions.SaveFullFont System.Boolean
• Aspose.Pdf.Rectangle.Empty Aspose.Pdf.Rectangle