readme.md

Aspose.Imaging .NET API allows to easily add digital signature to images in your .NET application or Web service.

You can:

• Add digital signature to images in all available formats (Supported formats table - https://docs.aspose.com/imaging/net/supported-file-formats/).

Interested ?

You may go further at : https://products.aspose.com/imaging/net/

AnalyzePercentageDigitalSignature.cs

using Aspose.Imaging;
using Aspose.Imaging.FileFormats.Png;

string dataDir = @"c:\Users\USER\Downloads\templates\";
string password = "veryStr0ngPassword";

using (Aspose.Imaging.RasterImage image = (Aspose.Imaging.RasterImage)Image.Load(Path.Combine(dataDir, @"template.png")))
{
    image.EmbedDigitalSignature(password); // Embeds LSB-based signature data into the image using the specified password.

    image.Save(Path.Combine(dataDir, @"result.png"));
}

using (Aspose.Imaging.RasterImage image = (Aspose.Imaging.RasterImage)Image.Load(Path.Combine(dataDir, @"result.png")))
{
    int signingPercentage = image.AnalyzePercentageDigitalSignature(password); // Calculates the probability (0–100%) that
                                                                               // the image contains a digital signature
                                                                               // generated using the specified password.
}

File.Delete(Path.Combine(dataDir, @"result.png"));

EmbedDigitalSignature.cs

using Aspose.Imaging;
using Aspose.Imaging.FileFormats.Png;

string dataDir = @"c:\Users\USER\Downloads\templates\";
string password = "veryStr0ngPassword";


using (Aspose.Imaging.RasterImage image = (Aspose.Imaging.RasterImage)Image.Load(Path.Combine(dataDir, @"template.png")))
{
    image.EmbedDigitalSignature(password); // Embeds LSB-based signature data into the image using the specified password.

    image.Save(Path.Combine(dataDir, @"result.png"));
}

File.Delete(Path.Combine(dataDir, @"result.png"));

IsDigitalSigned.cs

using Aspose.Imaging;
using Aspose.Imaging.FileFormats.Png;

string dataDir = @"c:\Users\USER\Downloads\templates\";
string password = "veryStr0ngPassword";
int threshold = 90;


using (Aspose.Imaging.RasterImage image = (Aspose.Imaging.RasterImage)Image.Load(Path.Combine(dataDir, @"template.png")))
{
    image.EmbedDigitalSignature(password); // Embeds LSB-based signature data into the image using the specified password.

    image.Save(Path.Combine(dataDir, @"result.png"));
}

using (Aspose.Imaging.RasterImage image = (Aspose.Imaging.RasterImage)Image.Load(Path.Combine(dataDir, @"result.png")))
{
    bool isSigned = image.IsDigitalSigned(password); // Validates that the embedded digital signature matches
                                                     // the provided password.
}

using (Aspose.Imaging.RasterImage image = (Aspose.Imaging.RasterImage)Image.Load(Path.Combine(dataDir, @"result.png")))
{
    bool isSigned = image.IsDigitalSigned(password, threshold); // Verifies that the embedded digital signature
                                                                // corresponds to the provided password based on the
                                                                // specified probability threshold.
}

File.Delete(Path.Combine(dataDir, @"result.png"));