C#

PDF Signatures with Built-in SVG Graphics

See more PDF Signatures Examples

This example demonstrates the built-in SVG graphics that can be applied to the appearance when signing a PDF.

Note: This example requires Chilkat v9.5.0.85 or greater.

C#

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Chilkat.Pdf pdf = new Chilkat.Pdf();

//  Load a PDF to be signed.
//  The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
success = pdf.LoadFile("qa_data/pdf/hello.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  Options for signing are specified in JSON.
Chilkat.JsonObject json = new Chilkat.JsonObject();

//  In most cases, the signingCertificateV2 and signingTime attributes are required.
json.UpdateInt("signingCertificateV2",1);
json.UpdateInt("signingTime",1);

//  Specify the location/position, scale, and content of the signature's appearance.
json.UpdateInt("page",1);
json.UpdateString("appearance.y","top");
json.UpdateString("appearance.x","left");
json.UpdateString("appearance.fontScale","10.0");
json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn");
json.UpdateString("appearance.text[1]","current_dt");
json.UpdateString("appearance.text[2]","The crazy brown fox jumps over the lazy dog.");

//  In addition to the above, this example adds a built-in SVG graphic to the appearance.
//  The built-in SVG graphic is specified by a name, such as "green-check-grey-circle".
//  The full list of graphic names and images are shown below.
json.UpdateString("appearance.image","green-check-grey-circle");

//  The graphic can be placed "left", "center", or "right".
//  If "center", then the graphic is displayed behind the text.
json.UpdateString("appearance.imagePlacement","left");

//  The graphic's opacity can range from 1 to 100.
//  Centered graphics look best with less opacity (50 or less).
//  In this example, we'll keep the opacity at 100.
json.UpdateString("appearance.imageOpacity","100");

//  Here's an example of the signature's appearance if we centered the SVG graphic with an opacity of 40%
//  (image:https://example-code.com/images/centered_svg.jpg/endImage)

//  Load the signing certificate. (Use your own certificate.)
Chilkat.Cert cert = new Chilkat.Cert();
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret");
if (success == false) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

//  Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

success = pdf.SignPdf(json,"qa_output/hello_signed.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("The PDF has been successfully cryptographically signed.");

//  The appearance of the signature appears in Adobe Acrobat as shown here:

//  (image:https://example-code.com/images/pdf_signature_green_check_grey_circle.jpg/endImage)

//  The SVG icon graphics are embedded within the Chilkat library, 
//  and were graciously provided by uxwing - Free SVG Icons 
//  
//  The uxwing licensing terms are reproduced here and can be verified at uxwing licensing

//  Icons from uxwing.com are free (see https://uxwing.com/license/)
//  	- All icons on UXWing free to download, and use personal, commercial projects.
//  	- Attribution and Credit is NOT required, however, any credit will be much appreciated.
//  	- There is no limit to the number of times you can use.
//  	- You may modify the resources according to your requirements.

//  The set of SVG names and the corresponding graphics are shown below.
//  
//  For example, if we specify "green-check-green-circle"
json.UpdateString("appearance.image","green-check-green-circle");
//  We get:
//  (image:https://example-code.com/images/green-check-green-circle.jpg/endImage)

//  "application-approved"
//  (image:https://example-code.com/images/application-approved.jpg/endImage)

//  "application-rejected"
//  (image:https://example-code.com/images/application-rejected.jpg/endImage)

//  "document-accepted"
//  (image:https://example-code.com/images/document-accepted.jpg/endImage)

//  "approved"
//  (image:https://example-code.com/images/approved.jpg/endImage)

//  "blue-check-mark"
//  (image:https://example-code.com/images/blue-check-mark.jpg/endImage)

//  "green-check-mark"
//  (image:https://example-code.com/images/green-check-mark.jpg/endImage)

//  "green-check-grey-circle"
//  (image:https://example-code.com/images/green-check-grey-circle.jpg/endImage)

//  "red-x-red-circle"
//  (image:https://example-code.com/images/red-x-red-circle.jpg/endImage)

//  "rejected"
//  (image:https://example-code.com/images/rejected.jpg/endImage)

//  "result-failure"
//  (image:https://example-code.com/images/result-failure.jpg/endImage)

//  "result-pass"
//  (image:https://example-code.com/images/result-pass.jpg/endImage)

//  "signature"
//  (image:https://example-code.com/images/signature.jpg/endImage)

//  "document-check"
//  (image:https://example-code.com/images/document-check.jpg/endImage)

//  "document-x"
//  (image:https://example-code.com/images/document-x.jpg/endImage)

//  "red-x-grey-circle"
//  (image:https://example-code.com/images/red-x-grey-circle.jpg/endImage)