C
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.
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#include <C_CkPdf.h>
#include <C_CkJsonObject.h>
#include <C_CkCert.h>
void ChilkatSample(void)
{
BOOL success;
HCkPdf pdf;
HCkJsonObject json;
HCkCert cert;
success = FALSE;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
pdf = CkPdf_Create();
// Load a PDF to be signed.
// The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
success = CkPdf_LoadFile(pdf,"qa_data/pdf/hello.pdf");
if (success == FALSE) {
printf("%s\n",CkPdf_lastErrorText(pdf));
CkPdf_Dispose(pdf);
return;
}
// Options for signing are specified in JSON.
json = CkJsonObject_Create();
// In most cases, the signingCertificateV2 and signingTime attributes are required.
CkJsonObject_UpdateInt(json,"signingCertificateV2",1);
CkJsonObject_UpdateInt(json,"signingTime",1);
// Specify the location/position, scale, and content of the signature's appearance.
CkJsonObject_UpdateInt(json,"page",1);
CkJsonObject_UpdateString(json,"appearance.y","top");
CkJsonObject_UpdateString(json,"appearance.x","left");
CkJsonObject_UpdateString(json,"appearance.fontScale","10.0");
CkJsonObject_UpdateString(json,"appearance.text[0]","Digitally signed by: cert_cn");
CkJsonObject_UpdateString(json,"appearance.text[1]","current_dt");
CkJsonObject_UpdateString(json,"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.
CkJsonObject_UpdateString(json,"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.
CkJsonObject_UpdateString(json,"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.
CkJsonObject_UpdateString(json,"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.)
cert = CkCert_Create();
success = CkCert_LoadPfxFile(cert,"qa_data/pfx/myPdfSigningCert.pfx","secret");
if (success == FALSE) {
printf("%s\n",CkCert_lastErrorText(cert));
CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkCert_Dispose(cert);
return;
}
// Tell the pdf object to use the certificate for signing.
success = CkPdf_SetSigningCert(pdf,cert);
if (success == FALSE) {
printf("%s\n",CkPdf_lastErrorText(pdf));
CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkCert_Dispose(cert);
return;
}
success = CkPdf_SignPdf(pdf,json,"qa_output/hello_signed.pdf");
if (success == FALSE) {
printf("%s\n",CkPdf_lastErrorText(pdf));
CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkCert_Dispose(cert);
return;
}
printf("The PDF has been successfully cryptographically signed.\n");
// 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"
CkJsonObject_UpdateString(json,"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)
CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkCert_Dispose(cert);
}