(Unicode 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_CkPdfW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    HCkPdfW pdf;
    BOOL success;
    HCkJsonObjectW json;
    HCkCertW cert;

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

    pdf = CkPdfW_Create();

    // Load a PDF to be signed.
    // The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    success = CkPdfW_LoadFile(pdf,L"qa_data/pdf/hello.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    // Options for signing are specified in JSON.
    json = CkJsonObjectW_Create();

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

    // Specify the location/position, scale, and content of the signature's appearance.
    CkJsonObjectW_UpdateInt(json,L"page",1);
    CkJsonObjectW_UpdateString(json,L"appearance.y",L"top");
    CkJsonObjectW_UpdateString(json,L"appearance.x",L"left");
    CkJsonObjectW_UpdateString(json,L"appearance.fontScale",L"10.0");
    CkJsonObjectW_UpdateString(json,L"appearance.text[0]",L"Digitally signed by: cert_cn");
    CkJsonObjectW_UpdateString(json,L"appearance.text[1]",L"current_dt");
    CkJsonObjectW_UpdateString(json,L"appearance.text[2]",L"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.
    CkJsonObjectW_UpdateString(json,L"appearance.image",L"green-check-grey-circle");

    // The graphic can be placed "left", "center", or "right".
    // If "center", then the graphic is displayed behind the text.
    CkJsonObjectW_UpdateString(json,L"appearance.imagePlacement",L"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.
    CkJsonObjectW_UpdateString(json,L"appearance.imageOpacity",L"100");

    // Here's an example of the signature's appearance if we centered the SVG graphic with an opacity of 40%
    

    // Load the signing certificate. (Use your own certificate.)
    cert = CkCertW_Create();
    success = CkCertW_LoadPfxFile(cert,L"qa_data/pfx/myPdfSigningCert.pfx",L"secret");
    if (success == FALSE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkCertW_Dispose(cert);
        return;
    }

    // Tell the pdf object to use the certificate for signing.
    success = CkPdfW_SetSigningCert(pdf,cert);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkCertW_Dispose(cert);
        return;
    }

    success = CkPdfW_SignPdf(pdf,json,L"qa_output/hello_signed.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkCertW_Dispose(cert);
        return;
    }

    wprintf(L"The PDF has been successfully cryptographically signed.\n");

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

    

    // 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"
    CkJsonObjectW_UpdateString(json,L"appearance.image",L"green-check-green-circle");
    // We get:
    

    // "application-approved"
    

    // "application-rejected"
    

    // "document-accepted"
    

    // "approved"
    

    // "blue-check-mark"
    

    // "green-check-mark"
    

    // "green-check-grey-circle"
    

    // "red-x-red-circle"
    

    // "rejected"
    

    // "result-failure"
    

    // "result-pass"
    

    // "signature"
    

    // "document-check"
    

    // "document-x"
    

    // "red-x-grey-circle"
    


    CkPdfW_Dispose(pdf);
    CkJsonObjectW_Dispose(json);
    CkCertW_Dispose(cert);

    }