(Go) PDF Signatures with Built-in SVG Graphics

See more PDF Signatures Examples

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

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

    pdf := chilkat.NewPdf()

    // 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 {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        return
    }

    // Options for signing are specified in JSON.
    json := chilkat.NewJsonObject()

    // 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%
    

    // Load the signing certificate. (Use your own certificate.)
    cert := chilkat.NewCert()
    success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret")
    if success == false {
        fmt.Println(cert.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        cert.DisposeCert()
        return
    }

    // Tell the pdf object to use the certificate for signing.
    success = pdf.SetSigningCert(cert)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        cert.DisposeCert()
        return
    }

    success = pdf.SignPdf(json,"qa_output/hello_signed.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        cert.DisposeCert()
        return
    }

    fmt.Println("The PDF has been successfully cryptographically signed.")

    // 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"
    json.UpdateString("appearance.image","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"
    

    pdf.DisposePdf()
    json.DisposeJsonObject()
    cert.DisposeCert()