Files
pdfsign/sign/pdfvisualsignature.go
2017-07-08 14:55:31 +02:00

45 lines
1.2 KiB
Go

package sign
import (
"errors"
"strconv"
)
func (context *SignContext) createVisualSignature() (visual_signature string, err error) {
visual_signature = strconv.Itoa(int(context.VisualSignData.ObjectId)) + " 0 obj\n"
visual_signature += "<< /Type /Annot"
visual_signature += " /Subtype /Widget"
visual_signature += " /Rect [0 0 0 0]"
root := context.PDFReader.Trailer().Key("Root")
root_keys := root.Keys()
found_pages := false
for _, key := range root_keys {
if key == "Pages" {
found_pages = true
break
}
}
if !found_pages {
return "", errors.New("Didn't find pages in PDF trailer Root.")
}
rootPtr := root.GetPtr()
context.CatalogData.RootString = strconv.Itoa(int(rootPtr.GetID())) + " " + strconv.Itoa(int(rootPtr.GetGen())) + " R"
page := root.Key("Pages").Key("Kids").Index(0).GetPtr()
visual_signature += " /P " + strconv.Itoa(int(page.GetID())) + " " + strconv.Itoa(int(page.GetGen())) + " R"
visual_signature += " /F 4"
visual_signature += " /FT /Sig"
visual_signature += " /T " + pdfString("Signature")
visual_signature += " /Ff 0"
visual_signature += " /V " + strconv.Itoa(int(context.SignData.ObjectId)) + " 0 R"
visual_signature += " >>"
visual_signature += "\nendobj\n"
return visual_signature, nil
}