Tryanks/pdfsign
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Xref stream progress

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This commit is contained in:
Jeroen Bobbeldijk
2017-09-10 17:26:01 +02:00
parent 1c9a9d60b1
commit d3dbbaa81b
2 changed files with 106 additions and 25 deletions
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49
sign/pdftrailer.go
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@@ -6,39 +6,42 @@ import (
)
func (context *SignContext) writeTrailer() error {
trailer_length := context.PDFReader.XrefInformation.IncludingTrailerEndPos - context.PDFReader.XrefInformation.EndPos
// Read the trailer so we can replace the size.
context.InputFile.Seek(context.PDFReader.XrefInformation.EndPos+1, 0)
trailer_buf := make([]byte, trailer_length)
if _, err := context.InputFile.Read(trailer_buf); err != nil {
return err
}
if context.PDFReader.XrefInformation.Type == "table" {
trailer_length := context.PDFReader.XrefInformation.IncludingTrailerEndPos - context.PDFReader.XrefInformation.EndPos
root_string := "Root " + context.CatalogData.RootString
new_root := "Root " + strconv.FormatInt(int64(context.CatalogData.ObjectId), 10) + " 0 R"
// Read the trailer so we can replace the size.
context.InputFile.Seek(context.PDFReader.XrefInformation.EndPos+1, 0)
trailer_buf := make([]byte, trailer_length)
if _, err := context.InputFile.Read(trailer_buf); err != nil {
return err
}
size_string := "Size " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount, 10)
new_size := "Size " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount+4, 10)
root_string := "Root " + context.CatalogData.RootString
new_root := "Root " + strconv.FormatInt(int64(context.CatalogData.ObjectId), 10) + " 0 R"
info := context.PDFReader.Trailer().Key("Info")
infoPtr := info.GetPtr()
size_string := "Size " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount, 10)
new_size := "Size " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount+4, 10)
info_string := "Info " + strconv.Itoa(int(infoPtr.GetID())) + " " + strconv.Itoa(int(infoPtr.GetGen())) + " R"
new_info := "Info " + strconv.FormatInt(int64(context.InfoData.ObjectId), 10) + " 0 R"
info := context.PDFReader.Trailer().Key("Info")
infoPtr := info.GetPtr()
trailer_string := string(trailer_buf)
trailer_string = strings.Replace(trailer_string, root_string, new_root, -1)
trailer_string = strings.Replace(trailer_string, size_string, new_size, -1)
trailer_string = strings.Replace(trailer_string, info_string, new_info, -1)
info_string := "Info " + strconv.Itoa(int(infoPtr.GetID())) + " " + strconv.Itoa(int(infoPtr.GetGen())) + " R"
new_info := "Info " + strconv.FormatInt(int64(context.InfoData.ObjectId), 10) + " 0 R"
// Write the new trailer.
if _, err := context.OutputFile.Write([]byte(trailer_string)); err != nil {
return err
trailer_string := string(trailer_buf)
trailer_string = strings.Replace(trailer_string, root_string, new_root, -1)
trailer_string = strings.Replace(trailer_string, size_string, new_size, -1)
trailer_string = strings.Replace(trailer_string, info_string, new_info, -1)
// Write the new trailer.
if _, err := context.OutputFile.Write([]byte(trailer_string)); err != nil {
return err
}
}
// Write the new xref start position.
if _, err := context.OutputFile.Write([]byte(strconv.FormatInt(context.NewXrefStart, 10) + "\n")); err != nil {
if _, err := context.OutputFile.Write([]byte("\nstartxref\n" + strconv.FormatInt(context.NewXrefStart, 10) + "\n")); err != nil {
return err
}