65 lines
2.2 KiB
Go
65 lines
2.2 KiB
Go
package sign
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import (
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"errors"
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"strconv"
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)
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func (context *SignContext) writeXref() error {
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// @todo: support stream xref.
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if context.PDFReader.XrefInformation.Type == "table" {
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if err := context.writeXrefTable(); err != nil {
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return err
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}
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} else {
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return errors.New("Unkwn xref type: " + context.PDFReader.XrefInformation.Type)
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}
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return nil
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}
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func (context *SignContext) writeXrefTable() error {
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xref_size := "xref\n0 " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount, 10)
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new_xref_size := "xref\n0 " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount+3, 10)
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if _, err := context.OutputFile.Write([]byte(new_xref_size)); err != nil {
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return err
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}
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// Write the old xref table to the output pdf.
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if err := writePartFromSourceFileToTargetFile(context.InputFile, context.OutputFile, context.PDFReader.XrefInformation.StartPos+int64(len(xref_size)), context.PDFReader.XrefInformation.Length-int64(len(xref_size))); err != nil {
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return err
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}
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// Create the new catalog xref line.
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visual_signature_object_start_position := strconv.FormatInt(context.Filesize, 10)
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visual_signature_xref_line := leftPad(visual_signature_object_start_position, "0", 10-len(visual_signature_object_start_position)) + " 00000 n\n"
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// Write the new catalog xref line.
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if _, err := context.OutputFile.Write([]byte(visual_signature_xref_line)); err != nil {
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return err
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}
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// Create the new catalog xref line.
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catalog_object_start_position := strconv.FormatInt(context.Filesize+context.VisualSignData.Length, 10)
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catalog_xref_line := leftPad(catalog_object_start_position, "0", 10-len(catalog_object_start_position)) + " 00000 n\n"
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// Write the new catalog xref line.
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if _, err := context.OutputFile.Write([]byte(catalog_xref_line)); err != nil {
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return err
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}
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// Create the new signature xref line.
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signature_object_start_position := strconv.FormatInt(context.Filesize+context.VisualSignData.Length+context.CatalogData.Length, 10)
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signature_xref_line := leftPad(signature_object_start_position, "0", 10-len(signature_object_start_position)) + " 00000 n\n"
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// Write the new signature xref line.
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if _, err := context.OutputFile.Write([]byte(signature_xref_line)); err != nil {
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return err
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}
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return nil
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}
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