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Merge pull request #67 from digitorus/revert-66-revert-65-fix-catalog-entries-discarded

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fix: Existing catalog entries are being discarded; this ensures that all catalog entries are copied to the new updated catalog.
This commit is contained in:
Paul van Brouwershaven
2025-02-25 15:11:16 +01:00
committed by GitHub
parent be2806bdb6 2d533be139
commit 1fb39a3ce9
2 changed files with 66 additions and 26 deletions
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80
sign/pdfcatalog.go
View File

@@ -2,7 +2,11 @@ package sign
import (
"bytes"
"fmt"
"io"
"strconv"
"github.com/digitorus/pdf"
)
func (context *SignContext) createCatalog() ([]byte, error) {
@@ -28,32 +32,18 @@ func (context *SignContext) createCatalog() ([]byte, error) {
// catalog_buffer.WriteString(" /Version /2.0")
// }
// Retrieve the root and check for necessary keys in one loop
// Retrieve the root, its pointer and set the root string
root := context.PDFReader.Trailer().Key("Root")
rootPtr := root.GetPtr()
context.CatalogData.RootString = strconv.Itoa(int(rootPtr.GetID())) + " " + strconv.Itoa(int(rootPtr.GetGen())) + " R"
foundPages, foundNames := false, false
// Copy over existing catalog entries except for type and AcroForum
for _, key := range root.Keys() {
switch key {
case "Pages":
foundPages = true
case "Names":
foundNames = true
if key != "Type" && key != "AcroForm" {
_, _ = fmt.Fprintf(&catalog_buffer, " /%s ", key)
context.serializeCatalogEntry(&catalog_buffer, rootPtr.GetID(), root.Key(key))
catalog_buffer.WriteString("\n")
}
if foundPages && foundNames {
break
}
}
// Add Pages and Names references if they exist
if foundPages {
pages := root.Key("Pages").GetPtr()
catalog_buffer.WriteString(" /Pages " + strconv.Itoa(int(pages.GetID())) + " " + strconv.Itoa(int(pages.GetGen())) + " R\n")
}
if foundNames {
names := root.Key("Names").GetPtr()
catalog_buffer.WriteString(" /Names " + strconv.Itoa(int(names.GetID())) + " " + strconv.Itoa(int(names.GetGen())) + " R\n")
}
// Start the AcroForm dictionary with /NeedAppearances
@@ -123,3 +113,53 @@ func (context *SignContext) createCatalog() ([]byte, error) {
return catalog_buffer.Bytes(), nil
}
// serializeCatalogEntry takes a pdf.Value and serializes it to the given writer.
func (context *SignContext) serializeCatalogEntry(w io.Writer, rootObjId uint32, value pdf.Value) {
if ptr := value.GetPtr(); ptr.GetID() != rootObjId {
// Indirect object
_, _ = fmt.Fprintf(w, "%d %d R", ptr.GetID(), ptr.GetGen())
return
}
// Direct object
switch value.Kind() {
case pdf.String:
_, _ = fmt.Fprintf(w, "(%s)", value.RawString())
case pdf.Null:
_, _ = fmt.Fprint(w, "null")
case pdf.Bool:
if value.Bool() {
_, _ = fmt.Fprint(w, "true")
} else {
_, _ = fmt.Fprint(w, "false")
}
case pdf.Integer:
_, _ = fmt.Fprintf(w, "%d", value.Int64())
case pdf.Real:
_, _ = fmt.Fprintf(w, "%f", value.Float64())
case pdf.Name:
_, _ = fmt.Fprintf(w, "/%s", value.Name())
case pdf.Dict:
_, _ = fmt.Fprint(w, "<<")
for idx, key := range value.Keys() {
if idx > 0 {
_, _ = fmt.Fprint(w, " ") // Space between items
}
_, _ = fmt.Fprintf(w, "/%s ", key)
context.serializeCatalogEntry(w, rootObjId, value.Key(key))
}
_, _ = fmt.Fprint(w, ">>")
case pdf.Array:
_, _ = fmt.Fprint(w, "[")
for idx := range value.Len() {
if idx > 0 {
_, _ = fmt.Fprint(w, " ") // Space between items
}
context.serializeCatalogEntry(w, rootObjId, value.Index(idx))
}
_, _ = fmt.Fprint(w, "]")
case pdf.Stream:
panic("stream cannot be a direct object")
}
}

12
sign/pdfcatalog_test.go
View File

@@ -15,17 +15,17 @@ var testFiles = []struct {
{
file: "../testfiles/testfile20.pdf",
expectedCatalogs: map[CertType]string{
CertificationSignature: "<<\n /Type /Catalog\n /Pages 3 0 R\n /AcroForm <<\n /Fields [10 0 R]\n /SigFlags 3\n >>\n>>\n",
UsageRightsSignature: "<<\n /Type /Catalog\n /Pages 3 0 R\n /AcroForm <<\n /Fields [10 0 R]\n /SigFlags 1\n >>\n>>\n",
ApprovalSignature: "<<\n /Type /Catalog\n /Pages 3 0 R\n /AcroForm <<\n /Fields [10 0 R]\n /SigFlags 3\n >>\n>>\n",
CertificationSignature: "<<\n /Type /Catalog\n /Metadata 2 0 R\n /Pages 3 0 R\n /AcroForm <<\n /Fields [10 0 R]\n /SigFlags 3\n >>\n>>\n",
UsageRightsSignature: "<<\n /Type /Catalog\n /Metadata 2 0 R\n /Pages 3 0 R\n /AcroForm <<\n /Fields [10 0 R]\n /SigFlags 1\n >>\n>>\n",
ApprovalSignature: "<<\n /Type /Catalog\n /Metadata 2 0 R\n /Pages 3 0 R\n /AcroForm <<\n /Fields [10 0 R]\n /SigFlags 3\n >>\n>>\n",
},
},
{
file: "../testfiles/testfile21.pdf",
expectedCatalogs: map[CertType]string{
CertificationSignature: "<<\n /Type /Catalog\n /Pages 9 0 R\n /Names 6 0 R\n /AcroForm <<\n /Fields [16 0 R]\n /SigFlags 3\n >>\n>>\n",
UsageRightsSignature: "<<\n /Type /Catalog\n /Pages 9 0 R\n /Names 6 0 R\n /AcroForm <<\n /Fields [16 0 R]\n /SigFlags 1\n >>\n>>\n",
ApprovalSignature: "<<\n /Type /Catalog\n /Pages 9 0 R\n /Names 6 0 R\n /AcroForm <<\n /Fields [16 0 R]\n /SigFlags 3\n >>\n>>\n",
CertificationSignature: "<<\n /Type /Catalog\n /Metadata 8 0 R\n /Names 6 0 R\n /Pages 9 0 R\n /AcroForm <<\n /Fields [16 0 R]\n /SigFlags 3\n >>\n>>\n",
UsageRightsSignature: "<<\n /Type /Catalog\n /Metadata 8 0 R\n /Names 6 0 R\n /Pages 9 0 R\n /AcroForm <<\n /Fields [16 0 R]\n /SigFlags 1\n >>\n>>\n",
ApprovalSignature: "<<\n /Type /Catalog\n /Metadata 8 0 R\n /Names 6 0 R\n /Pages 9 0 R\n /AcroForm <<\n /Fields [16 0 R]\n /SigFlags 3\n >>\n>>\n",
},
},
}