Merge branch 'main' into feature/image-appearance

go.mod

@@ -1,12 +1,14 @@
 module github.com/digitorus/pdfsign
 
-go 1.22
+go 1.23.0
+
+toolchain go1.23.6
 
 require (
 	github.com/digitorus/pdf v0.1.2
 	github.com/digitorus/pkcs7 v0.0.0-20230818184609-3a137a874352
 	github.com/digitorus/timestamp v0.0.0-20231217203849-220c5c2851b7
 	github.com/mattetti/filebuffer v1.0.1
-	golang.org/x/crypto v0.33.0
-	golang.org/x/text v0.22.0
+	golang.org/x/crypto v0.35.0
+	golang.org/x/text v0.25.0
 )

go.sum

@@ -7,7 +7,7 @@ github.com/digitorus/timestamp v0.0.0-20231217203849-220c5c2851b7 h1:lxmTCgmHE1G
 github.com/digitorus/timestamp v0.0.0-20231217203849-220c5c2851b7/go.mod h1:GvWntX9qiTlOud0WkQ6ewFm0LPy5JUR1Xo0Ngbd1w6Y=
 github.com/mattetti/filebuffer v1.0.1 h1:gG7pyfnSIZCxdoKq+cPa8T0hhYtD9NxCdI4D7PTjRLM=
 github.com/mattetti/filebuffer v1.0.1/go.mod h1:YdMURNDOttIiruleeVr6f56OrMc+MydEnTcXwtkxNVs=
-golang.org/x/crypto v0.33.0 h1:IOBPskki6Lysi0lo9qQvbxiQ+FvsCC/YWOecCHAixus=
-golang.org/x/crypto v0.33.0/go.mod h1:bVdXmD7IV/4GdElGPozy6U7lWdRXA4qyRVGJV57uQ5M=
-golang.org/x/text v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
-golang.org/x/text v0.22.0/go.mod h1:YRoo4H8PVmsu+E3Ou7cqLVH8oXWIHVoX0jqUWALQhfY=
+golang.org/x/crypto v0.35.0 h1:b15kiHdrGCHrP6LvwaQ3c03kgNhhiMgvlhxHQhmg2Xs=
+golang.org/x/crypto v0.35.0/go.mod h1:dy7dXNW32cAb/6/PRuTNsix8T+vJAqvuIy5Bli/x0YQ=
+golang.org/x/text v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4=
+golang.org/x/text v0.25.0/go.mod h1:WEdwpYrmk1qmdHvhkSTNPm3app7v4rsT8F2UD6+VHIA=

sign/pdfcatalog.go

@@ -28,9 +28,10 @@ func (context *SignContext) createCatalog() ([]byte, error) {
 	// written in the PDF file (for example, /1.4).
 	//
 	// If an incremental upgrade requires a version that is higher than specified by the document.
-	// if context.PDFReader.PDFVersion < "2.0" {
-	// catalog_buffer.WriteString(" /Version /2.0")
-	// }
+	// Ensure PDF version is at least 1.5 to support SigFlags in acroFormDict (1.4) and UF in the fileSpecDict (1.5)
+	if v, err := strconv.ParseFloat(context.PDFReader.PDFVersion, 64); err == nil && v < 1.5 {
+		catalog_buffer.WriteString("  /Version /1.5\n")
+	}
 
 	// Retrieve the root, its pointer and set the root string
 	root := context.PDFReader.Trailer().Key("Root")

sign/pdfcatalog_test.go

@@ -21,11 +21,11 @@ var testFiles = []struct {
 		},
 	},
 	{
-		file: "../testfiles/testfile21.pdf",
+		file: "../testfiles/testfile12.pdf",
 		expectedCatalogs: map[CertType]string{
-			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",
+			CertificationSignature: "<<\n  /Type /Catalog\n  /Version /1.5\n  /Outlines 2 0 R\n  /Pages 3 0 R\n  /AcroForm <<\n    /Fields [16 0 R]\n    /SigFlags 3\n  >>\n>>\n",
+			UsageRightsSignature:   "<<\n  /Type /Catalog\n  /Version /1.5\n  /Outlines 2 0 R\n  /Pages 3 0 R\n  /AcroForm <<\n    /Fields [16 0 R]\n    /SigFlags 1\n  >>\n>>\n",
+			ApprovalSignature:      "<<\n  /Type /Catalog\n  /Version /1.5\n  /Outlines 2 0 R\n  /Pages 3 0 R\n  /AcroForm <<\n    /Fields [16 0 R]\n    /SigFlags 3\n  >>\n>>\n",
 		},
 	},
 }

sign/pdftrailer.go

@@ -43,7 +43,7 @@ func (context *SignContext) writeTrailer() error {
 				lines[i] = "    " + strings.TrimSpace(line)
 			}
 		}
-		trailer_string = strings.Join(lines, "\n")
+		trailer_string = strings.Join(lines, "\n") + "\n"
 
 		// Write the new trailer.
 		if _, err := context.OutputBuffer.Write([]byte(trailer_string)); err != nil {
@@ -54,7 +54,6 @@ func (context *SignContext) writeTrailer() error {
 			return err
 		}
 	}
-
 	// Write the new xref start position.
 	if _, err := context.OutputBuffer.Write([]byte(strconv.FormatInt(context.NewXrefStart, 10) + "\n")); err != nil {
 		return err

sign/pdfvisualsignature.go

@@ -128,9 +128,25 @@ func (context *SignContext) createIncPageUpdate(pageNumber, annot uint32) ([]byt
 	// TODO: Update digitorus/pdf to get raw values without resolving pointers
 	for _, key := range page.Keys() {
 		switch key {
-		case "Contents", "Parent":
+		case "Parent":
 			ptr := page.Key(key).GetPtr()
 			page_buffer.WriteString(fmt.Sprintf("  /%s %d 0 R\n", key, ptr.GetID()))
+		case "Contents":
+			// Special handling for Contents - must preserve stream structure
+			contentsValue := page.Key(key)
+			if contentsValue.Kind() == pdf.Array {
+				// If Contents is an array, keep it as an array reference
+				page_buffer.WriteString("  /Contents [")
+				for i := 0; i < contentsValue.Len(); i++ {
+					ptr := contentsValue.Index(i).GetPtr()
+					page_buffer.WriteString(fmt.Sprintf(" %d 0 R", ptr.GetID()))
+				}
+				page_buffer.WriteString(" ]\n")
+			} else {
+				// If Contents is a single reference, keep it as a single reference
+				ptr := contentsValue.GetPtr()
+				page_buffer.WriteString(fmt.Sprintf("  /%s %d 0 R\n", key, ptr.GetID()))
+			}
 		case "Annots":
 			page_buffer.WriteString("  /Annots [\n")
 			for i := 0; i < page.Key("Annots").Len(); i++ {

sign/pdfxref_test.go

@@ -20,7 +20,6 @@ func TestGetLastObjectIDFromXref(t *testing.T) {
 		{"testfile16.pdf", 567},
 		{"testfile17.pdf", 20},
 		{"testfile20.pdf", 10},
-		{"testfile21.pdf", 16},
 	}
 
 	for _, tc := range testCases {