adbe.pkcs7.detached signature example with ECDSA key.

.github/workflows/go.yml

@@ -24,7 +24,7 @@ jobs:
 
     - name: Setup ImageMagick's MagickWand
       run:
-        sudo apt-get install libmagickwand-dev imagemagick
+        sudo apt-get update && sudo apt-get install libmagickwand-dev imagemagick
 
     - name: Build all
       run: |

accessibility/pdf_add_image_alt_text.go

@@ -49,7 +49,7 @@ func main() {
 
 	// Construct base K dictionary.
 	docK := model.NewKDictionary()
-	docK.S = core.MakeName(model.StructureTypeDocument)
+	docK.S = core.MakeName(string(model.StructureTypeDocument))
 	// Manually set optional ID for the K object
 	docK.ID = core.MakeString(kIds[0])
 	// Or generate the ID automatically using the following:
@@ -62,7 +62,7 @@ func main() {
 	pageMarkedContentSection := model.NewKDictionary()
 
 	// Set the structure type to Section.
-	pageMarkedContentSection.S = core.MakeName(model.StructureTypeSection)
+	pageMarkedContentSection.S = core.MakeName(string(model.StructureTypeSection))
 	pageMarkedContentSection.ID = core.MakeString(kIds[1])
 
 	// Add as a child
@@ -105,7 +105,12 @@ func addImage(c *creator.Creator, imageFile string, x, y float64, mcid int64, al
 	}
 
 	// Add the image to the marked content section.
-	altKdictEntry := img.SetMarkedContentID(mcid)
+	img.SetMarkedContentID(mcid)
+
+	altKdictEntry, err := img.GenerateKDict()
+	if err != nil {
+		fmt.Errorf("Error: %v", err)
+	}
 
 	// Set the alternate text.
 	altKdictEntry.Alt = core.MakeString(altText)

accessibility/pdf_copy_page_with_accessibility.go

@@ -65,7 +65,7 @@ func main() {
 
 	// Construct base K dictionary.
 	docK := model.NewKDictionary()
-	docK.S = core.MakeName(model.StructureTypeDocument)
+	docK.S = core.MakeName(string(model.StructureTypeDocument))
 
 	newStr.AddKDict(docK)
 
@@ -115,7 +115,7 @@ func main() {
 
 		// Add section K object to store all original K objects from template page.
 		sectK := model.NewKDictionary()
-		sectK.S = core.MakeName(model.StructureTypeSection)
+		sectK.S = core.MakeName(string(model.StructureTypeSection))
 		sectK.T = core.MakeString(fmt.Sprintf("Page %d", n))
 		sectK.GenerateRandomID()
 

accessibility/pdf_set_language_identifier.go

@@ -47,7 +47,7 @@ func main() {
 
 	// Construct base K dictionary.
 	docK := model.NewKDictionary()
-	docK.S = core.MakeName(model.StructureTypeDocument)
+	docK.S = core.MakeName(string(model.StructureTypeDocument))
 
 	str.AddKDict(docK)
 
@@ -57,7 +57,12 @@ func main() {
 	p.SetPos(100, 100)
 
 	// Set marked content identifier for the paragraph.
-	pMarkedContent := p.SetMarkedContentID(0)
+	p.SetMarkedContentID(0)
+
+	pMarkedContent, err := p.GenerateKDict()
+	if err != nil {
+		fmt.Errorf("Error: %v", err)
+	}
 
 	// Set the language identifier for the paragraph to British English.
 	pMarkedContent.Lang = core.MakeString("en-GB")
@@ -76,7 +81,11 @@ func main() {
 	// It's "Hello World" in Indonesian.
 	sp.SetText("Halo Dunia")
 	sp.SetPos(100, 200)
-	pMarkedContent = sp.SetMarkedContentID(1)
+	sp.SetMarkedContentID(1)
+	pMarkedContent, err = p.GenerateKDict()
+	if err != nil {
+		fmt.Errorf("Error: %v", err)
+	}
 
 	// Set the language identifier for the styled paragraph to Indonesian.
 	pMarkedContent.Lang = core.MakeString("id-ID")
@@ -88,7 +97,7 @@ func main() {
 
 	c.SetStructTreeRoot(str)
 
-	err := c.WriteToFile("pdf_set_language_identifier.pdf")
+	err = c.WriteToFile("pdf_set_language_identifier.pdf")
 	if err != nil {
 		fmt.Errorf("Error: %v", err)
 	}

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/unidoc/globalsign-dss v0.0.0-20220330092912-b69d85b63736
 	github.com/unidoc/pkcs7 v0.2.0
 	github.com/unidoc/unichart v0.4.0
-	github.com/unidoc/unipdf/v4 v4.1.0
+	github.com/unidoc/unipdf/v4 v4.2.0
 	golang.org/x/crypto v0.33.0
 	golang.org/x/image v0.24.0
 	golang.org/x/text v0.22.0
@@ -70,4 +70,5 @@ require (
 	google.golang.org/grpc v1.64.1 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	software.sslmate.com/src/go-pkcs12 v0.6.0 // indirect
 )

go.sum

@@ -131,6 +131,8 @@ github.com/unidoc/unichart v0.4.0 h1:uXk9ZjbqzKb8Lt2Qv2oM9D2ftNRXvezPevgxQhsTQys
 github.com/unidoc/unichart v0.4.0/go.mod h1:9QsE8RbS0fE7ndHNroeCEFkRPqqk47Qsoj6QSAtcwN0=
 github.com/unidoc/unipdf/v4 v4.1.0 h1:qeEUEVm0rVPocIGZdKoSsRCUTrA3RD+VlBQX7NnP/kY=
 github.com/unidoc/unipdf/v4 v4.1.0/go.mod h1:SbSYFUoutyBR+hLlsHyNiCzzcSVVuG10S5Xu8RIJ6EY=
+github.com/unidoc/unipdf/v4 v4.2.0 h1:nMBQMOp8WDmm0L1fAdPKZ57pVNloxG+JHClXucwufLo=
+github.com/unidoc/unipdf/v4 v4.2.0/go.mod h1:csApn6iwjybsHb43/6BSXAubkSumZ7et0zlcIpJ4iXI=
 github.com/unidoc/unitype v0.5.1 h1:UwTX15K6bktwKocWVvLoijIeu4JAVEAIeFqMOjvxqQs=
 github.com/unidoc/unitype v0.5.1/go.mod h1:3dxbRL+f1otNqFQIRHho8fxdg3CcUKrqS8w1SXTsqcI=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
@@ -238,3 +240,5 @@ gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+software.sslmate.com/src/go-pkcs12 v0.6.0 h1:f3sQittAeF+pao32Vb+mkli+ZyT+VwKaD014qFGq6oU=
+software.sslmate.com/src/go-pkcs12 v0.6.0/go.mod h1:Qiz0EyvDRJjjxGyUQa2cCNZn/wMyzrRJ/qcDXOQazLI=

signatures/pdf_sign_pkcs7_ecdsa.go

@@ -0,0 +1,119 @@
+/*
+ * This example showcases how to create an adbe.pkcs7.detached compatible digital signature for a PDF file
+ * using ECDSA (elliptic curve DSA) key. ECDSA keys can be used for signing PDF files starting from version 2.0.
+ *
+ * $ ./pdf_sign_pkcs7_ecdsa <FILE.PFX> <PASSWORD> <INPUT_PDF_PATH> <OUTPUT_PDF_PATH>
+ */
+package main
+
+import (
+	"crypto/ecdsa"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/unidoc/unipdf/v4/annotator"
+	"github.com/unidoc/unipdf/v4/common/license"
+	"github.com/unidoc/unipdf/v4/core"
+	"github.com/unidoc/unipdf/v4/model"
+	"github.com/unidoc/unipdf/v4/model/sighandler"
+
+	"software.sslmate.com/src/go-pkcs12"
+)
+
+func init() {
+	// Make sure to load your metered License API key prior to using the library.
+	// If you need a key, you can sign up and create a free one at https://cloud.unidoc.io
+	err := license.SetMeteredKey(os.Getenv(`UNIDOC_LICENSE_API_KEY`))
+	if err != nil {
+		panic(err)
+	}
+}
+
+const usagef = "Usage: %s PFX_FILE PASSWORD INPUT_PDF_PATH OUTPUT_PDF_PATH\n"
+
+func main() {
+	args := os.Args
+	if len(args) < 5 {
+		fmt.Printf(usagef, os.Args[0])
+		return
+	}
+	pfxPath := args[1]
+	password := args[2]
+	inputPath := args[3]
+	outputPath := args[4]
+
+	// Get private key and X509 certificate from the ECDSA PFX file.
+	pfxData, err := os.ReadFile(pfxPath)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	priv, cert, err := pkcs12.Decode(pfxData, password)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	// Create reader.
+	file, err := os.Open(inputPath)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+	defer file.Close()
+
+	reader, err := model.NewPdfReader(file)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	// Create appender.
+	appender, err := model.NewPdfAppender(reader)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	// Create signature handler with ECDSA key.
+	handler, err := sighandler.NewAdobePKCS7DetachedEcdsa(priv.(*ecdsa.PrivateKey), cert)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	// Create signature.
+	signature := model.NewPdfSignature(handler)
+	signature.SetName("adbe.pkcs7.detached ECDSA PDF")
+	signature.SetReason("Test ECDSA")
+	signature.SetDate(time.Now(), "")
+
+	if err := signature.Initialize(); err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	// Create signature field and appearance.
+	opts := annotator.NewSignatureFieldOpts()
+	opts.FontSize = 10
+	opts.Rect = []float64{10, 25, 75, 60}
+
+	field, err := annotator.NewSignatureField(
+		signature,
+		[]*annotator.SignatureLine{
+			annotator.NewSignatureLine("Name", "John Doe"),
+			annotator.NewSignatureLine("Date", "2025.07.28"),
+			annotator.NewSignatureLine("Reason", "Test"),
+		},
+		opts,
+	)
+	field.T = core.MakeString("Self signed PDF")
+
+	if err = appender.Sign(1, field); err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	// Write output PDF file.
+	err = appender.WriteToFile(outputPath)
+	if err != nil {
+		log.Fatal("Fail: %v\n", err)
+	}
+
+	log.Printf("PDF file successfully signed. Output path: %s\n", outputPath)
+}