chore: slight improvement of the encrypt feature to be more in line with others features

pkg/gotenberg/pdfengine.go

@@ -104,7 +104,7 @@ type PdfEngine interface {
 
 	// Flatten merges existing annotation appearances with page content,
 	// effectively deleting the original annotations. This process can flatten
-	// forms as well, as forms share a relationship with annotations. Note that
+	// forms as well as forms share a relationship with annotations. Note that
 	// this operation is irreversible.
 	Flatten(ctx context.Context, logger *zap.Logger, inputPath string) error
 

pkg/modules/libreoffice/routes.go

@@ -264,6 +264,11 @@ func convertRoute(libreOffice libreofficeapi.Uno, engine gotenberg.PdfEngine) ap
 				}
 			}
 
+			err = pdfengines.EncryptPdfStub(ctx, engine, userPassword, ownerPassword, outputPaths)
+			if err != nil {
+				return fmt.Errorf("encrypt PDFs: %w", err)
+			}
+
 			if len(outputPaths) > 1 && splitMode == zeroValuedSplitMode {
 				// If .zip archive, document.docx -> document.docx.pdf.
 				for i, inputPath := range inputPaths {
@@ -278,11 +283,6 @@ func convertRoute(libreOffice libreofficeapi.Uno, engine gotenberg.PdfEngine) ap
 				}
 			}
 
-			err = pdfengines.EncryptPdfStub(ctx, engine, userPassword, ownerPassword, outputPaths)
-			if err != nil {
-				return fmt.Errorf("encrypt PDFs: %w", err)
-			}
-
 			err = ctx.AddOutputPaths(outputPaths...)
 			if err != nil {
 				return fmt.Errorf("add output paths: %w", err)

pkg/modules/pdfcpu/pdfcpu.go

@@ -177,17 +177,16 @@ func (engine *PdfCpu) Encrypt(ctx context.Context, logger *zap.Logger, inputPath
 		return errors.New("user password cannot be empty")
 	}
 
-	// If owner password is not provided, use the user password as owner password
 	if ownerPassword == "" {
 		ownerPassword = userPassword
 	}
 
 	var args []string
 	args = append(args, "encrypt")
-	args = append(args, "-mode", "aes") // Use AES encryption
+	args = append(args, "-mode", "aes")
 	args = append(args, "-upw", userPassword)
 	args = append(args, "-opw", ownerPassword)
-	args = append(args, "-perm", "all") // Grant all permissions with owner password
+	args = append(args, "-perm", "all")
 	args = append(args, inputPath, inputPath)
 
 	cmd, err := gotenberg.CommandContext(ctx, logger, engine.binPath, args...)

pkg/modules/pdfengines/multi.go

@@ -41,8 +41,8 @@ func newMultiPdfEngines(
 	}
 }
 
-// Merge tries to merge the given PDFs into a unique PDF thanks to its
-// children. If the context is done, it stops and returns an error.
+// Merge combines multiple PDF files into a single document using the first
+// available engine that supports PDF merging.
 func (multi *multiPdfEngines) Merge(ctx context.Context, logger *zap.Logger, inputPaths []string, outputPath string) error {
 	var err error
 	errChan := make(chan error, 1)
@@ -71,8 +71,8 @@ type splitResult struct {
 	err         error
 }
 
-// Split tries to split at intervals a given PDF thanks to its children. If the
-// context is done, it stops and returns an error.
+// Split divides the PDF into separate pages using the first available engine
+// that supports PDF splitting.
 func (multi *multiPdfEngines) Split(ctx context.Context, logger *zap.Logger, mode gotenberg.SplitMode, inputPath, outputDirPath string) ([]string, error) {
 	var err error
 	var mu sync.Mutex // to safely append errors.
@@ -102,8 +102,8 @@ func (multi *multiPdfEngines) Split(ctx context.Context, logger *zap.Logger, mod
 	return nil, fmt.Errorf("split PDF with multi PDF engines: %w", err)
 }
 
-// Flatten merges existing annotation appearances with page content, thanks to
-// its children. If the context is done, it stops and returns an error
+// Flatten merges existing annotation appearances with page content using the
+// first available engine that supports flattening.
 func (multi *multiPdfEngines) Flatten(ctx context.Context, logger *zap.Logger, inputPath string) error {
 	var err error
 	errChan := make(chan error, 1)
@@ -127,8 +127,8 @@ func (multi *multiPdfEngines) Flatten(ctx context.Context, logger *zap.Logger, i
 	return fmt.Errorf("flatten PDF with multi PDF engines: %w", err)
 }
 
-// Convert converts the given PDF to a specific PDF format, thanks to its
-// children. If the context is done, it stops and returns an error.
+// Convert transforms the given PDF to a specific PDF format using the first
+// available engine that supports PDF conversion.
 func (multi *multiPdfEngines) Convert(ctx context.Context, logger *zap.Logger, formats gotenberg.PdfFormats, inputPath, outputPath string) error {
 	var err error
 	errChan := make(chan error, 1)
@@ -157,6 +157,8 @@ type readMetadataResult struct {
 	err      error
 }
 
+// ReadMetadata extracts metadata from a PDF file using the first available
+// engine that supports metadata reading.
 func (multi *multiPdfEngines) ReadMetadata(ctx context.Context, logger *zap.Logger, inputPath string) (map[string]interface{}, error) {
 	var err error
 	var mu sync.Mutex // to safely append errors.
@@ -186,6 +188,8 @@ func (multi *multiPdfEngines) ReadMetadata(ctx context.Context, logger *zap.Logg
 	return nil, fmt.Errorf("read PDF metadata with multi PDF engines: %w", err)
 }
 
+// WriteMetadata embeds metadata into a PDF file using the first available
+// engine that supports metadata writing.
 func (multi *multiPdfEngines) WriteMetadata(ctx context.Context, logger *zap.Logger, metadata map[string]interface{}, inputPath string) error {
 	var err error
 	errChan := make(chan error, 1)
@@ -209,8 +213,8 @@ func (multi *multiPdfEngines) WriteMetadata(ctx context.Context, logger *zap.Log
 	return fmt.Errorf("write PDF metadata with multi PDF engines: %w", err)
 }
 
-// Encrypt adds password protection to a PDF file using the first available engine
-// that supports password protection.
+// Encrypt adds password protection to a PDF file using the first available
+// engine that supports password protection.
 func (multi *multiPdfEngines) Encrypt(ctx context.Context, logger *zap.Logger, inputPath, userPassword, ownerPassword string) error {
 	var err error
 	errChan := make(chan error, 1)

pkg/modules/pdfengines/pdfengines.go

@@ -210,7 +210,7 @@ func (mod *PdfEngines) SystemMessages() []string {
 		fmt.Sprintf("convert engines - %s", strings.Join(mod.convertNames[:], " ")),
 		fmt.Sprintf("read metadata engines - %s", strings.Join(mod.readMetadataNames[:], " ")),
 		fmt.Sprintf("write metadata engines - %s", strings.Join(mod.writeMetadataNames[:], " ")),
-		fmt.Sprintf("password protection engines - %s", strings.Join(mod.encryptNames[:], " ")),
+		fmt.Sprintf("encrypt engines - %s", strings.Join(mod.encryptNames[:], " ")),
 	}
 }
 

pkg/modules/pdfengines/routes.go

@@ -254,7 +254,6 @@ func WriteMetadataStub(ctx *api.Context, engine gotenberg.PdfEngine, metadata ma
 	return nil
 }
 
-// EncryptPdfStub adds password protection to PDF files.
 // FormDataPdfEncrypt extracts encryption parameters from form data.
 func FormDataPdfEncrypt(form *api.FormData) (userPassword, ownerPassword string) {
 	form.String("userPassword", &userPassword, "")
@@ -262,6 +261,7 @@ func FormDataPdfEncrypt(form *api.FormData) (userPassword, ownerPassword string)
 	return userPassword, ownerPassword
 }
 
+// EncryptPdfStub adds password protection to PDF files.
 func EncryptPdfStub(ctx *api.Context, engine gotenberg.PdfEngine, userPassword, ownerPassword string, inputPaths []string) error {
 	if userPassword == "" {
 		return nil
@@ -459,7 +459,6 @@ func convertRoute(engine gotenberg.PdfEngine) api.Route {
 
 			form := ctx.FormData()
 			pdfFormats := FormDataPdfFormats(form)
-			userPassword, ownerPassword := FormDataPdfEncrypt(form)
 
 			var inputPaths []string
 			err := form.
@@ -496,11 +495,6 @@ func convertRoute(engine gotenberg.PdfEngine) api.Route {
 				}
 			}
 
-			err = EncryptPdfStub(ctx, engine, userPassword, ownerPassword, outputPaths)
-			if err != nil {
-				return fmt.Errorf("encrypt PDFs: %w", err)
-			}
-
 			err = ctx.AddOutputPaths(outputPaths...)
 			if err != nil {
 				return fmt.Errorf("add output paths: %w", err)

pkg/modules/pdftk/pdftk.go

@@ -151,7 +151,6 @@ func (engine *PdfTk) Encrypt(ctx context.Context, logger *zap.Logger, inputPath,
 		return errors.New("user password cannot be empty")
 	}
 
-	// If owner password is not provided, use the user password as owner password
 	if ownerPassword == "" {
 		ownerPassword = userPassword
 	}
@@ -160,14 +159,8 @@ func (engine *PdfTk) Encrypt(ctx context.Context, logger *zap.Logger, inputPath,
 	args = append(args, inputPath)
 	args = append(args, "output", inputPath)
 	args = append(args, "encrypt_128bit")
-
-	if userPassword != "" {
-		args = append(args, "user_pw", userPassword)
-	}
-
-	if ownerPassword != "" {
-		args = append(args, "owner_pw", ownerPassword)
-	}
+	args = append(args, "user_pw", userPassword)
+	args = append(args, "owner_pw", ownerPassword)
 
 	cmd, err := gotenberg.CommandContext(ctx, logger, engine.binPath, args...)
 	if err != nil {

pkg/modules/qpdf/qpdf.go

@@ -178,12 +178,10 @@ func (engine *QPdf) Encrypt(ctx context.Context, logger *zap.Logger, inputPath,
 		return errors.New("user password cannot be empty")
 	}
 
-	// If owner password is not provided, use the user password as owner password
 	if ownerPassword == "" {
 		ownerPassword = userPassword
 	}
 
-	// QPDF command to encrypt a PDF
 	var args []string
 	args = append(args, inputPath)
 	args = append(args, engine.globalArgs...)