Fix io.Reader based encryption #372

pkg/api/crypto.go

@@ -17,50 +17,258 @@
 package api
 
 import (
+	"io"
+	"os"
+
+	"github.com/pdfcpu/pdfcpu/pkg/log"
 	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu"
 	"github.com/pkg/errors"
 )
 
+// Encrypt reads a PDF stream from rs and writes the encrypted PDF stream to w.
+// A configuration containing at least the current passwords is required.
+func Encrypt(rs io.ReadSeeker, w io.Writer, conf *pdfcpu.Configuration) error {
+	if conf == nil {
+		return errors.New("pdfcpu: missing configuration for encryption")
+	}
+	conf.Cmd = pdfcpu.ENCRYPT
+
+	return Optimize(rs, w, conf)
+}
+
 // EncryptFile encrypts inFile and writes the result to outFile.
-// A configuration containing the current passwords is required.
-func EncryptFile(inFile, outFile string, conf *pdfcpu.Configuration) error {
+// A configuration containing at least the current passwords is required.
+func EncryptFile(inFile, outFile string, conf *pdfcpu.Configuration) (err error) {
 	if conf == nil {
 		return errors.New("pdfcpu: missing configuration for encryption")
 	}
 	conf.Cmd = pdfcpu.ENCRYPT
-	return OptimizeFile(inFile, outFile, conf)
+
+	var f1, f2 *os.File
+
+	if f1, err = os.Open(inFile); err != nil {
+		return err
+	}
+
+	tmpFile := inFile + ".tmp"
+	if outFile != "" && inFile != outFile {
+		tmpFile = outFile
+		log.CLI.Printf("writing %s...\n", outFile)
+	} else {
+		log.CLI.Printf("writing %s...\n", inFile)
+	}
+
+	if f2, err = os.Create(tmpFile); err != nil {
+		return err
+	}
+
+	defer func() {
+		if err != nil {
+			f2.Close()
+			f1.Close()
+			os.Remove(tmpFile)
+			return
+		}
+		if err = f2.Close(); err != nil {
+			return
+		}
+		if err = f1.Close(); err != nil {
+			return
+		}
+		if outFile == "" || inFile == outFile {
+			if err = os.Rename(tmpFile, inFile); err != nil {
+				return
+			}
+		}
+	}()
+
+	return Encrypt(f1, f2, conf)
+}
+
+// Decrypt reads a PDF stream from rs and writes the encrypted PDF stream to w.
+// A configuration containing at least the current passwords is required.
+func Decrypt(rs io.ReadSeeker, w io.Writer, conf *pdfcpu.Configuration) error {
+	if conf == nil {
+		return errors.New("pdfcpu: missing configuration for decryption")
+	}
+	conf.Cmd = pdfcpu.DECRYPT
+
+	return Optimize(rs, w, conf)
 }
 
 // DecryptFile decrypts inFile and writes the result to outFile.
-// A configuration containing the current passwords is required.
-func DecryptFile(inFile, outFile string, conf *pdfcpu.Configuration) error {
+// A configuration containing at least the current passwords is required.
+func DecryptFile(inFile, outFile string, conf *pdfcpu.Configuration) (err error) {
 	if conf == nil {
 		return errors.New("pdfcpu: missing configuration for decryption")
 	}
 	conf.Cmd = pdfcpu.DECRYPT
-	return OptimizeFile(inFile, outFile, conf)
+
+	var f1, f2 *os.File
+
+	if f1, err = os.Open(inFile); err != nil {
+		return err
+	}
+
+	tmpFile := inFile + ".tmp"
+	if outFile != "" && inFile != outFile {
+		tmpFile = outFile
+		log.CLI.Printf("writing %s...\n", outFile)
+	} else {
+		log.CLI.Printf("writing %s...\n", inFile)
+	}
+
+	if f2, err = os.Create(tmpFile); err != nil {
+		return err
+	}
+
+	defer func() {
+		if err != nil {
+			f2.Close()
+			f1.Close()
+			os.Remove(tmpFile)
+			return
+		}
+		if err = f2.Close(); err != nil {
+			return
+		}
+		if err = f1.Close(); err != nil {
+			return
+		}
+		if outFile == "" || inFile == outFile {
+			if err = os.Rename(tmpFile, inFile); err != nil {
+				return
+			}
+		}
+	}()
+
+	return Decrypt(f1, f2, conf)
+}
+
+// ChangeUserPassword reads a PDF stream from rs, changes the user password and writes the encrypted PDF stream to w.
+// A configuration containing the current passwords is required.
+func ChangeUserPassword(rs io.ReadSeeker, w io.Writer, pwOld, pwNew string, conf *pdfcpu.Configuration) error {
+	if conf == nil {
+		return errors.New("pdfcpu: missing configuration for change user password")
+	}
+	conf.Cmd = pdfcpu.CHANGEUPW
+	conf.UserPW = pwOld
+	conf.UserPWNew = &pwNew
+
+	return Optimize(rs, w, conf)
 }
 
 // ChangeUserPasswordFile reads inFile, changes the user password and writes the result to outFile.
 // A configuration containing the current passwords is required.
-func ChangeUserPasswordFile(inFile, outFile string, pwOld, pwNew string, conf *pdfcpu.Configuration) error {
+func ChangeUserPasswordFile(inFile, outFile string, pwOld, pwNew string, conf *pdfcpu.Configuration) (err error) {
 	if conf == nil {
 		return errors.New("pdfcpu: missing configuration for change user password")
 	}
 	conf.Cmd = pdfcpu.CHANGEUPW
 	conf.UserPW = pwOld
 	conf.UserPWNew = &pwNew
-	return OptimizeFile(inFile, outFile, conf)
+
+	var f1, f2 *os.File
+
+	if f1, err = os.Open(inFile); err != nil {
+		return err
+	}
+
+	tmpFile := inFile + ".tmp"
+	if outFile != "" && inFile != outFile {
+		tmpFile = outFile
+		log.CLI.Printf("writing %s...\n", outFile)
+	} else {
+		log.CLI.Printf("writing %s...\n", inFile)
+	}
+
+	if f2, err = os.Create(tmpFile); err != nil {
+		return err
+	}
+
+	defer func() {
+		if err != nil {
+			f2.Close()
+			f1.Close()
+			os.Remove(tmpFile)
+			return
+		}
+		if err = f2.Close(); err != nil {
+			return
+		}
+		if err = f1.Close(); err != nil {
+			return
+		}
+		if outFile == "" || inFile == outFile {
+			if err = os.Rename(tmpFile, inFile); err != nil {
+				return
+			}
+		}
+	}()
+
+	return ChangeUserPassword(f1, f2, pwOld, pwNew, conf)
+}
+
+// ChangeOwnerPassword reads a PDF stream from rs, changes the owner password and writes the encrypted PDF stream to w.
+// A configuration containing the current passwords is required.
+func ChangeOwnerPassword(rs io.ReadSeeker, w io.Writer, pwOld, pwNew string, conf *pdfcpu.Configuration) error {
+	if conf == nil {
+		return errors.New("pdfcpu: missing configuration for change owner password")
+	}
+	conf.Cmd = pdfcpu.CHANGEOPW
+	conf.OwnerPW = pwOld
+	conf.OwnerPWNew = &pwNew
+
+	return Optimize(rs, w, conf)
 }
 
-// ChangeOwnerPasswordFile reads inFile, changes the user password and writes the result to outFile.
+// ChangeOwnerPasswordFile reads inFile, changes the owner password and writes the result to outFile.
 // A configuration containing the current passwords is required.
-func ChangeOwnerPasswordFile(inFile, outFile string, pwOld, pwNew string, conf *pdfcpu.Configuration) error {
+func ChangeOwnerPasswordFile(inFile, outFile string, pwOld, pwNew string, conf *pdfcpu.Configuration) (err error) {
 	if conf == nil {
 		return errors.New("pdfcpu: missing configuration for change owner password")
 	}
 	conf.Cmd = pdfcpu.CHANGEOPW
 	conf.OwnerPW = pwOld
 	conf.OwnerPWNew = &pwNew
-	return OptimizeFile(inFile, outFile, conf)
+
+	var f1, f2 *os.File
+
+	if f1, err = os.Open(inFile); err != nil {
+		return err
+	}
+
+	tmpFile := inFile + ".tmp"
+	if outFile != "" && inFile != outFile {
+		tmpFile = outFile
+		log.CLI.Printf("writing %s...\n", outFile)
+	} else {
+		log.CLI.Printf("writing %s...\n", inFile)
+	}
+
+	if f2, err = os.Create(tmpFile); err != nil {
+		return err
+	}
+
+	defer func() {
+		if err != nil {
+			f2.Close()
+			f1.Close()
+			os.Remove(tmpFile)
+			return
+		}
+		if err = f2.Close(); err != nil {
+			return
+		}
+		if err = f1.Close(); err != nil {
+			return
+		}
+		if outFile == "" || inFile == outFile {
+			if err = os.Rename(tmpFile, inFile); err != nil {
+				return
+			}
+		}
+	}()
+
+	return ChangeOwnerPassword(f1, f2, pwOld, pwNew, conf)
 }