1 files changed, 134 insertions, 0 deletions
diff --git a/_example/file_encrypt/main.go b/_example/file_encrypt/main.go
new file mode 100644
index 0000000..c83cd8a
--- /dev/null
+++ b/_example/file_encrypt/main.go
@@ -0,0 +1,134 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strings"
+
+	"golang.org/x/sys/unix"
+	"snix.ir/rabaead"
+)
+
+const prefix = "enc_"
+
+func main() {
+	encFlag := flag.NewFlagSet("encrypt", flag.ExitOnError)
+	decFlag := flag.NewFlagSet("decrypt", flag.ExitOnError)
+	flag.Usage = flagUsage
+	if len(os.Args) < 2 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	switch os.Args[1] {
+	case "encrypt":
+		encrypt(encFlag)
+	case "decrypt":
+		decrypt(decFlag)
+	default:
+		flag.Usage()
+		os.Exit(1)
+	}
+}
+
+func encrypt(flagset *flag.FlagSet) {
+	plain := flagset.String("file", "plain.txt", "file to encrypt with RabbitPoly1305 aead")
+	keyva := flagset.String("key", "", "rabbit key string, must be 16-byte len")
+	ivxva := flagset.String("ivx", "", "rabbit iv string, must be 8-byte or nothing")
+	flagset.Parse(os.Args[2:])
+
+	file, err := os.Open(*plain)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer file.Close()
+
+	dest, err := os.OpenFile(prefix+file.Name(), os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer dest.Close()
+
+	cipw, err := rabaead.NewStreamWriter(dest, []byte(*keyva), []byte(*ivxva), nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	n, err := io.Copy(cipw, file)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// calc and write poly1305 tag at the end of write
+	if err := cipw.Close(); err != nil {
+		log.Fatal(err)
+	}
+
+	if err := unix.Unlink(file.Name()); err != nil {
+		log.Printf("syscall unlink(): %v", err)
+	}
+
+	log.Printf("file %s encrypted to %s, bytes written: %d", file.Name(), dest.Name(), n)
+}
+
+func decrypt(flagset *flag.FlagSet) {
+	dectx := flagset.String("file", "enc_plain.txt", "file to decrypt with RabbitPoly1305 aead")
+	keyva := flagset.String("key", "", "rabbit key string, must be 16-byte len")
+	ivxva := flagset.String("ivx", "", "rabbit iv string, must be 8-byte or nothing")
+	flagset.Parse(os.Args[2:])
+
+	file, err := os.Open(*dectx)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer file.Close()
+
+	name := strings.TrimPrefix(file.Name(), prefix)
+
+	dest, err := os.OpenFile(name, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer dest.Close()
+
+	cipr, err := rabaead.NewStreamReader(file, []byte(*keyva), []byte(*ivxva), nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	n, err := io.Copy(dest, cipr)
+	if err != nil {
+		if err := unix.Unlink(dest.Name()); err != nil {
+			log.Printf("syscall unlink(): %v", err)
+		}
+		log.Fatal(err)
+	}
+
+	if err := unix.Unlink(file.Name()); err != nil {
+		log.Printf("syscall unlink(): %v", err)
+	}
+
+	log.Printf("file %s encrypted to %s, bytes written: %d", file.Name(), dest.Name(), n)
+}
+
+func flagUsage() {
+	fmt.Printf(`usage of %v: commands <args...|help>
+commands:
+
+   encrypt <args...>     encrypt files with rabbit poly1305 aead cipher
+   decrypt <args...>     decrypt files with rabbit poly1305 aead cipher
+
+
+Copyright (c) 2022 snix.ir, All rights reserved.
+Developed BY <Sina Ghaderi> sina@snix.ir
+This work is licensed under the terms of GNU General Public license.
+Github: github.com/sina-ghaderi and Source: git.snix.ir
+`, os.Args[0])
+}