add demo

demo/go.mod

@@ -0,0 +1,11 @@
+module github.com/tolvumadur/rwcipher/demo
+
+go 1.21.5
+
+require github.com/tolvumadur/rwcipher v1.0.1
+
+require (
+	golang.org/x/crypto v0.18.0 // indirect
+	golang.org/x/sys v0.16.0 // indirect
+	golang.org/x/term v0.16.0 // indirect
+)

demo/go.sum

@@ -0,0 +1,8 @@
+github.com/tolvumadur/rwcipher v1.0.1 h1:BZ1XZ6/9jeT9jfXxa0+JiUwlxP7eq4Y2zz9qY5ouO8E=
+github.com/tolvumadur/rwcipher v1.0.1/go.mod h1:QvvqzFDk4YosKdqqvZsPRFAo+RMIvYIxFJ1AycrBnU4=
+golang.org/x/crypto v0.18.0 h1:PGVlW0xEltQnzFZ55hkuX5+KLyrMYhHld1YHO4AKcdc=
+golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1mg=
+golang.org/x/sys v0.16.0 h1:xWw16ngr6ZMtmxDyKyIgsE93KNKz5HKmMa3b8ALHidU=
+golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.16.0 h1:m+B6fahuftsE9qjo0VWp2FW0mB3MTJvR0BaMQrq0pmE=
+golang.org/x/term v0.16.0/go.mod h1:yn7UURbUtPyrVJPGPq404EukNFxcm/foM+bV/bfcDsY=

demo/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"flag"
+	"github.com/tolvumadur/rwcipher"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func init() {
+
+}
+
+
+func main() {
+
+	// Collect command line input
+	var dst = flag.String("o", "../test/test1.tmp", "output file")
+	var src = flag.String("i", "../test/test.txt", "input file")
+	var dec = flag.Bool("d", false, "set this flag for decrypting")
+	var enc = flag.Bool("e", false, "set this flag for encrypting")
+	var silent = flag.Bool("s", false, "set this flag to silence stdout")
+
+	flag.Parse()
+
+	// Validate boolean inputs
+	if (*enc && *dec) || (!*enc && !*dec) {
+		os.Stderr.WriteString("Must specify -d xor -e for decryption or encryption\n")
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	// Report actions unless silent
+	if !*silent {
+		if *enc {
+			fmt.Printf("Encrypting %s to outfile %s\n", *src, *dst)
+		} else if *dec {
+			fmt.Printf("Encrypting %s to outfile %s\n", *src, *dst)
+		}
+	}
+
+	// Decrypt or Encrypt using rwcipher, report any error
+	if *dec {
+		err := rwcipher.Decrypt(*src, *dst, nil)
+		if err != nil {
+			if strings.Contains(err.Error(), "message authentication failed") {
+				os.Stderr.WriteString("Decryption failed either due to a wrong password or altered ciphertext/nonce/salt in the encrypted file.\n")
+			} else {
+				os.Stderr.WriteString(fmt.Sprintf("Decryption Failed: %v\n", err))
+			}
+			os.Exit(4)
+		}
+	} else if *enc {
+		err := rwcipher.Encrypt(*src, *dst, nil)
+		if err != nil {
+			fmt.Printf("Encryption Failed: %v\n", err)
+			os.Exit(3)
+		}
+	} else {
+		os.Stderr.WriteString("Unknown operation requested\n")
+		flag.PrintDefaults()
+		os.Exit(2)
+	}
+
+	if !*silent {
+		fmt.Println("Operation Successful.\n")
+	}
+
+	os.Exit(0)
+}
+