add cli tool instead of examples

.gitignore

@@ -0,0 +1 @@
+./cmd/sss/sss

README.md

@@ -33,17 +33,23 @@ func main() {
 }
 ```
 
-Also see the two example programs in the `example` directory:
+Install `cmd/sss` to use the command line interface:
+
+	go install github.com/kyodo-tech/shamir/cmd/sss@latest
+
+Then run `sss` to split a secret into shares and combine them to reconstruct the secret:
 
 ```sh
-go run example/split.go "my secret"
+Usage: sss -mode=split -secret=<secret> -n=<number of shares> -T=<threshold>
+# Example:
+sss -secret "my secret"
 # Output:
-# Share 0: lK8LyefHjxzOAQ==
-# Share 1: 1Ws3IGJh/lVQAg==
-# Share 2: LL0cmuDFAyzqAw==
-# Share 3: Wf8RJQs43iALBA==
-# Share 4: oCk6n4mcI1mxBQ==
-go run ./example/combine.go lK8LyefHjxzOAQ==,LL0cmuDFAyzqAw==,oCk6n4mcI1mxBQ==
+# N8QLmd6YcLu2AQ==
+# Nnubhbvx52y8Ag==
+# bMawbwAK5bJ+Aw==
+# SurUYDi7Mfm4BA==
+# EFf/ioNAMyd6BQ==
+sss -mode combine -shares N8QLmd6YcLu2AQ==,bMawbwAK5bJ+Aw==,EFf/ioNAMyd6BQ==
 # Output:
-# Reconstructed secret: my secret
+# my secret
 ```

cmd/sss/main.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"bufio"
+	"encoding/base64"
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/kyodo-tech/shamir"
+)
+
+func main() {
+	mode := flag.String("mode", "split", "Mode: split or combine")
+	secret := flag.String("secret", "", "The secret to split (for split mode)")
+	sharesStr := flag.String("shares", "", "Comma-separated shares (for combine mode)")
+	N := flag.Int("n", 5, "Total number of shares")
+	T := flag.Int("t", 3, "Number of shares needed to reconstruct the secret")
+	flag.Parse()
+
+	switch *mode {
+	case "split":
+		if *secret == "" {
+			reader := bufio.NewReader(os.Stdin)
+			inputSecret, err := reader.ReadString('\n')
+			if err != nil {
+				fmt.Println("Error reading input:", err)
+				os.Exit(1)
+			}
+			inputSecret = strings.TrimSpace(inputSecret)
+			splitSecret(inputSecret, *N, *T)
+		} else {
+			splitSecret(*secret, *N, *T)
+		}
+	case "combine":
+		if *sharesStr == "" {
+			fmt.Println("Usage: go run main.go -mode=combine -shares=<share1>,<share2>,...,<shareN>")
+			os.Exit(1)
+		}
+		combineShares(*sharesStr)
+	default:
+		fmt.Println("Invalid mode. Use -mode=split or -mode=combine")
+		os.Exit(1)
+	}
+}
+
+func splitSecret(secret string, totalShares, T int) {
+	secretBytes := []byte(secret)
+	shares, err := shamir.Split(secretBytes, totalShares, T)
+	if err != nil {
+		panic(err)
+	}
+
+	// Print share strings
+	for _, share := range shares {
+		fmt.Println(base64.StdEncoding.EncodeToString(share))
+	}
+}
+
+func combineShares(sharesStr string) {
+	shareStrs := strings.Split(sharesStr, ",")
+
+	var shares [][]byte
+	for _, shareStr := range shareStrs {
+		share, err := base64.StdEncoding.DecodeString(shareStr)
+		if err != nil {
+			panic(err)
+		}
+
+		shares = append(shares, share)
+	}
+
+	reconstructed, err := shamir.Combine(shares)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(reconstructed)
+}

example/combine.go

@@ -1,39 +0,0 @@
-package main
-
-import (
-	"encoding/base64"
-	"fmt"
-	"os"
-	"strings"
-
-	"github.com/kyodo-tech/shamir"
-)
-
-func main() {
-	// read comma separated shares from command line
-	if len(os.Args) != 2 {
-		fmt.Println("Usage: go run main.go <share1>,<share2>,...,<shareN>")
-		os.Exit(1)
-	}
-
-	// split shares
-	sharesStr := strings.Split(os.Args[1], ",")
-
-	var shares [][]byte
-	for _, shareStr := range sharesStr {
-		share, err := base64.StdEncoding.DecodeString(shareStr)
-		if err != nil {
-			panic(err)
-		}
-
-		shares = append(shares, share)
-	}
-
-	// Use any 3 out of 5 shares to reconstruct the secret
-	reconstructed, err := shamir.Combine(shares[:3])
-	if err != nil {
-		panic(err)
-	}
-
-	fmt.Printf("Reconstructed secret: %s\n", reconstructed)
-}

example/split.go

@@ -1,27 +0,0 @@
-package main
-
-import (
-	"encoding/base64"
-	"fmt"
-	"os"
-
-	"github.com/kyodo-tech/shamir"
-)
-
-func main() {
-	if len(os.Args) != 2 {
-		fmt.Println("Usage: go run main.go <secret>")
-		os.Exit(1)
-	}
-
-	secret := []byte(os.Args[1])
-	shares, err := shamir.Split(secret, 5, 3)
-	if err != nil {
-		panic(err)
-	}
-
-	// print share strings
-	for i, share := range shares {
-		fmt.Printf("Share %d: %s\n", i, base64.StdEncoding.EncodeToString(share))
-	}
-}