Updated cmd line tool and gitignore

.gitignore

@@ -1,2 +1,3 @@
 vendor/
 .idea
+cmd/main

cmd/README.md

@@ -0,0 +1,39 @@
+# Simple Command Line Utility
+
+This CLI can be used in order to either generate a fresh mix-header or decode and fully process an existing one given a private key.
+
+## Usage
+
+To use the CLI, build it and then run the commands.
+
+```
+go build main.go
+./main <commands>
+```
+
+### Commands
+```
+./main (new|generate|decode) <private-keys>
+```
+
+#### `new`
+The `new` command creates a new keypair for use with `generate` and `decode`.
+
+#### `generate`
+The `generate` command generates a route, then uses that route to create a new sphinx onion packet, which includes all hop data along the route.
+
+#### `decode`
+The `decode` command reads an onion packet in from stdin and a private key as an argument to decode the message. See example below. 
+
+`decode` also creates a new router and starts an in-memory ReplayLog.
+
+Example:
+
+```
+$ ./main new
+privkey: 89301b800e26a4d406b3ddc7bca069ca563871ab32753a63ac72ec890004ba64
+pubkey: 035c6a3ce4d94a23071e4333e6ffb4f8aae0021319936e49920a390343f7b42770
+$ ./main generate 035c6a3ce4d94a23071e4333e6ffb4f8aae0021319936e49920a390343f7b42770 | ./main decode 89301b800e26a4d406b3ddc7bca069ca563871ab32753a63ac72ec890004ba64
+Node 0 pubkey 035c6a3ce4d94a23071e4333e6ffb4f8aae0021319936e49920a390343f7b42770
+0003e91983bc6cec837a26f97aa2dd90a90f0041fda04548f4262d9e14dec4c2ca4a0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000129b2a5683d565b0e394a4ee48f41eb8dc1d739dfeef13740524d8fdbc65b17baa67bb7b2309c6d4f440840862daa146bf396d6b8b83e47c487ce660a31c25fb5d0000000000000000000000000000000000000000000000000000000000000000
+```

cmd/main.go

@@ -9,9 +9,9 @@ import (
 	"os"
 	"strings"
 
-	sphinx "github.com/lightningnetwork/lightning-onion"
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/chaincfg"
+	sphinx "github.com/lightningnetwork/lightning-onion"
 )
 
 // main implements a simple command line utility that can be used in order to
@@ -23,7 +23,24 @@ func main() {
 	assocData := bytes.Repeat([]byte{'B'}, 32)
 
 	if len(args) == 1 {
-		fmt.Printf("Usage: %s (generate|decode) <private-keys>\n", args[0])
+		fmt.Printf("Usage: %s (new|generate|decode) <private-keys>\n", args[0])
+	} else if args[1] == "new" {
+		// generate a new private key
+		privKey1, err := btcec.NewPrivateKey(btcec.S256())
+		if err != nil {
+			fmt.Printf("private key generation error: %s\n", err)
+			return
+		}
+
+		privHex := hex.EncodeToString(privKey1.Serialize())
+		fmt.Printf("privkey: %s\n", privHex)
+
+		// get public key from private key
+		pub := privKey1.PubKey().SerializeCompressed()
+
+		// covert publick key to hex and print
+		pubHex := hex.EncodeToString(pub)
+		fmt.Printf("pubkey: %s\n", pubHex)
 	} else if args[1] == "generate" {
 		var route []*btcec.PublicKey
 		for i, hexKey := range args[2:] {
@@ -82,6 +99,12 @@ func main() {
 		s := sphinx.NewRouter(privkey, &chaincfg.TestNet3Params,
 			sphinx.NewMemoryReplayLog())
 
+		// start router (create memory log)
+		err = s.Start()
+		if err != nil {
+			log.Fatalf("Error starting router: %v", err)
+		}
+
 		var packet sphinx.OnionPacket
 		err = packet.Decode(bytes.NewBuffer(binMsg))