From 3995f96896c552feb8ddae3a263e61b6ee138f99 Mon Sep 17 00:00:00 2001
From: Simon El Nahas Christensen <simon.el.nahas@gmail.com>
Date: Sun, 21 Jul 2019 14:14:36 +0200
Subject: [PATCH] 08 solution proposal taking arguments

---
 problems/09.md | 36 ++++++++++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/problems/09.md b/problems/09.md
index f4f7af0..e09cecc 100644
--- a/problems/09.md
+++ b/problems/09.md
@@ -5,24 +5,44 @@
 
 ```js
 // sign.js
+// usage:
+// node sign.js "message"
+// signature and publickey will be in hex format
 var sodium = require('sodium-native')
+const args = process.argv.slice(2)
+const messageString = args[0]
 
-var publicKey = Buffer.alloc(sodium.crypto_sign_PUBLICKEYBYTES)
-var secretKey = Buffer.alloc(sodium.crypto_sign_SECRETKEYBYTES)
-sodium.crypto_sign_keypair(publicKey, secretKey)
-
-var message = Buffer.from('Hello world!')
+const messageBuffer = Buffer.from(messageString)
+var publickey = Buffer.alloc(sodium.crypto_sign_PUBLICKEYBYTES)
+var secretkey = Buffer.alloc(sodium.crypto_sign_SECRETKEYBYTES)
 var signature = Buffer.alloc(sodium.crypto_sign_BYTES)
 
-sodium.crypto_sign_detached(signature, message, secretKey)
+sodium.crypto_sign_keypair(publickey, secretkey)
+
+sodium.crypto_sign_detached(signature, messageBuffer, secretkey)
 
-console.log('Public key: ' + publicKey.toString('hex'))
-console.log('Message: ' + message.toString())
 console.log('Signature: ' + signature.toString('hex'))
+console.log('Message: "' + messageBuffer.toString()+'"')
+console.log('Public key: ' + publickey.toString('hex'))
 ```
 
 ```js
 // verify.js
+// usage:
+// node verify.js signature "message" publickey
+// signature and publickey should be in hex format
+
+var sodium = require('sodium-native')
+const args = process.argv.slice(2)
+var publickey = Buffer.alloc(sodium.crypto_sign_PUBLICKEYBYTES)
+var signature = Buffer.alloc(sodium.crypto_sign_BYTES)
+
+signature = Buffer.from(args[0],'hex')
+message = Buffer.from(args[1])
+publickey = Buffer.from(args[2],'hex')
+
+const isValid = sodium.crypto_sign_verify_detached(signature,message,publickey)
+console.log("isValid: "+isValid)
 
 ```