commit 58bcfb5325c1abd74af71664c9908003add751ee
Author: Valentin Boulanger <valentin.boulanger@protonmail.com>
Date:   Mon Jan 16 20:31:08 2023 +0100

    Ajout des sources

diff --git a/index.js b/index.js
new file mode 100644
index 0000000..e4cca88
--- /dev/null
+++ b/index.js
@@ -0,0 +1,68 @@
+const crypto = require('crypto');
+
+//Keys generation
+const alice = crypto.createECDH('secp256k1');
+alice.generateKeys();
+const bob = crypto.createECDH('secp256k1');
+bob.generateKeys();
+
+const alicePublicKeyBase64 = alice.getPublicKey().toString('base64');
+const bobPublicKeyBase64 = bob.getPublicKey().toString('base64');
+
+const aliceSharedKey = alice.computeSecret(bobPublicKeyBase64, 'base64', 'hex');
+const bobSharedKey = bob.computeSecret(alicePublicKeyBase64, 'base64', 'hex');
+
+//Alice encrypt the message
+const MESSAGE = "This is a text to encrypt";
+console.log("Message en clair : " + MESSAGE);
+
+const IV = crypto.randomBytes(16);
+const cipher = crypto.createCipheriv('aes-256-gcm', Buffer.from(aliceSharedKey, 'hex'), IV);
+
+let encrypted = cipher.update(MESSAGE, 'utf8', 'hex');
+encrypted += cipher.final('hex');
+
+const auth_tag = cipher.getAuthTag().toString('hex');
+
+console.table({
+    IV: IV.toString('hex'),
+    encrypted: encrypted,
+    auth_tag: auth_tag
+});
+
+const payload = IV.toString('hex') + encrypted + auth_tag;
+console.log("Chaine cryptée HEX : " + payload);
+
+const payload64 = Buffer.from(payload, 'hex').toString('base64');
+console.log("Chaine cryptée envoyée : " + payload64);
+
+//Send the payload64 to bob
+
+//Bob decrypt the message
+console.log("Chaine cryptée reçue : " + payload64);
+const bob_payload = Buffer.from(payload64, 'base64').toString('hex');
+console.log("Chaine cryptée HEX : " + bob_payload);
+
+const bob_iv = bob_payload.substr(0, 32);
+const bob_encrypted = bob_payload.substr(32, bob_payload.length -32 -32);
+const bob_auth_tag = bob_payload.substr(bob_payload.length -32, 32);
+
+console.table({ bob_iv, bob_encrypted, bob_auth_tag });
+
+try{
+    const decipher = crypto.createDecipheriv(
+        'aes-256-gcm', 
+        Buffer.from(bobSharedKey, 'hex'), 
+        Buffer.from(bob_iv, 'hex')
+    );
+
+    decipher.setAuthTag(Buffer.from(bob_auth_tag, 'hex'));
+
+    let decrypted = decipher.update(bob_encrypted, 'hex', 'utf8');
+    decrypted += decipher.final('utf8');
+
+    console.log("Message en clair : " + decrypted);
+
+}catch(error){
+    console.log(error)
+}
\ No newline at end of file
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..858ea73
--- /dev/null
+++ b/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "endtoendencryption",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC"
+}