From 175d8940be4527c938a66a9b91d9faa88b8d8ae0 Mon Sep 17 00:00:00 2001
From: morrigan <belma.dzi@gmail.com>
Date: Fri, 1 Nov 2019 11:30:28 +0100
Subject: [PATCH] Add encryption methods

---
 package.json |  3 ++-
 src/xx.ts    | 28 ++++++++++++++++++++++++++++
 yarn.lock    | 16 +++++++++++++++-
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index 14549b0..50ffcde 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,7 @@
   "dependencies": {
     "bn.js": "^5.0.0",
     "buffer": "^5.4.3",
-    "libp2p-crypto": "^0.17.1"
+    "libp2p-crypto": "^0.17.1",
+    "sodium-native": "^2.4.6"
   }
 }
diff --git a/src/xx.ts b/src/xx.ts
index c3b7238..05cd45c 100644
--- a/src/xx.ts
+++ b/src/xx.ts
@@ -1,6 +1,7 @@
 import {bytes32, bytes16, uint32, uint64, bytes} from './types/basic'
 import { Buffer } from 'buffer';
 import * as crypto from 'libp2p-crypto';
+import * as sodium from 'sodium-native';
 
 type KeyPair = {
   publicKey: bytes32,
@@ -60,11 +61,38 @@ class XXHandshake {
     return {ss, s, e, rs, re, psk};
   }
 
+  incrementNonce(n: uint32) : uint32 {
+    return n + 1;
+  }
+
+  encrypt(k: bytes32, n: uint32, ad: bytes, plaintext: bytes) : bytes {
+    const ElongatedNonce = sodium.sodium_malloc(sodium.crypto_aead_xchacha20poly1305_ietf_NPUBBYTES); // 12U ?
+    sodium.sodium_memzero(ElongatedNonce);
+    ElongatedNonce.set(n, 16);
+
+    const clen = plaintext.length + sodium.crypto_aead_xchacha20poly1305_ietf_ABYTES;
+    const c = sodium.sodium_malloc(clen);
+    sodium.crypto_aead_xchacha20poly1305_ietf_encrypt(c, plaintext, ad, null, ElongatedNonce, k);
+  }
+
+  // Cipher state related
   initializeKey(k: bytes32) : CipherState {
     const n = minNonce;
     return { k, n };
   }
 
+  setNonce(cs: CipherState, nonce: uint32) {
+    cs.n = nonce;
+  }
+
+  encryptWithAd(cs: CipherState, ad: bytes, plaintext: bytes) : bytes {
+    const e = this.encrypt(cs.k, cs.n, ad, plaintext);
+    this.setNonce(cs, this.incrementNonce(cs.n));
+    return e;
+  }
+
+  // Symmetric state related
+
   async initializeSymmetric(protocolName: string) : Promise<SymmetricState> {
     const h = await this.hashProtocolName(protocolName);
     const ck = h;
diff --git a/yarn.lock b/yarn.lock
index 833871e..1fcce3b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1984,7 +1984,7 @@ inherits@2, inherits@^2.0.1, inherits@^2.0.3, inherits@~2.0.3:
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.4.tgz#0fa2c64f932917c3433a0ded55363aae37416b7c"
   integrity sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==
 
-ini@~1.3.0:
+ini@^1.3.5, ini@~1.3.0:
   version "1.3.5"
   resolved "https://registry.yarnpkg.com/ini/-/ini-1.3.5.tgz#eee25f56db1c9ec6085e0c22778083f596abf927"
   integrity sha512-RZY5huIKCMRWDUqZlEi72f/lmXKMvuszcMBduliQ3nnWbx9X/ZBQO7DijMEYS9EhHBb2qacRUMtC7svLwe0lcw==
@@ -2616,6 +2616,11 @@ node-forge@~0.9.1:
   resolved "https://registry.yarnpkg.com/node-forge/-/node-forge-0.9.1.tgz#775368e6846558ab6676858a4d8c6e8d16c677b5"
   integrity sha512-G6RlQt5Sb4GMBzXvhfkeFmbqR6MzhtnT7VTHuLadjkii3rdYHNdw0m8zA4BTxVIh68FicCQ2NSUANpsqkr9jvQ==
 
+node-gyp-build@^4.1.0:
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/node-gyp-build/-/node-gyp-build-4.1.1.tgz#d7270b5d86717068d114cc57fff352f96d745feb"
+  integrity sha512-dSq1xmcPDKPZ2EED2S6zw/b9NKsqzXRE6dVr8TVQnI3FJOTteUMuqF3Qqs6LZg+mLGYJWqQzMbIjMtJqTv87nQ==
+
 node-modules-regexp@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/node-modules-regexp/-/node-modules-regexp-1.0.0.tgz#8d9dbe28964a4ac5712e9131642107c71e90ec40"
@@ -3305,6 +3310,15 @@ snapdragon@^0.8.1:
     source-map-resolve "^0.5.0"
     use "^3.1.0"
 
+sodium-native@^2.4.6:
+  version "2.4.6"
+  resolved "https://registry.yarnpkg.com/sodium-native/-/sodium-native-2.4.6.tgz#8a8173095e8cf4f997de393a2ba106c34870cac2"
+  integrity sha512-Ro9lhTjot8M01nwKLXiqLSmjR7B8o+Wg4HmJUjEShw/q6XPlNMzjPkA1VJKaMH8SO8fJ/sggAKVwreTaFszS2Q==
+  dependencies:
+    ini "^1.3.5"
+    nan "^2.14.0"
+    node-gyp-build "^4.1.0"
+
 source-map-resolve@^0.5.0:
   version "0.5.2"
   resolved "https://registry.yarnpkg.com/source-map-resolve/-/source-map-resolve-0.5.2.tgz#72e2cc34095543e43b2c62b2c4c10d4a9054f259"