Crypto in vc

src-tauri/Cargo.lock

@@ -8,6 +8,16 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
+[[package]]
+name = "aead"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1973cfbc1a2daf9cf550e74e1f088c28e7f7d8c1e1418fb6c9dc5184b7e84c99"
+dependencies = [
+ "crypto-common 0.2.2",
+ "inout",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.5"
@@ -319,6 +329,15 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "block-buffer"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2f6c7dbe95a6ed67ad9f18e57daf93a2f034c524b99fd2b76d18fdfeb6660aa"
+dependencies = [
+ "hybrid-array",
+]
+
 [[package]]
 name = "block2"
 version = "0.6.2"
@@ -508,6 +527,29 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "chacha20"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65c35e4b699c7e15ccbe7ee35c005e4fc0a278d22238a2857e6ce2dadeda1b06"
+dependencies = [
+ "cfg-if",
+ "cipher",
+ "cpufeatures 0.3.1",
+]
+
+[[package]]
+name = "chacha20poly1305"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b89e1c441e926b9c82a8d023f6e1b7ae0adcfaa7d621814e4d60789bac751cb"
+dependencies = [
+ "aead",
+ "chacha20",
+ "cipher",
+ "poly1305",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.45"
@@ -520,6 +562,23 @@ dependencies = [
  "windows-link 0.2.1",
 ]
 
+[[package]]
+name = "cipher"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8cf2a2c93cd704877c0858356ed03480ff301ee950b43f1cbe4573b088bfa6c"
+dependencies = [
+ "block-buffer 0.12.1",
+ "crypto-common 0.2.2",
+ "inout",
+]
+
+[[package]]
+name = "cmov"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c9ea0ac24bc397ab3c98583a3c9ba74fa56b09a4449bbe172b9b1ddb016027a"
+
 [[package]]
 name = "combine"
 version = "4.6.7"
@@ -642,6 +701,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "cpufeatures"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca28b0ae3115b884660db4118d803791fd6756b6e88f39c0f3f7859060d7566"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -676,6 +744,17 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "crypto-common"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce6e4c961d6cd6c9a86db418387425e8bdeaf05b3c8bc1411e6dca4c252f1453"
+dependencies = [
+ "getrandom 0.4.3",
+ "hybrid-array",
+ "rand_core",
+]
+
 [[package]]
 name = "cssparser"
 version = "0.36.0"
@@ -715,6 +794,15 @@ version = "0.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "52560adf09603e58c9a7ee1fe1dcb95a16927b17c127f0ac02d6e768a0e25bc1"
 
+[[package]]
+name = "ctutils"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d5515a3834141de9eafb9717ad39eea8247b5674e6066c404e8c4b365d2a29e"
+dependencies = [
+ "cmov",
+]
+
 [[package]]
 name = "darling"
 version = "0.23.0"
@@ -833,8 +921,8 @@ version = "0.10.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
- "block-buffer",
+ "block-buffer 0.10.4",
- "crypto-common",
+ "crypto-common 0.1.7",
 ]
 
 [[package]]
@@ -994,6 +1082,7 @@ checksum = "4ef6b89e5b37196644d8796de5268852ff179b44e96276cf4290264843743bb7"
 name = "enclave"
 version = "0.1.0"
 dependencies = [
+ "chacha20poly1305",
  "cpal",
  "ringbuf",
  "rubato",
@@ -1392,6 +1481,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "r-efi 6.0.0",
+ "rand_core",
 ]
 
 [[package]]
@@ -1627,6 +1717,15 @@ version = "1.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6dbf3de79e51f3d586ab4cb9d5c3e2c14aa28ed23d180cf89b4df0454a69cc87"
 
+[[package]]
+name = "hybrid-array"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "707114b52a152fa7bdb290cd7cd5912d9467273b6d74e21b8d81aca1f8533f6b"
+dependencies = [
+ "typenum",
+]
+
 [[package]]
 name = "hyper"
 version = "1.11.0"
@@ -1846,6 +1945,15 @@ dependencies = [
  "cfb",
 ]
 
+[[package]]
+name = "inout"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4250ce6452e92010fdf7268ccc5d14faa80bb12fc741938534c58f16804e03c7"
+dependencies = [
+ "hybrid-array",
+]
+
 [[package]]
 name = "ipnet"
 version = "2.12.1"
@@ -2807,6 +2915,16 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "poly1305"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e2d0073b297041425c7c3df6eb4792d598a15323fe63346852b092eca02904c"
+dependencies = [
+ "cpufeatures 0.3.1",
+ "universal-hash",
+]
+
 [[package]]
 name = "portable-atomic"
 version = "1.15.0"
@@ -2944,6 +3062,12 @@ version = "6.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
 [[package]]
 name = "raw-window-handle"
 version = "0.6.2"
@@ -3398,7 +3522,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
 dependencies = [
  "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.17",
  "digest",
 ]
 
@@ -4396,6 +4520,16 @@ version = "1.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"
 
+[[package]]
+name = "universal-hash"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4987bdc12753382e0bec4a65c50738ffaabc998b9cdd1f952fb5f39b0048a96"
+dependencies = [
+ "crypto-common 0.2.2",
+ "ctutils",
+]
+
 [[package]]
 name = "url"
 version = "2.5.8"

src-tauri/Cargo.toml

@@ -25,4 +25,5 @@ serde_json = "1"
 cpal = "0.18.2"
 ringbuf = "0.5.1"
 rubato = "5.0.0"
+chacha20poly1305 = "0.11.0"
 

src-tauri/src/commands/audio.rs

@@ -9,6 +9,7 @@ use std::{
     time::{Duration, Instant},
 };
 
+use chacha20poly1305::{aead::KeyInit, ChaCha20Poly1305, Key};
 use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use ringbuf::{
     storage::Heap,
@@ -17,11 +18,10 @@ use ringbuf::{
 };
 use tauri::State;
 
-use crate::commands::config::ConfigState;
+use crate::{commands::config::ConfigState, crypto::SessionCipher};
 
 const TARGET_SAMPLE_RATE: u32 = 48_000;
-const PACKET_SAMPLES: usize = 960; // 20ms @ 48kHz mono
+const PACKET_SAMPLES: usize = 960;
-const HEADER_SIZE: usize = 4;
 const MAX_PACKET_SIZE: usize = 4096;
 
 const INITIAL_PACKET_CUSHION: usize = 3;
@@ -345,11 +345,15 @@ pub fn disconnect_from_vc(voice_state: State<'_, VoiceState>) -> Result<(), Stri
 pub fn connect_to_vc(
     hostname: String,
     pin: u64,
+    shared_secret: Vec<u8>, // output of js `x25519.getSharedSecret`
     config_state: State<'_, ConfigState>,
     voice_state: State<'_, VoiceState>,
 ) -> Result<(), String> {
     disconnect_from_vc(voice_state.clone())?;
 
+    let key = Key::try_from(shared_secret.as_slice()).map_err(|v| v.to_string())?;
+    let cipher = Arc::new(Mutex::new(SessionCipher::new(ChaCha20Poly1305::new(&key))));
+
     let config = config_state.0.lock().unwrap().clone();
     let state_inner = Arc::clone(&voice_state.inner);
 
@@ -444,10 +448,10 @@ pub fn connect_to_vc(
     {
         let input_socket = socket.clone();
         let shutdown = shutdown.clone();
+        let cipher = cipher.clone();
 
         thread::spawn(move || {
             let mut sequence = 0u32;
-            let mut net_packet = vec![0u8; HEADER_SIZE + PACKET_SAMPLES * 2];
             let mut frame_buf = vec![0.0f32; PACKET_SAMPLES];
             let mut hangover_counter = 0;
 
@@ -469,13 +473,21 @@ pub fn connect_to_vc(
                     };
 
                     if is_speaking {
-                        net_packet[0..4].copy_from_slice(&sequence.to_be_bytes());
+                        // sequence goes INSIDE the plaintext now, prefixed before the PCM
-                        for (i, sample) in frame_buf.iter().enumerate() {
+                        let mut plaintext = Vec::with_capacity(4 + PACKET_SAMPLES * 2);
+                        plaintext.extend_from_slice(&sequence.to_be_bytes());
+
+                        for sample in frame_buf.iter() {
                             let pcm = (sample.clamp(-1.0, 1.0) * 32767.0) as i16;
-                            let offset = HEADER_SIZE + i * 2;
+                            plaintext.extend_from_slice(&pcm.to_be_bytes());
-                            net_packet[offset..offset + 2].copy_from_slice(&pcm.to_be_bytes());
                         }
 
+                        let Ok(net_packet) = cipher.lock().unwrap().encrypt(&plaintext) else {
+                            eprintln!("[vc] failed to encrypt outgoing packet");
+                            sequence = sequence.wrapping_add(1);
+                            continue;
+                        };
+
                         let _ = input_socket.send(&net_packet);
                         sequence = sequence.wrapping_add(1);
                     }
@@ -490,6 +502,7 @@ pub fn connect_to_vc(
     {
         let socket = socket.clone();
         let shutdown = shutdown.clone();
+        let cipher = cipher.clone();
 
         thread::spawn(move || {
             let mut packets: BTreeMap<u32, Vec<f32>> = BTreeMap::new();
@@ -501,15 +514,25 @@ pub fn connect_to_vc(
 
             while !shutdown.load(Ordering::Relaxed) {
                 if let Ok(len) = socket.recv(&mut udp_buffer) {
-                    if len > HEADER_SIZE {
+                    match cipher.lock().unwrap().decrypt(&udp_buffer[..len]) {
-                        let seq = u32::from_be_bytes(udp_buffer[0..4].try_into().unwrap());
+                        Ok(plaintext) => {
-                        let pcm = &udp_buffer[HEADER_SIZE..len];
+                            if plaintext.len() < 4 {
-                        let samples: Vec<f32> = pcm
+                                eprintln!("[vc] dropped packet: too short after decrypt");
-                            .chunks_exact(2)
+                            } else {
-                            .map(|c| i16::from_be_bytes([c[0], c[1]]) as f32 / 32768.0)
+                                let seq = u32::from_be_bytes(plaintext[..4].try_into().unwrap());
-                            .collect();
+                                let pcm = &plaintext[4..];
 
-                        packets.insert(seq, samples);
+                                let samples: Vec<f32> = pcm
+                                    .chunks_exact(2)
+                                    .map(|c| i16::from_be_bytes([c[0], c[1]]) as f32 / 32768.0)
+                                    .collect();
+
+                                packets.insert(seq, samples);
+                            }
+                        }
+                        Err(_) => {
+                            eprintln!("[vc] dropped packet: decryption failed");
+                        }
                     }
                 }
 

src-tauri/src/crypto.rs

@@ -0,0 +1,62 @@
+use chacha20poly1305::{aead::Aead, ChaCha20Poly1305, Nonce};
+
+pub struct SessionCipher {
+    cipher: ChaCha20Poly1305,
+    send_counter: u64,
+    recv_counter: u64,
+}
+
+impl SessionCipher {
+    pub fn new(cipher: ChaCha20Poly1305) -> Self {
+        Self {
+            cipher,
+            send_counter: 0,
+            recv_counter: 0,
+        }
+    }
+
+    pub fn next_send_nonce(&mut self) -> [u8; 12] {
+        let mut nonce = [0u8; 12];
+        nonce[..8].copy_from_slice(&self.send_counter.to_be_bytes());
+        // top bit distinguishes "send" direction from "recv" direction,
+        // so client-send and server-send counters never collide even if
+        // both happened to reach the same numeric value
+        nonce[11] |= 0b1000_0000;
+        self.send_counter += 1;
+        nonce
+    }
+
+    pub fn next_recv_nonce(&mut self) -> [u8; 12] {
+        let mut nonce = [0u8; 12];
+        nonce[..8].copy_from_slice(&self.recv_counter.to_be_bytes());
+        self.recv_counter += 1;
+        nonce
+    }
+
+    pub fn encrypt(&mut self, plaintext: &[u8]) -> Result<Vec<u8>, String> {
+        let nonce_bytes = self.next_send_nonce();
+        let nonce = Nonce::try_from(nonce_bytes).map_err(|v| v.to_string())?;
+
+        let ciphertext = self
+            .cipher
+            .encrypt(&nonce, plaintext)
+            .map_err(|v| v.to_string())?;
+
+        // prepend the nonce so the other side can reconstruct it on decrypt
+        let mut out = nonce_bytes.to_vec();
+        out.extend(ciphertext);
+        Ok(out)
+    }
+
+    pub fn decrypt(&mut self, data: &[u8]) -> Result<Vec<u8>, String> {
+        if data.len() < 12 {
+            return Err("message too short to contain a nonce".to_string());
+        }
+        let (nonce_bytes, ciphertext) = data.split_at(12);
+        let nonce = Nonce::try_from(nonce_bytes).map_err(|v| v.to_string())?;
+
+        self.cipher
+            .decrypt(&nonce, ciphertext)
+            .map_err(|v| v.to_string())
+    }
+}

src-tauri/src/lib.rs

@@ -3,6 +3,7 @@ use std::sync::Mutex;
 use crate::commands::config::ConfigState;
 
 pub mod commands;
+pub mod crypto;
 pub mod types;
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]

src/app/app.ts

@@ -171,7 +171,11 @@ export default class Enclave<P = Page> {
     if (!server || channel.kind !== "voice") return;
 
     server.voiceJoin = (pin, channelId) => {
-      invoke("connect_to_vc", { hostname: server.hostname, pin, channelId })
+      invoke("connect_to_vc", {
+        hostname: server.hostname,
+        pin,
+        sharedSecret: server.websocket?.sharedSecret,
+      })
         .then(() => {
           server.isInVoiceChat = true;
           server.voiceChannelId = channelId;

src/app/ws.ts

@@ -18,7 +18,7 @@ export default class EnclaveWebSocket {
 
   private sendCounter = 0n;
   private recvCounter = 0n;
-  private sharedSecret: Uint8Array | null = null;
+  public sharedSecret: Uint8Array | null = null;
 
   private readonly handshakeReady: Promise<void>;
   private resolveHandshake!: () => void;