WIP

crates/sp_client/src/api.rs

@@ -12,7 +12,6 @@ use sdk_common::crypto::AnkSharedSecret;
 use serde_json::Error as SerdeJsonError;
 use shamir::SecretData;
 use sp_client::bitcoin::consensus::{deserialize, serialize};
-use sp_client::silentpayments::bitcoin_hashes::{HashEngine, sha256, Hash};
 use sp_client::bitcoin::hex::{parse, DisplayHex, FromHex, HexToBytesError};
 use sp_client::bitcoin::secp256k1::ecdh::SharedSecret;
 use sp_client::bitcoin::secp256k1::{PublicKey, SecretKey};
@@ -31,7 +30,9 @@ use sp_client::spclient::{derive_keys_from_seed, OutputList, OwnedOutput, SpClie
 use sp_client::spclient::{SpWallet, SpendKey};
 
 use crate::images;
-use crate::silentpayments::{check_transaction, create_transaction_for_address};
+use crate::silentpayments::{
+    check_transaction, create_transaction_for_address_with_shared_secret, ScannedTransaction,
+};
 use crate::user::{lock_connected_users, User, UserWallets, CONNECTED_USERS};
 
 use crate::process::Process;
@@ -392,7 +393,7 @@ pub fn is_tx_owned_by_user(pre_id: String, tx: String) -> ApiResult<bool> {
 #[allow(non_camel_case_types)]
 pub struct createNotificationTransactionReturn {
     pub transaction: String,
-    pub spaddress2secret: HashMap<String, String>,
+    pub transaction2secret: ScannedTransaction,
 }
 
 #[wasm_bindgen]
@@ -402,22 +403,17 @@ pub fn create_notification_transaction(
 ) -> ApiResult<createNotificationTransactionReturn> {
     let sp_address: SilentPaymentAddress = recipient.try_into()?;
 
-    let (transaction, shared_point) =
+    let (transaction, shared_secret) =
         create_transaction_for_address_with_shared_secret(sp_address, message)?;
 
-    // The shared_point *must* be hashed to produce a proper ecdh secret
-    // For now we propose to implement a tagged hash for it
-    // It could be interesting to add some piece of data to allow for the derivation of multiple secrets 
-    let mut eng = sha256::HashEngine::default();
-    eng.write_all(&shared_point);
-    let shared_secret = sha256::Hash::from_engine(eng);
 
-    let mut spaddress2secret: HashMap<String, String> = HashMap::new();
+    // update our cache
 
-    spaddress2secret.insert(sp_address.into(), shared_secret.as_byte_array().to_lower_hex_string());
+    let mut transaction2secret = ScannedTransaction::new();
+    transaction2secret.get_mut().insert(transaction.txid(), vec![shared_secret]);
 
     Ok(createNotificationTransactionReturn {
         transaction: serialize(&transaction).to_lower_hex_string(),
-        spaddress2secret,
+        transaction2secret,
     })
 }

crates/sp_client/src/silentpayments.rs

@@ -1,14 +1,23 @@
-use std::collections::HashMap;
+// This file should move to common
+
+use std::collections::{HashMap, HashSet};
+use std::io::Write;
+use std::iter::Once;
+use std::sync::{Mutex, MutexGuard, OnceLock};
 
 use anyhow::{Error, Result};
 
+use log::debug;
 use rand::Rng;
+use sdk_common::crypto::{Aes256Encryption, Aes256Gcm, AeadCore, Purpose};
+use serde::{Deserialize, Serialize};
 use sp_client::bitcoin::policy::DUST_RELAY_TX_FEE;
 use sp_client::bitcoin::secp256k1::ecdh::shared_secret_point;
-use sp_client::bitcoin::{block, Amount, OutPoint};
+use sp_client::bitcoin::{block, Amount, OutPoint, Txid};
 use sp_client::silentpayments::sending::SilentPaymentAddress;
 use sp_client::silentpayments::utils::receiving::calculate_shared_secret;
 use sp_client::spclient::{OutputList, OwnedOutput, Recipient, SpClient, SpWallet};
+use sp_client::silentpayments::bitcoin_hashes::{sha256, Hash, HashEngine};
 use sp_client::{
     bitcoin::{
         secp256k1::{PublicKey, Scalar, XOnlyPublicKey},
@@ -16,17 +25,75 @@ use sp_client::{
     },
     silentpayments::receiving::Label,
 };
+use tsify::Tsify;
 
 use crate::user::{lock_connected_users, CONNECTED_USERS};
+use crate::MutexExt;
+
+#[derive(Debug, Serialize, Deserialize, Tsify)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+pub struct ScannedTransaction(HashMap<Txid, Vec<SharedSecret>>);
+
+impl ScannedTransaction {
+    pub fn new() -> Self {
+        Self(HashMap::new())
+    }
+
+    pub fn get_mut(&mut self) -> &mut HashMap<Txid, Vec<SharedSecret>> {
+        &mut self.0
+    }
+}
+
+pub static TRANSACTIONCACHE: OnceLock<Mutex<ScannedTransaction>> = OnceLock::new();
+
+pub fn lock_scanned_transactions() -> Result<MutexGuard<'static, ScannedTransaction>> {
+    TRANSACTIONCACHE
+        .get_or_init(|| Mutex::new(ScannedTransaction::new()))
+        .lock_anyhow()
+}
 
 type FoundOutputs = HashMap<Option<Label>, HashMap<XOnlyPublicKey, Scalar>>;
 
-type SharedPoint = [u8;64];
+#[derive(Debug)]
+pub struct SharedPoint([u8; 64]);
+
+impl SharedPoint {
+    pub fn as_inner(&self) -> &[u8; 64] {
+        &self.0
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize, Tsify)]
+#[tsify(from_wasm_abi, into_wasm_abi)]
+pub struct SharedSecret {
+    secret: [u8; 32],
+    shared_with: Option<String>, // SilentPaymentAddress
+}
+
+impl SharedSecret {
+    pub fn new(secret: [u8;32], shared_with: Option<String>) -> Result<Self> {
+        if let Some(ref shared) = shared_with {
+            if let Ok(_) = SilentPaymentAddress::try_from(shared.as_str()) {
+                Ok(Self {
+                    secret,
+                    shared_with
+                })
+            } else {
+                Err(Error::msg("Invalid silent payment address"))
+            }
+        } else {
+            Ok(Self {
+                secret, 
+                shared_with: None
+            })
+        }
+    }
+}
 
 pub fn create_transaction_for_address_with_shared_secret(
     sp_address: SilentPaymentAddress,
     message: String,
-) -> Result<(Transaction, SharedPoint)> {
+) -> Result<(Transaction, SharedSecret)> {
     let connected_users = lock_connected_users()?;
 
     let (_, wallets) = connected_users
@@ -34,6 +101,8 @@ pub fn create_transaction_for_address_with_shared_secret(
         .last()
         .ok_or(Error::msg("Unknown sender"))?;
 
+    debug!("Got user wallets");
+
     let sp_wallet = if sp_address.is_testnet() {
         &wallets.recover
     } else {
@@ -77,11 +146,38 @@ pub fn create_transaction_for_address_with_shared_secret(
 
     let mut new_psbt = sp_wallet
         .get_client()
-        .create_new_psbt(inputs, vec![recipient], None)?;
+        .create_new_psbt(inputs, vec![recipient], Some(message.as_bytes()))?;
     log::debug!("Created psbt: {}", new_psbt);
     SpClient::set_fees(&mut new_psbt, Amount::from_sat(1000), sp_address.into())?;
-    let partial_secret = sp_wallet.get_client().get_partial_secret_from_psbt(&new_psbt)?;
-    sp_wallet.get_client().fill_sp_outputs(&mut new_psbt, partial_secret)?;
+
+    let partial_secret = sp_wallet
+        .get_client()
+        .get_partial_secret_from_psbt(&new_psbt)?;
+
+    // This wouldn't work with many recipients in the same transaction
+    // each address (or more precisely each scan public key) would have its own point
+    let shared_point = shared_secret_point(&sp_address.get_scan_key(), &partial_secret);
+
+    // The shared_point *must* be hashed to produce a proper ecdh secret
+    let mut eng = sha256::HashEngine::default();
+    eng.write_all(&shared_point);
+    let shared_secret = sha256::Hash::from_engine(eng);
+
+    // encrypt the message with the new shared_secret
+    let message_encryption = Aes256Encryption::import_key(
+        Purpose::Arbitrary,
+        message.into_bytes(),
+        shared_secret.to_byte_array(),
+        Aes256Gcm::generate_nonce(&mut rand::thread_rng()).into(),
+    )?;
+
+    let cipher = message_encryption.encrypt_with_aes_key()?;
+
+    sp_client::spclient::SpClient::replace_op_return_with(&mut new_psbt, &cipher)?;
+
+    sp_wallet
+        .get_client()
+        .fill_sp_outputs(&mut new_psbt, partial_secret)?;
     log::debug!("Definitive psbt: {}", new_psbt);
     let mut aux_rand = [0u8; 32];
     rand::thread_rng().fill(&mut aux_rand);
@@ -91,17 +187,24 @@ pub fn create_transaction_for_address_with_shared_secret(
 
     let final_tx = signed.extract_tx()?;
 
-    // This should not be directly used without hashing
-    let shared_point = shared_secret_point(&sp_address.get_scan_key(), &partial_secret); 
-
-    Ok((final_tx, shared_point))
+    Ok((final_tx, SharedSecret {
+        secret: shared_secret.to_byte_array(),
+        shared_with: Some(sp_address.into())
+    }))
 }
 
+// This need to go
 pub fn check_transaction(
     tx: &Transaction,
     blockheight: u32,
     tweak_data: PublicKey,
 ) -> Result<String> {
+    // first check that we haven't scanned this transaction yet
+    if let Some((txid, _)) = lock_scanned_transactions()?.0.get_key_value(&tx.txid()) {
+        let err_msg = format!("Already scanned tx {}", txid);
+        return Err(Error::msg(err_msg));
+    }
+
     let connected_users = lock_connected_users()?;
 
     let txid = tx.txid().to_string();

src/services.ts

@@ -1,4 +1,4 @@
-import { createUserReturn, User, Process, createNotificationTransactionReturn, parse_network_msg, outputs_list, parseNetworkMsgReturn, FaucetMessage, AnkFlag } from '../dist/pkg/sdk_client';
+import { createUserReturn, User, Process, createNotificationTransactionReturn, parse_network_msg, outputs_list, parseNetworkMsgReturn, FaucetMessage, AnkFlag, NewTxMessage } from '../dist/pkg/sdk_client';
 import IndexedDB from './database'
 import { WebSocketClient } from './websockets';
 
@@ -86,7 +86,10 @@ class Services {
         const message = messageElement.value;
         const services = await Services.getInstance();
 
-        let notificationInfo = services.notify_address_for_message(recipientSpAddress, message);
+        let notificationInfo = await services.notify_address_for_message(recipientSpAddress, message);
+        if (notificationInfo) {
+            notificationInfo.transaction
+        }
         console.log(notificationInfo);
     }
 
@@ -751,6 +754,10 @@ class Services {
 
     public async notify_address_for_message(sp_address: string, message: string): Promise<createNotificationTransactionReturn | null> {
         const services = await Services.getInstance();
+        const connection = await services.pickWebsocketConnectionRandom();
+        if (!connection) {
+            return null;
+        }
         let user: User;
         try {
             let possibleUser = await services.getUserInfo();
@@ -766,9 +773,15 @@ class Services {
 
         try {
             let notificationInfo: createNotificationTransactionReturn = services.sdkClient.create_notification_transaction(user, sp_address, message);
+            const flag: AnkFlag = "NewTx";
+            const newTxMsg: NewTxMessage = {
+                'transaction': notificationInfo.transaction,
+                'tweak_data': null
+            }
+            connection.sendMessage(flag, JSON.stringify(newTxMsg));
             return notificationInfo;
-        } catch {
-            console.error("Failed to create notification transaction for user", user);
+        } catch (error) {
+            console.error("Failed to create notification transaction:", error);
             return null
         }
     }