Return transaction to confirm identity

crates/sp_client/src/api.rs

@@ -5,15 +5,16 @@ use std::str::FromStr;
 use std::string::FromUtf8Error;
 use std::sync::{Mutex, OnceLock, PoisonError};
 
-use log::debug;
+use log::{debug, warn};
 use rand::{Fill, Rng};
 
 use anyhow::Error as AnyhowError;
 use sdk_common::crypto::{
     AeadCore, Aes256Decryption, Aes256Encryption, Aes256Gcm, AnkSharedSecret, KeyInit, Purpose,
 };
-use serde_json::Error as SerdeJsonError;
+use serde_json::{Error as SerdeJsonError, Value};
 use shamir::SecretData;
+use sp_client::bitcoin::blockdata::fee_rate;
 use sp_client::bitcoin::consensus::{deserialize, serialize};
 use sp_client::bitcoin::hex::{parse, DisplayHex, FromHex, HexToBytesError};
 use sp_client::bitcoin::secp256k1::ecdh::shared_secret_point;
@@ -27,16 +28,16 @@ use tsify::Tsify;
 use wasm_bindgen::convert::FromWasmAbi;
 use wasm_bindgen::prelude::*;
 
-use sdk_common::network::{AnkFlag, AnkNetworkMsg, NewTxMessage};
+use sdk_common::network::{AnkFlag, AnkNetworkMsg, NewTxMessage, UnknownMessage};
 use sdk_common::silentpayments::{
-    check_transaction, create_transaction_for_address_with_shared_secret,
+    check_transaction, create_transaction, create_transaction_for_address_with_shared_secret,
 };
 
 use sp_client::spclient::{derive_keys_from_seed, OutputList, OwnedOutput, SpClient};
 use sp_client::spclient::{SpWallet, SpendKey};
 
 use crate::user::{lock_connected_user, User, UserWallets, CONNECTED_USER};
-use crate::{images, lock_scanned_transactions, Txid2Secrets};
+use crate::{images, lock_scanned_transactions, lock_secrets, lock_watched, Txid2Secrets};
 
 use crate::process::Process;
 
@@ -330,16 +331,80 @@ pub fn login_user(
     Ok(res)
 }
 
+pub fn scan_for_confirmation_transaction(tx_hex: String) -> anyhow::Result<String> {
+    let tx = deserialize::<Transaction>(&Vec::from_hex(&tx_hex)?)?;
+
+    for i in tx.input.iter() {
+        if let Some(waiting) = lock_watched()?.remove(&i.previous_output) {
+            match lock_secrets()?.get_mut(&waiting) {
+                None => return Err(anyhow::Error::msg("No secret match for an error we're waiting for")),
+                Some(secret) => {
+                    // for now we only handle the case of one secret for one transaction
+                    let res = secret.get_mut(0).unwrap();
+                    res.1.trusted = true;
+                    return Ok(res.0.clone());
+                }
+            }
+        }
+    }
+
+    Err(anyhow::Error::msg("Not spending a watched output"))
+}
+
+fn handle_recover_transaction(tx: Transaction, sp_wallet: &mut SpWallet, tweak_data: PublicKey, fee_rate: u32) -> anyhow::Result<Option<Transaction>> {
+    // does this transaction spent a txid and output we're waiting confirmation for?
+    let scan_sk = sp_wallet.get_client().get_scan_key();
+    let txid = tx.txid();
+    for input in tx.input {
+        let prevout = input.previous_output;
+        match lock_secrets()?.get_mut(&prevout.txid) {
+            None => {
+                continue;
+            }
+            Some(secret) => {
+                // We found an input spending a notification transaction we sent
+                if let Some(res) = secret.get_mut(prevout.vout as usize) {
+                    // This is a challenge from a previous message we sent
+                    // we toggle the trusted value
+                    if !res.1.trusted {
+                        res.1.trusted = true;
+                    } else {
+                        return Err(anyhow::Error::msg("Received a confirmation for a transaction we already confirmed"));
+                    }
+                    // We spend the output back to the receiver
+                    let sp_address = SilentPaymentAddress::try_from(res.0.as_str()).expect("Invalid silent payment address");
+                    let response_tx = create_transaction(sp_address, sp_wallet, Amount::from_sat(fee_rate.into()))?;
+                    return Ok(Some(response_tx));
+                } else {
+                    return Err(anyhow::Error::msg("Received a confirmation from an umapped output"));
+                }
+            }
+        }
+    }
+    // If we exhausted all inputs without finding one of our transaction, it means it's a notification
+    let shared_point =
+        shared_secret_point(&tweak_data, &scan_sk);
+    lock_secrets()?.insert(
+        txid,
+        vec![("".to_owned(), AnkSharedSecret::new(shared_point, false))],
+    );
+    Ok(None)
+}
+
 #[wasm_bindgen]
 pub fn check_transaction_for_silent_payments(
     tx_hex: String,
     blockheight: u32,
     tweak_data_hex: String,
+    fee_rate: u32,
 ) -> ApiResult<String> {
     let tx = deserialize::<Transaction>(&Vec::from_hex(&tx_hex)?)?;
-    // check that we don't already have scanned the tx
-    if lock_scanned_transactions()?.contains_key(&tx.txid()) {
-        return Err(ApiError { message: "Transaction already scanned".to_owned()});
+
+    // check that we don't already have scanned the tx, and insert it if we don't
+    if !lock_scanned_transactions()?.insert(tx.txid()) {
+        return Err(ApiError {
+            message: "Transaction already scanned".to_owned(),
+        });
     }
 
     let tweak_data = PublicKey::from_str(&tweak_data_hex)?;
@@ -347,30 +412,28 @@ pub fn check_transaction_for_silent_payments(
     let mut connected_user = lock_connected_user()?;
     if let Ok(recover) = connected_user.try_get_mut_recover() {
         if let Ok(txid) = check_transaction(&tx, recover, blockheight, tweak_data) {
-            let shared_point = shared_secret_point(&tweak_data, &recover.get_client().get_scan_key());
-            lock_scanned_transactions()?.insert(tx.txid(), vec![("".to_owned(), AnkSharedSecret::new(shared_point, false))]);
+            if let Err(e) = scan_for_confirmation_transaction(tx_hex) {
+                log::error!("{}", e);
+                handle_recover_transaction(tx, recover, tweak_data, fee_rate)?;
+            }
             return Ok(txid);
         }
     }
 
     if let Ok(main) = connected_user.try_get_mut_main() {
         if let Ok(txid) = check_transaction(&tx, main, blockheight, tweak_data) {
-            let shared_point = shared_secret_point(&tweak_data, &main.get_client().get_scan_key());
-            lock_scanned_transactions()?.insert(tx.txid(), vec![("".to_owned(), AnkSharedSecret::new(shared_point, false))]);
+            // TODO
             return Ok(txid);
         }
     }
 
     if let Ok(revoke) = connected_user.try_get_mut_revoke() {
         if let Ok(txid) = check_transaction(&tx, revoke, blockheight, tweak_data) {
-            let shared_point = shared_secret_point(&tweak_data, &revoke.get_client().get_scan_key());
-            lock_scanned_transactions()?.insert(tx.txid(), vec![("".to_owned(), AnkSharedSecret::new(shared_point, false))]);
+            // TODO
             return Ok(txid);
         }
     }
 
-    // we still want to insert an empty entry in our cache to make sure we don't scan the transaction again
-    lock_scanned_transactions()?.insert(tx.txid(), vec![("".to_owned(), AnkSharedSecret::default())]);
     Err(ApiError {
         message: "No output found".to_owned(),
     })
@@ -385,7 +448,7 @@ pub struct parseNetworkMsgReturn {
 }
 
 #[wasm_bindgen]
-pub fn parse_network_msg(raw: String) -> ApiResult<parseNetworkMsgReturn> {
+pub fn parse_network_msg(raw: String, fee_rate: u32) -> ApiResult<parseNetworkMsgReturn> {
     if let Ok(ank_msg) = serde_json::from_str::<AnkNetworkMsg>(&raw) {
         match ank_msg.flag {
             AnkFlag::NewTx => {
@@ -399,6 +462,7 @@ pub fn parse_network_msg(raw: String) -> ApiResult<parseNetworkMsgReturn> {
                     tx_message.transaction,
                     0,
                     tx_message.tweak_data.unwrap(),
+                    fee_rate,
                 )?;
                 return Ok(parseNetworkMsgReturn {
                     topic: AnkFlag::NewTx.as_str().to_owned(),
@@ -414,44 +478,60 @@ pub fn parse_network_msg(raw: String) -> ApiResult<parseNetworkMsgReturn> {
             }
             AnkFlag::Unknown => {
                 // try to decrypt the cipher with all available keys
-                let mut plaintext: String = "".to_owned();
-                for (txid, secret_vec) in lock_scanned_transactions()?.iter() {
-                    for (shared_with, ank_secret) in secret_vec.iter() {
-                        if *ank_secret == AnkSharedSecret::default() {
-                            continue;
-                        }
+                for (txid, secret_vec) in lock_secrets()?.iter_mut() {
+                    // Actually we probably will ever have only one secret in the case we're receiver
+                    for (shared_with, ank_secret) in secret_vec.iter_mut() {
+                        // if we already have shared_with, that means we already used that key for another message
+                        if !shared_with.is_empty() { continue }
                         let shared_secret = ank_secret.to_byte_array();
-                        if let Ok(msg_decrypt) = Aes256Decryption::new(
+                        debug!("{} {}", shared_with, shared_secret.to_lower_hex_string());
+                        let msg_decrypt = Aes256Decryption::new(
                             Purpose::Arbitrary,
                             Vec::from_hex(&ank_msg.content.trim_matches('\"'))?,
                             shared_secret,
-                        ) {
+                        )?;
                         match msg_decrypt.decrypt_with_key() {
-                                Ok(plain) => {
-                                    plaintext = String::from_utf8(plain)?;
-                                    break;
-                                },
+                            Ok(plaintext) => {
+                                let unknown_msg = serde_json::from_slice::<UnknownMessage>(&plaintext);
+                                if unknown_msg.is_err() {
+                                    // The message we were sent is invalid, drop everything
+                                    // for now let's just fill the shared_with with garbage
+                                    *shared_with = "a".to_owned();
+                                    return Err(ApiError { message: "Invalid msg".to_owned() })
+                                }
+                                let sender: Result<SilentPaymentAddress, SpError> = unknown_msg.unwrap().sender.try_into();
+                                if sender.is_err() {
+                                    // The sender is invalid address
+                                    *shared_with = "a".to_owned();
+                                    return Err(ApiError { message: "Invalid sp address".to_owned() })
+                                }
+
+                                // we update our list with the sender address
+                                *shared_with = sender.unwrap().into();
+
+                                // We return the whole message
+                                // ts is responsible for sending the confirmation message
+                                return Ok(parseNetworkMsgReturn {
+                                    topic: AnkFlag::Unknown.as_str().to_owned(),
+                                    message: String::from_utf8(plaintext)?,
+                                });
+                            }
                             Err(e) => {
                                 debug!("{}", e);
-                                    debug!("Failed to decrypt message {} with key {}", ank_msg.content, shared_secret.to_lower_hex_string());
+                                debug!(
+                                    "Failed to decrypt message {} with key {}",
+                                    ank_msg.content,
+                                    shared_secret.to_lower_hex_string()
+                                );
                             }
                         }
                     }
                 }
-                }
-                if plaintext.is_empty() {
-                    // keep the message in cache, just in case
+                // keep the message in cache, just in case?
                 // return an error
                 return Err(ApiError {
                     message: "No key found".to_owned(),
                 });
-                } else {
-                    // return the plain text
-                    return Ok(parseNetworkMsgReturn {
-                        topic: AnkFlag::Unknown.as_str().to_owned(),
-                        message: plaintext,
-                    });
-                }
             }
             _ => unimplemented!(),
         }
@@ -523,7 +603,7 @@ pub struct createNotificationTransactionReturn {
 #[wasm_bindgen]
 pub fn create_notification_transaction(
     recipient: String,
-    message: String,
+    message: Option<String>,
     fee_rate: u32,
 ) -> ApiResult<createNotificationTransactionReturn> {
     let sp_address: SilentPaymentAddress = recipient.try_into()?;
@@ -544,13 +624,16 @@ pub fn create_notification_transaction(
         Amount::from_sat(fee_rate.into()),
     )?;
 
-    debug!("Created transaction with secret {}", shared_secret.to_byte_array().to_lower_hex_string());
+    debug!(
+        "Created transaction with secret {}",
+        shared_secret.to_byte_array().to_lower_hex_string()
+    );
 
     let mut address2secret: Vec<(String, AnkSharedSecret)> = vec![];
     address2secret.push((sp_address.into(), shared_secret));
 
     // update our cache
-    lock_scanned_transactions()?.insert(transaction.txid(), address2secret.clone());
+    lock_secrets()?.insert(transaction.txid(), address2secret.clone());
 
     Ok(createNotificationTransactionReturn {
         txid: transaction.txid().to_string(),

crates/sp_client/src/lib.rs

@@ -2,9 +2,9 @@
 use anyhow::Error;
 use sdk_common::crypto::AnkSharedSecret;
 use serde::{Deserialize, Serialize};
-use sp_client::bitcoin::Txid;
+use sp_client::bitcoin::{OutPoint, Txid};
 use sp_client::silentpayments::sending::SilentPaymentAddress;
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::fmt::Debug;
 use std::sync::{Mutex, MutexGuard, OnceLock};
 use tsify::Tsify;
@@ -16,16 +16,40 @@ mod peers;
 mod process;
 mod user;
 
+/// We map txid with one or n secrets
+/// Each secret match one sp address
+/// When we first detect a transaction, we can't tell who's the sender, so we like sp address empty
+/// When we receive the corresponding message, we get a sp address declaration, we complete here
+/// Then when we send the confirmation transaction and got the response we can flip the secret to trusted
 pub type Txid2Secrets = HashMap<Txid, Vec<(String, AnkSharedSecret)>>;
 
-pub static TRANSACTIONCACHE: OnceLock<Mutex<Txid2Secrets>> = OnceLock::new();
+pub static SECRETCACHE: OnceLock<Mutex<Txid2Secrets>> = OnceLock::new();
 
-pub fn lock_scanned_transactions() -> Result<MutexGuard<'static, Txid2Secrets>, Error> {
-    TRANSACTIONCACHE
+pub fn lock_secrets() -> Result<MutexGuard<'static, Txid2Secrets>, Error> {
+    SECRETCACHE
         .get_or_init(|| Mutex::new(Txid2Secrets::new()))
         .lock_anyhow()
 }
 
+/// this is to keep track of transaction we already analysed without finding notification
+/// This is not critical and there's no need to keep that in persistent storage, as most transactions would only show up twice
+/// Worst case is we will scan again transactions when they got into a block
+pub static TRANSACTIONCACHE: OnceLock<Mutex<HashSet<Txid>>> = OnceLock::new();
+
+pub fn lock_scanned_transactions() -> Result<MutexGuard<'static, HashSet<Txid>>, Error> {
+    TRANSACTIONCACHE
+        .get_or_init(|| Mutex::new(HashSet::new()))
+        .lock_anyhow()
+}
+
+pub static WATCHEDUTXO: OnceLock<Mutex<HashMap<OutPoint, Txid>>> = OnceLock::new();
+
+pub fn lock_watched() -> Result<MutexGuard<'static, HashMap<OutPoint, Txid>>, Error> {
+    WATCHEDUTXO
+        .get_or_init(|| Mutex::new(HashMap::new()))
+        .lock_anyhow()
+}
+
 pub(crate) trait MutexExt<T> {
     fn lock_anyhow(&self) -> Result<MutexGuard<T>, Error>;
 }

src/services.ts

@@ -105,7 +105,7 @@ class Services {
         const recipientSpAddress = spAddressElement.value;
         const message = messageElement.value;
 
-        const msg_payload = JSON.stringify({sender: this.sp_address, payload: message});
+        const msg_payload = JSON.stringify({sender: this.sp_address, message: message});
 
         let notificationInfo = await services.notify_address_for_message(recipientSpAddress, msg_payload);
         if (notificationInfo) {
@@ -313,14 +313,13 @@ class Services {
         services.attachSubmitListener("form4nk", services.updateAnId);
     }
 
-    public async parseNetworkMessage(raw: string): Promise<parseNetworkMsgReturn | null> {
+    public async parseNetworkMessage(raw: string, feeRate: number): Promise<parseNetworkMsgReturn> {
         const services = await Services.getInstance();
         try {
-            const msg: parseNetworkMsgReturn = services.sdkClient.parse_network_msg(raw);
+            const msg: parseNetworkMsgReturn = services.sdkClient.parse_network_msg(raw, feeRate);
             return msg;
         } catch (error) {
-            console.error(error);
-            return null;
+            throw error;
         }
     }
 
@@ -802,6 +801,40 @@ class Services {
         }
     }
 
+    public async confirm_sender_address(sp_address: string): Promise<void> {
+        const services = await Services.getInstance();
+        const connection = await services.pickWebsocketConnectionRandom();
+        if (!connection) {
+            throw new Error("No connection to relay");
+        }
+        let user: User;
+        try {
+            let possibleUser = await services.getUserInfo();
+            if (!possibleUser) {
+                throw new Error("No user loaded, please first create a new user or login");
+            } else {
+                user = possibleUser;
+            }
+        } catch (error) {
+            throw error;
+        }
+
+        let notificationInfo: createNotificationTransactionReturn;
+        try {
+            const feeRate = 1;
+            notificationInfo = services.sdkClient.create_notification_transaction(sp_address, undefined, feeRate);
+        } catch (error) {
+            throw new Error(`Failed to create confirmation transaction: ${error}`);
+        }
+        const flag: AnkFlag = "NewTx";
+        const newTxMsg: NewTxMessage = {
+            'transaction': notificationInfo.transaction,
+            'tweak_data': null
+        }
+        connection.sendMessage(flag, JSON.stringify(newTxMsg));
+        return;
+    }
+
     public async notify_address_for_message(sp_address: string, message: string): Promise<createNotificationTransactionReturn | null> {
         const services = await Services.getInstance();
         const connection = await services.pickWebsocketConnectionRandom();

src/websockets.ts

@@ -25,28 +25,27 @@ class WebSocketClient {
 
             (async () => {
                 if (typeof(msgData) === 'string') {
-                    console.log("Received text message: "+msgData);
-                    let res = await services.parseNetworkMessage(msgData);
-                    if (res) {
+                    // console.log("Received text message: "+msgData);
+                    try {
+                        const feeRate = 1;
+                        let res = await services.parseNetworkMessage(msgData, feeRate);
                         if (res.topic === 'new_tx') { 
                             // we received a tx 
                             window.alert(`New tx\n${res.message}`);
                             await services.updateOwnedOutputsForUser();
                         } else if (res.topic === 'unknown') {
-                            // Do we have a json with a sender?
-                            try {
                             let parsed = JSON.parse(res.message);
-                                if (parsed.sender !== undefined) {
-                                    console.info(`Message sent by ${parsed.sender}`);
-                                }
-                                window.alert(`new message: ${parsed.payload}`);
-                            } catch (_) {
-                                window.alert(`new message: ${res.message}`);
-                            }
+                            let message = parsed['message'];
+                            let sender = parsed['sender'];
+                            window.alert(`new message: ${message}\nAsking sender ${sender} to confirm identity...`);
+                            console.debug(`sending confirm message to ${sender}`);
+                            await services.confirm_sender_address(sender);
                         }
+                    } catch (error) {
+                        console.error('Received an invalid message:', error);
                     }
                 } else {
-                    console.error("Received an invalid message");
+                    console.error('Received a non-string message');
                 }
             })();
         });