[experimental] identify transaction we sent according to commitment value

crates/sp_client/src/api.rs

@@ -508,9 +508,33 @@ fn handle_recover_transaction(
     } else {
         // We are sender of a transaction
         // We only need to return the message
+        // eiter this is notification, a challenge, or response to a challenge
+        // if notification, commitment is the same than in the message
+        // if challenge or response, commitment is H(commitment | b_scan), b_scan being different depending on who we are
         if let Some(message) = messages
             .iter()
-            .find(|m| m.commitment.as_ref() == Some(&commitment_str))
+            .find(|m| {
+                if commitment.is_empty() || m.commitment.is_none() { return false }
+                match m.status {
+                    CachedMessageStatus::SentWaitingConfirmation => {
+                        // commitment we're looking for is simply what's in the message
+                        m.commitment.as_ref().map(|c| Vec::from_hex(&c).unwrap()).unwrap() == commitment
+                    },
+                    CachedMessageStatus::MustSpendConfirmation | CachedMessageStatus::ReceivedMustConfirm => {
+                        // we compute the potential commitment
+                        let m_commitment = m.commitment.as_ref().map(|c| Vec::from_hex(&c).unwrap()).unwrap();
+                        let mut buf = [0u8;64];
+                        buf[..32].copy_from_slice(&m_commitment);
+                        buf[32..].copy_from_slice(&sp_wallet.get_client().get_scan_key().secret_bytes());
+                    
+                        let mut engine = sha256::HashEngine::default();
+                        engine.write_all(&buf).unwrap();
+                        let hash = sha256::Hash::from_engine(engine);
+                        hash.to_byte_array().to_vec() == commitment
+                    },
+                    _ => return false
+                }
+            }) 
         {
             return Ok(message.clone());
         } else {