connect: support both NIP04 and NIP44 for message decryption

This updates the NIP46 message handling to use either NIP04 or NIP44 decryption by checking for `?iv=` in the event content.

Closes #697

Co-authored-by: Yuki Kishimoto <yukikishimoto@protonmail.com>
Signed-off-by: Yuki Kishimoto <yukikishimoto@protonmail.com>

CHANGELOG.md

@@ -70,6 +70,7 @@
 * sdk: refactor POW difficulty management ([Yuki Kishimoto])
 * connect: require `fmt::Debug`, `Send` and `Sync` for `AuthUrlHandler` ([Yuki Kishimoto])
 * connect: improve secret matching for `NostrConnectRemoteSigner` ([Yuki Kishimoto])
+* connect: support both NIP04 and NIP44 for message decryption ([erskingardner])
 * zapper: bump `webln` to 0.4 ([Yuki Kishimoto])
 * zapper: require `fmt::Debug`, `Send` and `Sync` for `NostrZapper` ([Yuki Kishimoto])
 * bindings: refactor `SendEventOutput` and `SubscribeOutput` ([Yuki Kishimoto])

crates/nostr-connect/src/client.rs

@@ -17,6 +17,7 @@ use tokio::sync::broadcast::Receiver;
 use tokio::sync::OnceCell;
 
 use crate::error::Error;
+use crate::util;
 
 /// Nostr Connect Client
 ///
@@ -258,8 +259,8 @@ impl NostrConnect {
             while let Ok(notification) = notifications.recv().await {
                 if let RelayPoolNotification::Event { event, .. } = notification {
                     if event.kind == Kind::NostrConnect {
-                        let msg = nip04::decrypt(secret_key, &event.pubkey, &event.content)?;
-                        let msg = Message::from_json(msg)?;
+                        let msg: String = util::decrypt(secret_key, &event)?;
+                        let msg: Message = Message::from_json(msg)?;
 
                         tracing::debug!("Received NIP46 message: '{msg}'");
 
@@ -413,8 +414,7 @@ async fn get_remote_signer_public_key(
             if let RelayPoolNotification::Event { event, .. } = notification {
                 if event.kind == Kind::NostrConnect {
                     // Decrypt content
-                    let msg: String =
-                        nip04::decrypt(app_keys.secret_key(), &event.pubkey, event.content)?;
+                    let msg: String = util::decrypt(app_keys.secret_key(), &event)?;
 
                     tracing::debug!("Received Nostr Connect message: '{msg}'");
 

crates/nostr-connect/src/error.rs

@@ -7,7 +7,7 @@
 use std::convert::Infallible;
 
 use nostr::event::builder;
-use nostr::nips::{nip04, nip46};
+use nostr::nips::{nip04, nip44, nip46};
 use nostr::PublicKey;
 use thiserror::Error;
 use tokio::sync::SetError;
@@ -21,6 +21,9 @@ pub enum Error {
     /// NIP04 error
     #[error(transparent)]
     NIP04(#[from] nip04::Error),
+    /// NIP44 error
+    #[error(transparent)]
+    NIP44(#[from] nip44::Error),
     /// NIP46 error
     #[error(transparent)]
     NIP46(#[from] nip46::Error),

crates/nostr-connect/src/lib.rs

@@ -15,3 +15,4 @@ pub mod client;
 pub mod error;
 pub mod prelude;
 pub mod signer;
+mod util;

crates/nostr-connect/src/signer.rs

@@ -12,6 +12,7 @@ use nostr::nips::nip46::{Message, Request, ResponseResult};
 use nostr_relay_pool::prelude::*;
 
 use crate::error::Error;
+use crate::util;
 
 /// Nostr Connect Keys
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -176,11 +177,7 @@ impl NostrConnectRemoteSigner {
             .handle_notifications(|notification| async {
                 if let RelayPoolNotification::Event { event, .. } = notification {
                     if event.kind == Kind::NostrConnect {
-                        if let Ok(msg) = nip04::decrypt(
-                            self.keys.signer.secret_key(),
-                            &event.pubkey,
-                            event.content,
-                        ) {
+                        if let Ok(msg) = util::decrypt(self.keys.signer.secret_key(), &event) {
                             tracing::debug!("New Nostr Connect message received: {msg}");
 
                             let msg: Message = Message::from_json(msg)?;

crates/nostr-connect/src/util.rs

@@ -0,0 +1,25 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Copyright (c) 2023-2024 Rust Nostr Developers
+// Distributed under the MIT software license
+
+use nostr::nips::{nip04, nip44};
+use nostr::{Event, SecretKey};
+
+use crate::error::Error;
+
+/// Decrypt a NIP46 message. Support both NIP04 and NIP44.
+pub fn decrypt(secret_key: &SecretKey, event: &Event) -> Result<String, Error> {
+    if event.content.contains("?iv=") {
+        Ok(nip04::decrypt(
+            secret_key,
+            &event.pubkey,
+            event.content.as_str(),
+        )?)
+    } else {
+        Ok(nip44::decrypt(
+            secret_key,
+            &event.pubkey,
+            event.content.as_str(),
+        )?)
+    }
+}