Prefer nip04 encryption fallback for implicit wallets

js/payments/nwcClient.js

@@ -627,7 +627,8 @@ async function ensureEncryption(context) {
     }
   }
 
-  const { schemes: walletSchemes } = getWalletSupportedEncryption(infoEvent);
+  const { schemes: walletSchemes, explicit: walletSchemesExplicit } =
+    getWalletSupportedEncryption(infoEvent);
   const candidates = getEncryptionCandidates(context).filter((candidate) => {
     return !state.unsupported.has(candidate.scheme);
   });
@@ -636,6 +637,19 @@ async function ensureEncryption(context) {
     ? candidates.filter((candidate) => walletSchemes.includes(candidate.scheme))
     : candidates;
 
+  if (
+    compatibleCandidates.length > 1 &&
+    (!walletSchemesExplicit || !walletSchemes.includes("nip44_v2"))
+  ) {
+    const nip04Index = compatibleCandidates.findIndex(
+      (candidate) => candidate.scheme === "nip04"
+    );
+    if (nip04Index > 0) {
+      const [nip04Candidate] = compatibleCandidates.splice(nip04Index, 1);
+      compatibleCandidates.unshift(nip04Candidate);
+    }
+  }
+
   if (compatibleCandidates.length) {
     const selected = compatibleCandidates[0];
     context.encryption = selected;

tests/nwc-client.test.mjs

@@ -65,6 +65,14 @@ await (async () => {
         },
       },
     },
+    nip04: {
+      async encrypt() {
+        return "nip04";
+      },
+      async decrypt() {
+        return "nip04";
+      },
+    },
   };
 
   const walletPubkey = "b".repeat(64);
@@ -105,6 +113,107 @@ await (async () => {
   resetWalletClient();
 })();
 
+await (async () => {
+  resetWalletClient();
+
+  window.NostrTools = {
+    getPublicKey() {
+      return "c".repeat(64);
+    },
+    nip44: {
+      v2: {
+        async encrypt(plaintext, key) {
+          return `nip44:${key}:${plaintext}`;
+        },
+        async decrypt(ciphertext, key) {
+          return `nip44:${key}:${ciphertext}`;
+        },
+        utils: {
+          getConversationKey(secretBytes, pubkey) {
+            return `key-${pubkey}-${secretBytes.length}`;
+          },
+        },
+      },
+    },
+    nip04: {
+      async encrypt() {
+        return "nip04";
+      },
+      async decrypt() {
+        return "nip04";
+      },
+    },
+  };
+
+  const walletPubkey = "b".repeat(64);
+  const secretKey = "a".repeat(64);
+  const relays = ["wss://relay.one.example"];
+  const uri =
+    `nostr+walletconnect://${walletPubkey}` +
+    `?relay=${encodeURIComponent(relays[0])}` +
+    `&secret=${secretKey}`;
+
+  const context = ensureActiveState({ nwcUri: uri });
+  context.infoEvent = { kind: 13194, tags: [] };
+
+  const encryption = await __TESTING__.ensureEncryptionForContext(context);
+  assert.equal(encryption.scheme, "nip04");
+
+  resetWalletClient();
+})();
+
+await (async () => {
+  resetWalletClient();
+
+  window.NostrTools = {
+    getPublicKey() {
+      return "c".repeat(64);
+    },
+    nip44: {
+      v2: {
+        async encrypt(plaintext, key) {
+          return `nip44:${key}:${plaintext}`;
+        },
+        async decrypt(ciphertext, key) {
+          return `nip44:${key}:${ciphertext}`;
+        },
+        utils: {
+          getConversationKey(secretBytes, pubkey) {
+            return `key-${pubkey}-${secretBytes.length}`;
+          },
+        },
+      },
+    },
+    nip04: {
+      async encrypt() {
+        return "nip04";
+      },
+      async decrypt() {
+        return "nip04";
+      },
+    },
+  };
+
+  const walletPubkey = "b".repeat(64);
+  const secretKey = "a".repeat(64);
+  const relays = ["wss://relay.one.example"];
+  const uri =
+    `nostr+walletconnect://${walletPubkey}` +
+    `?relay=${encodeURIComponent(relays[0])}` +
+    `&secret=${secretKey}`;
+
+  const context = ensureActiveState({ nwcUri: uri });
+  context.infoEvent = {
+    kind: 13194,
+    tags: [["encryption", "nip04"]],
+  };
+
+  const encryption = await __TESTING__.ensureEncryptionForContext(context);
+  assert.equal(encryption.scheme, "nip04");
+
+  resetWalletClient();
+})();
+
 await (async () => {
   resetWalletClient();