Remove deprecated test files and optimize encryption functions

- Deleted `testresults.txt` and `testmain_test.go` as they were no longer needed.
- Updated the Go workflow to streamline the build process by removing commented-out build steps for various platforms.
- Refactored encryption benchmarks to improve performance and clarity in the `benchmark_test.go` file.
- Introduced a new LICENSE file for the encryption package, specifying the MIT License.
- Enhanced the README with usage instructions and links to the NIP-44 specification.
- Bumped version to v0.25.3 to reflect these changes.

pkg/protocol/nwc/client.go

@@ -58,13 +58,13 @@ func (cl *Client) Request(
 		return
 	}
 
-	var content []byte
-	if content, err = encryption.Encrypt(req, cl.conversationKey); chk.E(err) {
+	var content string
+	if content, err = encryption.Encrypt(cl.conversationKey, req, nil); chk.E(err) {
 		return
 	}
 
 	ev := &event.E{
-		Content:   content,
+		Content:   []byte(content),
 		CreatedAt: time.Now().Unix(),
 		Kind:      23194,
 		Tags: tag.NewS(
@@ -111,9 +111,9 @@ func (cl *Client) Request(
 		if len(e.Content) == 0 {
 			return fmt.Errorf("empty response content")
 		}
-		var raw []byte
+		var raw string
 		if raw, err = encryption.Decrypt(
-			e.Content, cl.conversationKey,
+			cl.conversationKey, string(e.Content),
 		); chk.E(err) {
 			return fmt.Errorf(
 				"decryption failed (invalid conversation key): %w", err,
@@ -121,7 +121,7 @@ func (cl *Client) Request(
 		}
 
 		var resp map[string]any
-		if err = json.Unmarshal(raw, &resp); chk.E(err) {
+		if err = json.Unmarshal([]byte(raw), &resp); chk.E(err) {
 			return
 		}
 
@@ -235,16 +235,16 @@ func (cl *Client) processNotificationEvent(
 	ev *event.E, handler NotificationHandler,
 ) (err error) {
 	// Decrypt the notification content
-	var decrypted []byte
+	var decrypted string
 	if decrypted, err = encryption.Decrypt(
-		ev.Content, cl.conversationKey,
+		cl.conversationKey, string(ev.Content),
 	); err != nil {
 		return fmt.Errorf("failed to decrypt notification: %w", err)
 	}
 
 	// Parse the notification JSON
 	var notification map[string]any
-	if err = json.Unmarshal(decrypted, &notification); err != nil {
+	if err = json.Unmarshal([]byte(decrypted), &notification); err != nil {
 		return fmt.Errorf("failed to parse notification JSON: %w", err)
 	}
 

pkg/protocol/nwc/crypto_test.go

@@ -70,7 +70,7 @@ func TestNWCEncryptionDecryption(t *testing.T) {
 	testMessage := `{"method":"get_info","params":null}`
 
 	// Test encryption
-	encrypted, err := encryption.Encrypt([]byte(testMessage), convKey)
+	encrypted, err := encryption.Encrypt(convKey, []byte(testMessage), nil)
 	if err != nil {
 		t.Fatalf("encryption failed: %v", err)
 	}
@@ -80,14 +80,14 @@ func TestNWCEncryptionDecryption(t *testing.T) {
 	}
 
 	// Test decryption
-	decrypted, err := encryption.Decrypt(encrypted, convKey)
+	decrypted, err := encryption.Decrypt(convKey, encrypted)
 	if err != nil {
 		t.Fatalf("decryption failed: %v", err)
 	}
 
-	if string(decrypted) != testMessage {
+	if decrypted != testMessage {
 		t.Fatalf(
-			"decrypted message mismatch: got %s, want %s", string(decrypted),
+			"decrypted message mismatch: got %s, want %s", decrypted,
 			testMessage,
 		)
 	}
@@ -111,8 +111,8 @@ func TestNWCEventCreation(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	convKey, err := encryption.GenerateConversationKeyWithSigner(
-		clientKey, walletPubkey,
+	convKey, err := encryption.GenerateConversationKey(
+		clientKey.Sec(), walletPubkey,
 	)
 	if err != nil {
 		t.Fatal(err)
@@ -124,14 +124,14 @@ func TestNWCEventCreation(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	encrypted, err := encryption.Encrypt(reqBytes, convKey)
+	encrypted, err := encryption.Encrypt(convKey, reqBytes, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	// Create NWC event
 	ev := &event.E{
-		Content:   encrypted,
+		Content:   []byte(encrypted),
 		CreatedAt: time.Now().Unix(),
 		Kind:      23194,
 		Tags: tag.NewS(

pkg/protocol/nwc/mock_wallet_service.go

@@ -181,8 +181,9 @@ func (m *MockWalletService) processRequestEvent(ev *event.E) (err error) {
 	if existingKey, exists := m.connectedClients[clientPubkeyHex]; exists {
 		conversationKey = existingKey
 	} else {
-		if conversationKey, err = encryption.GenerateConversationKeyWithSigner(
-			m.walletSecretKey, clientPubkey,
+		// Generate conversation key using the wallet's secret key and client's public key
+		if conversationKey, err = encryption.GenerateConversationKey(
+			m.walletSecretKey.Sec(), clientPubkey,
 		); chk.E(err) {
 			m.clientsMutex.Unlock()
 			return
@@ -192,15 +193,15 @@ func (m *MockWalletService) processRequestEvent(ev *event.E) (err error) {
 	m.clientsMutex.Unlock()
 
 	// Decrypt request content
-	var decrypted []byte
+	var decrypted string
 	if decrypted, err = encryption.Decrypt(
-		ev.Content, conversationKey,
+		conversationKey, string(ev.Content),
 	); chk.E(err) {
 		return
 	}
 
 	var request map[string]any
-	if err = json.Unmarshal(decrypted, &request); chk.E(err) {
+	if err = json.Unmarshal([]byte(decrypted), &request); chk.E(err) {
 		return
 	}
 
@@ -394,15 +395,15 @@ func (m *MockWalletService) sendErrorResponse(
 func (m *MockWalletService) sendEncryptedResponse(
 	clientPubkey []byte, conversationKey []byte, content []byte,
 ) (err error) {
-	var encrypted []byte
+	var encrypted string
 	if encrypted, err = encryption.Encrypt(
-		content, conversationKey,
+		conversationKey, content, nil,
 	); chk.E(err) {
 		return
 	}
 
 	ev := &event.E{
-		Content:   encrypted,
+		Content:   []byte(encrypted),
 		CreatedAt: time.Now().Unix(),
 		Kind:      23195,
 		Tags: tag.NewS(
@@ -442,15 +443,15 @@ func (m *MockWalletService) emitPaymentNotification(
 			continue
 		}
 
-		var encrypted []byte
+		var encrypted string
 		if encrypted, err = encryption.Encrypt(
-			content, conversationKey,
+			conversationKey, content, nil,
 		); chk.E(err) {
 			continue
 		}
 
 		ev := &event.E{
-			Content:   encrypted,
+			Content:   []byte(encrypted),
 			CreatedAt: time.Now().Unix(),
 			Kind:      23197,
 			Tags: tag.NewS(

pkg/protocol/nwc/uri.go

@@ -75,8 +75,8 @@ func ParseConnectionURI(nwcUri string) (parts *ConnectionParams, err error) {
 		return
 	}
 	parts.clientSecretKey = clientKey
-	if parts.conversationKey, err = encryption.GenerateConversationKeyWithSigner(
-		clientKey,
+	if parts.conversationKey, err = encryption.GenerateConversationKey(
+		clientKey.Sec(),
 		parts.walletPublicKey,
 	); chk.E(err) {
 		return