From 65fa12c9985e7b7b5c0dff9696ade2e7f6ba9ec9 Mon Sep 17 00:00:00 2001
From: dd dd <asmogo@protonmail.com>
Date: Sat, 27 Jul 2024 23:33:35 +0200
Subject: [PATCH] Refactor public key handling and decoding

Added schnorr public key parsing and hex package functions. Simplified subdomain decoding
---
 exit/exit.go   | 22 +++++++++++++++++++++-
 netstr/conn.go | 20 ++++++++++++++------
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/exit/exit.go b/exit/exit.go
index 7d5feeb..7b49751 100644
--- a/exit/exit.go
+++ b/exit/exit.go
@@ -3,11 +3,14 @@ package exit
 import (
 	"crypto/tls"
 	"encoding/base32"
+	"encoding/hex"
 	"fmt"
 	"github.com/asmogo/nws/config"
 	"github.com/asmogo/nws/netstr"
 	"github.com/asmogo/nws/protocol"
 	"github.com/asmogo/nws/socks5"
+	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
 	"github.com/nbd-wtf/go-nostr"
 	"github.com/nbd-wtf/go-nostr/nip04"
 	"github.com/nbd-wtf/go-nostr/nip19"
@@ -109,7 +112,13 @@ func NewExit(ctx context.Context, exitNodeConfig *config.ExitConfig) *Exit {
 			domain = fmt.Sprintf("%s.%s", domain, base32.HexEncoding.WithPadding(base32.NoPadding).EncodeToString([]byte(relayUrl)))
 		}
 	}
-	domain = strings.ToLower(fmt.Sprintf("%s.%s.nostr", domain, fmt.Sprintf("%s.%s", exit.publicKey[:32], exit.publicKey[32:])))
+
+	decoded, err := GetPublicKey(exit.config.NostrPrivateKey)
+	if err != nil {
+		panic(err)
+	}
+
+	domain = strings.ToLower(fmt.Sprintf("%s.%s.nostr", domain, decoded))
 	slog.Info("created exit node", "profile", profile, "domain", domain)
 	// setup subscriptions
 	err = exit.setSubscriptions(ctx)
@@ -119,6 +128,17 @@ func NewExit(ctx context.Context, exitNodeConfig *config.ExitConfig) *Exit {
 	return exit
 }
 
+func GetPublicKey(sk string) (string, error) {
+	b, err := hex.DecodeString(sk)
+	if err != nil {
+		return "", err
+	}
+
+	_, pk := btcec.PrivKeyFromBytes(b)
+
+	return base32.HexEncoding.WithPadding(base32.NoPadding).EncodeToString(schnorr.SerializePubKey(pk)), nil
+}
+
 // setSubscriptions sets up subscriptions for the Exit node to receive incoming events from the specified relays.
 // It first obtains the public key using the configured Nostr private key.
 // Then it calls the `handleSubscription` method to open a subscription to the relays with the specified filters.
diff --git a/netstr/conn.go b/netstr/conn.go
index 4889b8d..fd0d2a7 100644
--- a/netstr/conn.go
+++ b/netstr/conn.go
@@ -5,8 +5,10 @@ import (
 	"context"
 	"encoding/base32"
 	"encoding/base64"
+	"encoding/hex"
 	"fmt"
 	"github.com/asmogo/nws/protocol"
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
 	"github.com/google/uuid"
 	"github.com/nbd-wtf/go-nostr"
 	"github.com/nbd-wtf/go-nostr/nip04"
@@ -253,10 +255,7 @@ func ParseDestinationDomain(destination string) (string, []string, error) {
 	}
 	var subdomains []string
 	split := strings.Split(url.SubName, ".")
-	for i, subdomain := range split {
-		if i == len(split)-1 {
-			break
-		}
+	for _, subdomain := range split {
 		decodedSubDomain, err := base32.HexEncoding.WithPadding(base32.NoPadding).DecodeString(strings.ToUpper(subdomain))
 		if err != nil {
 			continue
@@ -265,8 +264,17 @@ func ParseDestinationDomain(destination string) (string, []string, error) {
 	}
 
 	// base32 decode the subdomain
-	domain := split[len(split)-1] + url.Name
-	return domain, subdomains, nil
+	decodedPubKey, err := base32.HexEncoding.WithPadding(base32.NoPadding).DecodeString(strings.ToUpper(url.Name))
+
+	if err != nil {
+		return "", nil, err
+	}
+	pk, err := schnorr.ParsePubKey(decodedPubKey)
+	if err != nil {
+		return "", nil, err
+	}
+
+	return hex.EncodeToString(pk.SerializeCompressed())[2:], subdomains, nil
 }
 
 func (nc *NostrConnection) Close() error {