From bea2bb8886f73d7422ea74aba2cf945fa6974a26 Mon Sep 17 00:00:00 2001
From: MikeIsAStar <99037623+MikeIsAStar@users.noreply.github.com>
Date: Mon, 12 Feb 2024 03:00:00 -0500
Subject: [PATCH] NAS: Add a profanity filter

---
 nas/auth.go      | 37 +++++++++++++++++++++++++++++--------
 nas/main.go      |  2 ++
 nas/profanity.go | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 8 deletions(-)
 create mode 100644 nas/profanity.go

diff --git a/nas/auth.go b/nas/auth.go
index 29f11b7..3e27899 100644
--- a/nas/auth.go
+++ b/nas/auth.go
@@ -63,7 +63,7 @@ func handleAuthRequest(moduleName string, w http.ResponseWriter, r *http.Request
 				return
 			}
 
-			if key == "ingamesn" || key == "devname" {
+			if key == "ingamesn" || key == "devname" || key == "words" {
 				// Special handling required for the UTF-16 string
 				var utf16String []uint16
 				if unitcdString == "0" {
@@ -249,8 +249,15 @@ func login(moduleName string, fields map[string]string, isLocalhost bool) map[st
 		return param
 	}
 
-	var authToken, challenge string
+	hasProfaneName := false
+	ingamesn, ok := fields["ingamesn"]
+	if ok {
+		if hasProfaneName, _ = IsBadWord(ingamesn); hasProfaneName {
+			logging.Info(moduleName, aurora.Cyan(strconv.FormatUint(userId, 10)), "has a profane name ("+aurora.Red(ingamesn).String()+")")
+		}
+	}
 
+	var authToken, challenge string
 	switch unitcdInt {
 	// ds
 	case 0:
@@ -303,7 +310,11 @@ func login(moduleName string, fields map[string]string, isLocalhost bool) map[st
 		logging.Notice(moduleName, "Login (Wii)", aurora.Cyan(strconv.FormatUint(userId, 10)), aurora.Cyan(gsbrcd), "ingamesn:", aurora.Cyan(fields["ingamesn"]))
 	}
 
-	param["returncd"] = "001"
+	if hasProfaneName {
+		param["returncd"] = "040"
+	} else {
+		param["returncd"] = "001"
+	}
 	param["challenge"] = challenge
 	param["token"] = authToken
 
@@ -341,14 +352,24 @@ func svcloc(fields map[string]string) map[string]string {
 }
 
 func handleProfanity(fields map[string]string) map[string]string {
-	prwords := ""
-	wordCount := strings.Count(fields["words"], "\t") + 1
-	for i := 0; i < wordCount; i++ {
-		prwords += "0"
+	var prwords string
+	for _, word := range strings.Split(fields["words"], "\t") {
+		if isBadWord, _ := IsBadWord(word); isBadWord {
+			prwords += "1"
+		} else {
+			prwords += "0"
+		}
+	}
+
+	var returncd string
+	if strings.Contains(prwords, "1") {
+		returncd = "040"
+	} else {
+		returncd = "000"
 	}
 
 	return map[string]string{
-		"returncd": "000",
+		"returncd": returncd,
 		"prwords":  prwords,
 	}
 }
diff --git a/nas/main.go b/nas/main.go
index 78f95d9..e2f03fe 100644
--- a/nas/main.go
+++ b/nas/main.go
@@ -49,6 +49,8 @@ func StartServer() {
 		go startHTTPSProxy(config)
 	}
 
+	CacheProfanityFile()
+
 	logging.Notice("NAS", "Starting HTTP server on", address)
 	panic(nhttp.ListenAndServe(address, http.HandlerFunc(handleRequest)))
 }
diff --git a/nas/profanity.go b/nas/profanity.go
new file mode 100644
index 0000000..587bee1
--- /dev/null
+++ b/nas/profanity.go
@@ -0,0 +1,39 @@
+package nas
+
+import (
+	"errors"
+	"os"
+	"strings"
+)
+
+var profanityFilePath = "./profanity.txt"
+var profanityFileLines []string = nil
+
+func CacheProfanityFile() bool {
+	contents, err := os.ReadFile(profanityFilePath)
+	if err != nil {
+		return false
+	}
+
+	lines := strings.Split(string(contents), "\n")
+	profanityFileLines = lines
+	return true
+}
+
+func IsBadWord(word string) (bool, error) {
+	if !isProfanityFileCached() {
+		return false, errors.New("the file '" + profanityFilePath + "' has not been cached")
+	}
+
+	for _, line := range profanityFileLines {
+		if strings.EqualFold(line, word) {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func isProfanityFileCached() bool {
+	return profanityFileLines != nil
+}