Fix subscribe and introduce nonstandard acl login

Author: willnode

README.md

@@ -4,6 +4,8 @@ This is a redis proxy to make ACL more convenient. It prefixes keys with the ACL
 
 Your app can connect to this instance listening by default at port `6479`. 
 
+If your framework doesn't have a way to log in via `AUTH username password`, you can log in using legacy password like `AUTH username:::password` (note the double colon). This nonstandard way of log in only works with this proxy and not with actual redis instance.
+
 ## What it does do
 
 Let's assume this software runs on port 6479 while the upstream Redis is on port 6379.
@@ -14,6 +16,8 @@ This is how it works when it executed serially:
 
 ```
 |GET foo| > |GET default:foo|
+|AUTH foo:::bar| > |AUTH foo bar|
+|GET baz| > |GET foo:baz|
 |AUTH user pass| > |AUTH user pass|
 |GET foo| > |GET user:foo|
 |SET foo bar| > |GET user:foo bar|

handler.go

@@ -111,23 +111,25 @@ func (m *Handler) subscriptionLoop(conn redcon.DetachedConn, upConn net.Conn) {
 	}
 
 	go (func() {
-		cmd, err := conn.ReadCommand()
-		if err != nil {
-			log.Printf("Failed to read command: %v", err)
-			conn.Close()
-			return
-		}
-		command := strings.ToUpper(string(cmd.Args[0]))
-		newArgs, _ := modSingleCommand(command, context.username, cmd.Args)
-		cmd.Args = newArgs
-
-		// Construct RESP command & send to redis
-		request := buildRESPCommand(cmd.Args)
-		_, err = upConn.Write(request)
-		if err != nil {
-			log.Printf("Failed to send command: %v", err)
-			conn.Close()
-			return
+		for {
+			cmd, err := conn.ReadCommand()
+			if err != nil {
+				log.Printf("Failed to read command: %v", err)
+				conn.Close()
+				return
+			}
+			command := strings.ToUpper(string(cmd.Args[0]))
+			newArgs, _ := modSingleCommand(command, context.username, cmd.Args)
+			cmd.Args = newArgs
+
+			// Construct RESP command & send to redis
+			request := buildRESPCommand(cmd.Args)
+			_, err = upConn.Write(request)
+			if err != nil {
+				log.Printf("Failed to send command: %v", err)
+				conn.Close()
+				return
+			}
 		}
 	})()
 

mod.go

@@ -7,6 +7,7 @@ import (
 
 // Command modification types
 const (
+	ModifyAuth         = "auth"
 	ModifyFirst        = "first"
 	ModifyFirstTwo     = "first_two"
 	ModifyAll          = "all"
@@ -26,6 +27,7 @@ const (
 
 // Define namespaced command rules (extracted from redis-namespace)
 var namespacedCommands = map[string]string{
+	"AUTH":   ModifyAuth,
 	"APPEND": ModifyFirst, "BITCOUNT": ModifyFirst, "BITFIELD": ModifyFirst,
 	"BITOP": ModifyExcludeFirst, "BITPOS": ModifyFirst, "BLPOP": ModifyExcludeLast,
 	"BRPOP": ModifyExcludeLast, "BRPOPLPUSH": ModifyExcludeLast, "BZPOPMIN": ModifyFirst,
@@ -89,6 +91,13 @@ func modSingleCommand(command, username string, args [][]byte) ([][]byte, revive
 	}
 
 	switch modType {
+	case ModifyAuth:
+		if len(args) == 2 {
+			if user, pass, found := strings.Cut(string(args[1]), ":::"); found {
+				args[1] = []byte(user)
+				args = append(args, []byte(pass))
+			}
+		}
 	case ModifyFirst:
 		if len(args) > 1 {
 			args[1] = appendPrefix(args[1])