From fcd51e57717f249d420030dfc2e8ac5533c8655d Mon Sep 17 00:00:00 2001
From: Lefteris Zafiris <zaf@fastmail.com>
Date: Tue, 26 Jul 2022 18:56:08 +0300
Subject: [PATCH] Use bufio.Scanner in parseEnv()

---
 agi.go     |  4 ++++
 parsers.go | 25 ++++++++++---------------
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/agi.go b/agi.go
index e084d61..e3bafa9 100644
--- a/agi.go
+++ b/agi.go
@@ -38,6 +38,10 @@ import (
 	"strings"
 )
 
+const (
+	envMin = 18 // Minimum number of AGI environment args
+)
+
 // Session is a struct holding AGI environment vars and the I/O handlers.
 type Session struct {
 	Env map[string]string //AGI environment variables.
diff --git a/parsers.go b/parsers.go
index e776dd7..046c51b 100644
--- a/parsers.go
+++ b/parsers.go
@@ -7,6 +7,7 @@
 package agi
 
 import (
+	"bufio"
 	"bytes"
 	"errors"
 	"fmt"
@@ -14,25 +15,18 @@ import (
 	"strings"
 )
 
-const (
-	envMin = 18  // Minimum number of AGI environment args
-	envMax = 150 // Maximum number of AGI environment args
-)
-
 // parseEnv reads and stores AGI environment.
 func (a *Session) parseEnv() error {
 	var err error
 	var line []byte
-	for i := 0; i <= envMax; i++ {
-		line, err = a.buf.ReadBytes(10)
-		if err != nil || len(line) <= len("\r\n") {
-			break
+	s := bufio.NewScanner(a.buf)
+	for s.Scan() {
+		line = s.Bytes()
+		if len(line) <= len("\r\n") {
+			break // end of input
 		}
-		// Strip trailing newline
-		line = line[:len(line)-1]
 		ind := bytes.IndexByte(line, ':')
-		// "agi_type" is the shortest length key, "agi_network_script" the longest, anything outside these boundaries is invalid.
-		if ind < len("agi_type") || ind > len("agi_network_script") || ind == len(line)-1 {
+		if ind == -1 || ind == len(line)-1 {
 			err = fmt.Errorf("malformed environment input: %s", string(line))
 			a.Env = nil
 			return err
@@ -42,9 +36,10 @@ func (a *Session) parseEnv() error {
 		value := string(line[ind:])
 		a.Env[key] = value
 	}
-	if len(a.Env) < envMin {
-		err = fmt.Errorf("incomplete environment with only %d env vars", len(a.Env))
+	if err := s.Err(); err != nil {
+		err = fmt.Errorf("error reading environment input: %s", err)
 		a.Env = nil
+		return err
 	}
 	return err
 }