From 7de126d52c3b150aa8288b672dde546bc99b2f5f Mon Sep 17 00:00:00 2001
From: Jianhui Zhao <jianhuizhao329@gmail.com>
Date: Wed, 1 May 2019 17:35:29 +0800
Subject: [PATCH] pwauth: Optimize code

Signed-off-by: Jianhui Zhao <jianhuizhao329@gmail.com>
---
 http.go                |  3 +--
 pwauth/auth_darwin.go  |  8 ++++++--
 pwauth/auth_freebsd.go | 13 +++++++++----
 pwauth/auth_linux.go   | 13 +++++++++----
 pwauth/auth_windows.go | 13 +++++++++++--
 pwauth/pwauth.go       |  7 +++++++
 6 files changed, 43 insertions(+), 14 deletions(-)
 create mode 100644 pwauth/pwauth.go

diff --git a/http.go b/http.go
index 030cb6d..337eeb3 100644
--- a/http.go
+++ b/http.go
@@ -47,8 +47,7 @@ func httpAuth(w http.ResponseWriter, r *http.Request) bool {
 }
 
 func httpLogin(cfg *RttysConfig, creds *Credentials) bool {
-	ok := pwauth.Auth(creds.Username, creds.Password)
-	if ok {
+	if err := pwauth.Auth(creds.Username, creds.Password); err == nil {
 		return true
 	}
 
diff --git a/pwauth/auth_darwin.go b/pwauth/auth_darwin.go
index d55d25e..87d5a84 100644
--- a/pwauth/auth_darwin.go
+++ b/pwauth/auth_darwin.go
@@ -1,6 +1,10 @@
 package pwauth
 
+import (
+	"errors"
+)
+
 // Need to be implemented
-func Auth(username, password string) bool {
-	return false
+func auth(username, password string) error {
+	return errors.New("not implemented")
 }
diff --git a/pwauth/auth_freebsd.go b/pwauth/auth_freebsd.go
index 967ac25..bfdbb51 100644
--- a/pwauth/auth_freebsd.go
+++ b/pwauth/auth_freebsd.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"io/ioutil"
 	"os"
+	"os/user"
 	"strings"
 
 	"github.com/GehirnInc/crypt"
@@ -37,16 +38,20 @@ func getPassword(name string) (string, error) {
 	return "", errors.New("Not found")
 }
 
-func Auth(username, password string) bool {
+func auth(username, password string) error {
 	if os.Getuid() != 0 {
-		return false
+		return errors.New("Cannot possibly work without effective root")
+	}
+
+	if _, err := user.Lookup(username); err != nil {
+		return err
 	}
 
 	pw, err := getPassword(username)
 	if err != nil {
-		return false
+		return err
 	}
 
 	c := crypt.NewFromHash(pw)
-	return c.Verify(pw, []byte(password)) == nil
+	return c.Verify(pw, []byte(password))
 }
diff --git a/pwauth/auth_linux.go b/pwauth/auth_linux.go
index fb6c6ad..9fbf631 100644
--- a/pwauth/auth_linux.go
+++ b/pwauth/auth_linux.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"io/ioutil"
 	"os"
+	"os/user"
 	"strings"
 
 	"github.com/GehirnInc/crypt"
@@ -37,16 +38,20 @@ func getPassword(name string) (string, error) {
 	return "", errors.New("Not found")
 }
 
-func Auth(username, password string) bool {
+func auth(username, password string) error {
 	if os.Getuid() != 0 {
-		return false
+		return errors.New("Cannot possibly work without effective root")
+	}
+
+	if _, err := user.Lookup(username); err != nil {
+		return err
 	}
 
 	pw, err := getPassword(username)
 	if err != nil {
-		return false
+		return err
 	}
 
 	c := crypt.NewFromHash(pw)
-	return c.Verify(pw, []byte(password)) == nil
+	return c.Verify(pw, []byte(password))
 }
diff --git a/pwauth/auth_windows.go b/pwauth/auth_windows.go
index bf549b9..f65c8c9 100644
--- a/pwauth/auth_windows.go
+++ b/pwauth/auth_windows.go
@@ -1,6 +1,7 @@
 package pwauth
 
 import (
+	"os/user"
 	"syscall"
 	"unsafe"
 )
@@ -31,12 +32,20 @@ func LogonUserW(username, domain, password *uint16, logonType, logonProvider uin
 	return token, nil
 }
 
-func Auth(username, password string) bool {
+func auth(username, password string) error {
+	if _, err := user.Lookup(username); err != nil {
+		return err
+	}
+
 	pUsername, _ := syscall.UTF16PtrFromString(username)
 	pDomain, _ := syscall.UTF16PtrFromString(".")
 	pPassword, _ := syscall.UTF16PtrFromString(password)
 
 	_, err := LogonUserW(pUsername, pDomain, pPassword, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT)
 
-	return err == nil || err == errERROR_ACCOUNT_RESTRICTION
+	if err == errERROR_ACCOUNT_RESTRICTION {
+		return nil
+	}
+
+	return err
 }
diff --git a/pwauth/pwauth.go b/pwauth/pwauth.go
new file mode 100644
index 0000000..e2f264d
--- /dev/null
+++ b/pwauth/pwauth.go
@@ -0,0 +1,7 @@
+package pwauth
+
+// Auth check the validity of the username/password pair.If the
+// credentials are not valid, this function will return an error.
+func Auth(username, password string) error {
+	return auth(username, password)
+}