Support bcrypt passwords in htpasswd

Author: brennie

Gopkg.lock

@@ -38,3 +38,7 @@
 [[constraint]]
   name = "gopkg.in/fsnotify.v1"
   version = "~1.2.0"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/crypto"

Gopkg.toml

@@ -7,10 +7,12 @@ import (
 	"io"
 	"log"
 	"os"
+
+	"golang.org/x/crypto/bcrypt"
 )
 
-// lookup passwords in a htpasswd file
-// The entries must have been created with -s for SHA encryption
+// Lookup passwords in a htpasswd file
+// Passwords must be generated with -B for bcrypt or -s for SHA1.
 
 type HtpasswdFile struct {
 	Users map[string]string
@@ -47,14 +49,20 @@ func (h *HtpasswdFile) Validate(user string, password string) bool {
 	if !exists {
 		return false
 	}
-	if realPassword[:5] == "{SHA}" {
+
+	shaPrefix := realPassword[:5]
+	if shaPrefix == "{SHA}" {
+		shaValue := realPassword[5:]
 		d := sha1.New()
 		d.Write([]byte(password))
-		if realPassword[5:] == base64.StdEncoding.EncodeToString(d.Sum(nil)) {
-			return true
-		}
-	} else {
-		log.Printf("Invalid htpasswd entry for %s. Must be a SHA entry.", user)
+		return shaValue == base64.StdEncoding.EncodeToString(d.Sum(nil))
 	}
+
+	bcryptPrefix := realPassword[:4]
+	if bcryptPrefix == "$2a$" || bcryptPrefix == "$2b$" || bcryptPrefix == "$2x$" || bcryptPrefix == "$2y$" {
+		return bcrypt.CompareHashAndPassword([]byte(realPassword), []byte(password)) == nil
+	}
+
+	log.Printf("Invalid htpasswd entry for %s. Must be a SHA or bcrypt entry.", user)
 	return false
 }

htpasswd.go

@@ -2,15 +2,36 @@ package main
 
 import (
 	"bytes"
-	"github.com/stretchr/testify/assert"
+	"fmt"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/crypto/bcrypt"
 )
 
-func TestHtpasswd(t *testing.T) {
+func TestSHA(t *testing.T) {
 	file := bytes.NewBuffer([]byte("testuser:{SHA}PaVBVZkYqAjCQCu6UBL2xgsnZhw=\n"))
 	h, err := NewHtpasswd(file)
 	assert.Equal(t, err, nil)
 
 	valid := h.Validate("testuser", "asdf")
 	assert.Equal(t, valid, true)
 }
+
+func TestBcrypt(t *testing.T) {
+	hash1, err := bcrypt.GenerateFromPassword([]byte("password"), 1)
+	hash2, err := bcrypt.GenerateFromPassword([]byte("top-secret"), 2)
+	assert.Equal(t, err, nil)
+
+	contents := fmt.Sprintf("testuser1:%s\ntestuser2:%s\n", hash1, hash2)
+	file := bytes.NewBuffer([]byte(contents))
+
+	h, err := NewHtpasswd(file)
+	assert.Equal(t, err, nil)
+
+	valid := h.Validate("testuser1", "password")
+	assert.Equal(t, valid, true)
+
+	valid = h.Validate("testuser2", "top-secret")
+	assert.Equal(t, valid, true)
+}

htpasswd_test.go

@@ -52,7 +52,7 @@ func main() {
 	flagSet.String("client-id", "", "the OAuth Client ID: ie: \"123456.apps.googleusercontent.com\"")
 	flagSet.String("client-secret", "", "the OAuth Client Secret")
 	flagSet.String("authenticated-emails-file", "", "authenticate against emails via file (one per line)")
-	flagSet.String("htpasswd-file", "", "additionally authenticate against a htpasswd file. Entries must be created with \"htpasswd -s\" for SHA encryption")
+	flagSet.String("htpasswd-file", "", "additionally authenticate against a htpasswd file. Entries must be created with \"htpasswd -s\" for SHA encryption or \"htpasswd -B\" for bcrypt encryption")
 	flagSet.Bool("display-htpasswd-form", true, "display username / password login form if an htpasswd file is provided")
 	flagSet.String("custom-templates-dir", "", "path to custom html templates")
 	flagSet.String("footer", "", "custom footer string. Use \"-\" to disable default footer.")