diff --git a/controller.go b/controller.go
index 342bf06b..034e4cb3 100644
--- a/controller.go
+++ b/controller.go
@@ -3,7 +3,6 @@ package beego
import (
"bytes"
"crypto/hmac"
- "crypto/rand"
"crypto/sha1"
"encoding/base64"
"errors"
@@ -22,6 +21,7 @@ import (
"github.com/astaxie/beego/context"
"github.com/astaxie/beego/session"
+ "github.com/astaxie/beego/utils"
)
var (
@@ -455,7 +455,7 @@ func (c *Controller) XsrfToken() string {
} else {
expire = int64(XSRFExpire)
}
- token = getRandomString(15)
+ token = string(utils.RandomCreateBytes(15))
c.SetSecureCookie(XSRFKEY, "_xsrf", token, expire)
}
c._xsrf_token = token
@@ -492,14 +492,3 @@ func (c *Controller) XsrfFormHtml() string {
func (c *Controller) GetControllerAndAction() (controllerName, actionName string) {
return c.controllerName, c.actionName
}
-
-// getRandomString returns random string.
-func getRandomString(n int) string {
- const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
- var bytes = make([]byte, n)
- rand.Read(bytes)
- for i, b := range bytes {
- bytes[i] = alphanum[b%byte(len(alphanum))]
- }
- return string(bytes)
-}
diff --git a/utils/captcha/captcha.go b/utils/captcha/captcha.go
new file mode 100644
index 00000000..174197a0
--- /dev/null
+++ b/utils/captcha/captcha.go
@@ -0,0 +1,184 @@
+package captcha
+
+// modifiy and integrated to Beego in one file from https://github.com/dchest/captcha
+
+import (
+ "fmt"
+ "html/template"
+ "net/http"
+ "path"
+ "strings"
+
+ "github.com/astaxie/beego"
+ "github.com/astaxie/beego/cache"
+ "github.com/astaxie/beego/context"
+ "github.com/astaxie/beego/utils"
+)
+
+var (
+ defaultChars = []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+)
+
+const (
+ challengeNums = 6
+ expiration = 600
+ fieldIdName = "captcha_id"
+ fieldCaptchaName = "captcha"
+ cachePrefix = "captcha_"
+ urlPrefix = "/captcha/"
+)
+
+type Captcha struct {
+ store cache.Cache
+ urlPrefix string
+ FieldIdName string
+ FieldCaptchaName string
+ StdWidth int
+ StdHeight int
+ ChallengeNums int
+ Expiration int64
+ CachePrefix string
+}
+
+func (c *Captcha) key(id string) string {
+ return c.CachePrefix + id
+}
+
+func (c *Captcha) genRandChars() []byte {
+ return utils.RandomCreateBytes(c.ChallengeNums, defaultChars...)
+}
+
+func (c *Captcha) Handler(ctx *context.Context) {
+ var chars []byte
+
+ id := path.Base(ctx.Request.RequestURI)
+ if i := strings.Index(id, "."); i != -1 {
+ id = id[:i]
+ }
+
+ key := c.key(id)
+
+ if v, ok := c.store.Get(key).([]byte); ok {
+ chars = v
+ } else {
+ ctx.Output.SetStatus(404)
+ ctx.WriteString("captcha not found")
+ return
+ }
+
+ // reload captcha
+ if len(ctx.Input.Query("reload")) > 0 {
+ chars = c.genRandChars()
+ if err := c.store.Put(key, chars, c.Expiration); err != nil {
+ ctx.Output.SetStatus(500)
+ ctx.WriteString("captcha reload error")
+ beego.Error("Reload Create Captcha Error:", err)
+ return
+ }
+ }
+
+ img := NewImage(chars, c.StdWidth, c.StdHeight)
+ if _, err := img.WriteTo(ctx.ResponseWriter); err != nil {
+ beego.Error("Write Captcha Image Error:", err)
+ }
+}
+
+func (c *Captcha) CreateCaptchaHtml() template.HTML {
+ value, err := c.CreateCaptcha()
+ if err != nil {
+ beego.Error("Create Captcha Error:", err)
+ return ""
+ }
+
+ // create html
+ return template.HTML(fmt.Sprintf(``+
+ ``+
+ ``+
+ ``, c.FieldIdName, value, c.urlPrefix, value, c.urlPrefix, value))
+}
+
+func (c *Captcha) CreateCaptcha() (string, error) {
+ // generate captcha id
+ id := string(utils.RandomCreateBytes(15))
+
+ // get the captcha chars
+ chars := c.genRandChars()
+
+ // save to store
+ if err := c.store.Put(c.key(id), chars, c.Expiration); err != nil {
+ return "", err
+ }
+
+ return id, nil
+}
+
+func (c *Captcha) VerifyReq(req *http.Request) bool {
+ req.ParseForm()
+ return c.Verify(req.Form.Get(c.FieldIdName), req.Form.Get(c.FieldCaptchaName))
+}
+
+func (c *Captcha) Verify(id string, challenge string) (success bool) {
+ if len(challenge) == 0 || len(id) == 0 {
+ return
+ }
+
+ var chars []byte
+
+ key := c.key(id)
+
+ if v, ok := c.store.Get(key).([]byte); ok && len(v) == len(challenge) {
+ chars = v
+ } else {
+ return
+ }
+
+ defer func() {
+ // finally remove it
+ c.store.Delete(key)
+ }()
+
+ // verify challenge
+ for i, c := range chars {
+ if c != challenge[i]-48 {
+ return
+ }
+ }
+
+ return true
+}
+
+func NewCaptcha(urlPrefix string, store cache.Cache) *Captcha {
+ cpt := &Captcha{}
+ cpt.store = store
+ cpt.FieldIdName = fieldIdName
+ cpt.FieldCaptchaName = fieldCaptchaName
+ cpt.ChallengeNums = challengeNums
+ cpt.Expiration = expiration
+ cpt.CachePrefix = cachePrefix
+ cpt.StdWidth = stdWidth
+ cpt.StdHeight = stdHeight
+
+ if len(urlPrefix) == 0 {
+ urlPrefix = urlPrefix
+ }
+
+ if urlPrefix[len(urlPrefix)-1] != '/' {
+ urlPrefix += "/"
+ }
+
+ cpt.urlPrefix = urlPrefix
+
+ return cpt
+}
+
+func NewWithFilter(urlPrefix string, store cache.Cache) *Captcha {
+ cpt := NewCaptcha(urlPrefix, store)
+
+ // create filter for serve captcha image
+ beego.AddFilter(urlPrefix+":", "BeforeRouter", cpt.Handler)
+
+ // add to template func map
+ beego.AddFuncMap("create_captcha", cpt.CreateCaptchaHtml)
+
+ return cpt
+}
diff --git a/utils/captcha/image.go b/utils/captcha/image.go
new file mode 100644
index 00000000..d9ae13a6
--- /dev/null
+++ b/utils/captcha/image.go
@@ -0,0 +1,484 @@
+package captcha
+
+import (
+ "bytes"
+ "image"
+ "image/color"
+ "image/png"
+ "io"
+ "math"
+ "math/rand"
+ "time"
+)
+
+const (
+ fontWidth = 11
+ fontHeight = 18
+ blackChar = 1
+
+ // Standard width and height of a captcha image.
+ stdWidth = 240
+ stdHeight = 80
+ // Maximum absolute skew factor of a single digit.
+ maxSkew = 0.7
+ // Number of background circles.
+ circleCount = 20
+)
+
+var font = [][]byte{
+ { // 0
+ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
+ 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1,
+ 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+ },
+ { // 1
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0,
+ 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0,
+ 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ },
+ { // 2
+ 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0,
+ 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0,
+ 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ },
+ { // 3
+ 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0,
+ 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
+ 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
+ },
+ { // 4
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0,
+ 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0,
+ 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0,
+ 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ },
+ { // 5
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0,
+ },
+ { // 6
+ 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0,
+ 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0,
+ 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0,
+ 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0,
+ 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0,
+ 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1,
+ 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+ },
+ { // 7
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
+ 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0,
+ 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
+ 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0,
+ 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0,
+ 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0,
+ 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
+ },
+ { // 8
+ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0,
+ 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0,
+ 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0,
+ 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
+ 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
+ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+ },
+ { // 9
+ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+ 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0,
+ 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1,
+ 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
+ 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1,
+ 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
+ 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0,
+ 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
+ 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
+ },
+}
+
+type Image struct {
+ *image.Paletted
+ numWidth int
+ numHeight int
+ dotSize int
+}
+
+func getrand() *rand.Rand {
+ return rand.New(rand.NewSource(time.Now().UnixNano()))
+}
+
+func randIntn(max int) int {
+ return getrand().Intn(max)
+}
+
+func randInt(min, max int) int {
+ return getrand().Intn(max-min) + min
+}
+
+func randFloat(min, max float64) float64 {
+ return (max-min)*getrand().Float64() + min
+}
+
+func randomPalette() color.Palette {
+ p := make([]color.Color, circleCount+1)
+ // Transparent color.
+ p[0] = color.RGBA{0xFF, 0xFF, 0xFF, 0x00}
+ // Primary color.
+ prim := color.RGBA{
+ uint8(randIntn(129)),
+ uint8(randIntn(129)),
+ uint8(randIntn(129)),
+ 0xFF,
+ }
+ p[1] = prim
+ // Circle colors.
+ for i := 2; i <= circleCount; i++ {
+ p[i] = randomBrightness(prim, 255)
+ }
+ return p
+}
+
+// NewImage returns a new captcha image of the given width and height with the
+// given digits, where each digit must be in range 0-9.
+func NewImage(digits []byte, width, height int) *Image {
+ m := new(Image)
+ m.Paletted = image.NewPaletted(image.Rect(0, 0, width, height), randomPalette())
+ m.calculateSizes(width, height, len(digits))
+ // Randomly position captcha inside the image.
+ maxx := width - (m.numWidth+m.dotSize)*len(digits) - m.dotSize
+ maxy := height - m.numHeight - m.dotSize*2
+ var border int
+ if width > height {
+ border = height / 5
+ } else {
+ border = width / 5
+ }
+ x := randInt(border, maxx-border)
+ y := randInt(border, maxy-border)
+ // Draw digits.
+ for _, n := range digits {
+ m.drawDigit(font[n], x, y)
+ x += m.numWidth + m.dotSize
+ }
+ // Draw strike-through line.
+ m.strikeThrough()
+ // Apply wave distortion.
+ m.distort(randFloat(5, 10), randFloat(100, 200))
+ // Fill image with random circles.
+ m.fillWithCircles(circleCount, m.dotSize)
+ return m
+}
+
+// encodedPNG encodes an image to PNG and returns
+// the result as a byte slice.
+func (m *Image) encodedPNG() []byte {
+ var buf bytes.Buffer
+ if err := png.Encode(&buf, m.Paletted); err != nil {
+ panic(err.Error())
+ }
+ return buf.Bytes()
+}
+
+// WriteTo writes captcha image in PNG format into the given writer.
+func (m *Image) WriteTo(w io.Writer) (int64, error) {
+ n, err := w.Write(m.encodedPNG())
+ return int64(n), err
+}
+
+func (m *Image) calculateSizes(width, height, ncount int) {
+ // Goal: fit all digits inside the image.
+ var border int
+ if width > height {
+ border = height / 4
+ } else {
+ border = width / 4
+ }
+ // Convert everything to floats for calculations.
+ w := float64(width - border*2)
+ h := float64(height - border*2)
+ // fw takes into account 1-dot spacing between digits.
+ fw := float64(fontWidth + 1)
+ fh := float64(fontHeight)
+ nc := float64(ncount)
+ // Calculate the width of a single digit taking into account only the
+ // width of the image.
+ nw := w / nc
+ // Calculate the height of a digit from this width.
+ nh := nw * fh / fw
+ // Digit too high?
+ if nh > h {
+ // Fit digits based on height.
+ nh = h
+ nw = fw / fh * nh
+ }
+ // Calculate dot size.
+ m.dotSize = int(nh / fh)
+ // Save everything, making the actual width smaller by 1 dot to account
+ // for spacing between digits.
+ m.numWidth = int(nw) - m.dotSize
+ m.numHeight = int(nh)
+}
+
+func (m *Image) drawHorizLine(fromX, toX, y int, colorIdx uint8) {
+ for x := fromX; x <= toX; x++ {
+ m.SetColorIndex(x, y, colorIdx)
+ }
+}
+
+func (m *Image) drawCircle(x, y, radius int, colorIdx uint8) {
+ f := 1 - radius
+ dfx := 1
+ dfy := -2 * radius
+ xo := 0
+ yo := radius
+
+ m.SetColorIndex(x, y+radius, colorIdx)
+ m.SetColorIndex(x, y-radius, colorIdx)
+ m.drawHorizLine(x-radius, x+radius, y, colorIdx)
+
+ for xo < yo {
+ if f >= 0 {
+ yo--
+ dfy += 2
+ f += dfy
+ }
+ xo++
+ dfx += 2
+ f += dfx
+ m.drawHorizLine(x-xo, x+xo, y+yo, colorIdx)
+ m.drawHorizLine(x-xo, x+xo, y-yo, colorIdx)
+ m.drawHorizLine(x-yo, x+yo, y+xo, colorIdx)
+ m.drawHorizLine(x-yo, x+yo, y-xo, colorIdx)
+ }
+}
+
+func (m *Image) fillWithCircles(n, maxradius int) {
+ maxx := m.Bounds().Max.X
+ maxy := m.Bounds().Max.Y
+ for i := 0; i < n; i++ {
+ colorIdx := uint8(randInt(1, circleCount-1))
+ r := randInt(1, maxradius)
+ m.drawCircle(randInt(r, maxx-r), randInt(r, maxy-r), r, colorIdx)
+ }
+}
+
+func (m *Image) strikeThrough() {
+ maxx := m.Bounds().Max.X
+ maxy := m.Bounds().Max.Y
+ y := randInt(maxy/3, maxy-maxy/3)
+ amplitude := randFloat(5, 20)
+ period := randFloat(80, 180)
+ dx := 2.0 * math.Pi / period
+ for x := 0; x < maxx; x++ {
+ xo := amplitude * math.Cos(float64(y)*dx)
+ yo := amplitude * math.Sin(float64(x)*dx)
+ for yn := 0; yn < m.dotSize; yn++ {
+ r := randInt(0, m.dotSize)
+ m.drawCircle(x+int(xo), y+int(yo)+(yn*m.dotSize), r/2, 1)
+ }
+ }
+}
+
+func (m *Image) drawDigit(digit []byte, x, y int) {
+ skf := randFloat(-maxSkew, maxSkew)
+ xs := float64(x)
+ r := m.dotSize / 2
+ y += randInt(-r, r)
+ for yo := 0; yo < fontHeight; yo++ {
+ for xo := 0; xo < fontWidth; xo++ {
+ if digit[yo*fontWidth+xo] != blackChar {
+ continue
+ }
+ m.drawCircle(x+xo*m.dotSize, y+yo*m.dotSize, r, 1)
+ }
+ xs += skf
+ x = int(xs)
+ }
+}
+
+func (m *Image) distort(amplude float64, period float64) {
+ w := m.Bounds().Max.X
+ h := m.Bounds().Max.Y
+
+ oldm := m.Paletted
+ newm := image.NewPaletted(image.Rect(0, 0, w, h), oldm.Palette)
+
+ dx := 2.0 * math.Pi / period
+ for x := 0; x < w; x++ {
+ for y := 0; y < h; y++ {
+ xo := amplude * math.Sin(float64(y)*dx)
+ yo := amplude * math.Cos(float64(x)*dx)
+ newm.SetColorIndex(x, y, oldm.ColorIndexAt(x+int(xo), y+int(yo)))
+ }
+ }
+ m.Paletted = newm
+}
+
+func randomBrightness(c color.RGBA, max uint8) color.RGBA {
+ minc := min3(c.R, c.G, c.B)
+ maxc := max3(c.R, c.G, c.B)
+ if maxc > max {
+ return c
+ }
+ n := randIntn(int(max-maxc)) - int(minc)
+ return color.RGBA{
+ uint8(int(c.R) + n),
+ uint8(int(c.G) + n),
+ uint8(int(c.B) + n),
+ uint8(c.A),
+ }
+}
+
+func min3(x, y, z uint8) (m uint8) {
+ m = x
+ if y < m {
+ m = y
+ }
+ if z < m {
+ m = z
+ }
+ return
+}
+
+func max3(x, y, z uint8) (m uint8) {
+ m = x
+ if y > m {
+ m = y
+ }
+ if z > m {
+ m = z
+ }
+ return
+}
diff --git a/utils/captcha/image_test.go b/utils/captcha/image_test.go
new file mode 100644
index 00000000..e80cc42c
--- /dev/null
+++ b/utils/captcha/image_test.go
@@ -0,0 +1,38 @@
+package captcha
+
+import (
+ "testing"
+
+ "github.com/astaxie/beego/utils"
+)
+
+type byteCounter struct {
+ n int64
+}
+
+func (bc *byteCounter) Write(b []byte) (int, error) {
+ bc.n += int64(len(b))
+ return len(b), nil
+}
+
+func BenchmarkNewImage(b *testing.B) {
+ b.StopTimer()
+ d := utils.RandomCreateBytes(challengeNums, defaultChars...)
+ b.StartTimer()
+ for i := 0; i < b.N; i++ {
+ NewImage(d, stdWidth, stdHeight)
+ }
+}
+
+func BenchmarkImageWriteTo(b *testing.B) {
+ b.StopTimer()
+ d := utils.RandomCreateBytes(challengeNums, defaultChars...)
+ b.StartTimer()
+ counter := &byteCounter{}
+ for i := 0; i < b.N; i++ {
+ img := NewImage(d, stdWidth, stdHeight)
+ img.WriteTo(counter)
+ b.SetBytes(counter.n)
+ counter.n = 0
+ }
+}
diff --git a/utils/rand.go b/utils/rand.go
new file mode 100644
index 00000000..482c7059
--- /dev/null
+++ b/utils/rand.go
@@ -0,0 +1,20 @@
+package utils
+
+import (
+ "crypto/rand"
+)
+
+// RandomCreateBytes generate random []byte by specify chars.
+func RandomCreateBytes(n int, alphabets ...byte) []byte {
+ const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+ var bytes = make([]byte, n)
+ rand.Read(bytes)
+ for i, b := range bytes {
+ if len(alphabets) == 0 {
+ bytes[i] = alphanum[b%byte(len(alphanum))]
+ } else {
+ bytes[i] = alphabets[b%byte(len(alphabets))]
+ }
+ }
+ return bytes
+}