.

go.mod

@@ -2,7 +2,6 @@ module gitler.moe/suwako/gocaptcha
 
 go 1.21.1
 
-require (
-	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
-	golang.org/x/image v0.12.0
-)
+require golang.org/x/image v0.12.0
+
+require golang.org/x/text v0.13.0 // indirect

go.sum

@@ -1,5 +1,3 @@
-github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
-github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
@@ -27,6 +25,7 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.13.0 h1:ablQoSUd0tRdKxZewP80B+BaqeKJuVhuRxj/dkrun3k=
 golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=

main.go

@@ -1,7 +1,6 @@
 package gocaptcha
 
 import (
-  "bytes"
   "crypto/rand"
   "encoding/base64"
   "image"
@@ -11,10 +10,12 @@ import (
   "io/ioutil"
   "math/big"
   "strings"
+  "bytes"
 
   "golang.org/x/image/font"
+  "golang.org/x/image/font/sfnt"
   "golang.org/x/image/math/fixed"
-  "github.com/golang/freetype/truetype"
+  "golang.org/x/image/font/opentype"
 )
 
 type Captcha struct {
@@ -38,23 +39,29 @@ func GenerateCaptcha(fontPath, charset string, length int) (*Captcha, error) {
     return nil, err
   }
 
-  f, err := truetype.Parse(fontBytes)
+  f, err := sfnt.Parse(fontBytes)
   if err != nil {
     return nil, err
   }
 
+  face, err := opentype.NewFace(f, &opentype.FaceOptions{
+    Size:    24,
+    DPI:     72,
+    Hinting: font.HintingFull,
+  })
+  if err != nil {
+    return nil, err
+  }
+  defer face.Close()
+
   img := image.NewRGBA(image.Rect(0, 0, 300, 100))
   bgColor := color.RGBA{0, 0, 0, 255}
   draw.Draw(img, img.Bounds(), &image.Uniform{bgColor}, image.Point{}, draw.Src)
 
   d := &font.Drawer{
-    Dst: img,
-    Src: image.NewUniform(color.RGBA{255, 255, 255, 255}),
-    Face: truetype.NewFace(f, &truetype.Options{
-      Size:    24,
-      DPI:     72,
-      Hinting: font.HintingFull,
-    }),
+    Dst:  img,
+    Src:  image.NewUniform(color.RGBA{255, 255, 255, 255}),
+    Face: face,
   }
 
   d.Dot = fixed.Point26_6{
@@ -83,12 +90,10 @@ func VerifyCaptcha(input, captchaText string) bool {
 }
 
 func genTxt(charset string, length int) string {
-  runes := []rune(charset)
   text := make([]rune, length)
   for i := range text {
-    bigIndex, _ := rand.Int(rand.Reader, big.NewInt(int64(len(runes))))
-    randomIndex := int(bigIndex.Int64())
-    text[i] = runes[randomIndex]
+    randomIndex, _ := rand.Int(rand.Reader, big.NewInt(int64(len(charset))))
+    text[i] = rune(charset[randomIndex.Int64()])
   }
   return string(text)
 }