Develop

lib/captcha.js

@@ -126,7 +126,7 @@ function filter(im) {
   om.copy(im)
 }
 
-async function captcha(size) {
+async function captcha(letters,size) {
   const rb = await urandom(size + 200 + 100 * 4 + 1 + 1)
   const l = Buffer.alloc(size)
   const swr = Buffer.alloc(200)
@@ -148,9 +148,9 @@ async function captcha(size) {
   let p = 30
 
   for (let n = 0; n < size; n++) {
-    l[n] %= 25
+    l[n] %= letters.length -1;
     p = letter(l[n], p, im, swr, s1, s2)
-    l[n] = LETTERS.charCodeAt(l[n])
+    l[n] = letters.charCodeAt(l[n])
   }
 
   line(im, swr, s1)
@@ -192,9 +192,9 @@ function makegif(im, gif, style) {
   gif.fill('\x01\x11\x00;', GIF_SIZE - 4)
 }
 
-async function generate({ size = SIZE, style = -1 } = {}) {
+async function generate({ size = SIZE, style = -1, letters = LETTERS } = {}) {
   const gif = Buffer.alloc(GIF_SIZE)
-  const { im, l } = await captcha(size)
+  const { im, l } = await captcha(letters,size)
   makegif(im, gif, style)
 
   return {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "trek-captcha",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "A Lightweight Pure JavaScript Captcha for Node.js. No C/C++, No ImageMagick, No canvas.",
   "repository": "trekjs/captcha",
   "author": {

test/index.js

@@ -7,3 +7,9 @@ test('should return an object and include token and buffer', async t => {
   t.is(token.length, 5)
   t.is(buffer.length, 17646)
 })
+test('random numbers should be from letters', async t => {
+	const { token } = await captcha({letters:'1'})
+	console.log(token);
+	t.is(token, '11111')
+  })
+