canvas-captcha
a captcha module for nodejs based on node-canvas
note
- install Cairo first, For system-specific installation view the Wiki from node-canvas
- if you can see the captcha image, but empty, try another font your server has or install proper font pack in your server, such as
sudo apt-get install ttf-mscorefonts-installer.
Installation
npm install canvas-captchause
//captcha
let captcha = require('canvas-captcha')
let captchaOptions = {
charPool: ('abcdefghijklmnopqrstuvwxyz' + 'abcdefghijklmnopqrstuvwxyz'.toUpperCase() + '1234567890').split('') //char pool Array
,size: {
width: 100
,height: 32
} //image size
,textPos: {
left: 15
,top: 26
} //text drawing start position
,rotate: .01 //text ratate
,charLength: 4 //how many chars
,font: '26px Unifont' //font size
,strokeStyle: '#0088cc' //style
,bgColor: '#eeeeee' //bg color
,confusion: true //draw another group background text to mangle the text
,cFont: '30px Arial' //bg text style
,cStrokeStyle: '#adc' //bg text color
,cRotate: -.05 //bg text rotate
}
//callback style
app.get('/captcha', function(req, res) {
captcha(captchaOptions, function(err, data) {
if(err) {
res.send(err)
}
else {
req.session.captcha = data.captchaStr
res.end(data.captchaImg)
}
})
})
//use promise
let captchaPromise = function(options) {
return new Promise(function(resolve, reject) {
captcha(options, function(err, data) {
if(err) reject(err)
else resolve(data)
})
})
}
//in express
app.get('/captcha', function(req, res) {
captchaPromise(captchaOptions)
.then(function(data) {
req.session.captcha = data.captchaStr
res.end(data.captchaImg)
}, function(err) {
res.send(err)
})
})
//in koa
app.get('/captcha', function* (next) {
var data = yield captchaPromise(captchaOptions)
this.session.captcha = data.captchaStr
this.body = data.captchaImg
})
//or
app.get('/captcha', async ctx => {
let data = await captchaPromise(captchaOptions)
ctx.session.captcha = data.captchaStr
ctx.body = data.captchaImg
})
test && example
git clone https://github.com/zxdong262/canvas-captcha.git
cd canvas-captcha
sudo npm install
# test
npm run test
# example
node test/app.js
# then visit http://127.0.0.1:5001changelog
- 2.1.0 use canvas 1.3.15, support node 6.2+
- 2.0.1 use canvas 1.3.12, a little rewrite
- 2.0.0 use canvas 1.2.9, compatible with nodejs v4
- 1.2.8 use 'Unifont' as default font
- 1.2.7 use 'system' as default font
- 1.2.6 just fix readme koa example
- 1.2.5 add some example to readme, use canvas version
1.2.1 - 1.2.4 make
errthe first callback param - 1.2.3 use canvas version
1.1.6version instead of version*
license
MIT
