freeptcha/routes.js

59 lines
1.7 KiB
JavaScript

const sharp = require('sharp');
const canvas = require('canvas');
const crypto = require('crypto')
/** @param {import('fastify').FastifyInstance} fastify */
module.exports = (fastify) => {
fastify.get('/captcha/v1/:text', async (req, res) => {
let pic = (await sharp({
create: {
width: 150,
height: 50,
channels: 4,
background: { r: 0, g: 0, b: 0, alpha: 0 }
}
}));
const text = req.params.text;
pic.composite([
{
input: {
text: {
text: text,
font: 'Arial',
dpi: crypto.randomInt(150, 200),
rgba: true
}
},
blend: 'over'
}
]);
const textpic = await pic
.ensureAlpha()
.toFormat('png', { compressionLevel: 6 })
.toBuffer();
const draw = canvas.createCanvas(150, 50);
const ctx = draw.getContext('2d');
ctx.drawImage(await canvas.loadImage(textpic), 0, 0, 150, 50);
const randint = (min, max) => { return crypto.randomInt(max) + min };
const strokes = randint(25, 50);
for (let i = 0; i != strokes; i++) {
ctx.strokeStyle = `rgba(0,0,0,${10})`;
ctx.beginPath();
ctx.bezierCurveTo(randint(0, 150), randint(0, 50), randint(0, 150), randint(0, 50), randint(0, 150), randint(0, 50));
ctx.stroke();
}
ctx.bezierCurveTo(20, 20, 20, 30, 70, 25);
ctx.stroke();
res.header('Content-Type', 'png');
return draw.toBuffer();
})
}