# Client certificate
Client certificate authentication can be configured with the `Client`, the required options are passed along through the `connect` option.
The client certificates must be signed by a trusted CA. The Node.js default is to trust the well-known CAs curated by Mozilla.
Setting the server option `requestCert: true` tells the server to request the client certificate.
The server option `rejectUnauthorized: false` allows us to handle any invalid certificate errors in client code. The `authorized` property on the socket of the incoming request will show if the client certificate was valid. The `authorizationError` property will give the reason if the certificate was not valid.
### Client Certificate Authentication
```js
const { readFileSync } = require('fs')
const { join } = require('path')
const { createServer } = require('https')
const { Client } = require('undici')
const serverOptions = {
ca: [
readFileSync(join(__dirname, 'client-ca-crt.pem'), 'utf8')
],
key: readFileSync(join(__dirname, 'server-key.pem'), 'utf8'),
cert: readFileSync(join(__dirname, 'server-crt.pem'), 'utf8'),
requestCert: true,
rejectUnauthorized: false
}
const server = createServer(serverOptions, (req, res) => {
// true if client cert is valid
if(req.client.authorized === true) {
console.log('valid')
} else {
console.error(req.client.authorizationError)
}
res.end()
})
server.listen(0, function () {
const tls = {
ca: [
readFileSync(join(__dirname, 'server-ca-crt.pem'), 'utf8')
],
key: readFileSync(join(__dirname, 'client-key.pem'), 'utf8'),
cert: readFileSync(join(__dirname, 'client-crt.pem'), 'utf8'),
rejectUnauthorized: false,
servername: 'agent1'
}
const client = new Client(`https://localhost:${server.address().port}`, {
connect: tls
})
client.request({
path: '/',
method: 'GET'
}, (err, { body }) => {
body.on('data', (buf) => {})
body.on('end', () => {
client.close()
server.close()
})
})
})
```
Generated by dwww version 1.15 on Sun Jun 30 09:59:44 CEST 2024.