TLS-Client

Preface

This TLS Client is built upon https://github.com/Carcraftz/fhttp and https://github.com/Carcraftz/utls. Big thanks to all contributors so far. Sadly it seems that the original repositories are not maintained anymore.

What is TLS Fingerprinting?

Some people think it is enough to change the user-agent header of a request to let the server think that the client requesting a resource is a specific browser. Nowadays this is not enough, because the server might use a technique to detect the client browser which is called TLS Fingerprinting.

Even tho this article is about TLS Fingerprinting in NodeJS it well describes the technique in general. https://httptoolkit.tech/blog/tls-fingerprinting-node-js/#how-does-tls-fingerprinting-work

Why is this library needed?

With this library you are able to create a http client implementing an interface which is similar to golangs net/http client interface. This TLS Client allows you to specify the Client (Browser and Version) you want to use, when requesting a server.

The Interface of the HTTP Client looks like the following and extends the base net/http Client Interface by some useful functions. Most likely you will use the Do() function like you did before with net/http Client.

type HttpClient interface {
    GetCookies(u *url.URL) []*http.Cookie
    SetCookies(u *url.URL, cookies []*http.Cookie)
    SetCookieJar(jar http.CookieJar)
    SetProxy(proxyUrl string) error
    GetProxy() string
    SetFollowRedirect(followRedirect bool)
    GetFollowRedirect() bool
    Do(req *http.Request) (*http.Response, error)
    Get(url string) (resp *http.Response, err error)
    Head(url string) (resp *http.Response, err error)
    Post(url, contentType string, body io.Reader) (resp *http.Response, err error)
}

Supported and tested Clients

Chrome
- 103 (chrome_103)
- 104 (chrome_104)
- 105 (chrome_105)
- 106 (chrome_106)
- 107 (chrome_107)
- 108 (chrome_108)
- 109 (chrome_109)
- 110 (chrome_110)
Safari
- 15.6.1 (safari_15_6_1)
- 16.0 (safari_16_0)
iOS (Safari)
- 15.5 (safari_ios_15_5)
- 15.6 (safari_ios_15_6)
- 16.0 (safari_ios_16_0)
iPadOS (Safari)
- 15.6 (safari_ios_15_6)
Firefox
- 102 (firefox_102)
- 104 (firefox_104)
- 105 (firefox_105)
- 106 (firefox_106)
- 108 (firefox_108)
- 110 (firefox_110)
Opera
- 89 (opera_89)
- 90 (opera_90)
- 91 (opera_91)
Custom Clients
- Zalando Android Mobile (zalando_android_mobile)
- Zalando iOS Mobile (zalando_ios_mobile)
- Nike IOS Mobile (nike_ios_mobile)
- Nike Android Mobile (nike_android_mobile)
- Cloudscraper
- MMS IOS (mms_ios)
- Mesh IOS (mesh_ios)

You can also provide your own client. See the example how to do it.

All Clients support Random TLS Extension Order by setting the option on the Http Client itself WithRandomTLSExtensionOrder(). This is needed for Chrome 107+

Installation

go get -u github.com/bogdanfinn/tls-client

// or specific version:
// go get github.com/bogdanfinn/tls-client@v0.5.2

Some users have trouble when using go get -u. If this is the case for you please cleanup your go.mod file and do a go get with a specific version.

I would recommend to check the github tags for the latest version and install that one explicit.

Quick Usage Example

package main

import (
	"fmt"
	"io"
	"log"

	http "github.com/bogdanfinn/fhttp"
	tls_client "github.com/bogdanfinn/tls-client"
)

func main() {
    jar := tls_client.NewCookieJar()
	options := []tls_client.HttpClientOption{
		tls_client.WithTimeoutSeconds(30),
		tls_client.WithClientProfile(tls_client.Chrome_105),
		tls_client.WithNotFollowRedirects(),
		tls_client.WithCookieJar(jar), // create cookieJar instance and pass it as argument
		//tls_client.WithProxyUrl("http://user:pass@host:port"),
		//tls_client.WithInsecureSkipVerify(),
	}

	client, err := tls_client.NewHttpClient(tls_client.NewNoopLogger(), options...)
	if err != nil {
		log.Println(err)
		return
	}

	req, err := http.NewRequest(http.MethodGet, "https://tls.peet.ws/api/all", nil)
	if err != nil {
		log.Println(err)
		return
	}

	req.Header = http.Header{
		"accept":                    {"*/*"},
		"accept-language":           {"de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7"},
		"user-agent":                {"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.75 Safari/537.36"},
		http.HeaderOrderKey: {
			"accept",
			"accept-language",
			"user-agent",
		},
	}

	resp, err := client.Do(req)
	if err != nil {
		log.Println(err)
		return
	}

	defer resp.Body.Close()

	log.Println(fmt.Sprintf("status code: %d", resp.StatusCode))

	readBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		log.Println(err)
		return
	}

	log.Println(string(readBytes))
}

For more configured clients check ./profiles.go, ./custom_profiles.go or use your own custom client. See examples folder how to use a complete custom tls client.

Client Options

List of current available client options.

WithTimeoutSeconds
WithTimeoutMilliseconds
WithProxyUrl
WithCookieJar
WithDebug
WithNotFollowRedirects
WithInsecureSkipVerify
WithClientProfile
WithServerNameOverwrite
WithForceHttp1
WithRandomTLSExtensionOrder
WithTransportOptions
WithCharlesProxy
WithCertificatePinning
WithCustomRedirectFunc
WithCatchPanics

Default Client

The implemented default client is currently Chrome 110 with a configured request timeout of 30 seconds and no automatic redirect following and with a cookiejar. Also Random Extension Order is activated for the default client.

Compile this client as a shared library for use in other languages like Python or NodeJS

Please take a look at the cross compile build script in cffi_dist/build.sh to build this tls-client as a shared library for other programming languages (.dll, .so, .dylib).

The build script is written to cross compile from OSX to all other platforms (osx, linux, windows). If your build os is not OSX you might need to adjust the build script.

You can also use the prebuilt packages in cffi_dist/dist

A python example on how to load and call the functionality can be found in cffi_dist/example_python. Please be aware that i'm not a python expert. I highly recommend to take a look at this repository, when you want to use this tls-client in python: https://github.com/FlorianREGAZ/Python-Tls-Client

A NodeJS example on how to load and call the functionality can be found in cffi_dist/example_node. Please be aware that you need to run npm install to install the node dependencies.

The basic logic behind the shared library is, that you pass all required information in a JSON string to the shared lib function which then creates the client, the request and the request data out of it and forwards the request. For more documentation on this JSON string please take a look at: https://github.com/bogdanfinn/tls-client-api

Every Response from the shared library will contain an id field like that: "id":"some-uuid-v4-value". You can use the id to free the memory. Otherwise you will end up with growing allocated memory. Basic Nodejs example:

const response = tlsClientLibrary.request(JSON.stringify(requestPayload));
const responseObject = JSON.parse(response)
tlsClientLibrary.freeMemory(responseObject.Id)

Further Information

This library uses the following api: https://tls.peet.ws/api/all to verify the hashes and fingerprints for akamai and ja3. Be aware that also peets api does not show every extension/cipher a tls client is using. Do not rely just on ja3 strings.

If you are not using go and do not want to implement the shared library but want to use the functionality check out this repository https://github.com/bogdanfinn/tls-client-api

Certificate Pinning

The client has built in certificate pinning support. Just use the WithCertificatePinning Option and provide the pins by hosts you want to enable pinning for. And if you want a callback to be executed on bad pin. Please refer to the examples in example/main.go to see how certificate pinning can be used in your application (sslPinning()). Also take a look at https://github.com/tam7t/hpkp to learn how to generate pins. You can install hpkp-pins by running go install github.com/tam7t/hpkp/cmd/hpkp-pins@latest

Frequently Asked Questions / Errors

How can I add GREASE to Custom Client Profiles when using the shared library?

Please refer to index_custom_client.js or example_custom_client.py in either NodeJS examples or Python Examples. You can use the Magic Number 2570. You can add it in a ja3 string for example to turn that into a GREASE cipher or tls extension.

I receive PROTOCOL_ERROR on POST Request

This is a very generic error and can have many root causes. Most likely users of this client are setting the content-length header manually with a (wrong) fixed value.

This client fails when I test on www.google.com

Please check this issue for explanation: bogdanfinn#6. Should be fixed since 0.8.3

I'm receiving tls: error decoding message when using this TLS Client.

This issue should be fixed since v0.3.0. There was an issue with the CompressCertExtension in the utls package dependency.

The TLS-Client does not set the user-agent header correctly

Do not mix up TLS-Fingerprints with HTTP Request Headers. They have more or less nothing in common. AntiBots using for example header order in addition to TLS-Fingerprinting. This library does only handle the TLS- and Akamai Fingerprint. You are still responsible to define the to be used headers and the header order. If you do not provide any headers the http client will use by default these two headers (nothing more):

accept-encoding: gzip, deflate, br
user-agent: Go-http-client/2.0

If I use the shared library in electron my application freezes? Please only load the dll once in your application and call every function async to not block the main thread. An example is added in the nodejs examples.
My Post Request is not working correctly? Please make sure that you set the correct Content-Type Header for your Post Body Payload.
About accept-encoding and automatic decompression If you are specifying accept-encoding header yourself and you are on http1 connection than you have to take care of the decompression yourself. It is not done automatically. Only if you are not adding accept-encoding header then the library adds it for you if not explicit disabled and also handles the decompression automatically.

On http2 the automatic decompression should always be in place according to the Content-Type Header on the Response.

So if you are trying to use "only" accept-encoding: gzip you have to take care of the decompression. DecompressBody is exported. You can just reuse it like that:

req, err := http.NewRequest(http.MethodGet, "https://tls.browserleaks.com/json", nil)
    if err != nil {
        log.Println(err)
        return
    }

    req.Header = http.Header{
        "accept":          {"*/*"},
        "accept-encoding": {"gzip"},
        "accept-language": {"de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7"},
        "user-agent":      {"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36"},
        http.HeaderOrderKey: {
            "accept",
            "accept-encoding",
            "accept-language",
            "user-agent",
        },
    }

    resp, err := client.Do(req)

    if err != nil {
        log.Println(err)
        return
    }

    defer resp.Body.Close()

    decomBody := http.DecompressBody(resp)

    all, err := io.ReadAll(decomBody)
    if err != nil {
        log.Println(err)
        return
    }
    log.Println(string(all))

Questions?

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nm235666/tls-client