curl-impersonate

Note

This is a (slightly) more active fork of curl-impersonate. With the following enhancements:

1. Encrypted Client Hello(ECH) support introduced in Chrome 119.
2. ZSTD compression support introduced in Chrome 123.
3. X25519Kyber768/X25519MLKEM curves introduced in Chrome 124 and 130.
4. More options for impersonating Akamai http/2 fingerprints, especially for Safari.
5. Upgrade to more recent version of curl, 8.7.1 as of April, 2024.
6. Ability to change extension orders and enable/disable TLS grease.
7. Single binary to support Chrome, Safari and Firefox.
8. (In progress) Built with http/3 enabled.
9. A user-friendly Python binding: curl_cffi.

A special build of curl that can impersonate the four major browsers: Chrome, Edge, Safari and Firefox. curl-impersonate is able to perform TLS and HTTP handshakes that are identical to that of a real browser.

curl-impersonate can be used either as a command line tool, similar to the regular curl, or as a library that can be integrated instead of the regular libcurl. See Usage below.

Why?

When you use an HTTP client with a TLS website, it first performs a TLS handshake. The first message of that handshake is called Client Hello. The Client Hello message that most HTTP clients and libraries produce differs drastically from that of a real browser.

If the server uses HTTP/2, then in addition to the TLS handshake there is also an HTTP/2 handshake where various settings are exchanged. The settings that most HTTP clients and libraries use differ as well from those of any real browsers.

For these reasons, some web services use the TLS and HTTP handshakes to fingerprint which client is accessing them, and then present different content for different clients. These methods are known as TLS fingerprinting and HTTP/2 fingerprinting respectively. Their widespread use has led to the web becoming less open, less private and much more restrictive towards specific web clients.

With the modified curl in this repository, the TLS and HTTP handshakes look exactly like those of a real browser.

How?

To make this work, curl was patched significantly to resemble a browser. Specifically, The modifications that were needed to make this work:

• Compiling with BoringSSL, Google's TLS library, which is used by Chrome and Safari.
• Modifying the way curl configures various TLS extensions and SSL options.
• Adding support for new TLS extensions.
• Changing the settings that curl uses for its HTTP/2 connections.
• Running curl with some non-default flags, for example --ciphers, --curves and some -H headers.

The resulting curl looks, from a network perspective, identical to a real browser.

Read the original technical description in the blog posts: part a, part b. Much more has been added since then, but you get the general ideas :P.

Supported browsers

The following browsers can be impersonated.

Browser	Version	Build	OS	Target name	Wrapper script
	99	99.0.4844.51	Windows 10	chrome99	curl_chrome99
	100	100.0.4896.75	Windows 10	chrome100	curl_chrome100
	101	101.0.4951.67	Windows 10	chrome101	curl_chrome101
	104	104.0.5112.81	Windows 10	chrome104	curl_chrome104
	107	107.0.5304.107	Windows 10	chrome107	curl_chrome107
	110	110.0.5481.177	Windows 10	chrome110	curl_chrome110
	116	116.0.5845.180	Windows 10	chrome116	curl_chrome116
	119	119.0.6045.199	macOS Sonoma	chrome119	curl_chrome119
	120	120.0.6099.109	macOS Sonoma	chrome120	curl_chrome120
	123	123.0.6312.124	macOS Sonoma	chrome123	curl_chrome123
	124	124.0.6367.60	macOS Sonoma	chrome124	curl_chrome124
	131	131.0.6778.86	macOS Sonoma	chrome131	curl_chrome131
	99	99.0.4844.73	Android 12	chrome99_android	curl_chrome99_android
	131	131.0.6778.81	Android 14	chrome131_android	curl_chrome131_android
	99	99.0.1150.30	Windows 10	edge99	curl_edge99
	101	101.0.1210.47	Windows 10	edge101	curl_edge101
	15.3	16612.4.9.1.8	MacOS Big Sur	safari15_3	curl_safari15_3
	15.5	17613.2.7.1.8	MacOS Monterey	safari15_5	curl_safari15_5
	17.0	unclear	MacOS Sonoma	safari17_0	curl_safari17_0
	17.2	unclear	iOS 17.2	safari17_2_ios	curl_safari17_2_ios
	18.0	unclear	MacOS Sequoia	safari18_0	curl_safari18_0
	18.0	unclear	iOS 18.0	safari18_0_ios	curl_safari18_0_ios
	133.0	133.0.3	macOS Sonoma	firefox133	curl_firefox133

Notes:

1. Chromium-based browsers all share the same fingerprints, except for the User-Agent header and sec-ch-ua-platform header. They will not be updated unless this assumption changed. Use your own header if you need to impersonate Edge, Chrome Android etc.
2. The original Safari fingerprints in the upstream fork are not correct.

This list is also available in the browsers.json file.() Needs to be updated.

Install

The simplest way is to download the prebuilt binaries from the release page. If you want to build by yourself, please refer to the INSTALL.md and docs/install.md.

Basic usage

For each supported browser there is a wrapper script that launches curl-impersonate with all the needed headers and flags. For example:

curl_chrome123 https://www.wikipedia.org

You can add command line flags and they will be passed on to curl. However, some flags change curl's TLS signature which may cause it to be detected.

To check the fingerprints are correct:

curl_firefox133 https://tls.browserleaks.com/json

Please note that the wrapper scripts use a default set of HTTP headers. If you want to change these headers, you may want to modify the wrapper scripts to fit your own purpose.

See the docs for more options, including using libcurl-impersonate as a library.

Documentation

More documentation is available in the docs/ directory.

Repository Contents

This repository contains these folders:

• chrome - Scripts and patches for building the Chrome version of curl-impersonate.
  • curl_chrome110, curl_chrome124 - Wrapper scripts that launch curl-impersonate with the correct flags.
  • curl-impersonate.patch - The main patch that makes curl use the same TLS extensions as Firefox. Also makes curl compile statically with libnghttp2.
  • boringssl.patch - The boringssl patch that tweaks boringssl behaviors.
• win - Scripts for building the Windows version of curl-impersonate, which is quite different from *nix.
• zigshim - We use the awesome zig toolchain to bring curl-impersonate to more archs on Linux.
• docker - Debian and alpine dockerfiles for this project.

Other files of interest:

• tests/signatures - YAML database of known browser signatures that can be impersonated.

Contributing

If you'd like to help, please check out the open issues in the origional repo and open issues here. You can open a pull request with your changes. Note that some of the upstream issues have been fixed.

This repository contains the build process for curl-impersonate. The actual patches to curl are maintained in a separate repository forked from lwthiker's fork of the upstream curl. The changes are maintained in the impersonate-firefox and impersonate-chrome branches.

You may also need the forked and patched BoringSSL.

Acknowledgements

• Special thanks to @bjia56 for making cross compiling possible.
• Special thanks to @smaug2309 and @afulsamet for bring back the Windows build.
• Special thanks to @penumbra-x for the boringssl patch on firefox.

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