Customized impersonating fingerprints

[T-256]

Is your feature request related to a problem? Please describe. Yes, I think for solving https://github.com/yifeikong/curl_cffi/issues/169 we need python level fingerprint generator.

Describe the solution you'd like Ability to create impersonation in python level and use it in requests.

Describe alternatives you've considered python-tls-client example

[perklet]

We need to get a list of customizable fields.

For TLS, there are too many, I have not bothered to collect them implementation is on the way.

For http2, we are almost there, only one part is missing everything is there.

All the options are listed here: https://github.com/yifeikong/curl-impersonate#libcurl-impersonate

We also need to implement a python class like ImpersonateSpec to specify the detailed instructions.

[perklet]

The first step is to be able to impersonate Firefox with BoringSSL.

• [x] The cipher list option does not work as expected, TLS 1.3 suites always go as the first ones. Added in https://github.com/yifeikong/curl-impersonate/pull/20/commits/8997c93e118e8dbc115d823a1bbe7bbb645d594e
• [x] The extension order can not be changed. Tracked in https://github.com/yifeikong/curl-impersonate/issues/24
• [x] Add option for disabling GREASE. Tracked in https://github.com/yifeikong/curl-impersonate/issues/27
• [x] Some extensions are missing, while some others should be disabled. https://github.com/yifeikong/curl-impersonate/issues/28
  • [x] Disable signed_certificate_timestamp.(Can be easily turned off)
  • [x] Disable application_settings.(Can be easily turned off)
  • [ ] Enable record_size_limit, which is not implemented by OpenSSL/BoringSSL, which means we have to do it ourselves. Tracked in https://github.com/yifeikong/curl-impersonate/issues/25
  • [ ] Enable delegated_credentials. BoringSSL only implemented the server side code, and it's using a different number for this extension. Since OpenSSL has not implemented it, it's unlikely that servers support this extension. We also need to implement this, but only fake the presense of it. It seems that only NSS supports these 2 extensions, utls fakes them anyway, we should do that too. Tracked in https://github.com/yifeikong/curl-impersonate/issues/26

These issues need to be resolved at boringssl level.

• [x] http2 stream priorities can not be customized. Added in https://github.com/yifeikong/curl-impersonate/commit/1d9d7a77afe080e20a2faedb05a05d7619083a2d

This issue can be fixed at curl level.

After the above issues are fixed, we need to

• [x] Export the struct impersonate_opts to Python via cffi.
• [x] Create corresponding Python class.
• [ ] Add a parser to convert other easily accessible formats(e.g. browserleaks/peet.ws) to our internal format.

[perklet]

Added in v0.7.0b7, examples.

[T-256]

I wished a base class that we could inherited browsers and change some of its parameters. Actually, I wish to have customizations same as files in https://github.com/yifeikong/curl-impersonate/blob/main/chrome directly in python.

class BaseFingerprint:
    @property
    def property_name(self): ...

class Chrome124(BaseFingerprint):
    """
    # Updates in this version since Chrome123:
    - Added X25519Kyber768 support
    - Added Priority header support
    """

    def __init__(self):
        self._ciphers ="TLS_AES_128_GCM_SHA256,TLS_AES_256_GCM_SHA384,TLS_CHACHA20_POLY1305_SHA256,ECDHE-ECDSA-AES128-GCM-SHA256,ECDHE-RSA-AES128-GCM-SHA256,ECDHE-ECDSA-AES256-GCM-SHA384,ECDHE-RSA-AES256-GCM-SHA384,ECDHE-ECDSA-CHACHA20-POLY1305,ECDHE-RSA-CHACHA20-POLY1305,ECDHE-RSA-AES128-SHA,ECDHE-RSA-AES256-SHA,AES128-GCM-SHA256,AES256-GCM-SHA384,AES128-SHA,AES256-SHA"
        self._curves = "X25519Kyber768Draft00:X25519:P-256:P-384"

    @property
    def ciphers(self):
        return self._ciphers

    @property
    def curves(self):
        return self._curves

[perklet]

It's my first thought, too.

However, since the fingerprints for browsers have been built into C, I don't feel it necessary to have an exact clone on Python side. If it was designed from ground up with python bindings in mind, I would have the browser settings in Python, too.

Nonetheless, the most common usecase for customized fingerprints should be impersonating other http libs, e.g. okhttp. The easist way to get their fingerprints for users is to copy the JA3 string from WireShark or somewhere.

If your usecase is to alter the browsers' fingerprints a little bit, you can simply add a curl setopt option using the curl_options parameter.