Sets up the ALPN protocols on the context.

Sets up the allowed ciphers. By default this matches the set in util.ssl_.DEFAULT_CIPHERS, at least as supported by macOS. This is do

Sets headers needed by proxies: specifically, the Accept and Host headers. Only sets headers not provided by the user.

This function creates a temporary Mac keychain that we can use to work with credentials. This keychain uses a one-time password and a tempora

Verifies that PyOpenSSL's package-level dependencies have been met. Throws `ImportError` if they are not met.

Validates that were not attempting to do TLS in TLS connections on Python2 or with unsupported SSL implementations.

Raises a ProxySchemeUnsupported if the provided ssl_context can't be used for TLS in TLS. The only requirement is that the s

Add any headers needed by the connection. As of v2.0 this does nothing by default, but is left for overriding by users that subclass t

This function allows you to check if an IP belongs to a network subnet Example: returns True if ip = 192.168.1.1 and net = 192.168.1.0/24

This function is designed to work in the context of getaddrinfo, where family=socket.AF_UNSPEC is the default and will perform a DNS search fo

Checks if given fingerprint matches the supplied certificate. :param cert: Certificate as bytes object. :param fingerprint:

Asserts whether all headers have been successfully parsed. Extracts encountered errors from the result of parsing headers. Only works on

Backport of ``socket.makefile`` from Python 3.5.

Builds a :class:`Response <requests.Response>` object from a urllib3 response. This should not be called from user code, and is only exposed

Verify a SSL certificate. This method should not be called from user code, and is only exposed for use when subclassing the :class:`HT

Verifies that header value is a string which doesn't contain leading whitespace or return characters. This prevents unintended header injectio

Our embarrassingly-simple replacement for mimetools.choose_boundary.