CHANGES.rst

2.11.910 (2024-11-08)

• Improved reliability of reusing a specific outgoing port. The feature is no longer experimental.

2.11.909 (2024-11-07)

• Fixed DNS-over-QUIC, DNS-over-TLS, and DNS-over-UDP(Cleartext) connection procedure on network that lacks IPv6 access.
• Fixed DNS-over-TLS unstable over a slow network.
• Fixed a bug when setting a specific port in source_address and setting happy_eyeballs=True. We now silently discard the specific port to avoid a conflict / race condition with OS outgoing port allocation.
• Improved reliability of our tests and fixed warnings in them.
• Preemptively disabled QUIC (HTTP/3 included) with interpreter built with FIPS-compliant SSL module. Our QUIC implementation isn't FIPS-compliant for the moment. To force using non-FIPS QUIC implementation, please patch urllib3.util.ssl_.IS_FIPS and set it to False.
• Fixed DoQ default certs loading as done in DoT, and DoH.
• Improved reusability of a specific outgoing port. This is still an experimental feature, it is likely that CPython have a bug that prevent consistent behavior for this.

2.11.908 (2024-11-03)

• Fixed async connection shutdown in HTTP/1.1 and HTTP/2 leaving a asyncio.TransportSocket and _SelectorSocketTransport partially closed.
• Added automatic mitigation of using deprecated PROTOCOL_TLS_* constants in ssl_version parameter.

2.11.907 (2024-10-30)

• Fixed attempt to send ping frame in our discrete background idle watcher when the connection has just been closed.

2.11.906 (2024-10-26)

• Fixed unexpected exception when recreating a connection using the same outgoing port. Add SO_REUSEPORT if available, fallback to SO_REUSEADDR. This socket option is not bullet proof against reusability errors. Some OS differs in behaviors.

2.11.905 (2024-10-26)

• Fixed custom loop like uvloop needing advanced error handling on transport close.
• Fixed MacOS connection reset by peer handling to detect connection close (continuation of fix in 2.11.902)

2.11.904 (2024-10-25)

• Improve (async) close procedure when used in a uvloop.

2.11.903 (2024-10-22)

• Fixed (low-level) exception leak when using get_response(...) after urlopen(..., multiplexed=True).
• Fixed erroneous calculated maximal wait when starting a connection upgrade to a higher protocol version in rare cases (async+windows only).

2.11.902 (2024-10-22)

• Added viable replacement for connection close detection since we stopped using the function wait_for_read in property is_connected of a HTTPConnection object. And we harmonized the behavior whether you use async or sync.

2.11.901 (2024-10-21)

• Fixed error in is_connected for a Connection. The logic is no longer applicable due to how urllib3-future grows. We no longer use the function wait_for_read. Also we stopped using MSG_PEEK for our discrete incoming data watcher due to suspicious behavior noticed. Finally we shielded any exception from attempting to close a broken socket.

2.11.900 (2024-10-21)

• Added a discrete task for each instantiated ConnectionPool to watch for unsolicited incoming data. This improves the fix shipped in v2.10.906 and avoid having to recycle your multiplexed connection in idle moments. A new keyword argument is supported in your PoolManager configuration, namely background_watch_delay. This parameter takes a int or float as the delay between checks. Set it to None to void this background task. Anything lower than 0.01 will be interpreted as None, therefor disabling the discrete watch.
• Added managed keepalive for HTTP/2 and HTTP/3 over QUIC. A new keyword argument, named keepalive_delay that takes a value expressed in seconds for how long urllib3-future should automatically keep the connection alive. This is done in direct extension to our "discrete task" mentioned just before. We will send PING frame automatically to the remote peer every 60s by default (after idle for 60s to be clear). The window delay for sending a PING is configurable via the keepalive_idle_window parameter. Learn more about this in our documentation.
• Fixed evaluation of fp in our LowLevelResponse instance to raise AttributeError when it cannot be accessed. This will help with cachecontrol[filecache] way of determining if response was consumed entirely.

2.10.906 (2024-10-17)

• Fixed handling aggressive ACKs watcher in some QUIC server implementation leading to a ProtocolError. We're actively working toward a solution that will avoid to recycle the QUIC connection.

2.10.905 (2024-10-15)

• Fixed dangling task waiting for timeout when using Happy Eyeballs in a synchronous context.

2.10.904 (2024-10-13)

• Fixed thread/task safety with WebSocket R/W operations.
• Fixed missing propagation of callbacks (e.g. on_post_connection) in retries of failed requests.

2.10.903 (2024-10-12)

• Fixed exception leaks in ExtensionFromHTTP plugins. Now every extension behave and raise urllib3 own exceptions.
• Added automatic connection downgrade HTTP/2 -> HTTP/1.1 or HTTP/3 -> (HTTP/2 or HTTP/1.1) in case of known recoverable issues.
• Fixed a rare issue where the write semaphore (async context) for a datagram socket would be locked forever in case of an error.

2.10.902 (2024-10-09)

• Fixed call to stream(..) on (early) informational responses. The inner fp was set to None and the function is_fp_closed is not meant to handle this case. Through you should never expect a body in those responses.
• Fixed read(), and data returns None for (early) informational responses.

2.10.901 (2024-10-08)

• Fixed closed state on a WebSocketExtensionFromHTTP when the remote send a CloseConnection event.
• Fixed an edge case where a DNS-over-HTTPS would start of a non-multiplexed connection but immediately upgrade to a multiplexed capable connection would induce an error.
• Allow to disable HTTP/1.1 in a DNS-over-HTTPS resolver.
• Extra "qh3" lower bound aligned with the main constraint >=1.2,<2.

2.10.900 (2024-10-06)

• Added complete support for Informational Response whether it's an early response or not. We introduced a callback named on_early_response that takes exactly one parameter, namely a HTTPResponse. You may start leveraging Early Hints! This works regardless of the negotiated protocol: HTTP/1.1, HTTP/2 or HTTP/3! As always, you may use that feature in a synchronous or asynchronous context.
• Changed qh3 lower bound version to v1.2 in order to support Informational Response in HTTP/3 also.
• Added full automated support for WebSocket through HTTP/1.1, HTTP/2 or HTTP/3. In order to leverage this feature, urllib3-future now recognize url scheme ws:// (insecure) and wss:// (secure). The response will be of status 101 (Switching Protocol) and the body will be None. Most servers out there only support WebSocket through HTTP/1.1, and using HTTP/2 or HTTP/3 usually ends up in stream (reset) error. By default, connecting to wss:// or ws:// use HTTP/1.1, but if you desire to leverage the WebSocket through a multiplexed connection, use wss+rfc8441:// or ws+rfc8441://. A new property has been introduced in HTTPResponse, namely extension to be able to interact with the websocket server. Everything is handled automatically, from thread safety to all the protocol logic. See the documentation for more. This will require the installation of an optional dependency wsproto, to do so, please install urllib3-future with pip install urllib3-future[ws].
• Fixed a rare issue where the :authority (special header) value might be malformed.

2.9.900 (2024-09-24)

• Fixed a rare issue where HTTPS record is misinterpreted, thus leading to a missed preemptive HTTP/3 negotiation.
• Restored support for older-and-deprecated PySocks if installed and python-socks is absent for synchronous support of SOCKS proxies.
• Added support for HTTP Trailers across HTTP/1, HTTP/2 and HTTP/3 responses. We added the property trailers in HTTPResponse to reflect that.
• Fixed unclosed resource warning for socket created in asynchronous mode.
• Added support for Upgrading to HTTP/2 (If coming from HTTP/1) via Alt-Svc. Whether it's h2c (http/2 over cleartext) or h2.
• Largely improve download speed on the QUIC layer by increasing automatically the blocksize to the largest value allowed on UDP (value taken from sysconf).
• Fixed the test suite outcome if no support for HTTP/3 exist in current environment.

2.8.907 (2024-08-20)

• Fixed http2 maximum frame size error when the remote explicitly set a lower value than the default blocksize. This can happen when facing an Apache (httpd) server see https://github.com/apache/httpd/commit/ff6b8026acb8610e4faf10ee345141a3da85946e Now we monitor the max_frame setting value to ensure we don't exceed it.

2.8.906 (2024-08-15)

• Removed opinionated OpenSSL version constraint that forbid any version lower than 1.1.1. The reasoning behind this is that some companies expressed (to us) the need to upgrade urllib3 to urllib3-future in (very) old Python 3.7 built against patched OpenSSL 1.0.2 or 1.0.8 and collaborative testing showed us that this constraint is overly protective. Those build often lack TLS 1.3 support and may contain major vulnerabilities, but we have to be optimistic on their awareness. TLS 1.3 / QUIC is also an option for them as it works out of the box on those old distributions. Effective immediately, we added a dedicated pipeline in our CI to verify that urllib3-future works with the oldest Python 3.7 build we found out there. Blindly removing support for those libraries when supporting Python 3.7 ... 3.9 is as we "partially" support this range and end-users have no to little clues for why it's rejected when it clearly works. The only issue that can appear is for users that have Python built against a SSL library that does not support either TLS 1.2 or 1.3, they will encounter errors for sure.
• Changed to submodule http2 to subpackage http2. Purely upstream sync. Still no use for us.
• Changed minimum (C)Python interpreter version for qh3 automatic pickup to 3.7.11 as it bundle pip 21.2.4 and is the minimum version to pick an appropriate (abi3) pre-built wheel. You may still install qh3 manually by first upgrading your pip installation by running python -m pip install -U pip.
• Fixed an issue where a server is yielding an invalid/malformed Alt-Svc header and urllib3-future may crash upon it.
• Fixed an issue where sending a str body using a bytes value for Content-Type would induce a crash. This was due to our unicode transparency policy. See #142

2.8.905 (2024-08-04)

• Fixed wrong upgrade attempt to QUIC when using a SOCKS proxy. Any usage of a proxy disable HTTP/3 over QUIC as per documented. until proper support is implemented in a next minor version.
• Backported upstream urllib3 #3434: util/ssl: make code resilient to missing hash functions. In certain environments such as in a FIPS enabled system, certain algorithms such as md5 may be unavailable. Due to the importing of such a module on a system where it is unavailable, urllib3(-future) will crash and is unusable. urllib3#3434
• Backported upstream urllib3 GHSA-34jh-p97f-mpxf: Strip Proxy-Authorization header on redirects. Added the Proxy-Authorization header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via Retry.remove_headers_on_redirect.
• Fixed state-machine desync on a rare scenario when uploading a body using HTTP/3 over QUIC.

2.8.904 (2024-07-18)

• Relaxed h11 constraint around "pending proposal" and coming server event about upgrade. This is made to ensure near perfect compatibility against the legacy urllib3 which is based on http.client.
• Fixed h11 yielding bytearray instead of bytes in rare circumstances.
• Added docker-py in our CI/integration pipeline.

2.8.903 (2024-07-17)

• Added IS_PYOPENSSL constant that is exposed by upstream in urllib3.util.ssl_ submodule.
• Fixed missing exception (ImportError) when importing urllib3.contrib.pyopenssl when PyOpenSSL isn't present in environment.
• Lowered and simplified testing requirements for HTTP/2, and HTTP/3.
• Added boto3, sphinx, and requests to our downstream test cases (nox).

2.8.902 (2024-07-07)

• Added support for async iterable yielding either bytes or str when passing a body into your requests.
• Added dummy module (e.g. http2 and emscriptem) like upstream without serving any of them. Those modules won't be served and are empty as we diverged since.
• Added a better error message for http3 handshake failure to help out users figuring out what is happening.
• Added official support for Python 3.13

2.8.901 (2024-06-27)

• Improved compatibility with httplib exception for IncompleteRead that did not behave exactly like expected (repr/str format over it).
• The metric TLS handshake delay was wrongfully set when using HTTP/2 over cleartext.
• Fixed compatibility with some third-party mocking library that are injecting io.BytesIO in HTTPResponse. In some cases, IncompleteRead might not be raised like expected.

2.8.900 (2024-06-24)

• Support for HTTP/2 with prior knowledge over non-encrypted connection to leverage multiplexing in internal networks. To leverage this feature, you have to disable HTTP/1.1 so that urllib3-future can infer your intent. Disabling HTTP/1.1 is to be made as follow: PoolManager(disabled_svn={HttpVersion.h11}).
• Added raw data bytes counter in LowLevelResponse to help end-users track download speed accordingly if they use brotli, gzip or zstd transfer-encoding during downloads.

2.7.914 (2024-06-15)

• Further improved compatibility with some third party programs that accessed hazardous materials within http.client standard library.
• Add "ARM64" architecture for qh3 automatic installation on Windows.

2.7.913 (2024-05-31)

• Relaxed constraints around HTTPConnectionPool._new_conn private method in order to ensure a broader compatibility. (#122)

2.7.912 (2024-05-27)

• Fixed unset tls_version within ConnectionInfo when using the legacy TLSv1 protocol.
• Fixed license metadata SPDX in package.
• Fixed custom ssl context with OP_NO_TLSv1_3 option that did not disable HTTP/3.
• Fixed custom ssl context with assert_hostname=False parameter not forwarded to QUIC configuration.

2.7.911 (2024-05-24)

• Fixed the ability to override properly the :authority special header via the legacy Host header.

2.7.910 (2024-05-22)

• Removed workaround for a bug that existed in qh3 < 1.0 with cryptography in a concurrent (thread) environment.
• Avoid loading qh3 at runtime in order to improve import delay. It was used to probe HTTP/3 support. We compute it lazily from now on.
• Added the possibility to use the preemptive_quic_cache MutableMapping to exclude endpoints. If your implementation discard the recently set key/entry it will prevent the connection from upgrading itself.

2.7.909 (2024-05-17)

• Improve (large) data download performance by increasing the default blocksize.
• Improve HTTP/1.1 performance by reducing the amount of time we want to infer "if next cycle" should be triggered.

2.7.908 (2024-05-16)

• Improve traffic_state_of function to improve the overall performance in a highly concurrent context.

2.7.907 (2024-05-05)

• Passing a ssl context containing manually loaded root certificates no longer is ignored with HTTP/3 over QUIC.

2.7.906 (2024-05-02)

• Overall performance improvement with HTTP/2 in a highly concurrent context.

2.7.905 (2024-04-28)

• Added support for jh2>=5,<6 instead of h2~=4.0 as a drop-in replacement. Expect a significant performance improvement with HTTP/2. We successfully reduced our dependency footprint to the minimum.

2.7.904 (2024-04-20)

• Added support for qh3 version v1
• Security: Fixed ignored DNS matching with its certificate in certain conditions while negotiating HTTP/3 over QUIC

2.7.903 (2024-04-04)

• Removed warning about "unresponsive" pool of connection due to how it can confuse users.

2.7.902 (2024-04-03)

• Fixed a rare racing condition occurring on PyPy when using DNS-over-HTTPS leading to a socket.gaierror exception.
• Fixed retrieving the dict peer certificate when cert_reqs=0 aka. disabled TLS over TCP verification.

2.7.901 (2024-03-27)

• Fixed an edge case with Response::read() confusing situation where passing a positive amount to read then passing None n-times would continuously return cached data if the stream was closed (content consumed).
• Fixed IncompleteRead exception property expected that did not contain the "remaining" amount expected but rather the total expected.

2.7.900 (2024-03-25)

• Added Happy-Eyeballs support. This feature is disabled by default, you can enable it by passing happy_eyeballs=True into AsyncPoolManager, AsyncHTTPConnectionPool or its synchronous counterparts. See the documentation to learn more.
• Fixed an issue where passing a IPv6 address to the in-memory resolver provider would be improperly registered.
• Fixed unclosed socket when the user attempt to set a impossible port to bind on (i.e. not in range 0-65535) leading to a ResourceWarning.
• Fixed a rare issue with DNS-over-HTTPS where a HTTPS record would also be interpreted as a normal record.

2.6.906 (2024-03-18)

• Fixed SSL context cache construction that did not take key_password into account.
• Prefer return NotImplemented instead of raising NotImplementedError to avoid polluting the stack trace when trying to initialize the external tls layer when not concerned (e.g. not http3 over QUIC).

2.6.905 (2024-03-17)

• Fixed traffic police shutdown procedure to avoid killing needlessly a new connection or pool.

2.6.904 (2024-03-17)

• Overall performance improvements for both async and sync calls.
• Removed TrafficPolice internal caching for obj states of contained elements due to its inability to be up-to-date in some cases.
• Fixed SSLError wrong message displayed when using the underlying qh3 library (HTTP/3 only).
• Fixed graceful shutdown for rare HTTP/2 servers configured to immediately forbid opening new streams.

2.6.903 (2024-03-10)

• Overall performance improvements for both async and sync calls.

2.6.902 (2024-03-04)

• Fixed PyPy error when running asynchronous code on Windows after trying to create a datagram socket. This error is due to an incomplete implementation of the Windows socket API. We silently disabled HTTP/3 if running PyPy+Windows+asyncio until upstream issue resolution.
• Overall performance improvements for both async and sync calls.
• Fixed ProtocolError (No recent network activity after XYZ) error when it should recycle the connection automatically (sync only).
• Added a user-friendly error message when invoking get_response from either PoolManager or ConnectionPool with anything else than a ResponsePromise.

2.6.901 (2024-02-28)

• Fixed blocking IO just after HTTP/3 is negotiated in an asynchronous context.
• Added explicit warning in case your pool of connections is insufficiently sized for the given charge in an asynchronous context.
• Fixed automatic retrieval of the issuer certificate in an asynchronous context (ConnectionInfo).

2.6.900 (2024-02-26)

• Added full asynchronous support using asyncio. urllib3.future officially support asyncio as his asynchronous scheduler. The following public classes are immediately available:

  AsyncPoolManager, AsyncHTTPConnectionPool, AsyncHTTPSConnectionPool, AsyncProxyManager, AsyncResolverDescription.

  Finally, bellow functions are also available:

  async_proxy_from_url, and async_connection_from_url.

  Explore the documentation section about async to learn more about this awesome feature with detailed examples. No extra dependencies are required. We rely exclusively on the standard library.

  Async SOCKS proxies are also supported at no additional costs with contrib.socks.AsyncSOCKSProxyManager.

2.5.904 (2024-02-21)

• Improved reliability with PoliceTraffic.borrow with type as indicator when heavily accessed by many threads.

2.5.903 (2024-02-20)

• Fixed an edge case where a simultaneous call to get_response() without a specific promise could lead to a non-thread safe operation.

2.5.902 (2024-02-04)

• Fixed missed cleanup of unused PoolKey stored in PoliceTraffic upon a full PoolManager.

2.5.901 (2024-02-02)

• Fixed a compatibility issue with boto3 when trying to send data (got an unexpected keyword argument). #79

2.5.900 (2024-02-02)

• Improved performance and reliability for concurrent streams handled by a single connection. We relied on a flat array of events generated by the protocol state-machine that unfortunately was not efficient. urllib3-future now handle the events with a matrix/multi-dimensional array bound to time.
• Fixed a thread safety issue when a single multiplexed connection was used across many threads. We revised in-depth the logic wrapper around the connection locking to make sure you may go all-in when using threads in that particular context. In consequence to that: 1) We are, effective immediately, deprecating RecentlyUsedContainer in favor of our internal PoliceTraffic that was used in PoolManager. 2) No longer using Queue to manage the Connection in HTTPConnectionPool. If you try to set HTTPConnectionPool.QueueCls it will raise a deprecation warning. Starting today, we no longer accept implementation like queue.Queue because it cannot fit the need of this complex HTTP client, especially with the multiplexing aspect.
• Increased default pool maxsize for DNS-over-HTTPS from 1 to 10.

2.4.906 (2024-01-19)

• Fixed a rare case of HTTP/3 being disabled when forwarding a custom SSLContext created.
• Re-introduce DEFAULT_CIPHERS constant in urllib3.util.ssl_ due to the demands. It contains the Mozilla recommended cipher suite that was introduced in version 2.2.900.
• Fixed handling of OpenSSL 3.2.0 new error message for misconfiguring an HTTP proxy as HTTPS. Ported from urllib3/3271.
• Fixed request_sent_latency that wasn't computed when request was stopped early (prior to sending the complete body).

2.4.905 (2024-01-16)

• Fixed an edge case where a HTTPS record was misinterpreted when using a DNS-over-HTTPS resolver.

2.4.904 (2024-01-15)

• Fixed an issue where a idle QUIC connection would not be recycled properly when expired.
• Added support for passing -1 as the amt in HTTPResponse (read, or stream) as the strict equivalent of read1. This allows you to fetch content as soon as it arrive.
• Removed orphaned method _handle_chunk, _update_chunk_length from HTTPResponse.
• Fixed the iterator in HTTPResponse that hung until the complete content was downloaded.

2.4.903 (2024-01-07)

• Fixed an issue where setting None for a header value could cause an exception.

2.4.902 (2024-01-01)

• Fixed compatibility with older PyPy 3.7 interpreters when HTTP/3 (qh3) can be unavailable.
• Fixed undesired DGRAM/QUIC preemptive upgrade using insecure protocol.

2.4.901 (2023-12-31)

• Fixed an issue where a stateless resolver (e.g. nullresolver) could not be recycled.
• Fixed an issue where one would attempt to close a resolver multiple times.

2.4.900 (2023-12-30)

• Added issuer certificate extraction from SSLSocket with native calls with Python 3.10+ in ConnectionInfo.

• Added support for DNS over TLS, DNS over HTTPS, DNS over QUIC, DNS over UDP, and local hosts-like DNS. PoolManager, and HTTPPoolManager constructor now expose an additional keyword argument, resolver=.... You can assign to it one of the presented protocol. Also, you may chain a list of resolver, each resolver can be limited to a list of host-pattern or not. Default is the system DNS. This new feature is covered by our thread-safety promise.

  You can now do the following: PoolManage(resolver="doh://dns.google") for example. Refer to the official documentation to learn about the full capabilities.

• Support for SOCKS proxies is now provided by python-socks instead of PySocks due to being largely unmaintained within a reasonable period of time. This change is made completely transparent.

• Added details in ConnectionInfo about detailed timings and others details. established_latency is a _timedelta_ that represent the amount of time consumed to get an ESTABLISHED network link. resolution_latency is a _timedelta_ that represent the amount of time consumed for the hostname resolution. tls_handshake_latency is a _timedelta_ that represent the amount of time consumed for the TLS handshake. request_sent_latency is a _timedelta_ that represent the amount of time consumed to encode and send the whole request through the socket.

• Fixed a rare thread safety issue when using at least one HTTP/3 multiplexed connection.

• Deprecated function util.connection.create_connection(..) in favor of newly added contrib.resolver that will host from now on that function within BaseResolver as a method. Users are encouraged to migrate as soon as possible.

• Support for preemptively negotiating HTTP/3 over QUIC based on RFC 9460 via a HTTPS DNS record.

• Added support for enforcing IPv6, and/or IPv4 using the keyword parameter socket_family that can be provided in PoolManager, HTTP(S)ConnectionPool and HTTP(S)Connection. The three accepted values are socket.AF_UNSPEC socket.AF_INET, and socket.AF_INET6. Respectively, allow all, ipv4 only, and ipv6 only. Anything else will raise ValueError.

2.3.902 (2023-12-08)

• Fixed an issue where specifying cert_reqs=ssl.CERT_NONE or assert_hostname was ignored when using HTTP/3 over QUIC.

2.3.901 (2023-11-26)

• Small performance improvement while in HTTP/1.1
• Any string passed down to the body will enforce a default Content-Type: text/plain; charset=utf-8 for safety, unless you specified a Content-Type header yourself. The charset parameter will always be set to utf-8. It is recommended that you pass bytes instead of a plain string. If a conflicting charset has been set that does not refer to utf-8, a warning will be raised.
• Added callable argument in urlopen, and request named on_upload_body that enable you to track body upload progress for a single request. It takes 4 positional arguments, namely: (total_sent: int, total_to_be_sent: int | None, is_completed: bool, any_error: bool) total_to_be_sent may be set to None if we're unable to know in advance the total size (blind iterator/generator).
• Fixed a rare case where ProtocolError was raised instead of expected IncompleteRead exception.
• Improved HTTP/3 overall performance.
• Changed the default max connection per host for (http, https) pools managed by PoolManager. If the PoolManager is instantiated with num_pools=10, each (managed) subsequent pool will have maxsize=10.
• Improved performance while in a multithreading context while using many multiplexed connections.
• Changed the default max saturated multiplexed connections to 64 as the minimum. Now a warning will be fired if you reach the maximum capacity of stored saturated multiplexed connections.

2.3.900 (2023-11-18)

• Disabled unsafe renegotiation option with TLS by default where applicable.
• Added fallback package urllib3_future in addition to urllib3. This became increasingly needed as a significant number of projects requires urllib3 and accidentally override this fork.

2.2.907 (2023-11-11)

• Reverted relying on qh3 to dynamically retrieve the max concurrent streams allowed before connection saturation.

2.2.906 (2023-11-11)

• Bumped minimum requirement for qh3 to version 0.14.0 in order to drop private calls in contrib.hface.protocols._qh3.
• Cache last 1024 parse_url function call as it is costly.
• Fixed incomplete flow control window checks while sending data in HTTP/2.
• Fixed unexpected BrokenPipeError exception in a rare edge case.
• Changed behavior for efficiency around socket.recv to pull conn.blocksize bytes regardless of Response.read(amt=...).

2.2.905 (2023-11-08)

• Fixed loss of a QUIC connection due to an inappropriate check in conn.is_connected.
• Separate saturated (multiplexed) connections from the main pool to a distinct one.

2.2.904 (2023-11-06)

• Fixed concurrent/multiplexed request overflow in a full connection pool.
• Fixed connection close that had in-flight request (in multiplexed mode), the connection appeared as not idle on clean reuse.

2.2.903 (2023-11-06)

• Improved overall performances in HTTP/2, and HTTP/3, with or without multiplexed.

2.2.902 (2023-11-05)

• Fixed QUIC connection not taking cert_data due to an accidental variable override.

2.2.901 (2023-11-04)

• Fixed several issues with multiplexing. (i) Fixed max concurrent streams in HTTP/2, and HTTP/3. (ii) Fixed tracking of unconsumed response prior to try upgrade the connection (to HTTP/3). (iii) Fixed (always) releasing multiplexed connections into pool. (iv) Fixed request having body being interrupted by the EarlyResponse exception 'signal'.

2.2.900 (2023-11-01)

• Added support for in-memory client (intermediary) certificate to be used with mTLS. This feature compensate for the complete removal of pyOpenSSL. Unfortunately it is only available on Linux, OpenBSD, and FreeBSD. Using newly added cert_data and key_data arguments in HTTPSConnection and HTTPSPoolConnection you will be capable of passing the certificate along with its key without getting nowhere near your filesystem. MacOS and Windows are not concerned by this feature when using HTTP/1.1, and HTTP/2 with TLS over TCP.

• Removed remnant SSLTransport.makefile as it was built to circumvent a legacy constraint when urllib3 depended upon http.client.

• Bumped minimum requirement for qh3 to version 0.13.0 in order to support in-memory client certificate (mTLS).

• Symbolic complete detachment from http.client. Removed all references and imports to http.client. Farewell!

• Changed the default ciphers in default SSLContext for an increased security level. Rational: Earlier in v2.1.901 we initialized the SSLContext ciphers with the value DEFAULT but after much consideration, after we saw that the associated ciphers (e.g. DEFAULT from OpenSSL) includes some weak suites we decided to inject a rather safer and limited cipher suite. It is based on https://ssl-config.mozilla.org Starting now, urllib3.future will match Mozilla cipher recommendations (intermediary) and will regularly update the suite.

• Added support for multiplexed connection. HTTP/2 and HTTP/3 can benefit from this. urllib3.future no longer blocks when urlopen(...) is invoked using multiplexed=True, and return a ResponsePromise instead of a HTTPResponse. You may dispatch as much requests as the protocol permits you (concurrent stream) and then retrieve the response(s) using the get_response(...). get_response(...) can take up to one kwarg to specify the target promise, if none specified, will retrieve the first available response. multiplexed is set to False by default and will likely be the default for a long time. Here is an example:

  from urllib3 import PoolManager
  
  with PoolManager() as pm:
      promise0 = pm.urlopen("GET", "https://pie.dev/delay/3", multiplexed=True)
      # <ResponsePromise 'IOYTFooi0bCuaQ9mwl4HaA==' HTTP/2.0 Stream[1]>
      promise1 = pm.urlopen("GET", "https://pie.dev/delay/1", multiplexed=True)
      # <ResponsePromise 'U9xT9dPVGnozL4wzDbaA3w==' HTTP/2.0 Stream[3]>
      response0 = pm.get_response()
      # the second request arrived first
      response0.json()["url"]  # https://pie.dev/delay/1
      # the first arrived last
      response1 = pm.get_response()
      response1.json()["url"]  # https://pie.dev/delay/3
  

  or you may do:

  from urllib3 import PoolManager
  
  with PoolManager() as pm:
      promise0 = pm.urlopen("GET", "https://pie.dev/delay/3", multiplexed=True)
      # <ResponsePromise 'IOYTFooi0bCuaQ9mwl4HaA==' HTTP/2.0 Stream[1]>
      promise1 = pm.urlopen("GET", "https://pie.dev/delay/1", multiplexed=True)
      # <ResponsePromise 'U9xT9dPVGnozL4wzDbaA3w==' HTTP/2.0 Stream[3]>
      response0 = pm.get_response(promise=promise0)
      # forcing retrieving promise0
      response0.json()["url"]  # https://pie.dev/delay/3
      # then pick first available
      response1 = pm.get_response()
      response1.json()["url"]  # https://pie.dev/delay/1
  

  You may do multiplexing using PoolManager, and HTTPSPoolConnection. Connection upgrade to HTTP/3 cannot be done until all in-flight requests are completed. Be aware that a non-capable connection (e.g. HTTP/1.1) will just ignore the multiplexed=True setting and act traditionally.

• Connection are now released into their respective pool when the connection support multiplexing (HTTP/2, HTTP/3) before the response has been consumed. This allows to have multiple response half-consumed from a single connection.

2.1.903 (2023-10-23)

• Removed BaseHTTPConnection, and BaseHTTPSConnection. Rationale: The initial idea, as far as I understand it, was to create a HTTPSConnection per protocols, e.g. HTTP/2, and HTTP/3. From the point of view of urllib3.future it was taken care of in contrib.hface where the protocols state-machines are handled. We plan to always have a unified Connection class that regroup all protocols for convenience. The private module urllib3._base_connection is renamed to urllib3._typing. It brings a lot of simplification, which is welcomed.
• Reduced BaseHTTPResponse to a mere alias of HTTPResponse for the same reasoning as before. There is absolutely no need whatsoever in the foreseeable future to ship urllib3.future with an alternative implementation of HTTPResponse. It will be removed in a future major.
• Removed RECENT_DATE and linked logic as it does not make sense to (i) maintain it (ii) the certificate verification failure won't be avoided anyway, so it is a warning prior to an unavoidable error. The warning class SystemTimeWarning will be removed in a future major.
• Added support for stopping sending body if the server responded early in HTTP/2, or HTTP/3. This can happen when a server says that you exhausted the size limit or if previously sent headers were rejected for example. This should save a lot of time to users in given cases.
• Refactored scattered typing aliases across the sources. urllib3._typing now contain all of our definitions.
• Avoid installation of qh3 in PyPy 3.11+ while pre-built wheels are unavailable.

2.1.902 (2023-10-21)

• Fixed an issue where streaming response did not yield data until the stream was closed.
• Unified peercert/issuercert dict output in ConnectionInfo output format when HTTP/3.
• Made body stripped from HTTP requests changing the request method to GET after HTTP 303 "See Other" redirect responses. Headers content-encoding, content-language, content-location, content-type, content-length, digest, last-modified are also stripped in the said case. Port of the security fix GHSA-g4mx-q9vg-27p4
• _TYPE_BODY now accept Iterable[str] in addition to Iterable[bytes].

2.1.901 (2023-10-10)

• Set DEFAULT (as OpenSSL default list) for ciphers in SSLContext if none is provided instead of Python default.
• Fixed an edge case where chosen state machine would be indicated to not end stream where it should.
• Fixed a rare case where ProtocolError was raised instead of SSLError in the underlying QUIC layer state-machine.
• Small performance improvement in sending a body by removing an obsolete logic made for a removed constraint.
• Changed default User-Agent to urllib3.future/x.y.z.
• Removed a compatibility operation that added a Content-Length header on request with unknown body length. This was present due to a bug in Traefik server. A investigation will be conducted and a relevant issue will be addressed.

2.1.900 (2023-10-07)

• Added cipher in ConnectionInfo when using HTTP/3 over QUIC.

• Added issuer_certificate_der, issuer_certificate_dict into ConnectionInfo.

  By default, it is set to None. This property is filled automatically on a QUIC connection. It cannot be done automatically when using native Python capabilities.

• Removed support for SecureTransport.

• Removed support for PyOpenSSL.

  This module is not delete but rendered ineffective. An explicit warning still appear.

• Improved automated exchange between the socket and the HTTP state machines.

• Removed all dependencies in the secure extra.

• Fixed disabling HTTP/3 over QUIC if specified settings were incompatible with TLS over QUIC.

  Previously if ssl_context was set and specifying a list of ciphers it was discarded on upgrade. Also, if ssl_maximum_version was set to TLS v1.2. Now those parameters are correctly forwarded to the custom QUIC/TLS layer.

• Fixed ConnectionInfo repr that did not shown the http_version property.

• Undeprecated 'ssl_version' option in create_urllib3_context.

• Undeprecated 'format_header_param_rfc2231'.

• Removed warning about the 'strict' parameter.

• Removed constant IS_PYOPENSSL and IS_SECURETRANSPORT from urllib3.utils.

• Added raise warning when using environment variables SSLKEYLOGFILE, and QUICLOGDIR.

• Added the Cookie header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via Retry.remove_headers_on_redirect.

• Removed warning about ssl not being the OpenSSL backend. You are free to choose.

  Users are simply encouraged to report issues if any to the jawah/urllib3.future repository. Support will be provided by the best of our abilities.

2.0.936 (2023-10-01)

• Added support for event StreamReset to raise a ProtocolError when received from either h2 or h3. (#28)

2.0.935 (2023-10-01)

• Fixed a violation in our QUIC transmission due to sending multiple datagram at once. (#26)

2.0.934 (2023-09-23)

• Added public ConnectionInfo class that will be present in each HttpConnection instance.

  Passing the kwarg on_post_connection that accept a callable with a single positional argument in PoolManager.urlopen method will result in a call each time a connection is picked out of the pool. The function will be passed a ConnectionInfo object. The same argument (on_post_connection) can be passed down to the HTTPConnectionPool.urlopen method. (#23)

• #22

2.0.933 (2023-09-21)

• Fixed HTTPSConnectionPool not accepting and forwarding ca_cert_data. (#20)

2.0.932 (2023-09-12)

• Fixed assert_hostname behavior when HTTPSConnection targets HTTP/3 over QUIC (#8)
• Fixed protocol violation for HTTP/2 and HTTP/3 where we sent Connection: keep-alive when it is forbidden. (#16)
• Fixed unpack_chunk workaround function in the send method when body is multipart/form-data (#17)
• Fixed the flow control when sending a body for a HTTP/2 connection. The body will be split into numerous chunks if the size exceed the specified blocksize when not using HTTP/1.1 in order to avoid ProtocolError (flow control) (#18)

2.0.931 (2023-07-16)

Features

• Added experimental support for HTTP/1.1, HTTP/2 and HTTP/3 independently of httplib.

  Currently urllib3 does not offer async http request and the backend is the http.client package shipped alongside Python. This implementation is not scheduled to improve, even less to support latest protocol.

  Without proxies, the negotiation is as follow:

  • http requests are always made using HTTP/1.1.
  • https requests are made with HTTP/2 if TLS-ALPN yield its support otherwise HTTP/1.1.
  • https requests may upgrade to HTTP/3 if latest response contain a valid Alt-Svc header.

  With proxies:

  • The initial proxy request is always issued using HTTP/1.1 regardless if its http or https.
  • Subsequents requests follow the previous section (Without proxies) at the sole exception that HTTP/3 upgrade is disabled.

  You may explicitly disable HTTP/2 or, and, HTTP/3 by passing disabled_svn={HttpVersion.h2} to your BaseHttpConnection instance. Disabling HTTP/1.1 is forbidden and raise an error.

  Note that a valid or accepted Alt-Svc header in urllib3 means looking for the "h3" (final specification) protocol and disallow switching hostname for security reasons. (#1)

• Added BaseHTTPResponse to __all__ in __init__.py (#3078)

2.0.3 (2023-06-07)

• Allowed alternative SSL libraries such as LibreSSL, while still issuing a warning as we cannot help users facing issues with implementations other than OpenSSL. (#3020)
• Deprecated URLs which don't have an explicit scheme (#2950)
• Fixed response decoding with Zstandard when compressed data is made of several frames. (#3008)
• Fixed assert_hostname=False to correctly skip hostname check. (#3051)

2.0.2 (2023-05-03)

• Fixed HTTPResponse.stream() to continue yielding bytes if buffered decompressed data was still available to be read even if the underlying socket is closed. This prevents a compressed response from being truncated. (#3009)

2.0.1 (2023-04-30)

• Fixed a socket leak when fingerprint or hostname verifications fail. (#2991)
• Fixed an error when HTTPResponse.read(0) was the first read call or when the internal response body buffer was otherwise empty. (#2998)

2.0.0 (2023-04-26)

Read the v2.0 migration guide for help upgrading to the latest version of urllib3.

Removed

• Removed support for Python 2.7, 3.5, and 3.6 (#883, #2336).
• Removed fallback on certificate commonName in match_hostname() function. This behavior was deprecated in May 2000 in RFC 2818. Instead only subjectAltName is used to verify the hostname by default. To enable verifying the hostname against commonName use SSLContext.hostname_checks_common_name = True (#2113).
• Removed support for Python with an ssl module compiled with LibreSSL, CiscoSSL, wolfSSL, and all other OpenSSL alternatives. Python is moving to require OpenSSL with PEP 644 (#2168).
• Removed support for OpenSSL versions earlier than 1.1.1 or that don't have SNI support. When an incompatible OpenSSL version is detected an ImportError is raised (#2168).
• Removed the list of default ciphers for OpenSSL 1.1.1+ and SecureTransport as their own defaults are already secure (#2082).
• Removed urllib3.contrib.appengine.AppEngineManager and support for Google App Engine Standard Environment (#2044).
• Removed deprecated Retry options method_whitelist, DEFAULT_REDIRECT_HEADERS_BLACKLIST (#2086).
• Removed urllib3.HTTPResponse.from_httplib (#2648).
• Removed default value of None for the request_context parameter of urllib3.PoolManager.connection_from_pool_key. This change should have no effect on users as the default value of None was an invalid option and was never used (#1897).
• Removed the urllib3.request module. urllib3.request.RequestMethods has been made a private API. This change was made to ensure that from urllib3 import request imported the top-level request() function instead of the urllib3.request module (#2269).
• Removed support for SSLv3.0 from the urllib3.contrib.pyopenssl even when support is available from the compiled OpenSSL library (#2233).
• Removed the deprecated urllib3.contrib.ntlmpool module (#2339).
• Removed DEFAULT_CIPHERS, HAS_SNI, USE_DEFAULT_SSLCONTEXT_CIPHERS, from the private module urllib3.util.ssl_ (#2168).
• Removed urllib3.exceptions.SNIMissingWarning (#2168).
• Removed the _prepare_conn method from HTTPConnectionPool. Previously this was only used to call HTTPSConnection.set_cert() by HTTPSConnectionPool (#1985).
• Removed tls_in_tls_required property from HTTPSConnection. This is now determined from the scheme parameter in HTTPConnection.set_tunnel() (#1985).
• Removed the strict parameter/attribute from HTTPConnection, HTTPSConnection, HTTPConnectionPool, HTTPSConnectionPool, and HTTPResponse (#2064).

Deprecated

• Deprecated HTTPResponse.getheaders() and HTTPResponse.getheader() which will be removed in urllib3 v2.1.0. Instead use HTTPResponse.headers and HTTPResponse.headers.get(name, default). (#1543, #2814).
• Deprecated urllib3.contrib.pyopenssl module which will be removed in urllib3 v2.1.0 (#2691).
• Deprecated urllib3.contrib.securetransport module which will be removed in urllib3 v2.1.0 (#2692).
• Deprecated ssl_version option in favor of ssl_minimum_version. ssl_version will be removed in urllib3 v2.1.0 (#2110).
• Deprecated the strict parameter of PoolManager.connection_from_context() as it's not longer needed in Python 3.x. It will be removed in urllib3 v2.1.0 (#2267)
• Deprecated the NewConnectionError.pool attribute which will be removed in urllib3 v2.1.0 (#2271).
• Deprecated format_header_param_html5 and format_header_param in favor of format_multipart_header_param (#2257).
• Deprecated RequestField.header_formatter parameter which will be removed in urllib3 v2.1.0 (#2257).
• Deprecated HTTPSConnection.set_cert() method. Instead pass parameters to the HTTPSConnection constructor (#1985).
• Deprecated HTTPConnection.request_chunked() method which will be removed in urllib3 v2.1.0. Instead pass chunked=True to HTTPConnection.request() (#1985).

Added

• Added top-level urllib3.request function which uses a preconfigured module-global PoolManager instance (#2150).
• Added the json parameter to urllib3.request(), PoolManager.request(), and ConnectionPool.request() methods to send JSON bodies in requests. Using this parameter will set the header Content-Type: application/json if Content-Type isn't already defined. Added support for parsing JSON response bodies with HTTPResponse.json() method (#2243).
• Added type hints to the urllib3 module (#1897).
• Added ssl_minimum_version and ssl_maximum_version options which set SSLContext.minimum_version and SSLContext.maximum_version (#2110).
• Added support for Zstandard (RFC 8878) when zstandard 1.18.0 or later is installed. Added the zstd extra which installs the zstandard package (#1992).
• Added urllib3.response.BaseHTTPResponse class. All future response classes will be subclasses of BaseHTTPResponse (#2083).
• Added FullPoolError which is raised when PoolManager(block=True) and a connection is returned to a full pool (#2197).
• Added HTTPHeaderDict to the top-level urllib3 namespace (#2216).
• Added support for configuring header merging behavior with HTTPHeaderDict When using a HTTPHeaderDict to provide headers for a request, by default duplicate header values will be repeated. But if combine=True is passed into a call to HTTPHeaderDict.add, then the added header value will be merged in with an existing value into a comma-separated list (X-My-Header: foo, bar) (#2242).
• Added NameResolutionError exception when a DNS error occurs (#2305).
• Added proxy_assert_hostname and proxy_assert_fingerprint kwargs to ProxyManager (#2409).
• Added a configurable backoff_max parameter to the Retry class. If a custom backoff_max is provided to the Retry class, it will replace the Retry.DEFAULT_BACKOFF_MAX (#2494).
• Added the authority property to the Url class as per RFC 3986 3.2. This property should be used in place of netloc for users who want to include the userinfo (auth) component of the URI (#2520).
• Added the scheme parameter to HTTPConnection.set_tunnel to configure the scheme of the origin being tunnelled to (#1985).
• Added the is_closed, is_connected and has_connected_to_proxy properties to HTTPConnection (#1985).
• Added optional backoff_jitter parameter to Retry. (#2952)

Changed

• Changed urllib3.response.HTTPResponse.read to respect the semantics of io.BufferedIOBase regardless of compression. Specifically, this method:

  • Only returns an empty bytes object to indicate EOF (that is, the response has been fully consumed).
  • Never returns more bytes than requested.
  • Can issue any number of system calls: zero, one or multiple.

  If you want each urllib3.response.HTTPResponse.read call to issue a single system call, you need to disable decompression by setting decode_content=False (#2128).

• Changed urllib3.HTTPConnection.getresponse to return an instance of urllib3.HTTPResponse instead of http.client.HTTPResponse (#2648).

• Changed ssl_version to instead set the corresponding SSLContext.minimum_version and SSLContext.maximum_version values. Regardless of ssl_version passed SSLContext objects are now constructed using ssl.PROTOCOL_TLS_CLIENT (#2110).

• Changed default SSLContext.minimum_version to be TLSVersion.TLSv1_2 in line with Python 3.10 (#2373).

• Changed ProxyError to wrap any connection error (timeout, TLS, DNS) that occurs when connecting to the proxy (#2482).

• Changed urllib3.util.create_urllib3_context to not override the system cipher suites with a default value. The new default will be cipher suites configured by the operating system (#2168).

• Changed multipart/form-data header parameter formatting matches the WHATWG HTML Standard as of 2021-06-10. Control characters in filenames are no longer percent encoded (#2257).

• Changed the error raised when connecting via HTTPS when the ssl module isn't available from SSLError to ImportError (#2589).

• Changed HTTPConnection.request() to always use lowercase chunk boundaries when sending requests with Transfer-Encoding: chunked (#2515).

• Changed enforce_content_length default to True, preventing silent data loss when reading streamed responses (#2514).

• Changed internal implementation of HTTPHeaderDict to use dict instead of collections.OrderedDict for better performance (#2080).

• Changed the urllib3.contrib.pyopenssl module to wrap OpenSSL.SSL.Error with ssl.SSLError in PyOpenSSLContext.load_cert_chain (#2628).

• Changed usage of the deprecated socket.error to OSError (#2120).

• Changed all parameters in the HTTPConnection and HTTPSConnection constructors to be keyword-only except host and port (#1985).

• Changed HTTPConnection.getresponse() to set the socket timeout from HTTPConnection.timeout value before reading data from the socket. This previously was done manually by the HTTPConnectionPool calling HTTPConnection.sock.settimeout(...) (#1985).

• Changed the _proxy_host property to _tunnel_host in HTTPConnectionPool to more closely match how the property is used (value in HTTPConnection.set_tunnel()) (#1985).

• Changed name of Retry.BACK0FF_MAX to be Retry.DEFAULT_BACKOFF_MAX.

• Changed TLS handshakes to use SSLContext.check_hostname when possible (#2452).

• Changed server_hostname to behave like other parameters only used by HTTPSConnectionPool (#2537).

• Changed the default blocksize to 16KB to match OpenSSL's default read amounts (#2348).

• Changed HTTPResponse.read() to raise an error when calling with decode_content=False after using decode_content=True to prevent data loss (#2800).

Fixed

• Fixed thread-safety issue where accessing a PoolManager with many distinct origins would cause connection pools to be closed while requests are in progress (#1252).
• Fixed an issue where an HTTPConnection instance would erroneously reuse the socket read timeout value from reading the previous response instead of a newly configured connect timeout. Instead now if HTTPConnection.timeout is updated before sending the next request the new timeout value will be used (#2645).
• Fixed socket.error.errno when raised from pyOpenSSL's OpenSSL.SSL.SysCallError (#2118).
• Fixed the default value of HTTPSConnection.socket_options to match HTTPConnection (#2213).
• Fixed a bug where headers would be modified by the remove_headers_on_redirect feature (#2272).
• Fixed a reference cycle bug in urllib3.util.connection.create_connection() (#2277).
• Fixed a socket leak if HTTPConnection.connect() fails (#2571).
• Fixed urllib3.contrib.pyopenssl.WrappedSocket and urllib3.contrib.securetransport.WrappedSocket close methods (#2970)

1.26.16 (2023-05-23)

• Fixed thread-safety issue where accessing a PoolManager with many distinct origins would cause connection pools to be closed while requests are in progress (#2954)

1.26.15 (2023-03-10)

• Fix socket timeout value when HTTPConnection is reused (#2645)
• Remove "!" character from the unreserved characters in IPv6 Zone ID parsing (#2899)
• Fix IDNA handling of 'x80' byte (#2901)

1.26.14 (2023-01-11)

• Fixed parsing of port 0 (zero) returning None, instead of 0. (#2850)
• Removed deprecated getheaders() calls in contrib module. Fixed the type hint of PoolKey.key_retries by adding bool to the union. (#2865)

1.26.13 (2022-11-23)

• Deprecated the HTTPResponse.getheaders() and HTTPResponse.getheader() methods.
• Fixed an issue where parsing a URL with leading zeroes in the port would be rejected even when the port number after removing the zeroes was valid.
• Fixed a deprecation warning when using cryptography v39.0.0.
• Removed the <4 in the Requires-Python packaging metadata field.

1.26.12 (2022-08-22)

• Deprecated the urllib3[secure] extra and the urllib3.contrib.pyopenssl module. Both will be removed in v2.x. See this GitHub issue for justification and info on how to migrate.

1.26.11 (2022-07-25)

• Fixed an issue where reading more than 2 GiB in a call to HTTPResponse.read would raise an OverflowError on Python 3.9 and earlier.

1.26.10 (2022-07-07)

• Removed support for Python 3.5
• Fixed an issue where a ProxyError recommending configuring the proxy as HTTP instead of HTTPS could appear even when an HTTPS proxy wasn't configured.

1.26.9 (2022-03-16)

• Changed urllib3[brotli] extra to favor installing Brotli libraries that are still receiving updates like brotli and brotlicffi instead of brotlipy. This change does not impact behavior of urllib3, only which dependencies are installed.
• Fixed a socket leaking when HTTPSConnection.connect() raises an exception.
• Fixed server_hostname being forwarded from PoolManager to HTTPConnectionPool when requesting an HTTP URL. Should only be forwarded when requesting an HTTPS URL.

1.26.8 (2022-01-07)

• Added extra message to urllib3.exceptions.ProxyError when urllib3 detects that a proxy is configured to use HTTPS but the proxy itself appears to only use HTTP.
• Added a mention of the size of the connection pool when discarding a connection due to the pool being full.
• Added explicit support for Python 3.11.
• Deprecated the Retry.MAX_BACKOFF class property in favor of Retry.DEFAULT_MAX_BACKOFF to better match the rest of the default parameter names. Retry.MAX_BACKOFF is removed in v2.0.
• Changed location of the vendored ssl.match_hostname function from urllib3.packages.ssl_match_hostname to urllib3.util.ssl_match_hostname to ensure Python 3.10+ compatibility after being repackaged by downstream distributors.
• Fixed absolute imports, all imports are now relative.

1.26.7 (2021-09-22)

• Fixed a bug with HTTPS hostname verification involving IP addresses and lack of SNI. (Issue #2400)
• Fixed a bug where IPv6 braces weren't stripped during certificate hostname matching. (Issue #2240)

1.26.6 (2021-06-25)

• Deprecated the urllib3.contrib.ntlmpool module. urllib3 is not able to support it properly due to reasons listed in this issue. If you are a user of this module please leave a comment.
• Changed HTTPConnection.request_chunked() to not erroneously emit multiple Transfer-Encoding headers in the case that one is already specified.
• Fixed typo in deprecation message to recommend Retry.DEFAULT_ALLOWED_METHODS.

1.26.5 (2021-05-26)

• Fixed deprecation warnings emitted in Python 3.10.
• Updated vendored six library to 1.16.0.
• Improved performance of URL parser when splitting the authority component.

1.26.4 (2021-03-15)

• Changed behavior of the default SSLContext when connecting to HTTPS proxy during HTTPS requests. The default SSLContext now sets check_hostname=True.

1.26.3 (2021-01-26)

• Fixed bytes and string comparison issue with headers (Pull #2141)
• Changed ProxySchemeUnknown error message to be more actionable if the user supplies a proxy URL without a scheme. (Pull #2107)

1.26.2 (2020-11-12)

• Fixed an issue where wrap_socket and CERT_REQUIRED wouldn't be imported properly on Python 2.7.8 and earlier (Pull #2052)

1.26.1 (2020-11-11)

• Fixed an issue where two User-Agent headers would be sent if a User-Agent header key is passed as bytes (Pull #2047)

1.26.0 (2020-11-10)

• NOTE: urllib3 v2.0 will drop support for Python 2. Read more in the v2.0 Roadmap.
• Added support for HTTPS proxies contacting HTTPS servers (Pull #1923, Pull #1806)
• Deprecated negotiating TLSv1 and TLSv1.1 by default. Users that still wish to use TLS earlier than 1.2 without a deprecation warning should opt-in explicitly by setting ssl_version=ssl.PROTOCOL_TLSv1_1 (Pull #2002) Starting in urllib3 v2.0: Connections that receive a ``DeprecationWarning`` will fail
• Deprecated Retry options Retry.DEFAULT_METHOD_WHITELIST, Retry.DEFAULT_REDIRECT_HEADERS_BLACKLIST and Retry(method_whitelist=...) in favor of Retry.DEFAULT_ALLOWED_METHODS, Retry.DEFAULT_REMOVE_HEADERS_ON_REDIRECT, and Retry(allowed_methods=...) (Pull #2000) Starting in urllib3 v2.0: Deprecated options will be removed
• Added default User-Agent header to every request (Pull #1750)
• Added urllib3.util.SKIP_HEADER for skipping User-Agent, Accept-Encoding, and Host headers from being automatically emitted with requests (Pull #2018)
• Collapse transfer-encoding: chunked request data and framing into the same socket.send() call (Pull #1906)
• Send http/1.1 ALPN identifier with every TLS handshake by default (Pull #1894)
• Properly terminate SecureTransport connections when CA verification fails (Pull #1977)
• Don't emit an SNIMissingWarning when passing server_hostname=None to SecureTransport (Pull #1903)
• Disabled requesting TLSv1.2 session tickets as they weren't being used by urllib3 (Pull #1970)
• Suppress BrokenPipeError when writing request body after the server has closed the socket (Pull #1524)
• Wrap ssl.SSLError that can be raised from reading a socket (e.g. "bad MAC") into an urllib3.exceptions.SSLError (Pull #1939)

1.25.11 (2020-10-19)

• Fix retry backoff time parsed from Retry-After header when given in the HTTP date format. The HTTP date was parsed as the local timezone rather than accounting for the timezone in the HTTP date (typically UTC) (Pull #1932, Pull #1935, Pull #1938, Pull #1949)
• Fix issue where an error would be raised when the SSLKEYLOGFILE environment variable was set to the empty string. Now SSLContext.keylog_file is not set in this situation (Pull #2016)

1.25.10 (2020-07-22)

• Added support for SSLKEYLOGFILE environment variable for logging TLS session keys with use with programs like Wireshark for decrypting captured web traffic (Pull #1867)
• Fixed loading of SecureTransport libraries on macOS Big Sur due to the new dynamic linker cache (Pull #1905)
• Collapse chunked request bodies data and framing into one call to send() to reduce the number of TCP packets by 2-4x (Pull #1906)
• Don't insert None into ConnectionPool if the pool was empty when requesting a connection (Pull #1866)
• Avoid hasattr call in BrotliDecoder.decompress() (Pull #1858)

1.25.9 (2020-04-16)

• Added InvalidProxyConfigurationWarning which is raised when erroneously specifying an HTTPS proxy URL. urllib3 doesn't currently support connecting to HTTPS proxies but will soon be able to and we would like users to migrate properly without much breakage.

  See this GitHub issue for more information on how to fix your proxy config. (Pull #1851)

• Drain connection after PoolManager redirect (Pull #1817)

• Ensure load_verify_locations raises SSLError for all backends (Pull #1812)

• Rename VerifiedHTTPSConnection to HTTPSConnection (Pull #1805)

• Allow the CA certificate data to be passed as a string (Pull #1804)

• Raise ValueError if method contains control characters (Pull #1800)

• Add __repr__ to Timeout (Pull #1795)

1.25.8 (2020-01-20)

• Drop support for EOL Python 3.4 (Pull #1774)
• Optimize _encode_invalid_chars (Pull #1787)

1.25.7 (2019-11-11)

• Preserve chunked parameter on retries (Pull #1715, Pull #1734)
• Allow unset SERVER_SOFTWARE in App Engine (Pull #1704, Issue #1470)
• Fix issue where URL fragment was sent within the request target. (Pull #1732)
• Fix issue where an empty query section in a URL would fail to parse. (Pull #1732)
• Remove TLS 1.3 support in SecureTransport due to Apple removing support (Pull #1703)

1.25.6 (2019-09-24)

• Fix issue where tilde (~) characters were incorrectly percent-encoded in the path. (Pull #1692)

1.25.5 (2019-09-19)

• Add mitigation for BPO-37428 affecting Python <3.7.4 and OpenSSL 1.1.1+ which caused certificate verification to be enabled when using cert_reqs=CERT_NONE. (Issue #1682)

1.25.4 (2019-09-19)

• Propagate Retry-After header settings to subsequent retries. (Pull #1607)
• Fix edge case where Retry-After header was still respected even when explicitly opted out of. (Pull #1607)
• Remove dependency on rfc3986 for URL parsing.
• Fix issue where URLs containing invalid characters within Url.auth would raise an exception instead of percent-encoding those characters.
• Add support for HTTPResponse.auto_close = False which makes HTTP responses work well with BufferedReaders and other io module features. (Pull #1652)
• Percent-encode invalid characters in URL for HTTPConnectionPool.request() (Pull #1673)

1.25.3 (2019-05-23)

• Change HTTPSConnection to load system CA certificates when ca_certs, ca_cert_dir, and ssl_context are unspecified. (Pull #1608, Issue #1603)
• Upgrade bundled rfc3986 to v1.3.2. (Pull #1609, Issue #1605)

1.25.2 (2019-04-28)

• Change is_ipaddress to not detect IPvFuture addresses. (Pull #1583)
• Change parse_url to percent-encode invalid characters within the path, query, and target components. (Pull #1586)

1.25.1 (2019-04-24)

• Add support for Google's Brotli package. (Pull #1572, Pull #1579)
• Upgrade bundled rfc3986 to v1.3.1 (Pull #1578)

1.25 (2019-04-22)

• Require and validate certificates by default when using HTTPS (Pull #1507)
• Upgraded urllib3.utils.parse_url() to be RFC 3986 compliant. (Pull #1487)
• Added support for key_password for HTTPSConnectionPool to use encrypted key_file without creating your own SSLContext object. (Pull #1489)
• Add TLSv1.3 support to CPython, pyOpenSSL, and SecureTransport SSLContext implementations. (Pull #1496)
• Switched the default multipart header encoder from RFC 2231 to HTML 5 working draft. (Issue #303, Pull #1492)
• Fixed issue where OpenSSL would block if an encrypted client private key was given and no password was given. Instead an SSLError is raised. (Pull #1489)
• Added support for Brotli content encoding. It is enabled automatically if brotlipy package is installed which can be requested with urllib3[brotli] extra. (Pull #1532)
• Drop ciphers using DSS key exchange from default TLS cipher suites. Improve default ciphers when using SecureTransport. (Pull #1496)
• Implemented a more efficient HTTPResponse.__iter__() method. (Issue #1483)

1.24.3 (2019-05-01)

• Apply fix for CVE-2019-9740. (Pull #1591)

1.24.2 (2019-04-17)

• Don't load system certificates by default when any other ca_certs, ca_certs_dir or ssl_context parameters are specified.
• Remove Authorization header regardless of case when redirecting to cross-site. (Issue #1510)
• Add support for IPv6 addresses in subjectAltName section of certificates. (Issue #1269)

1.24.1 (2018-11-02)

• Remove quadratic behavior within GzipDecoder.decompress() (Issue #1467)
• Restored functionality of ciphers parameter for create_urllib3_context(). (Issue #1462)

1.24 (2018-10-16)

• Allow key_server_hostname to be specified when initializing a PoolManager to allow custom SNI to be overridden. (Pull #1449)
• Test against Python 3.7 on AppVeyor. (Pull #1453)
• Early-out ipv6 checks when running on App Engine. (Pull #1450)
• Change ambiguous description of backoff_factor (Pull #1436)
• Add ability to handle multiple Content-Encodings (Issue #1441 and Pull #1442)
• Skip DNS names that can't be idna-decoded when using pyOpenSSL (Issue #1405).
• Add a server_hostname parameter to HTTPSConnection which allows for overriding the SNI hostname sent in the handshake. (Pull #1397)
• Drop support for EOL Python 2.6 (Pull #1429 and Pull #1430)
• Fixed bug where responses with header Content-Type: message/* erroneously raised HeaderParsingError, resulting in a warning being logged. (Pull #1439)
• Move urllib3 to src/urllib3 (Pull #1409)

1.23 (2018-06-04)

• Allow providing a list of headers to strip from requests when redirecting to a different host. Defaults to the Authorization header. Different headers can be set via Retry.remove_headers_on_redirect. (Issue #1316)
• Fix util.selectors._fileobj_to_fd to accept long (Issue #1247).
• Dropped Python 3.3 support. (Pull #1242)
• Put the connection back in the pool when calling stream() or read_chunked() on a chunked HEAD response. (Issue #1234)
• Fixed pyOpenSSL-specific ssl client authentication issue when clients attempted to auth via certificate + chain (Issue #1060)
• Add the port to the connectionpool connect print (Pull #1251)
• Don't use the uuid module to create multipart data boundaries. (Pull #1380)
• read_chunked() on a closed response returns no chunks. (Issue #1088)
• Add Python 2.6 support to contrib.securetransport (Pull #1359)
• Added support for auth info in url for SOCKS proxy (Pull #1363)

1.22 (2017-07-20)

• Fixed missing brackets in HTTP CONNECT when connecting to IPv6 address via IPv6 proxy. (Issue #1222)
• Made the connection pool retry on SSLError. The original SSLError is available on MaxRetryError.reason. (Issue #1112)
• Drain and release connection before recursing on retry/redirect. Fixes deadlocks with a blocking connectionpool. (Issue #1167)
• Fixed compatibility for cookiejar. (Issue #1229)
• pyopenssl: Use vendored version of six. (Issue #1231)

1.21.1 (2017-05-02)

• Fixed SecureTransport issue that would cause long delays in response body delivery. (Pull #1154)
• Fixed regression in 1.21 that threw exceptions when users passed the socket_options flag to the PoolManager. (Issue #1165)
• Fixed regression in 1.21 that threw exceptions when users passed the assert_hostname or assert_fingerprint flag to the PoolManager. (Pull #1157)

1.21 (2017-04-25)

• Improved performance of certain selector system calls on Python 3.5 and later. (Pull #1095)
• Resolved issue where the PyOpenSSL backend would not wrap SysCallError exceptions appropriately when sending data. (Pull #1125)
• Selectors now detects a monkey-patched select module after import for modules that patch the select module like eventlet, greenlet. (Pull #1128)
• Reduced memory consumption when streaming zlib-compressed responses (as opposed to raw deflate streams). (Pull #1129)
• Connection pools now use the entire request context when constructing the pool key. (Pull #1016)
• PoolManager.connection_from_* methods now accept a new keyword argument, pool_kwargs, which are merged with the existing connection_pool_kw. (Pull #1016)
• Add retry counter for status_forcelist. (Issue #1147)
• Added contrib module for using SecureTransport on macOS: urllib3.contrib.securetransport. (Pull #1122)
• urllib3 now only normalizes the case of http:// and https:// schemes: for schemes it does not recognise, it assumes they are case-sensitive and leaves them unchanged. (Issue #1080)

1.20 (2017-01-19)

• Added support for waiting for I/O using selectors other than select, improving urllib3's behaviour with large numbers of concurrent connections. (Pull #1001)
• Updated the date for the system clock check. (Issue #1005)
• ConnectionPools now correctly consider hostnames to be case-insensitive. (Issue #1032)
• Outdated versions of PyOpenSSL now cause the PyOpenSSL contrib module to fail when it is injected, rather than at first use. (Pull #1063)
• Outdated versions of cryptography now cause the PyOpenSSL contrib module to fail when it is injected, rather than at first use. (Issue #1044)
• Automatically attempt to rewind a file-like body object when a request is retried or redirected. (Pull #1039)
• Fix some bugs that occur when modules incautiously patch the queue module. (Pull #1061)
• Prevent retries from occurring on read timeouts for which the request method was not in the method whitelist. (Issue #1059)
• Changed the PyOpenSSL contrib module to lazily load idna to avoid unnecessarily bloating the memory of programs that don't need it. (Pull #1076)
• Add support for IPv6 literals with zone identifiers. (Pull #1013)
• Added support for socks5h:// and socks4a:// schemes when working with SOCKS proxies, and controlled remote DNS appropriately. (Issue #1035)

1.19.1 (2016-11-16)

• Fixed AppEngine import that didn't function on Python 3.5. (Pull #1025)

1.19 (2016-11-03)

• urllib3 now respects Retry-After headers on 413, 429, and 503 responses when using the default retry logic. (Pull #955)
• Remove markers from setup.py to assist ancient setuptools versions. (Issue #986)
• Disallow superscripts and other integerish things in URL ports. (Issue #989)
• Allow urllib3's HTTPResponse.stream() method to continue to work with non-httplib underlying FPs. (Pull #990)
• Empty filenames in multipart headers are now emitted as such, rather than being suppressed. (Issue #1015)
• Prefer user-supplied Host headers on chunked uploads. (Issue #1009)

1.18.1 (2016-10-27)

• CVE-2016-9015. Users who are using urllib3 version 1.17 or 1.18 along with PyOpenSSL injection and OpenSSL 1.1.0 must upgrade to this version. This release fixes a vulnerability whereby urllib3 in the above configuration would silently fail to validate TLS certificates due to erroneously setting invalid flags in OpenSSL's SSL_CTX_set_verify function. These erroneous flags do not cause a problem in OpenSSL versions before 1.1.0, which interprets the presence of any flag as requesting certificate validation.

  There is no PR for this patch, as it was prepared for simultaneous disclosure and release. The master branch received the same fix in Pull #1010.

1.18 (2016-09-26)

• Fixed incorrect message for IncompleteRead exception. (Pull #973)
• Accept iPAddress subject alternative name fields in TLS certificates. (Issue #258)
• Fixed consistency of HTTPResponse.closed between Python 2 and 3. (Issue #977)
• Fixed handling of wildcard certificates when using PyOpenSSL. (Issue #979)

1.17 (2016-09-06)

• Accept SSLContext objects for use in SSL/TLS negotiation. (Issue #835)
• ConnectionPool debug log now includes scheme, host, and port. (Issue #897)
• Substantially refactored documentation. (Issue #887)
• Used URLFetch default timeout on AppEngine, rather than hardcoding our own. (Issue #858)
• Normalize the scheme and host in the URL parser (Issue #833)
• HTTPResponse contains the last Retry object, which now also contains retries history. (Issue #848)
• Timeout can no longer be set as boolean, and must be greater than zero. (Pull #924)
• Removed pyasn1 and ndg-httpsclient from dependencies used for PyOpenSSL. We now use cryptography and idna, both of which are already dependencies of PyOpenSSL. (Pull #930)
• Fixed infinite loop in stream when amt=None. (Issue #928)
• Try to use the operating system's certificates when we are using an SSLContext. (Pull #941)
• Updated cipher suite list to allow ChaCha20+Poly1305. AES-GCM is preferred to ChaCha20, but ChaCha20 is then preferred to everything else. (Pull #947)
• Updated cipher suite list to remove 3DES-based cipher suites. (Pull #958)
• Removed the cipher suite fallback to allow HIGH ciphers. (Pull #958)
• Implemented length_remaining to determine remaining content to be read. (Pull #949)
• Implemented enforce_content_length to enable exceptions when incomplete data chunks are received. (Pull #949)
• Dropped connection start, dropped connection reset, redirect, forced retry, and new HTTPS connection log levels to DEBUG, from INFO. (Pull #967)

1.16 (2016-06-11)

• Disable IPv6 DNS when IPv6 connections are not possible. (Issue #840)
• Provide key_fn_by_scheme pool keying mechanism that can be overridden. (Issue #830)
• Normalize scheme and host to lowercase for pool keys, and include source_address. (Issue #830)
• Cleaner exception chain in Python 3 for _make_request. (Issue #861)
• Fixed installing urllib3[socks] extra. (Issue #864)
• Fixed signature of ConnectionPool.close so it can actually safely be called by subclasses. (Issue #873)
• Retain release_conn state across retries. (Issues #651, #866)
• Add customizable HTTPConnectionPool.ResponseCls, which defaults to HTTPResponse but can be replaced with a subclass. (Issue #879)

1.15.1 (2016-04-11)

• Fix packaging to include backports module. (Issue #841)

1.15 (2016-04-06)

• Added Retry(raise_on_status=False). (Issue #720)
• Always use setuptools, no more distutils fallback. (Issue #785)
• Dropped support for Python 3.2. (Issue #786)
• Chunked transfer encoding when requesting with chunked=True. (Issue #790)
• Fixed regression with IPv6 port parsing. (Issue #801)
• Append SNIMissingWarning messages to allow users to specify it in the PYTHONWARNINGS environment variable. (Issue #816)
• Handle unicode headers in Py2. (Issue #818)
• Log certificate when there is a hostname mismatch. (Issue #820)
• Preserve order of request/response headers. (Issue #821)

1.14 (2015-12-29)

• contrib: SOCKS proxy support! (Issue #762)
• Fixed AppEngine handling of transfer-encoding header and bug in Timeout defaults checking. (Issue #763)

1.13.1 (2015-12-18)

• Fixed regression in IPv6 + SSL for match_hostname. (Issue #761)

1.13 (2015-12-14)

• Fixed pip install urllib3[secure] on modern pip. (Issue #706)
• pyopenssl: Fixed SSL3_WRITE_PENDING error. (Issue #717)
• pyopenssl: Support for TLSv1.1 and TLSv1.2. (Issue #696)
• Close connections more defensively on exception. (Issue #734)
• Adjusted read_chunked to handle gzipped, chunk-encoded bodies without repeatedly flushing the decoder, to function better on Jython. (Issue #743)
• Accept ca_cert_dir for SSL-related PoolManager configuration. (Issue #758)

1.12 (2015-09-03)

• Rely on six for importing httplib to work around conflicts with other Python 3 shims. (Issue #688)
• Add support for directories of certificate authorities, as supported by OpenSSL. (Issue #701)
• New exception: NewConnectionError, raised when we fail to establish a new connection, usually ECONNREFUSED socket error.

1.11 (2015-07-21)

• When ca_certs is given, cert_reqs defaults to 'CERT_REQUIRED'. (Issue #650)
• pip install urllib3[secure] will install Certifi and PyOpenSSL as dependencies. (Issue #678)
• Made HTTPHeaderDict usable as a headers input value (Issues #632, #679)
• Added urllib3.contrib.appengine which has an AppEngineManager for using URLFetch in a Google AppEngine environment. (Issue #664)
• Dev: Added test suite for AppEngine. (Issue #631)
• Fix performance regression when using PyOpenSSL. (Issue #626)
• Passing incorrect scheme (e.g. foo://) will raise ValueError instead of AssertionError (backwards compatible for now, but please migrate). (Issue #640)
• Fix pools not getting replenished when an error occurs during a request using release_conn=False. (Issue #644)
• Fix pool-default headers not applying for url-encoded requests like GET. (Issue #657)
• log.warning in Python 3 when headers are skipped due to parsing errors. (Issue #642)
• Close and discard connections if an error occurs during read. (Issue #660)
• Fix host parsing for IPv6 proxies. (Issue #668)
• Separate warning type SubjectAltNameWarning, now issued once per host. (Issue #671)
• Fix httplib.IncompleteRead not getting converted to ProtocolError when using HTTPResponse.stream() (Issue #674)

1.10.4 (2015-05-03)

• Migrate tests to Tornado 4. (Issue #594)
• Append default warning configuration rather than overwrite. (Issue #603)
• Fix streaming decoding regression. (Issue #595)
• Fix chunked requests losing state across keep-alive connections. (Issue #599)
• Fix hanging when chunked HEAD response has no body. (Issue #605)

1.10.3 (2015-04-21)

• Emit InsecurePlatformWarning when SSLContext object is missing. (Issue #558)
• Fix regression of duplicate header keys being discarded. (Issue #563)
• Response.stream() returns a generator for chunked responses. (Issue #560)
• Set upper-bound timeout when waiting for a socket in PyOpenSSL. (Issue #585)
• Work on platforms without ssl module for plain HTTP requests. (Issue #587)
• Stop relying on the stdlib's default cipher list. (Issue #588)

1.10.2 (2015-02-25)

• Fix file descriptor leakage on retries. (Issue #548)
• Removed RC4 from default cipher list. (Issue #551)
• Header performance improvements. (Issue #544)
• Fix PoolManager not obeying redirect retry settings. (Issue #553)

1.10.1 (2015-02-10)

• Pools can be used as context managers. (Issue #545)
• Don't re-use connections which experienced an SSLError. (Issue #529)
• Don't fail when gzip decoding an empty stream. (Issue #535)
• Add sha256 support for fingerprint verification. (Issue #540)
• Fixed handling of header values containing commas. (Issue #533)

1.10 (2014-12-14)

• Disabled SSLv3. (Issue #473)
• Add Url.url property to return the composed url string. (Issue #394)
• Fixed PyOpenSSL + gevent WantWriteError. (Issue #412)
• MaxRetryError.reason will always be an exception, not string. (Issue #481)
• Fixed SSL-related timeouts not being detected as timeouts. (Issue #492)
• Py3: Use ssl.create_default_context() when available. (Issue #473)
• Emit InsecureRequestWarning for every insecure HTTPS request. (Issue #496)
• Emit SecurityWarning when certificate has no subjectAltName. (Issue #499)
• Close and discard sockets which experienced SSL-related errors. (Issue #501)
• Handle body param in .request(...). (Issue #513)
• Respect timeout with HTTPS proxy. (Issue #505)
• PyOpenSSL: Handle ZeroReturnError exception. (Issue #520)

1.9.1 (2014-09-13)

• Apply socket arguments before binding. (Issue #427)
• More careful checks if fp-like object is closed. (Issue #435)
• Fixed packaging issues of some development-related files not getting included. (Issue #440)
• Allow performing only fingerprint verification. (Issue #444)
• Emit SecurityWarning if system clock is waaay off. (Issue #445)
• Fixed PyOpenSSL compatibility with PyPy. (Issue #450)
• Fixed BrokenPipeError and ConnectionError handling in Py3. (Issue #443)

1.9 (2014-07-04)

• Shuffled around development-related files. If you're maintaining a distro package of urllib3, you may need to tweak things. (Issue #415)
• Unverified HTTPS requests will trigger a warning on the first request. See our new security documentation for details. (Issue #426)
• New retry logic and urllib3.util.retry.Retry configuration object. (Issue #326)
• All raised exceptions should now wrapped in a urllib3.exceptions.HTTPException-extending exception. (Issue #326)
• All errors during a retry-enabled request should be wrapped in urllib3.exceptions.MaxRetryError, including timeout-related exceptions which were previously exempt. Underlying error is accessible from the .reason property. (Issue #326)
• urllib3.exceptions.ConnectionError renamed to urllib3.exceptions.ProtocolError. (Issue #326)
• Errors during response read (such as IncompleteRead) are now wrapped in urllib3.exceptions.ProtocolError. (Issue #418)
• Requesting an empty host will raise urllib3.exceptions.LocationValueError. (Issue #417)
• Catch read timeouts over SSL connections as urllib3.exceptions.ReadTimeoutError. (Issue #419)
• Apply socket arguments before connecting. (Issue #427)

1.8.3 (2014-06-23)

• Fix TLS verification when using a proxy in Python 3.4.1. (Issue #385)
• Add disable_cache option to urllib3.util.make_headers. (Issue #393)
• Wrap socket.timeout exception with urllib3.exceptions.ReadTimeoutError. (Issue #399)
• Fixed proxy-related bug where connections were being reused incorrectly. (Issues #366, #369)
• Added socket_options keyword parameter which allows to define setsockopt configuration of new sockets. (Issue #397)
• Removed HTTPConnection.tcp_nodelay in favor of HTTPConnection.default_socket_options. (Issue #397)
• Fixed TypeError bug in Python 2.6.4. (Issue #411)

1.8.2 (2014-04-17)

• Fix urllib3.util not being included in the package.

1.8.1 (2014-04-17)

• Fix AppEngine bug of HTTPS requests going out as HTTP. (Issue #356)
• Don't install dummyserver into site-packages as it's only needed for the test suite. (Issue #362)
• Added support for specifying source_address. (Issue #352)

1.8 (2014-03-04)

• Improved url parsing in urllib3.util.parse_url (properly parse '@' in username, and blank ports like 'hostname:').
• New urllib3.connection module which contains all the HTTPConnection objects.
• Several urllib3.util.Timeout-related fixes. Also changed constructor signature to a more sensible order. [Backwards incompatible] (Issues #252, #262, #263)
• Use backports.ssl_match_hostname if it's installed. (Issue #274)
• Added .tell() method to urllib3.response.HTTPResponse which returns the number of bytes read so far. (Issue #277)
• Support for platforms without threading. (Issue #289)
• Expand default-port comparison in HTTPConnectionPool.is_same_host to allow a pool with no specified port to be considered equal to to an HTTP/HTTPS url with port 80/443 explicitly provided. (Issue #305)
• Improved default SSL/TLS settings to avoid vulnerabilities. (Issue #309)
• Fixed urllib3.poolmanager.ProxyManager not retrying on connect errors. (Issue #310)
• Disable Nagle's Algorithm on the socket for non-proxies. A subset of requests will send the entire HTTP request ~200 milliseconds faster; however, some of the resulting TCP packets will be smaller. (Issue #254)
• Increased maximum number of SubjectAltNames in urllib3.contrib.pyopenssl from the default 64 to 1024 in a single certificate. (Issue #318)
• Headers are now passed and stored as a custom urllib3.collections_.HTTPHeaderDict object rather than a plain dict. (Issue #329, #333)
• Headers no longer lose their case on Python 3. (Issue #236)
• urllib3.contrib.pyopenssl now uses the operating system's default CA certificates on inject. (Issue #332)
• Requests with retries=False will immediately raise any exceptions without wrapping them in MaxRetryError. (Issue #348)
• Fixed open socket leak with SSL-related failures. (Issue #344, #348)

1.7.1 (2013-09-25)

• Added granular timeout support with new urllib3.util.Timeout class. (Issue #231)
• Fixed Python 3.4 support. (Issue #238)

1.7 (2013-08-14)

• More exceptions are now pickle-able, with tests. (Issue #174)
• Fixed redirecting with relative URLs in Location header. (Issue #178)
• Support for relative urls in Location: ... header. (Issue #179)
• urllib3.response.HTTPResponse now inherits from io.IOBase for bonus file-like functionality. (Issue #187)
• Passing assert_hostname=False when creating a HTTPSConnectionPool will skip hostname verification for SSL connections. (Issue #194)
• New method urllib3.response.HTTPResponse.stream(...) which acts as a generator wrapped around .read(...). (Issue #198)
• IPv6 url parsing enforces brackets around the hostname. (Issue #199)
• Fixed thread race condition in urllib3.poolmanager.PoolManager.connection_from_host(...) (Issue #204)
• ProxyManager requests now include non-default port in Host: ... header. (Issue #217)
• Added HTTPS proxy support in ProxyManager. (Issue #170 #139)
• New RequestField object can be passed to the fields=... param which can specify headers. (Issue #220)
• Raise urllib3.exceptions.ProxyError when connecting to proxy fails. (Issue #221)
• Use international headers when posting file names. (Issue #119)
• Improved IPv6 support. (Issue #203)

1.6 (2013-04-25)

• Contrib: Optional SNI support for Py2 using PyOpenSSL. (Issue #156)
• ProxyManager automatically adds Host: ... header if not given.
• Improved SSL-related code. cert_req now optionally takes a string like "REQUIRED" or "NONE". Same with ssl_version takes strings like "SSLv23" The string values reflect the suffix of the respective constant variable. (Issue #130)
• Vendored socksipy now based on Anorov's fork which handles unexpectedly closed proxy connections and larger read buffers. (Issue #135)
• Ensure the connection is closed if no data is received, fixes connection leak on some platforms. (Issue #133)
• Added SNI support for SSL/TLS connections on Py32+. (Issue #89)
• Tests fixed to be compatible with Py26 again. (Issue #125)
• Added ability to choose SSL version by passing an ssl.PROTOCOL_* constant to the ssl_version parameter of HTTPSConnectionPool. (Issue #109)
• Allow an explicit content type to be specified when encoding file fields. (Issue #126)
• Exceptions are now pickleable, with tests. (Issue #101)
• Fixed default headers not getting passed in some cases. (Issue #99)
• Treat "content-encoding" header value as case-insensitive, per RFC 2616 Section 3.5. (Issue #110)
• "Connection Refused" SocketErrors will get retried rather than raised. (Issue #92)
• Updated vendored six, no longer overrides the global six module namespace. (Issue #113)
• urllib3.exceptions.MaxRetryError contains a reason property holding the exception that prompted the final retry. If reason is None then it was due to a redirect. (Issue #92, #114)
• Fixed PoolManager.urlopen() from not redirecting more than once. (Issue #149)
• Don't assume Content-Type: text/plain for multi-part encoding parameters that are not files. (Issue #111)
• Pass strict param down to httplib.HTTPConnection. (Issue #122)
• Added mechanism to verify SSL certificates by fingerprint (md5, sha1) or against an arbitrary hostname (when connecting by IP or for misconfigured servers). (Issue #140)
• Streaming decompression support. (Issue #159)

1.5 (2012-08-02)

• Added urllib3.add_stderr_logger() for quickly enabling STDERR debug logging in urllib3.
• Native full URL parsing (including auth, path, query, fragment) available in urllib3.util.parse_url(url).
• Built-in redirect will switch method to 'GET' if status code is 303. (Issue #11)
• urllib3.PoolManager strips the scheme and host before sending the request uri. (Issue #8)
• New urllib3.exceptions.DecodeError exception for when automatic decoding, based on the Content-Type header, fails.
• Fixed bug with pool depletion and leaking connections (Issue #76). Added explicit connection closing on pool eviction. Added urllib3.PoolManager.clear().
• 99% -> 100% unit test coverage.

1.4 (2012-06-16)

• Minor AppEngine-related fixes.
• Switched from mimetools.choose_boundary to uuid.uuid4().
• Improved url parsing. (Issue #73)
• IPv6 url support. (Issue #72)

1.3 (2012-03-25)

• Removed pre-1.0 deprecated API.
• Refactored helpers into a urllib3.util submodule.
• Fixed multipart encoding to support list-of-tuples for keys with multiple values. (Issue #48)
• Fixed multiple Set-Cookie headers in response not getting merged properly in Python 3. (Issue #53)
• AppEngine support with Py27. (Issue #61)
• Minor encode_multipart_formdata fixes related to Python 3 strings vs bytes.

1.2.2 (2012-02-06)

• Fixed packaging bug of not shipping test-requirements.txt. (Issue #47)

1.2.1 (2012-02-05)

• Fixed another bug related to when ssl module is not available. (Issue #41)
• Location parsing errors now raise urllib3.exceptions.LocationParseError which inherits from ValueError.

1.2 (2012-01-29)

• Added Python 3 support (tested on 3.2.2)
• Dropped Python 2.5 support (tested on 2.6.7, 2.7.2)
• Use select.poll instead of select.select for platforms that support it.
• Use Queue.LifoQueue instead of Queue.Queue for more aggressive connection reusing. Configurable by overriding ConnectionPool.QueueCls.
• Fixed ImportError during install when ssl module is not available. (Issue #41)
• Fixed PoolManager redirects between schemes (such as HTTP -> HTTPS) not completing properly. (Issue #28, uncovered by Issue #10 in v1.1)
• Ported dummyserver to use tornado instead of webob + eventlet. Removed extraneous unsupported dummyserver testing backends. Added socket-level tests.
• More tests. Achievement Unlocked: 99% Coverage.

1.1 (2012-01-07)

• Refactored dummyserver to its own root namespace module (used for testing).
• Added hostname verification for VerifiedHTTPSConnection by vendoring in Py32's ssl_match_hostname. (Issue #25)
• Fixed cross-host HTTP redirects when using PoolManager. (Issue #10)
• Fixed decode_content being ignored when set through urlopen. (Issue #27)
• Fixed timeout-related bugs. (Issues #17, #23)

1.0.2 (2011-11-04)

• Fixed typo in VerifiedHTTPSConnection which would only present as a bug if you're using the object manually. (Thanks pyos)
• Made RecentlyUsedContainer (and consequently PoolManager) more thread-safe by wrapping the access log in a mutex. (Thanks @christer)
• Made RecentlyUsedContainer more dict-like (corrected __delitem__ and __getitem__ behaviour), with tests. Shouldn't affect core urllib3 code.

1.0.1 (2011-10-10)

• Fixed a bug where the same connection would get returned into the pool twice, causing extraneous "HttpConnectionPool is full" log warnings.

1.0 (2011-10-08)

• Added PoolManager with LRU expiration of connections (tested and documented).
• Added ProxyManager (needs tests, docs, and confirmation that it works with HTTPS proxies).
• Added optional partial-read support for responses when preload_content=False. You can now make requests and just read the headers without loading the content.
• Made response decoding optional (default on, same as before).
• Added optional explicit boundary string for encode_multipart_formdata.
• Convenience request methods are now inherited from RequestMethods. Old helpers like get_url and post_url should be abandoned in favour of the new request(method, url, ...).
• Refactored code to be even more decoupled, reusable, and extendable.
• License header added to .py files.
• Embiggened the documentation: Lots of Sphinx-friendly docstrings in the code and docs in docs/ and on https://urllib3.readthedocs.io/.
• Embettered all the things!
• Started writing this file.

0.4.1 (2011-07-17)

• Minor bug fixes, code cleanup.

0.4 (2011-03-01)

• Better unicode support.
• Added VerifiedHTTPSConnection.
• Added NTLMConnectionPool in contrib.
• Minor improvements.

0.3.1 (2010-07-13)

• Added assert_host_name optional parameter. Now compatible with proxies.

0.3 (2009-12-10)

• Added HTTPS support.
• Minor bug fixes.
• Refactored, broken backwards compatibility with 0.2.
• API to be treated as stable from this version forward.

0.2 (2008-11-17)

• Added unit tests.
• Bug fixes.

0.1 (2008-11-16)

• First release.