HTTPS proxies:
An HTTPS proxy receives all transactions over an SSL/TLS connection. Once a
secure connection with the proxy is established, the user agent uses the proxy
as usual, including sending CONNECT requests to instruct the proxy to establish
a [usually secure] TCP tunnel with an origin server. HTTPS proxies protect
nearly all aspects of user-proxy communications as opposed to HTTP proxies that
receive all requests (including CONNECT requests) in vulnerable clear text.
With HTTPS proxies, it is possible to have two concurrent _nested_ SSL/TLS
sessions: the "outer" one between the user agent and the proxy and the "inner"
one between the user agent and the origin server (through the proxy). This
change adds supports for such nested sessions as well.
The secure connection with the proxy requires its own set of the usual
SSL/TLS-related options (their descriptions need polishing):
--proxy-cacert FILE CA certificate to verify peer against
--proxy-capath DIR CA directory to verify peer against
--proxy-cert CERT[:PASSWD] Client certificate file and password
--proxy-cert-type TYPE Certificate file type (DER/PEM/ENG)
--proxy-ciphers LIST SSL ciphers to use
--proxy-crlfile FILE Get a CRL list in PEM format from the given file
--proxy-insecure Allow connections to SSL sites without certs
--proxy-key KEY Private key file name
--proxy-key-type TYPE Private key file type (DER/PEM/ENG)
--proxy-pass PASS Pass phrase for the private key
--proxy-ssl-allow-beast Allow security flaw to improve interop
--proxy-sslv2 Use SSLv2
--proxy-sslv3 Use SSLv3
--proxy-tlsv1 Use TLSv1
--proxy-tlsuser USER TLS username
--proxy-tlspassword STRING TLS password
--proxy-tlsauthtype STRING TLS authentication type (default SRP)
All --proxy-foo options are independent from their --foo counterparts, except
--proxy-crlfile defaults to --crlfile and --proxy-capath defaults to --capath.
Curl now also supports %{proxy_ssl_verify_result} --write-out variable,
similar to the existing %{ssl_verify_result} variable.
SOCKS proxy + HTTP/HTTPS proxy combination:
If both --socks* and --proxy options are given, Curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy.
This avoids unnecessary dynamic allocs and as this also removed the last
users of *hash_alloc() and *hash_destroy(), those two functions are now
removed.
The code used some happy eyeballs logic even _after_ CONNECT has been
sent to a proxy, while the happy eyeball phase is already (should be)
over by then.
This is solved by splitting the multi state into two separate states
introducing the new SENDPROTOCONNECT state.
Bug: http://curl.haxx.se/mail/lib-2015-01/0170.html
Reported-by: Peter Laser
... instead of scanning through all handles, stash only the actual
handles that are in that state in the new ->pending list and scan that
list only. It should be mostly empty or very short. And only used for
pipelining.
This avoids a rather hefty slow-down especially notable if you add many
handles to the same multi handle. Regression introduced in commit
0f147887 (version 7.30.0).
Bug: http://curl.haxx.se/mail/lib-2014-07/0206.html
Reported-by: David Meyer
The motivation for having a separate struct that keep track of an easy
handle when using the multi handle was removed when we switched to
always using the multi interface internally. Now they were just two
separate struct that was always allocated for each easy handle.
This first step just moves the Curl_one_easy struct members into the
SessionHandle struct and hides this somehow (== keeps the source code
changes to a minimum) by defining Curl_one_easy to SessionHandle
The biggest changes in this commit are:
1 - the linked list of easy handles had to be changed somewhat due
to the new struct layout. This made the main linked list pointer
get renamed to 'easyp' and there's also a new pointer to the last
node, called easylp. It is no longer circular but ends with ->next
pointing to NULL. New nodes are still added last.
2 - easy->state is now called easy->mstate to avoid name collision
Introducing a number of options to the multi interface that
allows for multiple pipelines to the same host, in order to
optimize the balance between the penalty for opening new
connections and the potential pipelining latency.
Two new options for limiting the number of connections:
CURLMOPT_MAX_HOST_CONNECTIONS - Limits the number of running connections
to the same host. When adding a handle that exceeds this limit,
that handle will be put in a pending state until another handle is
finished, so we can reuse the connection.
CURLMOPT_MAX_TOTAL_CONNECTIONS - Limits the number of connections in total.
When adding a handle that exceeds this limit,
that handle will be put in a pending state until another handle is
finished. The free connection will then be reused, if possible, or
closed if the pending handle can't reuse it.
Several new options for pipelining:
CURLMOPT_MAX_PIPELINE_LENGTH - Limits the pipeling length. If a
pipeline is "full" when a connection is to be reused, a new connection
will be opened if the CURLMOPT_MAX_xxx_CONNECTIONS limits allow it.
If not, the handle will be put in a pending state until a connection is
ready (either free or a pipe got shorter).
CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE - A pipelined connection will not
be reused if it is currently processing a transfer with a content
length that is larger than this.
CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE - A pipelined connection will not
be reused if it is currently processing a chunk larger than this.
CURLMOPT_PIPELINING_SITE_BL - A blacklist of hosts that don't allow
pipelining.
CURLMOPT_PIPELINING_SERVER_BL - A blacklist of server types that don't allow
pipelining.
See the curl_multi_setopt() man page for details.
Remove internal separated behavior of the easy vs multi intercace.
curl_easy_perform() is now using the multi interface itself.
Several minor multi interface quirks and bugs have been fixed in the
process.
Much help with debugging this has been provided by: Yang Tse
