* 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.
A secure connection with a proxy requires its own set of the usual SSL
options (their actual descriptions differ and need polishing, see TODO):
--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 file
--proxy-insecure Allow connections to proxies with bad 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 which defaults to --crlfile and --proxy-capath
which defaults to --capath.
Curl now also supports %{proxy_ssl_verify_result} --write-out variable,
similar to the existing %{ssl_verify_result} variable.
Supported backends: OpenSSL, GnuTLS, and NSS.
* A 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.
TODO: Update documentation for the new APIs and --proxy-* options.
Look for "Added in 7.XXX" marks.
- Fix GnuTLS code for CURL_SSLVERSION_TLSv1_2 that broke when the
TLS 1.3 support was added in 6ad3add.
- Homogenize across code for all backends the error message when TLS 1.3
is not available to "<backend>: TLS 1.3 is not yet supported".
- Return an error when a user-specified ssl version is unrecognized.
---
Prior to this change our code for some of the backends used the
'default' label in the switch statement (ie ver unrecognized) for
ssl.version and treated it the same as CURL_SSLVERSION_DEFAULT.
Bug: https://curl.haxx.se/mail/lib-2016-11/0048.html
Reported-by: Kamil Dudka
We're mostly saying just "curl" in lower case these days so here's a big
cleanup to adapt to this reality. A few instances are left as the
project could still formally be considered called cURL.
... to make it less likely that we forget that the function actually
does case insentive compares. Also replaced several invokes of the
function with a plain strcmp when case sensitivity is not an issue (like
comparing with "-").
Curl_select_ready() was the former API that was replaced with
Curl_select_check() a while back and the former arg setup was provided
with a define (in order to leave existing code unmodified).
Now we instead offer SOCKET_READABLE and SOCKET_WRITABLE for the most
common shortcuts where only one socket is checked. They're also more
visibly macros.
LibreSSL defines `OPENSSL_VERSION_NUMBER` as `0x20000000L` for all
versions returning `LibreSSL/2.0.0` for any LibreSSL version.
This change provides a local OpenSSL_version_num function replacement
returning LIBRESSL_VERSION_NUMBER instead.
Closes#1029
The OpenSSL function CRYTPO_cleanup_all_ex_data() cannot be called
multiple times without crashing - and other libs might call it! We
basically cannot call it without risking a crash. The function is a
no-op since OpenSSL 1.1.0.
Not calling this function only risks a small memory leak with OpenSSL <
1.1.0.
Bug: https://curl.haxx.se/mail/lib-2016-09/0045.html
Reported-by: Todd Short
OpenSSL 1.0.1 and 1.0.2 build an error queue that is stored per-thread
so we need to clean it when easy handles are freed, in case the thread
will be killed in which the easy handle was used. All OpenSSL code in
libcurl should extract the error in association with the error already
so clearing this queue here should be harmless at worst.
Fixes#964
... by partially reverting f975f06033. The allocation could be made by
OpenSSL so the free must be made with OPENSSL_free() to avoid problems.
Reported-by: Harold Stuart
Fixes#1005
CURLINFO_SSL_VERIFYRESULT does not get the certificate verification
result when SSL_connect fails because of a certificate verification
error.
This fix saves the result of SSL_get_verify_result so that it is
returned by CURLINFO_SSL_VERIFYRESULT.
Closes https://github.com/curl/curl/pull/995
Undo change introduced in d4643d6 which caused iPAddress match to be
ignored if dNSName was present but did not match.
Also, if iPAddress is present but does not match, and dNSName is not
present, fail as no-match. Prior to this change in such a case the CN
would be checked for a match.
Bug: https://github.com/curl/curl/issues/959
Reported-by: wmsch@users.noreply.github.com
Prior to this change we called Curl_ssl_getsessionid and
Curl_ssl_addsessionid regardless of whether session ID reusing was
enabled. According to comments that is in case session ID reuse was
disabled but then later enabled.
The old way was not intuitive and probably not something users expected.
When a user disables session ID caching I'd guess they don't expect the
session ID to be cached anyway in case the caching is later enabled.
Sessionid cache management is inseparable from managing individual
session lifetimes. E.g. for reference-counted sessions (like those in
SChannel and OpenSSL engines) every session addition and removal
should be accompanied with refcount increment and decrement
respectively. Failing to do so synchronously leads to a race condition
that causes symptoms like use-after-free and memory corruption.
This commit:
- makes existing session cache locking explicit, thus allowing
individual engines to manage lock's scope.
- fixes OpenSSL and SChannel engines by putting refcount management
inside this lock's scope in relevant places.
- adds these explicit locking calls to other engines that use
sessionid cache to accommodate for this change. Note, however,
that it is unknown whether any of these engines could also have
this race.
Bug: https://github.com/curl/curl/issues/815Fixes#815Closes#847
... introduced in curl-7_48_0-293-g2968c83:
Error: COMPILER_WARNING:
lib/vtls/openssl.c: scope_hint: In function ‘Curl_ossl_check_cxn’
lib/vtls/openssl.c:767:15: warning: conversion to ‘int’ from ‘ssize_t’
may alter its value [-Wconversion]
- In the case of recv error, limit returning 'connection still in place'
to EINPROGRESS, EAGAIN and EWOULDBLOCK.
This is an improvement on the parent commit which changed the openssl
connection check to use recv MSG_PEEK instead of SSL_peek.
Ref: https://github.com/curl/curl/commit/856baf5#comments
Calling SSL_peek can cause bytes to be read from the raw socket which in
turn can upset the select machinery that determines whether there's data
available on the socket.
Since Curl_ossl_check_cxn only tries to determine whether the socket is
alive and doesn't actually need to see the bytes SSL_peek seems like
the wrong function to call.
We're able to occasionally reproduce a connect timeout due to this
bug. What happens is that Curl doesn't know to call SSL_connect again
after the peek happens since data is buffered in the SSL buffer and thus
select won't fire for this socket.
Closes#795
Only protocols that actually have a protocol registered for ALPN and NPN
should try to get that negotiated in the TLS handshake. That is only
HTTPS (well, http/1.1 and http/2) right now. Previously ALPN and NPN
would wrongly be used in all handshakes if libcurl was built with it
enabled.
Reported-by: Jay Satiro
Fixes#789
When compiling with OpenSSL 1.1.0 (so that the HAVE_X509_GET0_SIGNATURE
&& HAVE_X509_GET0_EXTENSIONS pre-processor block is active), Visual C++
14 complains:
warning C4701: potentially uninitialized local variable 'palg' used
warning C4701: potentially uninitialized local variable 'psig' used
... to allow users to see which specfic wildcard that matched when such
is used.
Also minor logic cleanup to simplify the code, and I removed all tabs
from verbose strings.
