* 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
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.
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
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
The function is only present in wolfssl/cyassl if it was built with
--enable-opensslextra. With these checks added, pinning support is disabled
unless the TLS lib has that function available.
Also fix the mistake in configure that checks for the wrong lib name.
Closes#566
Prior to this change libcurl could show multiple 'CyaSSL: Connecting to'
messages since cyassl_connect_step2 is called multiple times, typically.
The message is superfluous even once since libcurl already informs the
user elsewhere in code that it is connecting.
This change is to allow the user's CTX callback to change the minimum
protocol version in the CTX without us later overriding it, as we did
prior to this change.
SSL_CTX_load_verify_locations can return negative values on fail,
therefore to check for failure we check if load is != 1 (success)
instead of if load is == 0 (failure), the latter being incorrect given
that behavior.
(Curl_cyassl_init)
- Return 1 on success, 0 in failure.
Prior to this change the fail path returned an incorrect value and the
evaluation to determine whether CyaSSL_Init had succeeded was incorrect.
Ironically that combined with the way curl_global_init tests SSL library
initialization (!Curl_ssl_init()) meant that CyaSSL having been
successfully initialized would be seen as that even though the code path
and return value in Curl_cyassl_init were wrong.
(cyassl_connect_step1)
- Use TLS 1.0-1.2 by default when available.
CyaSSL/wolfSSL >= v3.3.0 supports setting a minimum protocol downgrade
version.
cyassl/cyassl@322f79f
This header file must be included after all header files except
memdebug.h, as it does similar memory function redefinitions and can be
similarly affected by conflicting definitions in system or dependent
library headers.
Carrying on from commit 037cd0d991, removed the following unimplemented
instances of curlssl_close_all():
Curl_axtls_close_all()
Curl_darwinssl_close_all()
Curl_cyassl_close_all()
Curl_gskit_close_all()
Curl_gtls_close_all()
Curl_nss_close_all()
Curl_polarssl_close_all()
The return type of this function is a boolean value, and even uses a
bool internally, so use bool in the function declaration as well as
the variables that store the return value, to avoid any confusion.
- Remove SSLv3 from SSL default in darwinssl, schannel, cyassl, nss,
openssl effectively making the default TLS 1.x. axTLS is not affected
since it supports only TLS, and gnutls is not affected since it already
defaults to TLS 1.x.
- Update CURLOPT_SSLVERSION doc
