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.
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
CyaSSL 3.0.0 returns a unique error code if no CA cert is available,
so translate that into CURLE_SSL_CACERT_BADFILE when peer verification
is requested.
