curl/lib/http_negotiate.c
Alex Rousskov cb4e2be7c6 proxy: Support HTTPS proxy and SOCKS+HTTP(s)
* 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.
2016-11-24 23:41:44 +01:00

139 lines
3.9 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#if !defined(CURL_DISABLE_HTTP) && defined(USE_SPNEGO)
#include "urldata.h"
#include "sendf.h"
#include "http_negotiate.h"
#include "vauth/vauth.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
CURLcode Curl_input_negotiate(struct connectdata *conn, bool proxy,
const char *header)
{
CURLcode result;
struct Curl_easy *data = conn->data;
size_t len;
/* Point to the username, password, service and host */
const char *userp;
const char *passwdp;
const char *service;
const char *host;
/* Point to the correct struct with this */
struct negotiatedata *neg_ctx;
if(proxy) {
userp = conn->http_proxy.user;
passwdp = conn->http_proxy.passwd;
service = data->set.str[STRING_PROXY_SERVICE_NAME] ?
data->set.str[STRING_PROXY_SERVICE_NAME] : "HTTP";
host = conn->http_proxy.host.name;
neg_ctx = &data->state.proxyneg;
}
else {
userp = conn->user;
passwdp = conn->passwd;
service = data->set.str[STRING_SERVICE_NAME] ?
data->set.str[STRING_SERVICE_NAME] : "HTTP";
host = conn->host.name;
neg_ctx = &data->state.negotiate;
}
/* Not set means empty */
if(!userp)
userp = "";
if(!passwdp)
passwdp = "";
/* Obtain the input token, if any */
header += strlen("Negotiate");
while(*header && ISSPACE(*header))
header++;
len = strlen(header);
if(!len) {
/* Is this the first call in a new negotiation? */
if(neg_ctx->context) {
/* The server rejected our authentication and hasn't suppled any more
negotiation mechanisms */
return CURLE_LOGIN_DENIED;
}
}
/* Initilise the security context and decode our challenge */
result = Curl_auth_decode_spnego_message(data, userp, passwdp, service,
host, header, neg_ctx);
if(result)
Curl_auth_spnego_cleanup(neg_ctx);
return result;
}
CURLcode Curl_output_negotiate(struct connectdata *conn, bool proxy)
{
struct negotiatedata *neg_ctx = proxy ? &conn->data->state.proxyneg :
&conn->data->state.negotiate;
char *base64 = NULL;
size_t len = 0;
char *userp;
CURLcode result;
result = Curl_auth_create_spnego_message(conn->data, neg_ctx, &base64, &len);
if(result)
return result;
userp = aprintf("%sAuthorization: Negotiate %s\r\n", proxy ? "Proxy-" : "",
base64);
if(proxy) {
Curl_safefree(conn->allocptr.proxyuserpwd);
conn->allocptr.proxyuserpwd = userp;
}
else {
Curl_safefree(conn->allocptr.userpwd);
conn->allocptr.userpwd = userp;
}
free(base64);
return (userp == NULL) ? CURLE_OUT_OF_MEMORY : CURLE_OK;
}
void Curl_cleanup_negotiate(struct Curl_easy *data)
{
Curl_auth_spnego_cleanup(&data->state.negotiate);
Curl_auth_spnego_cleanup(&data->state.proxyneg);
}
#endif /* !CURL_DISABLE_HTTP && USE_SPNEGO */