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mirror of https://github.com/moparisthebest/curl synced 2024-12-22 16:18:48 -05:00
curl/lib/pingpong.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

511 lines
15 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.
*
* 'pingpong' is for generic back-and-forth support functions used by FTP,
* IMAP, POP3, SMTP and whatever more that likes them.
*
***************************************************************************/
#include "curl_setup.h"
#include "urldata.h"
#include "sendf.h"
#include "select.h"
#include "progress.h"
#include "speedcheck.h"
#include "pingpong.h"
#include "multiif.h"
#include "non-ascii.h"
#include "vtls/vtls.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
#ifdef USE_PINGPONG
/* Returns timeout in ms. 0 or negative number means the timeout has already
triggered */
time_t Curl_pp_state_timeout(struct pingpong *pp)
{
struct connectdata *conn = pp->conn;
struct Curl_easy *data=conn->data;
time_t timeout_ms; /* in milliseconds */
time_t timeout2_ms; /* in milliseconds */
long response_time= (data->set.server_response_timeout)?
data->set.server_response_timeout: pp->response_time;
/* if CURLOPT_SERVER_RESPONSE_TIMEOUT is set, use that to determine
remaining time, or use pp->response because SERVER_RESPONSE_TIMEOUT is
supposed to govern the response for any given server response, not for
the time from connect to the given server response. */
/* Without a requested timeout, we only wait 'response_time' seconds for the
full response to arrive before we bail out */
timeout_ms = response_time -
Curl_tvdiff(Curl_tvnow(), pp->response); /* spent time */
if(data->set.timeout) {
/* if timeout is requested, find out how much remaining time we have */
timeout2_ms = data->set.timeout - /* timeout time */
Curl_tvdiff(Curl_tvnow(), conn->now); /* spent time */
/* pick the lowest number */
timeout_ms = CURLMIN(timeout_ms, timeout2_ms);
}
return timeout_ms;
}
/*
* Curl_pp_statemach()
*/
CURLcode Curl_pp_statemach(struct pingpong *pp, bool block)
{
struct connectdata *conn = pp->conn;
curl_socket_t sock = conn->sock[FIRSTSOCKET];
int rc;
time_t interval_ms;
time_t timeout_ms = Curl_pp_state_timeout(pp);
struct Curl_easy *data=conn->data;
CURLcode result = CURLE_OK;
if(timeout_ms <=0) {
failf(data, "server response timeout");
return CURLE_OPERATION_TIMEDOUT; /* already too little time */
}
if(block) {
interval_ms = 1000; /* use 1 second timeout intervals */
if(timeout_ms < interval_ms)
interval_ms = timeout_ms;
}
else
interval_ms = 0; /* immediate */
if(Curl_ssl_data_pending(conn, FIRSTSOCKET))
rc = 1;
else if(Curl_pp_moredata(pp))
/* We are receiving and there is data in the cache so just read it */
rc = 1;
else if(!pp->sendleft && Curl_ssl_data_pending(conn, FIRSTSOCKET))
/* We are receiving and there is data ready in the SSL library */
rc = 1;
else
rc = Curl_socket_check(pp->sendleft?CURL_SOCKET_BAD:sock, /* reading */
CURL_SOCKET_BAD,
pp->sendleft?sock:CURL_SOCKET_BAD, /* writing */
interval_ms);
if(block) {
/* if we didn't wait, we don't have to spend time on this now */
if(Curl_pgrsUpdate(conn))
result = CURLE_ABORTED_BY_CALLBACK;
else
result = Curl_speedcheck(data, Curl_tvnow());
if(result)
return result;
}
if(rc == -1) {
failf(data, "select/poll error");
result = CURLE_OUT_OF_MEMORY;
}
else if(rc)
result = pp->statemach_act(conn);
return result;
}
/* initialize stuff to prepare for reading a fresh new response */
void Curl_pp_init(struct pingpong *pp)
{
struct connectdata *conn = pp->conn;
pp->nread_resp = 0;
pp->linestart_resp = conn->data->state.buffer;
pp->pending_resp = TRUE;
pp->response = Curl_tvnow(); /* start response time-out now! */
}
/***********************************************************************
*
* Curl_pp_vsendf()
*
* Send the formated string as a command to a pingpong server. Note that
* the string should not have any CRLF appended, as this function will
* append the necessary things itself.
*
* made to never block
*/
CURLcode Curl_pp_vsendf(struct pingpong *pp,
const char *fmt,
va_list args)
{
ssize_t bytes_written;
size_t write_len;
char *fmt_crlf;
char *s;
CURLcode result;
struct connectdata *conn = pp->conn;
struct Curl_easy *data = conn->data;
#ifdef HAVE_GSSAPI
enum protection_level data_sec = conn->data_prot;
#endif
DEBUGASSERT(pp->sendleft == 0);
DEBUGASSERT(pp->sendsize == 0);
DEBUGASSERT(pp->sendthis == NULL);
fmt_crlf = aprintf("%s\r\n", fmt); /* append a trailing CRLF */
if(!fmt_crlf)
return CURLE_OUT_OF_MEMORY;
s = vaprintf(fmt_crlf, args); /* trailing CRLF appended */
free(fmt_crlf);
if(!s)
return CURLE_OUT_OF_MEMORY;
bytes_written = 0;
write_len = strlen(s);
Curl_pp_init(pp);
result = Curl_convert_to_network(data, s, write_len);
/* Curl_convert_to_network calls failf if unsuccessful */
if(result) {
free(s);
return result;
}
#ifdef HAVE_GSSAPI
conn->data_prot = PROT_CMD;
#endif
result = Curl_write(conn, conn->sock[FIRSTSOCKET], s, write_len,
&bytes_written);
#ifdef HAVE_GSSAPI
DEBUGASSERT(data_sec > PROT_NONE && data_sec < PROT_LAST);
conn->data_prot = data_sec;
#endif
if(result) {
free(s);
return result;
}
if(conn->data->set.verbose)
Curl_debug(conn->data, CURLINFO_HEADER_OUT,
s, (size_t)bytes_written, conn);
if(bytes_written != (ssize_t)write_len) {
/* the whole chunk was not sent, keep it around and adjust sizes */
pp->sendthis = s;
pp->sendsize = write_len;
pp->sendleft = write_len - bytes_written;
}
else {
free(s);
pp->sendthis = NULL;
pp->sendleft = pp->sendsize = 0;
pp->response = Curl_tvnow();
}
return CURLE_OK;
}
/***********************************************************************
*
* Curl_pp_sendf()
*
* Send the formated string as a command to a pingpong server. Note that
* the string should not have any CRLF appended, as this function will
* append the necessary things itself.
*
* made to never block
*/
CURLcode Curl_pp_sendf(struct pingpong *pp,
const char *fmt, ...)
{
CURLcode result;
va_list ap;
va_start(ap, fmt);
result = Curl_pp_vsendf(pp, fmt, ap);
va_end(ap);
return result;
}
/*
* Curl_pp_readresp()
*
* Reads a piece of a server response.
*/
CURLcode Curl_pp_readresp(curl_socket_t sockfd,
struct pingpong *pp,
int *code, /* return the server code if done */
size_t *size) /* size of the response */
{
ssize_t perline; /* count bytes per line */
bool keepon=TRUE;
ssize_t gotbytes;
char *ptr;
struct connectdata *conn = pp->conn;
struct Curl_easy *data = conn->data;
char * const buf = data->state.buffer;
CURLcode result = CURLE_OK;
*code = 0; /* 0 for errors or not done */
*size = 0;
ptr=buf + pp->nread_resp;
/* number of bytes in the current line, so far */
perline = (ssize_t)(ptr-pp->linestart_resp);
while((pp->nread_resp<BUFSIZE) && (keepon && !result)) {
if(pp->cache) {
/* we had data in the "cache", copy that instead of doing an actual
* read
*
* pp->cache_size is cast to ssize_t here. This should be safe, because
* it would have been populated with something of size int to begin
* with, even though its datatype may be larger than an int.
*/
DEBUGASSERT((ptr+pp->cache_size) <= (buf+BUFSIZE+1));
memcpy(ptr, pp->cache, pp->cache_size);
gotbytes = (ssize_t)pp->cache_size;
free(pp->cache); /* free the cache */
pp->cache = NULL; /* clear the pointer */
pp->cache_size = 0; /* zero the size just in case */
}
else {
#ifdef HAVE_GSSAPI
enum protection_level prot = conn->data_prot;
conn->data_prot = PROT_CLEAR;
#endif
DEBUGASSERT((ptr+BUFSIZE-pp->nread_resp) <= (buf+BUFSIZE+1));
result = Curl_read(conn, sockfd, ptr, BUFSIZE-pp->nread_resp,
&gotbytes);
#ifdef HAVE_GSSAPI
DEBUGASSERT(prot > PROT_NONE && prot < PROT_LAST);
conn->data_prot = prot;
#endif
if(result == CURLE_AGAIN)
return CURLE_OK; /* return */
if(!result && (gotbytes > 0))
/* convert from the network encoding */
result = Curl_convert_from_network(data, ptr, gotbytes);
/* Curl_convert_from_network calls failf if unsuccessful */
if(result)
/* Set outer result variable to this error. */
keepon = FALSE;
}
if(!keepon)
;
else if(gotbytes <= 0) {
keepon = FALSE;
result = CURLE_RECV_ERROR;
failf(data, "response reading failed");
}
else {
/* we got a whole chunk of data, which can be anything from one
* byte to a set of lines and possible just a piece of the last
* line */
ssize_t i;
ssize_t clipamount = 0;
bool restart = FALSE;
data->req.headerbytecount += (long)gotbytes;
pp->nread_resp += gotbytes;
for(i = 0; i < gotbytes; ptr++, i++) {
perline++;
if(*ptr=='\n') {
/* a newline is CRLF in pp-talk, so the CR is ignored as
the line isn't really terminated until the LF comes */
/* output debug output if that is requested */
#ifdef HAVE_GSSAPI
if(!conn->sec_complete)
#endif
if(data->set.verbose)
Curl_debug(data, CURLINFO_HEADER_IN,
pp->linestart_resp, (size_t)perline, conn);
/*
* We pass all response-lines to the callback function registered
* for "headers". The response lines can be seen as a kind of
* headers.
*/
result = Curl_client_write(conn, CLIENTWRITE_HEADER,
pp->linestart_resp, perline);
if(result)
return result;
if(pp->endofresp(conn, pp->linestart_resp, perline, code)) {
/* This is the end of the last line, copy the last line to the
start of the buffer and zero terminate, for old times sake */
size_t n = ptr - pp->linestart_resp;
memmove(buf, pp->linestart_resp, n);
buf[n]=0; /* zero terminate */
keepon=FALSE;
pp->linestart_resp = ptr+1; /* advance pointer */
i++; /* skip this before getting out */
*size = pp->nread_resp; /* size of the response */
pp->nread_resp = 0; /* restart */
break;
}
perline=0; /* line starts over here */
pp->linestart_resp = ptr+1;
}
}
if(!keepon && (i != gotbytes)) {
/* We found the end of the response lines, but we didn't parse the
full chunk of data we have read from the server. We therefore need
to store the rest of the data to be checked on the next invoke as
it may actually contain another end of response already! */
clipamount = gotbytes - i;
restart = TRUE;
DEBUGF(infof(data, "Curl_pp_readresp_ %d bytes of trailing "
"server response left\n",
(int)clipamount));
}
else if(keepon) {
if((perline == gotbytes) && (gotbytes > BUFSIZE/2)) {
/* We got an excessive line without newlines and we need to deal
with it. We keep the first bytes of the line then we throw
away the rest. */
infof(data, "Excessive server response line length received, "
"%zd bytes. Stripping\n", gotbytes);
restart = TRUE;
/* we keep 40 bytes since all our pingpong protocols are only
interested in the first piece */
clipamount = 40;
}
else if(pp->nread_resp > BUFSIZE/2) {
/* We got a large chunk of data and there's potentially still
trailing data to take care of, so we put any such part in the
"cache", clear the buffer to make space and restart. */
clipamount = perline;
restart = TRUE;
}
}
else if(i == gotbytes)
restart = TRUE;
if(clipamount) {
pp->cache_size = clipamount;
pp->cache = malloc(pp->cache_size);
if(pp->cache)
memcpy(pp->cache, pp->linestart_resp, pp->cache_size);
else
return CURLE_OUT_OF_MEMORY;
}
if(restart) {
/* now reset a few variables to start over nicely from the start of
the big buffer */
pp->nread_resp = 0; /* start over from scratch in the buffer */
ptr = pp->linestart_resp = buf;
perline = 0;
}
} /* there was data */
} /* while there's buffer left and loop is requested */
pp->pending_resp = FALSE;
return result;
}
int Curl_pp_getsock(struct pingpong *pp,
curl_socket_t *socks,
int numsocks)
{
struct connectdata *conn = pp->conn;
if(!numsocks)
return GETSOCK_BLANK;
socks[0] = conn->sock[FIRSTSOCKET];
if(pp->sendleft) {
/* write mode */
return GETSOCK_WRITESOCK(0);
}
/* read mode */
return GETSOCK_READSOCK(0);
}
CURLcode Curl_pp_flushsend(struct pingpong *pp)
{
/* we have a piece of a command still left to send */
struct connectdata *conn = pp->conn;
ssize_t written;
curl_socket_t sock = conn->sock[FIRSTSOCKET];
CURLcode result = Curl_write(conn, sock, pp->sendthis + pp->sendsize -
pp->sendleft, pp->sendleft, &written);
if(result)
return result;
if(written != (ssize_t)pp->sendleft) {
/* only a fraction was sent */
pp->sendleft -= written;
}
else {
free(pp->sendthis);
pp->sendthis=NULL;
pp->sendleft = pp->sendsize = 0;
pp->response = Curl_tvnow();
}
return CURLE_OK;
}
CURLcode Curl_pp_disconnect(struct pingpong *pp)
{
free(pp->cache);
pp->cache = NULL;
return CURLE_OK;
}
bool Curl_pp_moredata(struct pingpong *pp)
{
return (!pp->sendleft && pp->cache && pp->nread_resp < pp->cache_size) ?
TRUE : FALSE;
}
#endif