/
http.c
1472 lines (1283 loc) · 36.3 KB
/
http.c
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/*
* OpenConnect (SSL + DTLS) VPN client
*
* Copyright © 2008-2012 Intel Corporation.
* Copyright © 2008 Nick Andrew <nick@nick-andrew.net>
*
* Author: David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to:
*
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include <netdb.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <string.h>
#include <ctype.h>
#include <pwd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include "openconnect-internal.h"
static int proxy_write(struct openconnect_info *vpninfo, int fd,
unsigned char *buf, size_t len);
static int proxy_read(struct openconnect_info *vpninfo, int fd,
unsigned char *buf, size_t len);
#define MAX_BUF_LEN 131072
#define BUF_CHUNK_SIZE 4096
struct oc_text_buf {
char *data;
int pos;
int buf_len;
int error;
};
static struct oc_text_buf *buf_alloc(void)
{
return calloc(1, sizeof(struct oc_text_buf));
}
static void buf_append(struct oc_text_buf *buf, const char *fmt, ...)
{
va_list ap;
if (!buf || buf->error)
return;
if (!buf->data) {
buf->data = malloc(BUF_CHUNK_SIZE);
if (!buf->data) {
buf->error = -ENOMEM;
return;
}
buf->buf_len = BUF_CHUNK_SIZE;
}
while (1) {
int max_len = buf->buf_len - buf->pos, ret;
va_start(ap, fmt);
ret = vsnprintf(buf->data + buf->pos, max_len, fmt, ap);
va_end(ap);
if (ret < 0) {
buf->error = -EIO;
break;
} else if (ret < max_len) {
buf->pos += ret;
break;
} else {
int new_buf_len = buf->buf_len + BUF_CHUNK_SIZE;
if (new_buf_len > MAX_BUF_LEN) {
/* probably means somebody is messing with us */
buf->error = -E2BIG;
break;
}
realloc_inplace(buf->data, new_buf_len);
if (!buf->data) {
buf->error = -ENOMEM;
break;
}
buf->buf_len = new_buf_len;
}
}
}
static int buf_error(struct oc_text_buf *buf)
{
return buf ? buf->error : -ENOMEM;
}
static int buf_free(struct oc_text_buf *buf)
{
int error = buf_error(buf);
if (buf) {
if (buf->data)
free(buf->data);
free(buf);
}
return error;
}
/*
* We didn't really want to have to do this for ourselves -- one might have
* thought that it would be available in a library somewhere. But neither
* cURL nor Neon have reliable cross-platform ways of either using a cert
* from the TPM, or just reading from / writing to a transport which is
* provided by their caller.
*/
static int http_add_cookie(struct openconnect_info *vpninfo,
const char *option, const char *value)
{
struct vpn_option *new, **this;
if (*value) {
new = malloc(sizeof(*new));
if (!new) {
vpn_progress(vpninfo, PRG_ERR,
_("No memory for allocating cookies\n"));
return -ENOMEM;
}
new->next = NULL;
new->option = strdup(option);
new->value = strdup(value);
if (!new->option || !new->value) {
free(new->option);
free(new->value);
free(new);
return -ENOMEM;
}
} else {
/* Kill cookie; don't replace it */
new = NULL;
}
for (this = &vpninfo->cookies; *this; this = &(*this)->next) {
if (!strcmp(option, (*this)->option)) {
/* Replace existing cookie */
if (new)
new->next = (*this)->next;
else
new = (*this)->next;
free((*this)->option);
free((*this)->value);
free(*this);
*this = new;
break;
}
}
if (new && !*this) {
*this = new;
new->next = NULL;
}
return 0;
}
#define BODY_HTTP10 -1
#define BODY_CHUNKED -2
static int process_http_response(struct openconnect_info *vpninfo, int *result,
int (*header_cb)(struct openconnect_info *, char *, char *),
char **body_ret)
{
char buf[MAX_BUF_LEN];
char *body = NULL;
int bodylen = BODY_HTTP10;
int done = 0;
int closeconn = 0;
int i;
cont:
if (openconnect_SSL_gets(vpninfo, buf, sizeof(buf)) < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Error fetching HTTPS response\n"));
return -EINVAL;
}
if (!strncmp(buf, "HTTP/1.0 ", 9))
closeconn = 1;
if ((!closeconn && strncmp(buf, "HTTP/1.1 ", 9)) || !(*result = atoi(buf+9))) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to parse HTTP response '%s'\n"), buf);
return -EINVAL;
}
vpn_progress(vpninfo, (*result == 200) ? PRG_TRACE : PRG_INFO,
_("Got HTTP response: %s\n"), buf);
/* Eat headers... */
while ((i = openconnect_SSL_gets(vpninfo, buf, sizeof(buf)))) {
char *colon;
if (i < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Error processing HTTP response\n"));
return -EINVAL;
}
colon = strchr(buf, ':');
if (!colon) {
vpn_progress(vpninfo, PRG_ERR,
_("Ignoring unknown HTTP response line '%s'\n"), buf);
continue;
}
*(colon++) = 0;
if (*colon == ' ')
colon++;
/* Handle Set-Cookie first so that we can avoid printing the
webvpn cookie in the verbose debug output */
if (!strcasecmp(buf, "Set-Cookie")) {
char *semicolon = strchr(colon, ';');
const char *print_equals;
char *equals = strchr(colon, '=');
int ret;
if (semicolon)
*semicolon = 0;
if (!equals) {
vpn_progress(vpninfo, PRG_ERR,
_("Invalid cookie offered: %s\n"), buf);
return -EINVAL;
}
*(equals++) = 0;
print_equals = equals;
/* Don't print the webvpn cookie unless it's empty; we don't
want people posting it in public with debugging output */
if (!strcmp(colon, "webvpn") && *equals)
print_equals = _("<elided>");
vpn_progress(vpninfo, PRG_TRACE, "%s: %s=%s%s%s\n",
buf, colon, print_equals, semicolon ? ";" : "",
semicolon ? (semicolon+1) : "");
/* The server tends to ask for the username and password as
usual, even if we've already failed because it didn't like
our cert. Thankfully it does give us this hint... */
if (!strcmp(colon, "ClientCertAuthFailed"))
vpn_progress(vpninfo, PRG_ERR,
_("SSL certificate authentication failed\n"));
ret = http_add_cookie(vpninfo, colon, equals);
if (ret)
return ret;
} else {
vpn_progress(vpninfo, PRG_TRACE, "%s: %s\n", buf, colon);
}
if (!strcasecmp(buf, "Connection")) {
if (!strcasecmp(colon, "Close"))
closeconn = 1;
#if 0
/* This might seem reasonable, but in fact it breaks
certificate authentication with some servers. If
they give an HTTP/1.0 response, even if they
explicitly give a Connection: Keep-Alive header,
just close the connection. */
else if (!strcasecmp(colon, "Keep-Alive"))
closeconn = 0;
#endif
}
if (!strcasecmp(buf, "Location")) {
vpninfo->redirect_url = strdup(colon);
if (!vpninfo->redirect_url)
return -ENOMEM;
}
if (!strcasecmp(buf, "Content-Length")) {
bodylen = atoi(colon);
if (bodylen < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Response body has negative size (%d)\n"),
bodylen);
return -EINVAL;
}
}
if (!strcasecmp(buf, "Transfer-Encoding")) {
if (!strcasecmp(colon, "chunked"))
bodylen = BODY_CHUNKED;
else {
vpn_progress(vpninfo, PRG_ERR,
_("Unknown Transfer-Encoding: %s\n"),
colon);
return -EINVAL;
}
}
if (header_cb && !strncmp(buf, "X-", 2))
header_cb(vpninfo, buf, colon);
}
/* Handle 'HTTP/1.1 100 Continue'. Not that we should ever see it */
if (*result == 100)
goto cont;
/* Now the body, if there is one */
vpn_progress(vpninfo, PRG_TRACE, _("HTTP body %s (%d)\n"),
bodylen == BODY_HTTP10 ? "http 1.0" :
bodylen == BODY_CHUNKED ? "chunked" : "length: ",
bodylen);
/* If we were given Content-Length, it's nice and easy... */
if (bodylen > 0) {
body = malloc(bodylen + 1);
if (!body)
return -ENOMEM;
while (done < bodylen) {
i = openconnect_SSL_read(vpninfo, body + done, bodylen - done);
if (i < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Error reading HTTP response body\n"));
free(body);
return -EINVAL;
}
done += i;
}
} else if (bodylen == BODY_CHUNKED) {
/* ... else, chunked */
while ((i = openconnect_SSL_gets(vpninfo, buf, sizeof(buf)))) {
int chunklen, lastchunk = 0;
if (i < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Error fetching chunk header\n"));
return i;
}
chunklen = strtol(buf, NULL, 16);
if (!chunklen) {
lastchunk = 1;
goto skip;
}
realloc_inplace(body, done + chunklen + 1);
if (!body)
return -ENOMEM;
while (chunklen) {
i = openconnect_SSL_read(vpninfo, body + done, chunklen);
if (i < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Error reading HTTP response body\n"));
free(body);
return -EINVAL;
}
chunklen -= i;
done += i;
}
skip:
if ((i = openconnect_SSL_gets(vpninfo, buf, sizeof(buf)))) {
if (i < 0) {
vpn_progress(vpninfo, PRG_ERR,
_("Error fetching HTTP response body\n"));
} else {
vpn_progress(vpninfo, PRG_ERR,
_("Error in chunked decoding. Expected '', got: '%s'"),
buf);
}
free(body);
return -EINVAL;
}
if (lastchunk)
break;
}
} else if (bodylen == BODY_HTTP10) {
if (!closeconn) {
vpn_progress(vpninfo, PRG_ERR,
_("Cannot receive HTTP 1.0 body without closing connection\n"));
openconnect_close_https(vpninfo, 0);
return -EINVAL;
}
/* HTTP 1.0 response. Just eat all we can in 16KiB chunks */
while (1) {
realloc_inplace(body, done + 16384);
if (!body)
return -ENOMEM;
i = openconnect_SSL_read(vpninfo, body + done, 16384);
if (i > 0) {
/* Got more data */
done += i;
} else if (i < 0) {
/* Error */
free(body);
return i;
} else {
/* Connection closed. Reduce allocation to just what we need */
realloc_inplace(body, done + 1);
if (!body)
return -ENOMEM;
break;
}
}
}
if (closeconn || vpninfo->no_http_keepalive)
openconnect_close_https(vpninfo, 0);
if (body)
body[done] = 0;
*body_ret = body;
return done;
}
static void add_common_headers(struct openconnect_info *vpninfo, struct oc_text_buf *buf)
{
struct vpn_option *opt;
buf_append(buf, "Host: %s\r\n", vpninfo->hostname);
buf_append(buf, "User-Agent: %s\r\n", vpninfo->useragent);
buf_append(buf, "Accept: */*\r\n");
buf_append(buf, "Accept-Encoding: identity\r\n");
if (vpninfo->cookies) {
buf_append(buf, "Cookie: ");
for (opt = vpninfo->cookies; opt; opt = opt->next)
buf_append(buf, "%s=%s%s", opt->option,
opt->value, opt->next ? "; " : "\r\n");
}
buf_append(buf, "X-Transcend-Version: 1\r\n");
buf_append(buf, "X-Aggregate-Auth: 1\r\n");
buf_append(buf, "X-AnyConnect-Platform: %s\r\n", vpninfo->platname);
}
static int fetch_config(struct openconnect_info *vpninfo, char *fu, char *bu,
char *server_sha1)
{
struct oc_text_buf *buf;
char *config_buf = NULL;
int result, buflen;
unsigned char local_sha1_bin[SHA1_SIZE];
char local_sha1_ascii[(SHA1_SIZE * 2)+1];
int i;
if (openconnect_open_https(vpninfo)) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open HTTPS connection to %s\n"),
vpninfo->hostname);
return -EINVAL;
}
buf = buf_alloc();
buf_append(buf, "GET %s%s HTTP/1.1\r\n", fu, bu);
add_common_headers(vpninfo, buf);
buf_append(buf, "\r\n");
if (buf_error(buf))
return buf_free(buf);
if (openconnect_SSL_write(vpninfo, buf->data, buf->pos) != buf->pos) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to send GET request for new config\n"));
buf_free(buf);
return -EIO;
}
buf_free(buf);
buflen = process_http_response(vpninfo, &result, NULL, &config_buf);
if (buflen < 0) {
/* We'll already have complained about whatever offended us */
return -EINVAL;
}
if (result != 200) {
free(config_buf);
return -EINVAL;
}
openconnect_sha1(local_sha1_bin, config_buf, buflen);
for (i = 0; i < SHA1_SIZE; i++)
sprintf(&local_sha1_ascii[i*2], "%02x", local_sha1_bin[i]);
if (strcasecmp(server_sha1, local_sha1_ascii)) {
vpn_progress(vpninfo, PRG_ERR,
_("Downloaded config file did not match intended SHA1\n"));
free(config_buf);
return -EINVAL;
}
result = vpninfo->write_new_config(vpninfo->cbdata, config_buf, buflen);
free(config_buf);
return result;
}
static int run_csd_script(struct openconnect_info *vpninfo, char *buf, int buflen)
{
char fname[16];
int fd, ret;
if (!vpninfo->uid_csd_given && !vpninfo->csd_wrapper) {
vpn_progress(vpninfo, PRG_ERR,
_("Error: Server asked us to download and run a 'Cisco Secure Desktop' trojan.\n"
"This facility is disabled by default for security reasons, so you may wish to enable it.\n"));
return -EPERM;
}
#ifndef __linux__
vpn_progress(vpninfo, PRG_INFO,
_("Trying to run Linux CSD trojan script.\n"));
#endif
sprintf(fname, "/tmp/csdXXXXXX");
fd = mkstemp(fname);
if (fd < 0) {
int err = -errno;
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open temporary CSD script file: %s\n"),
strerror(errno));
return err;
}
ret = proxy_write(vpninfo, fd, (void *)buf, buflen);
if (ret) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to write temporary CSD script file: %s\n"),
strerror(-ret));
return ret;
}
fchmod(fd, 0755);
close(fd);
if (!fork()) {
char scertbuf[MD5_SIZE * 2 + 1];
char ccertbuf[MD5_SIZE * 2 + 1];
char *csd_argv[32];
int i = 0;
if (vpninfo->uid_csd_given && vpninfo->uid_csd != getuid()) {
struct passwd *pw;
if (setuid(vpninfo->uid_csd)) {
fprintf(stderr, _("Failed to set uid %ld\n"),
(long)vpninfo->uid_csd);
exit(1);
}
if (!(pw = getpwuid(vpninfo->uid_csd))) {
fprintf(stderr, _("Invalid user uid=%ld\n"),
(long)vpninfo->uid_csd);
exit(1);
}
setenv("HOME", pw->pw_dir, 1);
if (chdir(pw->pw_dir)) {
fprintf(stderr, _("Failed to change to CSD home directory '%s': %s\n"),
pw->pw_dir, strerror(errno));
exit(1);
}
}
if (getuid() == 0 && !vpninfo->csd_wrapper) {
fprintf(stderr, _("Warning: you are running insecure "
"CSD code with root privileges\n"
"\t Use command line option \"--csd-user\"\n"));
}
if (vpninfo->uid_csd_given == 2) {
/* The NM tool really needs not to get spurious output
on stdout, which the CSD trojan spews. */
dup2(2, 1);
}
if (vpninfo->csd_wrapper)
csd_argv[i++] = vpninfo->csd_wrapper;
csd_argv[i++] = fname;
csd_argv[i++] = (char *)"-ticket";
if (asprintf(&csd_argv[i++], "\"%s\"", vpninfo->csd_ticket) == -1)
goto out;
csd_argv[i++] = (char *)"-stub";
csd_argv[i++] = (char *)"\"0\"";
csd_argv[i++] = (char *)"-group";
if (asprintf(&csd_argv[i++], "\"%s\"", vpninfo->authgroup?:"") == -1)
goto out;
openconnect_local_cert_md5(vpninfo, ccertbuf);
scertbuf[0] = 0;
get_cert_md5_fingerprint(vpninfo, vpninfo->peer_cert, scertbuf);
csd_argv[i++] = (char *)"-certhash";
if (asprintf(&csd_argv[i++], "\"%s:%s\"", scertbuf, ccertbuf) == -1)
goto out;
csd_argv[i++] = (char *)"-url";
if (asprintf(&csd_argv[i++], "\"https://%s%s\"", vpninfo->hostname, vpninfo->csd_starturl) == -1)
goto out;
csd_argv[i++] = (char *)"-langselen";
csd_argv[i++] = NULL;
if (setenv("CSD_TOKEN", vpninfo->csd_token, 1))
goto out;
if (setenv("CSD_HOSTNAME", vpninfo->hostname, 1))
goto out;
execv(csd_argv[0], csd_argv);
out:
vpn_progress(vpninfo, PRG_ERR,
_("Failed to exec CSD script %s\n"), csd_argv[0]);
exit(1);
}
free(vpninfo->csd_stuburl);
vpninfo->csd_stuburl = NULL;
free(vpninfo->urlpath);
vpninfo->urlpath = strdup(vpninfo->csd_waiturl +
(vpninfo->csd_waiturl[0] == '/' ? 1 : 0));
free(vpninfo->csd_waiturl);
vpninfo->csd_waiturl = NULL;
vpninfo->csd_scriptname = strdup(fname);
http_add_cookie(vpninfo, "sdesktop", vpninfo->csd_token);
return 0;
}
int internal_parse_url(char *url, char **res_proto, char **res_host,
int *res_port, char **res_path, int default_port)
{
char *proto = url;
char *host, *path, *port_str;
int port;
host = strstr(url, "://");
if (host) {
*host = 0;
host += 3;
if (!strcasecmp(proto, "https"))
port = 443;
else if (!strcasecmp(proto, "http"))
port = 80;
else if (!strcasecmp(proto, "socks") ||
!strcasecmp(proto, "socks4") ||
!strcasecmp(proto, "socks5"))
port = 1080;
else
return -EPROTONOSUPPORT;
} else {
if (default_port) {
proto = NULL;
port = default_port;
host = url;
} else
return -EINVAL;
}
path = strchr(host, '/');
if (path)
*(path++) = 0;
port_str = strrchr(host, ':');
if (port_str) {
char *end;
int new_port = strtol(port_str + 1, &end, 10);
if (!*end) {
*port_str = 0;
port = new_port;
}
}
if (res_proto)
*res_proto = proto ? strdup(proto) : NULL;
if (res_host)
*res_host = strdup(host);
if (res_port)
*res_port = port;
if (res_path)
*res_path = (path && *path) ? strdup(path) : NULL;
/* Undo the damage we did to the original string */
if (port_str)
*(port_str) = ':';
if (path)
*(path - 1) = '/';
if (proto)
*(host - 3) = ':';
return 0;
}
static void clear_cookies(struct openconnect_info *vpninfo)
{
struct vpn_option *opt, *next;
for (opt = vpninfo->cookies; opt; opt = next) {
next = opt->next;
free(opt->option);
free(opt->value);
free(opt);
}
vpninfo->cookies = NULL;
}
/* Return value:
* < 0, on error
* = 0, on success (go ahead and retry with the latest vpninfo->{hostname,urlpath,port,...})
*/
static int handle_redirect(struct openconnect_info *vpninfo)
{
vpninfo->redirect_type = REDIR_TYPE_LOCAL;
if (!strncmp(vpninfo->redirect_url, "https://", 8)) {
/* New host. Tear down the existing connection and make a new one */
char *host;
int port;
int ret;
free(vpninfo->urlpath);
vpninfo->urlpath = NULL;
ret = internal_parse_url(vpninfo->redirect_url, NULL, &host, &port, &vpninfo->urlpath, 0);
if (ret) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to parse redirected URL '%s': %s\n"),
vpninfo->redirect_url, strerror(-ret));
free(vpninfo->redirect_url);
vpninfo->redirect_url = NULL;
return ret;
}
if (strcasecmp(vpninfo->hostname, host) || port != vpninfo->port) {
free(vpninfo->unique_hostname);
vpninfo->unique_hostname = NULL;
free(vpninfo->hostname);
vpninfo->hostname = host;
vpninfo->port = port;
/* Kill the existing connection, and a new one will happen */
free(vpninfo->peer_addr);
vpninfo->peer_addr = NULL;
openconnect_close_https(vpninfo, 0);
clear_cookies(vpninfo);
vpninfo->redirect_type = REDIR_TYPE_NEWHOST;
} else
free(host);
free(vpninfo->redirect_url);
vpninfo->redirect_url = NULL;
return 0;
} else if (strstr(vpninfo->redirect_url, "://")) {
vpn_progress(vpninfo, PRG_ERR,
_("Cannot follow redirection to non-https URL '%s'\n"),
vpninfo->redirect_url);
free(vpninfo->redirect_url);
vpninfo->redirect_url = NULL;
return -EINVAL;
} else if (vpninfo->redirect_url[0] == '/') {
/* Absolute redirect within same host */
free(vpninfo->urlpath);
vpninfo->urlpath = strdup(vpninfo->redirect_url + 1);
free(vpninfo->redirect_url);
vpninfo->redirect_url = NULL;
return 0;
} else {
char *lastslash = NULL;
if (vpninfo->urlpath)
lastslash = strrchr(vpninfo->urlpath, '/');
if (!lastslash) {
free(vpninfo->urlpath);
vpninfo->urlpath = vpninfo->redirect_url;
vpninfo->redirect_url = NULL;
} else {
char *oldurl = vpninfo->urlpath;
*lastslash = 0;
vpninfo->urlpath = NULL;
if (asprintf(&vpninfo->urlpath, "%s/%s",
oldurl, vpninfo->redirect_url) == -1) {
int err = -errno;
vpn_progress(vpninfo, PRG_ERR,
_("Allocating new path for relative redirect failed: %s\n"),
strerror(-err));
return err;
}
free(oldurl);
free(vpninfo->redirect_url);
vpninfo->redirect_url = NULL;
}
return 0;
}
}
/* Inputs:
* method: GET or POST
* vpninfo->hostname: Host DNS name
* vpninfo->port: TCP port, typically 443
* vpninfo->urlpath: Relative path, e.g. /+webvpn+/foo.html
* request_body_type: Content type for a POST (e.g. text/html). Can be NULL.
* request_body: POST content
* form_buf: Callee-allocated buffer for server content
*
* Return value:
* < 0, on error
* >=0, on success, indicating the length of the data in *form_buf
*/
static int do_https_request(struct openconnect_info *vpninfo, const char *method,
const char *request_body_type, const char *request_body,
char **form_buf, int fetch_redirect)
{
struct oc_text_buf *buf;
int result, buflen;
retry:
vpninfo->redirect_type = REDIR_TYPE_NONE;
if (*form_buf) {
free(*form_buf);
*form_buf = NULL;
}
if (openconnect_open_https(vpninfo)) {
vpn_progress(vpninfo, PRG_ERR,
_("Failed to open HTTPS connection to %s\n"),
vpninfo->hostname);
return -EINVAL;
}
/*
* It would be nice to use cURL for this, but we really need to guarantee
* that we'll be using OpenSSL (for the TPM stuff), and it doesn't seem
* to have any way to let us provide our own socket read/write functions.
* We can only provide a socket _open_ function. Which would require having
* a socketpair() and servicing the "other" end of it.
*
* So we process the HTTP for ourselves...
*/
buf = buf_alloc();
buf_append(buf, "%s /%s HTTP/1.1\r\n", method, vpninfo->urlpath ?: "");
add_common_headers(vpninfo, buf);
if (request_body_type) {
buf_append(buf, "Content-Type: %s\r\n", request_body_type);
buf_append(buf, "Content-Length: %zd\r\n", strlen(request_body));
}
buf_append(buf, "\r\n");
if (request_body_type)
buf_append(buf, "%s", request_body);
if (vpninfo->port == 443)
vpn_progress(vpninfo, PRG_INFO, "%s https://%s/%s\n",
method, vpninfo->hostname,
vpninfo->urlpath ?: "");
else
vpn_progress(vpninfo, PRG_INFO, "%s https://%s:%d/%s\n",
method, vpninfo->hostname, vpninfo->port,
vpninfo->urlpath ?: "");
if (buf_error(buf))
return buf_free(buf);
result = openconnect_SSL_write(vpninfo, buf->data, buf->pos);
buf_free(buf);
if (result < 0)
return result;
buflen = process_http_response(vpninfo, &result, NULL, form_buf);
if (buflen < 0) {
/* We'll already have complained about whatever offended us */
return buflen;
}
if (result != 200 && vpninfo->redirect_url) {
result = handle_redirect(vpninfo);
if (result == 0) {
if (!fetch_redirect)
return 0;
goto retry;
}
goto out;
}
if (!*form_buf || result != 200) {
vpn_progress(vpninfo, PRG_ERR,
_("Unexpected %d result from server\n"),
result);
result = -EINVAL;
goto out;
}
return buflen;
out:
free(*form_buf);
*form_buf = NULL;
return result;
}
/* Return value:
* < 0, if the data is unrecognized
* = 0, if the page contains an XML document
* = 1, if the page is a wait/refresh HTML page
*/
static int check_response_type(struct openconnect_info *vpninfo, char *form_buf)
{
if (strncmp(form_buf, "<?xml", 5)) {
/* Not XML? Perhaps it's HTML with a refresh... */
if (strcasestr(form_buf, "http-equiv=\"refresh\""))
return 1;
vpn_progress(vpninfo, PRG_ERR,
_("Unknown response from server\n"));
return -EINVAL;
}
return 0;
}
/* Return value:
* < 0, on error
* > 0, no cookie (user cancel)
* = 0, obtained cookie
*/
int openconnect_obtain_cookie(struct openconnect_info *vpninfo)
{
struct vpn_option *opt;
char *form_buf = NULL;
struct oc_auth_form *form = NULL;
int result, buflen, tries;
char request_body[2048];
const char *request_body_type = "application/x-www-form-urlencoded";
const char *method = "POST";
int xmlpost = 1;
/* Step 1: Unlock software token (if applicable) */
if (vpninfo->use_stoken) {
result = prepare_stoken(vpninfo);
if (result)
return result;
}
/*
* Step 2: Probe for XML POST compatibility
*
* This can get stuck in a redirect loop, so give up after any of:
*
* a) HTTP error (e.g. 400 Bad Request)
* b) Same-host redirect (e.g. Location: /foo/bar)
* c) Three redirects without seeing a plausible login form
*/
result = xmlpost_initial_req(vpninfo, request_body, sizeof(request_body));
if (result < 0)
return result;
for (tries = 0; ; tries++) {
if (tries == 3) {
fail:
if (xmlpost) {
/* Try without XML POST this time... */
tries = 0;
xmlpost = 0;
request_body_type = NULL;
request_body[0] = 0;
method = "GET";
} else {
return -EIO;
}
}
buflen = do_https_request(vpninfo, method, request_body_type, request_body,
&form_buf, 0);
if (buflen == -EINVAL)
goto fail;
if (buflen < 0)
return buflen;
/* XML POST does not allow local redirects, but GET does. */
if (xmlpost && vpninfo->redirect_type == REDIR_TYPE_LOCAL)
goto fail;
else if (vpninfo->redirect_type != REDIR_TYPE_NONE)
continue;
result = parse_xml_response(vpninfo, form_buf, &form);
if (result < 0)
goto fail;
if (form->action) {
vpninfo->redirect_url = strdup(form->action);
handle_redirect(vpninfo);
}
break;
}
if (xmlpost)
vpn_progress(vpninfo, PRG_INFO, _("XML POST enabled\n"));