From fffd213c8cba2135afda493d797c41c10354770e Mon Sep 17 00:00:00 2001 From: Othmar Gsenger Date: Sat, 12 Apr 2008 11:38:42 +0000 Subject: big svn cleanup --- src/openvpn/proxy.c | 490 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 490 insertions(+) create mode 100644 src/openvpn/proxy.c (limited to 'src/openvpn/proxy.c') diff --git a/src/openvpn/proxy.c b/src/openvpn/proxy.c new file mode 100644 index 0000000..a32e8e1 --- /dev/null +++ b/src/openvpn/proxy.c @@ -0,0 +1,490 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2005 OpenVPN Solutions LLC + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program (see the file COPYING included with this + * distribution); if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifdef WIN32 +#include "config-win32.h" +#else +#include "config.h" +#endif + +#ifdef ENABLE_HTTP_PROXY + +#include "syshead.h" + +#include "common.h" +#include "misc.h" +#include "win32.h" +#include "socket.h" +#include "fdmisc.h" +#include "proxy.h" +#include "base64.h" +#include "ntlm.h" + +#include "memdbg.h" + +/* cached proxy username/password */ +static struct user_pass static_proxy_user_pass; + +static bool +recv_line (socket_descriptor_t sd, + char *buf, + int len, + const int timeout_sec, + const bool verbose, + struct buffer *lookahead, + volatile int *signal_received) +{ + struct buffer la; + int lastc = 0; + + CLEAR (la); + if (lookahead) + la = *lookahead; + + while (true) + { + int status; + ssize_t size; + fd_set reads; + struct timeval tv; + uint8_t c; + + if (buf_defined (&la)) + { + ASSERT (buf_init (&la, 0)); + } + + FD_ZERO (&reads); + FD_SET (sd, &reads); + tv.tv_sec = timeout_sec; + tv.tv_usec = 0; + + status = select (sd + 1, &reads, NULL, NULL, &tv); + + get_signal (signal_received); + if (*signal_received) + goto error; + + /* timeout? */ + if (status == 0) + { + if (verbose) + msg (D_LINK_ERRORS | M_ERRNO_SOCK, "recv_line: TCP port read timeout expired"); + goto error; + } + + /* error */ + if (status < 0) + { + if (verbose) + msg (D_LINK_ERRORS | M_ERRNO_SOCK, "recv_line: TCP port read failed on select()"); + goto error; + } + + /* read single char */ + size = recv (sd, &c, 1, MSG_NOSIGNAL); + + /* error? */ + if (size != 1) + { + if (verbose) + msg (D_LINK_ERRORS | M_ERRNO_SOCK, "recv_line: TCP port read failed on recv()"); + goto error; + } + +#if 0 + if (isprint(c)) + msg (M_INFO, "PROXY: read '%c' (%d)", c, (int)c); + else + msg (M_INFO, "PROXY: read (%d)", (int)c); +#endif + + /* store char in buffer */ + if (len > 1) + { + *buf++ = c; + --len; + } + + /* also store char in lookahead buffer */ + if (buf_defined (&la)) + { + buf_write_u8 (&la, c); + if (!isprint(c) && !isspace(c)) /* not ascii? */ + { + if (verbose) + msg (D_LINK_ERRORS | M_ERRNO_SOCK, "recv_line: Non-ASCII character (%d) read on recv()", (int)c); + *lookahead = la; + return false; + } + } + + /* end of line? */ + if (lastc == '\r' && c == '\n') + break; + + lastc = c; + } + + /* append trailing null */ + if (len > 0) + *buf++ = '\0'; + + return true; + + error: + return false; +} + +static bool +send_line (socket_descriptor_t sd, + const char *buf) +{ + const ssize_t size = send (sd, buf, strlen (buf), MSG_NOSIGNAL); + if (size != (ssize_t) strlen (buf)) + { + msg (D_LINK_ERRORS | M_ERRNO_SOCK, "send_line: TCP port write failed on send()"); + return false; + } + return true; +} + +static bool +send_line_crlf (socket_descriptor_t sd, + const char *src) +{ + bool ret; + + struct buffer buf = alloc_buf (strlen (src) + 3); + ASSERT (buf_write (&buf, src, strlen (src))); + ASSERT (buf_write (&buf, "\r\n", 3)); + ret = send_line (sd, BSTR (&buf)); + free_buf (&buf); + return ret; +} + +static bool +send_crlf (socket_descriptor_t sd) +{ + return send_line_crlf (sd, ""); +} + +uint8_t * +make_base64_string2 (const uint8_t *str, int src_len, struct gc_arena *gc) +{ + uint8_t *ret = NULL; + char *b64out = NULL; + ASSERT (base64_encode ((const void *)str, src_len, &b64out) >= 0); + ret = (uint8_t *) string_alloc (b64out, gc); + free (b64out); + return ret; +} + +uint8_t * +make_base64_string (const uint8_t *str, struct gc_arena *gc) +{ + return make_base64_string2 (str, strlen ((const char *)str), gc); +} + +static const char * +username_password_as_base64 (const struct http_proxy_info *p, + struct gc_arena *gc) +{ + struct buffer out = alloc_buf_gc (strlen (p->up.username) + strlen (p->up.password) + 2, gc); + ASSERT (strlen (p->up.username) > 0); + buf_printf (&out, "%s:%s", p->up.username, p->up.password); + return (const char *)make_base64_string ((const uint8_t*)BSTR (&out), gc); +} + +struct http_proxy_info * +new_http_proxy (const struct http_proxy_options *o, + struct gc_arena *gc) +{ + struct http_proxy_info *p; + ALLOC_OBJ_CLEAR_GC (p, struct http_proxy_info, gc); + + if (!o->server) + msg (M_FATAL, "HTTP_PROXY: server not specified"); + + ASSERT (legal_ipv4_port (o->port)); + + p->options = *o; + + /* parse authentication method */ + p->auth_method = HTTP_AUTH_NONE; + if (o->auth_method_string) + { + if (!strcmp (o->auth_method_string, "none")) + p->auth_method = HTTP_AUTH_NONE; + else if (!strcmp (o->auth_method_string, "basic")) + p->auth_method = HTTP_AUTH_BASIC; + else if (!strcmp (o->auth_method_string, "ntlm")) + p->auth_method = HTTP_AUTH_NTLM; + else + msg (M_FATAL, "ERROR: unknown HTTP authentication method: '%s' -- only the 'none', 'basic', or 'ntlm' methods are currently supported", + o->auth_method_string); + } + + /* only basic and NTLM authentication supported so far */ + if (p->auth_method == HTTP_AUTH_BASIC || p->auth_method == HTTP_AUTH_NTLM) + { + get_user_pass (&static_proxy_user_pass, + o->auth_file, + false, + "HTTP Proxy", + GET_USER_PASS_MANAGEMENT); + p->up = static_proxy_user_pass; + } + +#if !NTLM + if (p->auth_method == HTTP_AUTH_NTLM) + msg (M_FATAL, "Sorry, this version of " PACKAGE_NAME " was built without NTLM Proxy support."); +#endif + + p->defined = true; + return p; +} + +void +establish_http_proxy_passthru (struct http_proxy_info *p, + socket_descriptor_t sd, /* already open to proxy */ + const char *host, /* openvpn server remote */ + const int port, /* openvpn server port */ + struct buffer *lookahead, + volatile int *signal_received) +{ + struct gc_arena gc = gc_new (); + char buf[256]; + char buf2[128]; + char get[80]; + int status; + int nparms; + + /* format HTTP CONNECT message */ + openvpn_snprintf (buf, sizeof(buf), "CONNECT %s:%d HTTP/%s", + host, + port, + p->options.http_version); + + msg (D_PROXY, "Send to HTTP proxy: '%s'", buf); + + /* send HTTP CONNECT message to proxy */ + if (!send_line_crlf (sd, buf)) + goto error; + + /* send User-Agent string if provided */ + if (p->options.user_agent) + { + openvpn_snprintf (buf, sizeof(buf), "User-Agent: %s", + p->options.user_agent); + if (!send_line_crlf (sd, buf)) + goto error; + } + + /* auth specified? */ + switch (p->auth_method) + { + case HTTP_AUTH_NONE: + break; + + case HTTP_AUTH_BASIC: + openvpn_snprintf (buf, sizeof(buf), "Proxy-Authorization: Basic %s", + username_password_as_base64 (p, &gc)); + msg (D_PROXY, "Attempting Basic Proxy-Authorization"); + dmsg (D_SHOW_KEYS, "Send to HTTP proxy: '%s'", buf); + openvpn_sleep (1); + if (!send_line_crlf (sd, buf)) + goto error; + break; + +#if NTLM + case HTTP_AUTH_NTLM: + openvpn_snprintf (buf, sizeof(buf), "Proxy-Authorization: NTLM %s", + ntlm_phase_1 (p, &gc)); + msg (D_PROXY, "Attempting NTLM Proxy-Authorization phase 1"); + dmsg (D_SHOW_KEYS, "Send to HTTP proxy: '%s'", buf); + openvpn_sleep (1); + if (!send_line_crlf (sd, buf)) + goto error; + break; +#endif + + default: + ASSERT (0); + } + + /* send empty CR, LF */ + openvpn_sleep (1); + if (!send_crlf (sd)) + goto error; + + /* receive reply from proxy */ + if (!recv_line (sd, buf, sizeof(buf), p->options.timeout, true, NULL, signal_received)) + goto error; + + /* remove trailing CR, LF */ + chomp (buf); + + msg (D_PROXY, "HTTP proxy returned: '%s'", buf); + + /* parse return string */ + nparms = sscanf (buf, "%*s %d", &status); + + /* check for a "407 Proxy Authentication Required" response */ + if (nparms >= 1 && status == 407) + { + msg (D_PROXY, "Proxy requires authentication"); + + /* check for NTLM */ + if (p->auth_method == HTTP_AUTH_NTLM) + { +#if NTLM + /* look for the phase 2 response */ + + while (true) + { + if (!recv_line (sd, buf, sizeof(buf), p->options.timeout, true, NULL, signal_received)) + goto error; + chomp (buf); + msg (D_PROXY, "HTTP proxy returned: '%s'", buf); + + openvpn_snprintf (get, sizeof get, "%%*s NTLM %%%ds", (int) sizeof (buf2) - 1); + nparms = sscanf (buf, get, buf2); + buf2[127] = 0; /* we only need the beginning - ensure it's null terminated. */ + + /* check for "Proxy-Authenticate: NTLM TlRM..." */ + if (nparms == 1) + { + /* parse buf2 */ + msg (D_PROXY, "auth string: '%s'", buf2); + break; + } + } + /* if we are here then auth string was got */ + msg (D_PROXY, "Received NTLM Proxy-Authorization phase 2 response"); + + /* receive and discard everything else */ + while (recv_line (sd, NULL, 0, p->options.timeout, true, NULL, signal_received)) + ; + + /* now send the phase 3 reply */ + + /* format HTTP CONNECT message */ + openvpn_snprintf (buf, sizeof(buf), "CONNECT %s:%d HTTP/%s", + host, + port, + p->options.http_version); + + msg (D_PROXY, "Send to HTTP proxy: '%s'", buf); + + /* send HTTP CONNECT message to proxy */ + if (!send_line_crlf (sd, buf)) + goto error; + + /* send HOST etc, */ + openvpn_sleep (1); + openvpn_snprintf (buf, sizeof(buf), "Host: %s", host); + msg (D_PROXY, "Send to HTTP proxy: '%s'", buf); + if (!send_line_crlf (sd, buf)) + goto error; + + openvpn_snprintf (buf, sizeof(buf), "Proxy-Authorization: NTLM %s", + ntlm_phase_3 (p, buf2, &gc)); + msg (D_PROXY, "Attempting NTLM Proxy-Authorization phase 3"); + msg (D_PROXY, "Send to HTTP proxy: '%s'", buf); + openvpn_sleep (1); + if (!send_line_crlf (sd, buf)) + goto error; + /* ok so far... */ + /* send empty CR, LF */ + openvpn_sleep (1); + if (!send_crlf (sd)) + goto error; + + /* receive reply from proxy */ + if (!recv_line (sd, buf, sizeof(buf), p->options.timeout, true, NULL, signal_received)) + goto error; + + /* remove trailing CR, LF */ + chomp (buf); + + msg (D_PROXY, "HTTP proxy returned: '%s'", buf); + + /* parse return string */ + nparms = sscanf (buf, "%*s %d", &status); +#else + ASSERT (0); /* No NTLM support */ +#endif + } + else goto error; + } + + + /* check return code, success = 200 */ + if (nparms < 1 || status != 200) + { + msg (D_LINK_ERRORS, "HTTP proxy returned bad status"); +#if 0 + /* DEBUGGING -- show a multi-line HTTP error response */ + while (true) + { + if (!recv_line (sd, buf, sizeof (buf), p->options.timeout, true, NULL, signal_received)) + goto error; + chomp (buf); + msg (D_PROXY, "HTTP proxy returned: '%s'", buf); + } +#endif + goto error; + } + + /* receive line from proxy and discard */ + if (!recv_line (sd, NULL, 0, p->options.timeout, true, NULL, signal_received)) + goto error; + + /* + * Toss out any extraneous chars, but don't throw away the + * start of the OpenVPN data stream (put it in lookahead). + */ + while (recv_line (sd, NULL, 0, 2, false, lookahead, signal_received)) + ; + +#if 0 + if (lookahead && BLEN (lookahead)) + msg (M_INFO, "HTTP PROXY: lookahead: %s", format_hex (BPTR (lookahead), BLEN (lookahead), 0)); +#endif + + gc_free (&gc); + return; + + error: + /* on error, should we exit or restart? */ + if (!*signal_received) + *signal_received = (p->options.retry ? SIGUSR1 : SIGTERM); /* SOFT-SIGUSR1 -- HTTP proxy error */ + gc_free (&gc); + return; +} + +#else +static void dummy(void) {} +#endif /* ENABLE_HTTP_PROXY */ -- cgit v1.2.3