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-rw-r--r--proxy.c534
1 files changed, 440 insertions, 94 deletions
diff --git a/proxy.c b/proxy.c
index 6e5a30a..fce64a1 100644
--- a/proxy.c
+++ b/proxy.c
@@ -5,7 +5,7 @@
* packet encryption, packet authentication, and
* packet compression.
*
- * Copyright (C) 2002-2009 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
@@ -26,11 +26,13 @@
#include "common.h"
#include "misc.h"
+#include "crypto.h"
#include "win32.h"
#include "socket.h"
#include "fdmisc.h"
#include "proxy.h"
#include "base64.h"
+#include "httpdigest.h"
#include "ntlm.h"
#ifdef WIN32
@@ -41,6 +43,8 @@
#ifdef ENABLE_HTTP_PROXY
+#define UP_TYPE_PROXY "HTTP Proxy"
+
/* cached proxy username/password */
static struct user_pass static_proxy_user_pass;
@@ -220,13 +224,200 @@ get_user_pass_http (struct http_proxy_info *p, const bool force)
{
if (!static_proxy_user_pass.defined || force)
{
+ unsigned int flags = GET_USER_PASS_MANAGEMENT;
+ if (p->queried_creds)
+ flags |= GET_USER_PASS_PREVIOUS_CREDS_FAILED;
get_user_pass (&static_proxy_user_pass,
p->options.auth_file,
- "HTTP Proxy",
- GET_USER_PASS_MANAGEMENT);
+ UP_TYPE_PROXY,
+ flags);
+ p->queried_creds = true;
p->up = static_proxy_user_pass;
}
}
+static void
+clear_user_pass_http (void)
+{
+ purge_user_pass (&static_proxy_user_pass, true);
+}
+
+static void
+dump_residual (socket_descriptor_t sd,
+ int timeout,
+ volatile int *signal_received)
+{
+ char buf[256];
+ while (true)
+ {
+ if (!recv_line (sd, buf, sizeof (buf), timeout, true, NULL, signal_received))
+ return;
+ chomp (buf);
+ msg (D_PROXY, "PROXY HEADER: '%s'", buf);
+ }
+}
+
+/*
+ * Extract the Proxy-Authenticate header from the stream.
+ * Consumes all headers.
+ */
+static int
+get_proxy_authenticate (socket_descriptor_t sd,
+ int timeout,
+ char **data,
+ struct gc_arena *gc,
+ volatile int *signal_received)
+{
+ char buf[256];
+ int ret = HTTP_AUTH_NONE;
+ while (true)
+ {
+ if (!recv_line (sd, buf, sizeof (buf), timeout, true, NULL, signal_received))
+ {
+ *data = NULL;
+ return HTTP_AUTH_NONE;
+ }
+ chomp (buf);
+ if (!strlen(buf))
+ return ret;
+ if (ret == HTTP_AUTH_NONE && !strncmp(buf, "Proxy-Authenticate: ", 20))
+ {
+ if (!strncmp(buf+20, "Basic ", 6))
+ {
+ msg (D_PROXY, "PROXY AUTH BASIC: '%s'", buf);
+ *data = string_alloc(buf+26, gc);
+ ret = HTTP_AUTH_BASIC;
+ }
+#if PROXY_DIGEST_AUTH
+ else if (!strncmp(buf+20, "Digest ", 7))
+ {
+ msg (D_PROXY, "PROXY AUTH DIGEST: '%s'", buf);
+ *data = string_alloc(buf+27, gc);
+ ret = HTTP_AUTH_DIGEST;
+ }
+#endif
+#if NTLM
+ else if (!strncmp(buf+20, "NTLM", 4))
+ {
+ msg (D_PROXY, "PROXY AUTH HTLM: '%s'", buf);
+ *data = NULL;
+ ret = HTTP_AUTH_NTLM;
+ }
+#endif
+ }
+ }
+}
+
+static void
+store_proxy_authenticate (struct http_proxy_info *p, char *data)
+{
+ if (p->proxy_authenticate)
+ free (p->proxy_authenticate);
+ p->proxy_authenticate = data;
+}
+
+/*
+ * Parse out key/value pairs from Proxy-Authenticate string.
+ * Return true on success, or false on parse failure.
+ */
+static bool
+get_key_value(const char *str, /* source string */
+ char *key, /* key stored here */
+ char *value, /* value stored here */
+ int max_key_len,
+ int max_value_len,
+ const char **endptr) /* next search position */
+{
+ int c;
+ bool starts_with_quote = false;
+ bool escape = false;
+
+ for (c = max_key_len-1; (*str && (*str != '=') && c--); )
+ *key++ = *str++;
+ *key = '\0';
+
+ if('=' != *str++)
+ /* no key/value found */
+ return false;
+
+ if('\"' == *str)
+ {
+ /* quoted string */
+ str++;
+ starts_with_quote = true;
+ }
+
+ for (c = max_value_len-1; *str && c--; str++)
+ {
+ switch (*str)
+ {
+ case '\\':
+ if (!escape)
+ {
+ /* possibly the start of an escaped quote */
+ escape = true;
+ *value++ = '\\'; /* even though this is an escape character, we still
+ store it as-is in the target buffer */
+ continue;
+ }
+ break;
+ case ',':
+ if (!starts_with_quote)
+ {
+ /* this signals the end of the value if we didn't get a starting quote
+ and then we do "sloppy" parsing */
+ c=0; /* the end */
+ continue;
+ }
+ break;
+ case '\r':
+ case '\n':
+ /* end of string */
+ c=0;
+ continue;
+ case '\"':
+ if (!escape && starts_with_quote)
+ {
+ /* end of string */
+ c=0;
+ continue;
+ }
+ break;
+ }
+ escape = false;
+ *value++ = *str;
+ }
+ *value = '\0';
+
+ *endptr = str;
+
+ return true; /* success */
+}
+
+static char *
+get_pa_var (const char *key, const char *pa, struct gc_arena *gc)
+{
+ char k[64];
+ char v[256];
+ const char *content = pa;
+
+ while (true)
+ {
+ const int status = get_key_value(content, k, v, sizeof(k), sizeof(v), &content);
+ if (status)
+ {
+ if (!strcmp(key, k))
+ return string_alloc(v, gc);
+ }
+ else
+ return NULL;
+
+ /* advance to start of next key */
+ if (*content == ',')
+ ++content;
+ while (*content && isspace(*content))
+ ++content;
+ }
+}
struct http_proxy_info *
http_proxy_new (const struct http_proxy_options *o,
@@ -263,7 +454,8 @@ http_proxy_new (const struct http_proxy_options *o,
opt.server = auto_proxy_info->http.server;
opt.port = auto_proxy_info->http.port;
- opt.auth_retry = true;
+ if (!opt.auth_retry)
+ opt.auth_retry = PAR_ALL;
o = &opt;
}
@@ -285,12 +477,14 @@ http_proxy_new (const struct http_proxy_options *o,
p->auth_method = HTTP_AUTH_NONE;
else if (!strcmp (o->auth_method_string, "basic"))
p->auth_method = HTTP_AUTH_BASIC;
+#if NTLM
else if (!strcmp (o->auth_method_string, "ntlm"))
p->auth_method = HTTP_AUTH_NTLM;
else if (!strcmp (o->auth_method_string, "ntlm2"))
p->auth_method = HTTP_AUTH_NTLM2;
+#endif
else
- msg (M_FATAL, "ERROR: unknown HTTP authentication method: '%s' -- only the 'none', 'basic', 'ntlm', or 'ntlm2' methods are currently supported",
+ msg (M_FATAL, "ERROR: unknown HTTP authentication method: '%s'",
o->auth_method_string);
}
@@ -324,101 +518,117 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
volatile int *signal_received)
{
struct gc_arena gc = gc_new ();
- char buf[256];
+ char buf[512];
char buf2[128];
char get[80];
int status;
int nparms;
bool ret = false;
+ bool processed = false;
/* get user/pass if not previously given or if --auto-proxy is being used */
if (p->auth_method == HTTP_AUTH_BASIC
+ || p->auth_method == HTTP_AUTH_DIGEST
|| p->auth_method == HTTP_AUTH_NTLM)
get_user_pass_http (p, false);
- /* 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)
+ /* are we being called again after getting the digest server nonce in the previous transaction? */
+ if (p->auth_method == HTTP_AUTH_DIGEST && p->proxy_authenticate)
{
- openvpn_snprintf (buf, sizeof(buf), "User-Agent: %s",
- p->options.user_agent);
- if (!send_line_crlf (sd, buf))
- goto error;
+ nparms = 1;
+ status = 407;
}
-
- /* auth specified? */
- switch (p->auth_method)
+ else
{
- case HTTP_AUTH_NONE:
- break;
+ /* format HTTP CONNECT message */
+ openvpn_snprintf (buf, sizeof(buf), "CONNECT %s:%d HTTP/%s",
+ host,
+ port,
+ p->options.http_version);
- 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);
+ msg (D_PROXY, "Send to HTTP proxy: '%s'", buf);
+
+ /* send HTTP CONNECT message to proxy */
if (!send_line_crlf (sd, buf))
goto error;
- break;
+
+ openvpn_snprintf(buf, sizeof(buf), "Host: %s", host);
+ 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);
+ if (!send_line_crlf (sd, buf))
+ goto error;
+ break;
#if NTLM
- case HTTP_AUTH_NTLM:
- case HTTP_AUTH_NTLM2:
- /* keep-alive connection */
- openvpn_snprintf (buf, sizeof(buf), "Proxy-Connection: Keep-Alive");
- if (!send_line_crlf (sd, buf))
- goto error;
+ case HTTP_AUTH_NTLM:
+ case HTTP_AUTH_NTLM2:
+ /* keep-alive connection */
+ openvpn_snprintf (buf, sizeof(buf), "Proxy-Connection: Keep-Alive");
+ if (!send_line_crlf (sd, buf))
+ goto error;
- 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;
+ 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);
+ if (!send_line_crlf (sd, buf))
+ goto error;
+ break;
#endif
- default:
- ASSERT (0);
- }
+ default:
+ ASSERT (0);
+ }
- /* send empty CR, LF */
- openvpn_sleep (1);
- if (!send_crlf (sd))
- goto error;
+ /* send empty CR, LF */
+ 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;
+ /* 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);
+ /* remove trailing CR, LF */
+ chomp (buf);
- msg (D_PROXY, "HTTP proxy returned: '%s'", buf);
+ msg (D_PROXY, "HTTP proxy returned: '%s'", buf);
- /* parse return string */
- nparms = sscanf (buf, "%*s %d", &status);
+ /* parse return string */
+ nparms = sscanf (buf, "%*s %d", &status);
+
+ }
/* check for a "407 Proxy Authentication Required" response */
- if (nparms >= 1 && status == 407)
+ while (nparms >= 1 && status == 407)
{
msg (D_PROXY, "Proxy requires authentication");
- /* check for NTLM */
- if (p->auth_method == HTTP_AUTH_NTLM || p->auth_method == HTTP_AUTH_NTLM2)
+ if (p->auth_method == HTTP_AUTH_BASIC && !processed)
+ {
+ processed = true;
+ }
+ else if ((p->auth_method == HTTP_AUTH_NTLM || p->auth_method == HTTP_AUTH_NTLM2) && !processed) /* check for NTLM */
{
#if NTLM
/* look for the phase 2 response */
@@ -446,7 +656,7 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
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))
+ while (recv_line (sd, NULL, 0, 2, true, NULL, signal_received))
;
/* now send the phase 3 reply */
@@ -470,7 +680,6 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
/* 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))
@@ -488,12 +697,10 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
}
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;
@@ -508,27 +715,167 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
/* parse return string */
nparms = sscanf (buf, "%*s %d", &status);
-#else
- ASSERT (0); /* No NTLM support */
+ processed = true;
#endif
}
- else if (p->auth_method == HTTP_AUTH_NONE && p->options.auth_retry)
+#if PROXY_DIGEST_AUTH
+ else if (p->auth_method == HTTP_AUTH_DIGEST && !processed)
{
- /*
- * Proxy needs authentication, but we don't have a user/pass.
- * Now we will change p->auth_method and return true so that
- * our caller knows to call us again on a newly opened socket.
- * JYFIXME: This code needs to check proxy error output and set
- * JYFIXME: p->auth_method = HTTP_AUTH_NTLM if necessary.
- */
- p->auth_method = HTTP_AUTH_BASIC;
- ret = true;
- goto done;
+ char *pa = p->proxy_authenticate;
+ const int method = p->auth_method;
+ ASSERT(pa);
+
+ if (method == HTTP_AUTH_DIGEST)
+ {
+ const char *http_method = "CONNECT";
+ const char *nonce_count = "00000001";
+ const char *qop = "auth";
+ const char *username = p->up.username;
+ const char *password = p->up.password;
+ char *opaque_kv = "";
+ char uri[128];
+ uint8_t cnonce_raw[8];
+ uint8_t *cnonce;
+ HASHHEX session_key;
+ HASHHEX response;
+
+ const char *realm = get_pa_var("realm", pa, &gc);
+ const char *nonce = get_pa_var("nonce", pa, &gc);
+ const char *algor = get_pa_var("algorithm", pa, &gc);
+ const char *opaque = get_pa_var("opaque", pa, &gc);
+
+ /* generate a client nonce */
+ ASSERT(RAND_bytes(cnonce_raw, sizeof(cnonce_raw)));
+ cnonce = make_base64_string2(cnonce_raw, sizeof(cnonce_raw), &gc);
+
+
+ /* build the digest response */
+ openvpn_snprintf (uri, sizeof(uri), "%s:%d",
+ host,
+ port);
+
+ if (opaque)
+ {
+ const int len = strlen(opaque)+16;
+ opaque_kv = gc_malloc(len, false, &gc);
+ openvpn_snprintf (opaque_kv, len, ", opaque=\"%s\"", opaque);
+ }
+
+ DigestCalcHA1(algor,
+ username,
+ realm,
+ password,
+ nonce,
+ (char *)cnonce,
+ session_key);
+ DigestCalcResponse(session_key,
+ nonce,
+ nonce_count,
+ (char *)cnonce,
+ qop,
+ http_method,
+ uri,
+ NULL,
+ response);
+
+ /* format HTTP CONNECT message */
+ openvpn_snprintf (buf, sizeof(buf), "%s %s HTTP/%s",
+ http_method,
+ uri,
+ 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_snprintf (buf, sizeof(buf), "Host: %s", host);
+ msg (D_PROXY, "Send to HTTP proxy: '%s'", buf);
+ if (!send_line_crlf (sd, buf))
+ goto error;
+
+ /* send digest response */
+ openvpn_snprintf (buf, sizeof(buf), "Proxy-Authorization: Digest username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", qop=%s, nc=%s, cnonce=\"%s\", response=\"%s\"%s",
+ username,
+ realm,
+ nonce,
+ uri,
+ qop,
+ nonce_count,
+ cnonce,
+ response,
+ opaque_kv
+ );
+ msg (D_PROXY, "Send to HTTP proxy: '%s'", buf);
+ if (!send_line_crlf (sd, buf))
+ goto error;
+ 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);
+ processed = true;
+ }
+ else
+ {
+ msg (D_PROXY, "HTTP proxy: digest method not supported");
+ goto error;
+ }
+ }
+#endif
+ else if (p->options.auth_retry)
+ {
+ /* figure out what kind of authentication the proxy needs */
+ char *pa = NULL;
+ const int method = get_proxy_authenticate(sd,
+ p->options.timeout,
+ &pa,
+ NULL,
+ signal_received);
+ if (method != HTTP_AUTH_NONE)
+ {
+ if (pa)
+ msg (D_PROXY, "HTTP proxy authenticate '%s'", pa);
+ if (p->options.auth_retry == PAR_NCT && method == HTTP_AUTH_BASIC)
+ {
+ msg (D_PROXY, "HTTP proxy: support for basic auth and other cleartext proxy auth methods is disabled");
+ goto error;
+ }
+ p->auth_method = method;
+ store_proxy_authenticate(p, pa);
+ ret = true;
+ goto done;
+ }
+ else
+ {
+ msg (D_PROXY, "HTTP proxy: do not recognize the authentication method required by proxy");
+ free (pa);
+ goto error;
+ }
}
else
- goto error;
- }
+ {
+ if (!processed)
+ msg (D_PROXY, "HTTP proxy: no support for proxy authentication method");
+ goto error;
+ }
+ /* clear state */
+ if (p->options.auth_retry)
+ clear_user_pass_http();
+ store_proxy_authenticate(p, NULL);
+ }
/* check return code, success = 200 */
if (nparms < 1 || status != 200)
@@ -536,17 +883,13 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
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);
- }
+ dump_residual(sd, p->options.timeout, signal_received);
#endif
goto error;
}
+ /* SUCCESS */
+
/* receive line from proxy and discard */
if (!recv_line (sd, NULL, 0, p->options.timeout, true, NULL, signal_received))
goto error;
@@ -558,6 +901,9 @@ establish_http_proxy_passthru (struct http_proxy_info *p,
while (recv_line (sd, NULL, 0, 2, false, lookahead, signal_received))
;
+ /* reset queried_creds so that we don't think that the next creds request is due to an auth error */
+ p->queried_creds = false;
+
#if 0
if (lookahead && BLEN (lookahead))
msg (M_INFO, "HTTP PROXY: lookahead: %s", format_hex (BPTR (lookahead), BLEN (lookahead), 0));