[tor-commits] [tor/master] bug1666 - Pass-through support for SOCKS5 authentication
nickm at torproject.org
nickm at torproject.org
Wed Jul 13 16:13:21 UTC 2011
commit bf136b94de39de65638ce3daaf2e87731cd0a44a
Author: Robert Hogan <robert at roberthogan.net>
Date: Tue Aug 3 22:28:55 2010 +0100
bug1666 - Pass-through support for SOCKS5 authentication
If a SOCKS5 client insists on authentication, allow it to
negotiate a connection with Tor's SOCKS server successfully.
Any credentials the client provides are ignored.
This allows Tor to work with SOCKS5 clients that can only
support 'authenticated' connections.
Also add a bunch of basic unit tests for SOCKS4/4a/5 support
in buffers.c.
---
doc/spec/socks-extensions.txt | 5 +-
src/or/buffers.c | 62 ++++++++---
src/or/config.c | 3 +-
src/or/config.h | 2 +
src/or/or.h | 2 +
src/test/test.c | 237 +++++++++++++++++++++++++++++++++++++++++
6 files changed, 293 insertions(+), 18 deletions(-)
diff --git a/doc/spec/socks-extensions.txt b/doc/spec/socks-extensions.txt
index 62d86ac..52d6834 100644
--- a/doc/spec/socks-extensions.txt
+++ b/doc/spec/socks-extensions.txt
@@ -31,8 +31,9 @@ Tor's extensions to the SOCKS protocol
SOCKS5:
- The (SOCKS5) "UDP ASSOCIATE" command is not supported.
- IPv6 is not supported in CONNECT commands.
- - Only the "NO AUTHENTICATION" (SOCKS5) authentication method [00] is
- supported.
+ - The "NO AUTHENTICATION" (SOCKS5) authentication method [00] and the
+ "USERNAME/PASSWORD" (SOCKS5) authentication method [02] are both
+ supported. Any credentials passed in the latter are ignored.
2. Name lookup
diff --git a/src/or/buffers.c b/src/or/buffers.c
index 11c4fc8..534f31c 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -1633,40 +1633,74 @@ parse_socks(const char *data, size_t datalen, socks_request_t *req,
uint8_t socksver;
enum {socks4, socks4a} socks4_prot = socks4a;
char *next, *startaddr;
+ unsigned char usernamelen, passlen;
struct in_addr in;
socksver = *data;
switch (socksver) { /* which version of socks? */
+ case 1: /* socks5: username/password authentication request */
+
+ usernamelen = (unsigned char)*(buf->head->data + 1);
+ if (buf->datalen < 2u + usernamelen)
+ return 0;
+ buf_pullup(buf, 2u + usernamelen + 1, 0);
+ passlen = (unsigned char)*(buf->head->data + 2u + usernamelen);
+ if (buf->datalen < 2u + usernamelen + 1u + passlen)
+ return 0;
+ if (buf->datalen > 2u + usernamelen + 1u + passlen) {
+ log_warn(LD_APP,
+ "socks5: Malformed username/password. Rejecting.");
+ return -1;
+ }
+ req->replylen = 2; /* 2 bytes of response */
+ req->reply[0] = 5;
+ req->reply[1] = 0; /* authentication successful */
+ buf_clear(buf);
+ log_debug(LD_APP,
+ "socks5: Accepted username/password without checking.");
+ return 0;
+
case 5: /* socks5 */
if (req->socks_version != 5) { /* we need to negotiate a method */
unsigned char nummethods = (unsigned char)*(data+1);
+ int r=0;
tor_assert(!req->socks_version);
if (datalen < 2u+nummethods) {
*want_length_out = 2u+nummethods;
return 0;
}
- if (!nummethods || !memchr(data+2, 0, nummethods)) {
+ buf_pullup(buf, 2u+nummethods, 0);
+ if (!nummethods)
+ return -1;
+ req->replylen = 2; /* 2 bytes of response */
+ req->reply[0] = 5; /* socks5 reply */
+ if (memchr(buf->head->data+2, SOCKS_NO_AUTH, nummethods)) {
+ req->reply[1] = SOCKS_NO_AUTH; /* tell client to use "none" auth
+ method */
+ req->socks_version = 5; /* remember we've already negotiated auth */
+ log_debug(LD_APP,"socks5: accepted method 0 (no authentication)");
+ r=0;
+ }else if (memchr(buf->head->data+2, SOCKS_USER_PASS,nummethods)) {
+ req->reply[1] = SOCKS_USER_PASS; /* tell client to use "user/pass"
+ auth method */
+ req->socks_version = 5; /* remember we've already negotiated auth */
+ log_debug(LD_APP,"socks5: accepted method 2 (username/password)");
+ r=0;
+ } else {
log_warn(LD_APP,
- "socks5: offered methods don't include 'no auth'. "
- "Rejecting.");
- req->replylen = 2; /* 2 bytes of response */
- req->reply[0] = 5;
+ "socks5: offered methods don't include 'no auth' or "
+ "username/password. Rejecting.");
req->reply[1] = '\xFF'; /* reject all methods */
- return -1;
+ r=-1;
}
/* remove packet from buf. also remove any other extraneous
* bytes, to support broken socks clients. */
*drain_out = -1;
- req->replylen = 2; /* 2 bytes of response */
- req->reply[0] = 5; /* socks5 reply */
- req->reply[1] = 0; /* tell client to use "none" auth method */
- req->socks_version = 5; /* remember we've already negotiated auth */
- log_debug(LD_APP,"socks5: accepted method 0");
- return 0;
+ return r;
}
/* we know the method; read in the request */
log_debug(LD_APP,"socks5: checking request");
@@ -1761,8 +1795,8 @@ parse_socks(const char *data, size_t datalen, socks_request_t *req,
}
tor_assert(0);
case 4: /* socks4 */
- /* http://archive.socks.permeo.com/protocol/socks4.protocol */
- /* http://archive.socks.permeo.com/protocol/socks4a.protocol */
+ /* http://ss5.sourceforge.net/socks4.protocol.txt */
+ /* http://ss5.sourceforge.net/socks4A.protocol.txt */
req->socks_version = 4;
if (datalen < SOCKS4_NETWORK_LEN) {/* basic info available? */
diff --git a/src/or/config.c b/src/or/config.c
index cd6b0b0..d2dbdaa 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -542,7 +542,6 @@ static int options_transition_affects_workers(or_options_t *old_options,
static int options_transition_affects_descriptor(or_options_t *old_options,
or_options_t *new_options);
static int check_nickname_list(const char *lst, const char *name, char **msg);
-static void config_register_addressmaps(or_options_t *options);
static int parse_bridge_line(const char *line, int validate_only);
static int parse_dir_server_line(const char *line,
@@ -4314,7 +4313,7 @@ get_torrc_fname(void)
/** Adjust the address map based on the MapAddress elements in the
* configuration <b>options</b>
*/
-static void
+void
config_register_addressmaps(or_options_t *options)
{
smartlist_t *elts;
diff --git a/src/or/config.h b/src/or/config.h
index bd5827b..db871d4 100644
--- a/src/or/config.h
+++ b/src/or/config.h
@@ -76,5 +76,7 @@ uint32_t get_effective_bwburst(or_options_t *options);
or_options_t *options_new(void);
#endif
+void config_register_addressmaps(or_options_t *options);
+
#endif
diff --git a/src/or/or.h b/src/or/or.h
index c5349ae..6ae62e8 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3067,6 +3067,8 @@ static INLINE void or_state_mark_dirty(or_state_t *state, time_t when)
#define MAX_SOCKS_REPLY_LEN 1024
#define MAX_SOCKS_ADDR_LEN 256
+#define SOCKS_NO_AUTH 0x00
+#define SOCKS_USER_PASS 0x02
/** Please open a TCP connection to this addr:port. */
#define SOCKS_COMMAND_CONNECT 0x01
diff --git a/src/test/test.c b/src/test/test.c
index 9b0251b..68f1aeb 100644
--- a/src/test/test.c
+++ b/src/test/test.c
@@ -197,6 +197,207 @@ free_pregenerated_keys(void)
}
}
+/** Helper: Perform supported SOCKS 5 commands */
+static void
+test_buffers_socks4_unsupported_commands_helper(const char *cp, buf_t *buf,
+ socks_request_t *socks)
+{
+ /* SOCKS 4 Send BIND [02] to IP address 2.2.2.2:4369 */
+ cp = "\x04\x02\x11\x11\x02\x02\x02\x02\x00";
+ write_to_buf(cp, 9, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == -1);
+ test_eq(4, socks->socks_version);
+ test_eq(0, socks->replylen); /* XXX: shouldn't tor reply? */
+
+done:
+ ;
+}
+
+/** Helper: Perform supported SOCKS 5 commands */
+static void
+test_buffers_socks4_supported_commands_helper(const char *cp, buf_t *buf,
+ socks_request_t *socks)
+{
+ /* SOCKS 4 Send CONNECT [01] to IP address 2.2.2.2:4369 */
+ cp = "\x04\x01\x11\x11\x02\x02\x02\x02\x00";
+ write_to_buf(cp, 9, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == 1);
+ test_eq(4, socks->socks_version);
+ test_eq(0, socks->replylen); /* XXX: shouldn't tor reply? */
+ test_streq("2.2.2.2", socks->address);
+ test_eq(4369, socks->port);
+
+ /* SOCKS 4 Send CONNECT [01] to IP address 2.2.2.2:4369 with userid*/
+ cp = "\x04\x01\x11\x11\x02\x02\x02\x02\x02me\x00";
+ write_to_buf(cp, 12, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == 1);
+ test_eq(4, socks->socks_version);
+ test_eq(0, socks->replylen); /* XXX: shouldn't tor reply? */
+ test_streq("2.2.2.2", socks->address);
+ test_eq(4369, socks->port);
+
+ /* SOCKS 4a Send RESOLVE [F0] request for torproject.org:4369 */
+ cp = "\x04\xF0\x01\x01\x00\x00\x00\x02\x02me\x00tor.org\x00";
+ write_to_buf(cp, 20, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(4, socks->socks_version);
+ test_eq(0, socks->replylen); /* XXX: shouldn't tor reply? */
+ test_streq("tor.org", socks->address);
+
+done:
+ ;
+}
+
+/** Helper: Perform supported SOCKS 5 commands */
+static void
+test_buffers_socks5_unsupported_commands_helper(const char *cp, buf_t *buf,
+ socks_request_t *socks)
+{
+ /* SOCKS 5 Send unsupported BIND [02] command */
+ cp = "\x05\x02\x00\x01\x02\x02\x02\x02\x01\x01";
+ write_to_buf(cp, 10, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == -1);
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]); /* XXX: shouldn't tor reply 'command
+ not supported' [07]? */
+
+ /* SOCKS 5 Send unsupported UDP_ASSOCIATE [03] command */
+ cp = "\x05\x03\x00\x01\x02\x02\x02\x02\x01\x01";
+ write_to_buf(cp, 10, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == -1);
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]); /* XXX: shouldn't tor reply 'command
+ not supported' [07]? */
+
+done:
+ ;
+}
+
+/** Helper: Perform supported SOCKS 5 commands */
+static void
+test_buffers_socks5_supported_commands_helper(const char *cp, buf_t *buf,
+ socks_request_t *socks)
+{
+ /* SOCKS 5 Send CONNECT [01] to IP address 2.2.2.2:4369 */
+ cp = "\x05\x01\x00\x01\x02\x02\x02\x02\x11\x11";
+ write_to_buf(cp, 10, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == 1);
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]);
+ test_streq("2.2.2.2", socks->address);
+ test_eq(4369, socks->port);
+
+ /* SOCKS 5 Send CONNECT [01] to FQDN torproject.org:4369 */
+ cp = "\x05\x01\x00\x03\x07tor.org\x11\x11";
+ write_to_buf(cp, 14, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]);
+ test_streq("tor.org", socks->address);
+ test_eq(4369, socks->port);
+
+ /* SOCKS 5 Send RESOLVE [F0] request for torproject.org:4369 */
+ cp = "\x05\xF0\x00\x03\x07tor.org";
+ write_to_buf(cp, 14, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]);
+ test_streq("tor.org", socks->address);
+
+ /* SOCKS 5 Send RESOLVE_PTR [F1] for IP address 2.2.2.2 */
+ cp = "\x05\xF1\x00\x01\x02\x02\x02\x02";
+ write_to_buf(cp, 10, buf);
+ test_assert(fetch_from_buf_socks(buf, socks, get_options()->TestSocks,
+ get_options()->SafeSocks) == 1);
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]);
+ test_streq("2.2.2.2", socks->address);
+
+done:
+ ;
+}
+
+/** Helper: Perform SOCKS 5 authentication */
+static void
+test_buffers_socks5_no_authenticate_helper(const char *cp, buf_t *buf,
+ socks_request_t *socks)
+{
+ /*SOCKS 5 No Authentication */
+ cp = "\x05\x01\x00";
+ write_to_buf(cp, 3, buf);
+ test_assert(!fetch_from_buf_socks(buf, socks,
+ get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(SOCKS_NO_AUTH, socks->reply[1]);
+
+ /*SOCKS 5 Send username/password anyway - pretend to be broken */
+ cp = "\x01\x02\x01\x01\x02\x01\x01";
+ write_to_buf(cp, 7, buf);
+ test_assert(!fetch_from_buf_socks(buf, socks,
+ get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]);
+
+done:
+ ;
+}
+
+/** Helper: Perform SOCKS 5 authentication */
+static void
+test_buffers_socks5_authenticate_helper(const char *cp, buf_t *buf,
+ socks_request_t *socks)
+{
+ /* SOCKS 5 Negotiate username/password authentication */
+ cp = "\x05\x01\x02";
+ write_to_buf(cp, 3, buf);
+ test_assert(!fetch_from_buf_socks(buf, socks,
+ get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(SOCKS_USER_PASS, socks->reply[1]);
+ test_eq(5, socks->socks_version);
+
+ /* SOCKS 5 Send username/password */
+ cp = "\x01\x02me\x02me";
+ write_to_buf(cp, 7, buf);
+ test_assert(!fetch_from_buf_socks(buf, socks,
+ get_options()->TestSocks,
+ get_options()->SafeSocks));
+ test_eq(5, socks->socks_version);
+ test_eq(2, socks->replylen);
+ test_eq(5, socks->reply[0]);
+ test_eq(0, socks->reply[1]);
+done:
+ ;
+}
+
/** Run unit tests for buffers.c */
static void
test_buffers(void)
@@ -206,6 +407,7 @@ test_buffers(void)
buf_t *buf = NULL, *buf2 = NULL;
const char *cp;
+ socks_request_t *socks;
int j;
size_t r;
@@ -363,6 +565,41 @@ test_buffers(void)
buf_free(buf);
buf = NULL;
+ /* Test fetch_from_buf_socks() */
+ buf = buf_new_with_capacity(256);
+ socks = tor_malloc_zero(sizeof(socks_request_t));;
+ config_register_addressmaps(get_options());
+
+ /* A SOCKS 5 client that only supports authentication */
+ test_buffers_socks5_authenticate_helper(cp, buf, socks);
+ test_buffers_socks5_supported_commands_helper(cp, buf, socks);
+ test_buffers_socks5_unsupported_commands_helper(cp, buf, socks);
+
+ tor_free(socks);
+ buf_free(buf);
+ buf = NULL;
+ buf = buf_new_with_capacity(256);
+ socks = tor_malloc_zero(sizeof(socks_request_t));;
+
+ /* A SOCKS 5 client that doesn't want authentication */
+ test_buffers_socks5_no_authenticate_helper(cp, buf, socks);
+ test_buffers_socks5_supported_commands_helper(cp, buf, socks);
+ test_buffers_socks5_unsupported_commands_helper(cp, buf, socks);
+
+ tor_free(socks);
+ buf_free(buf);
+ buf = NULL;
+ buf = buf_new_with_capacity(256);
+ socks = tor_malloc_zero(sizeof(socks_request_t));;
+
+ /* A SOCKS 4(a) client */
+ test_buffers_socks4_supported_commands_helper(cp, buf, socks);
+ test_buffers_socks4_unsupported_commands_helper(cp, buf, socks);
+
+ tor_free(socks);
+ buf_free(buf);
+ buf = NULL;
+
done:
if (buf)
buf_free(buf);
More information about the tor-commits
mailing list