commit 790150e57a98221fbb4cfdc5c34b3395808416b4 Author: rl1987 <rl1987@sdf.lonestar.org> Date: Sat Jan 26 10:55:53 2019 +0200 Allow empty username/password in SOCKS5 username/password auth message --- changes/bug29175_035 | 4 ++++ src/core/proto/proto_socks.c | 12 ++++++++---- src/test/test_socks.c | 39 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 51 insertions(+), 4 deletions(-) diff --git a/changes/bug29175_035 b/changes/bug29175_035 new file mode 100644 index 000000000..134c1d952 --- /dev/null +++ b/changes/bug29175_035 @@ -0,0 +1,4 @@ + o Major bugfixes (networking): + - Gracefully handle empty username/password fields in SOCKS5 + username/password auth messsage and allow SOCKS5 handshake to + continue. Fixes bug 29175; bugfix on 0.3.5.1-alpha. diff --git a/src/core/proto/proto_socks.c b/src/core/proto/proto_socks.c index a8f4a06c2..8b78ed44c 100644 --- a/src/core/proto/proto_socks.c +++ b/src/core/proto/proto_socks.c @@ -450,18 +450,22 @@ parse_socks5_userpass_auth(const uint8_t *raw_data, socks_request_t *req, tor_free(req->username); req->username = tor_memdup_nulterm(username, usernamelen); req->usernamelen = usernamelen; - - req->got_auth = 1; } if (passwordlen && password) { tor_free(req->password); req->password = tor_memdup_nulterm(password, passwordlen); req->passwordlen = passwordlen; - - req->got_auth = 1; } + /** + * Yes, we allow username and/or password to be empty. Yes, that does + * violate RFC 1929. However, some client software can send a username/ + * password message with these fields being empty and we want to allow them + * to be used with Tor. + */ + req->got_auth = 1; + end: socks5_client_userpass_auth_free(trunnel_req); return res; diff --git a/src/test/test_socks.c b/src/test/test_socks.c index 2832d42fc..783f4726e 100644 --- a/src/test/test_socks.c +++ b/src/test/test_socks.c @@ -479,6 +479,44 @@ test_socks_5_authenticate(void *ptr) ; } +/** Perform SOCKS 5 authentication with empty username/password fields. + * Technically this violates RfC 1929, but some client software will send + * this kind of message to Tor. + * */ +static void +test_socks_5_authenticate_empty_user_pass(void *ptr) +{ + SOCKS_TEST_INIT(); + + /* SOCKS 5 Negotiate username/password authentication */ + ADD_DATA(buf, "\x05\x01\x02"); + + tt_assert(!fetch_from_buf_socks(buf, socks, + get_options()->TestSocks, + get_options()->SafeSocks)); + tt_int_op(2,OP_EQ, socks->replylen); + tt_int_op(5,OP_EQ, socks->reply[0]); + tt_int_op(SOCKS_USER_PASS,OP_EQ, socks->reply[1]); + tt_int_op(5,OP_EQ, socks->socks_version); + + tt_int_op(0,OP_EQ, buf_datalen(buf)); + + /* SOCKS 5 Send username/password auth message with empty user/pass fields */ + ADD_DATA(buf, "\x01\x00\x00"); + tt_assert(!fetch_from_buf_socks(buf, socks, + get_options()->TestSocks, + get_options()->SafeSocks)); + tt_int_op(5,OP_EQ, socks->socks_version); + tt_int_op(2,OP_EQ, socks->replylen); + tt_int_op(1,OP_EQ, socks->reply[0]); + tt_int_op(0,OP_EQ, socks->reply[1]); + + tt_int_op(0,OP_EQ, socks->usernamelen); + tt_int_op(0,OP_EQ, socks->passwordlen); + + done: + ; +} /** Perform SOCKS 5 authentication and send data all in one go */ static void test_socks_5_authenticate_with_data(void *ptr) @@ -1035,6 +1073,7 @@ struct testcase_t socks_tests[] = { SOCKSENT(5_auth_unsupported_version), SOCKSENT(5_auth_before_negotiation), SOCKSENT(5_authenticate), + SOCKSENT(5_authenticate_empty_user_pass), SOCKSENT(5_authenticate_with_data), SOCKSENT(5_malformed_commands), SOCKSENT(5_bad_arguments),