July 2012 - tor-commits - lists.torproject.org

[stegotorus/master] transmit_room() now takes 3 arguments and the chopper produces exactly what is asked for. As a side-effect this made HTTP reliable under automated test.
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 9a6de8ce32c36d04fd96e48194230dfcdc1132cf Author: Zack Weinberg <zackw(a)panix.com> Date: Sun Apr 1 14:23:17 2012 -0700 transmit_room() now takes 3 arguments and the chopper produces exactly what is asked for. As a side-effect this made HTTP reliable under automated test. --- src/protocol/chop.cc | 106 ++++++++++++++++++++++++++--------------- src/steg.h | 66 +++++++++++++++----------- src/steg/embed.cc | 5 ++- src/steg/http.cc | 124 ++++++++++++++++++++----------------------------- src/steg/nosteg.cc | 4 +- src/steg/nosteg_rr.cc | 4 +- 6 files changed, 165 insertions(+), 144 deletions(-) diff --git a/src/protocol/chop.cc b/src/protocol/chop.cc index a46d0ac..ad8ac9f 100644 --- a/src/protocol/chop.cc +++ b/src/protocol/chop.cc @@ -73,6 +73,8 @@ const size_t SECTION_LEN = UINT16_MAX; const size_t MIN_BLOCK_SIZE = HEADER_LEN + TRAILER_LEN; const size_t MAX_BLOCK_SIZE = MIN_BLOCK_SIZE + SECTION_LEN*2; +const size_t HANDSHAKE_LEN = sizeof(uint32_t); + enum opcode_t { op_DAT = 0, // Pass data section along to upstream @@ -729,16 +731,18 @@ chop_circuit_t::send_special(opcode_t f, struct evbuffer *payload) size_t blocksize; log_assert(d <= SECTION_LEN); chop_conn_t *conn = pick_connection(d, &blocksize); + size_t lo = MIN_BLOCK_SIZE + ((conn && !conn->sent_handshake) + ? HANDSHAKE_LEN : 0); - if (!conn || (blocksize - MIN_BLOCK_SIZE < d)) { + if (!conn || (blocksize - lo < d)) { log_warn("no usable connection for special block " "(opcode %02x, need %lu bytes, have %lu)", - (unsigned int)f, (unsigned long)(d + MIN_BLOCK_SIZE), + (unsigned int)f, (unsigned long)(d + lo), (unsigned long)blocksize); return -1; } - return send_targeted(conn, d, (blocksize - MIN_BLOCK_SIZE) - d, f, payload); + return send_targeted(conn, d, (blocksize - lo) - d, f, payload); } int @@ -749,33 +753,47 @@ chop_circuit_t::send_targeted(chop_conn_t *conn) avail = SECTION_LEN; avail += MIN_BLOCK_SIZE; - size_t room = conn->steg->transmit_room(); - if (room < MIN_BLOCK_SIZE) { - log_warn(conn, "send() called without enough transmit room " - "(have %lu, need %lu)", (unsigned long)room, - (unsigned long)MIN_BLOCK_SIZE); - return -1; + // If we have any data to transmit, ensure we do not send a block + // that contains no data at all. + size_t lo = MIN_BLOCK_SIZE + (avail == MIN_BLOCK_SIZE ? 0 : 1); + + // If this connection has not yet sent a handshake, it will need to. + size_t hi = MAX_BLOCK_SIZE; + if (!conn->sent_handshake) { + lo += HANDSHAKE_LEN; + hi += HANDSHAKE_LEN; + avail += HANDSHAKE_LEN; } - log_debug(conn, "offers %lu bytes (%s)", (unsigned long)room, - conn->steg->cfg()->name()); - if (room < avail) - avail = room; + size_t room = conn->steg->transmit_room(avail, lo, hi); + if (room == 0) + log_abort(conn, "must send but cannot send"); + if (room < lo || room >= hi) + log_abort(conn, "steg size request (%lu) out of range [%lu, %lu]", + (unsigned long)room, (unsigned long)lo, (unsigned long)hi); - return send_targeted(conn, avail); + log_debug(conn, "requests %lu bytes (%s)", (unsigned long)room, + conn->steg->cfg()->name()); + + return send_targeted(conn, room); } int chop_circuit_t::send_targeted(chop_conn_t *conn, size_t blocksize) { - log_assert(blocksize >= MIN_BLOCK_SIZE && blocksize <= MAX_BLOCK_SIZE); + size_t lo = MIN_BLOCK_SIZE, hi = MAX_BLOCK_SIZE; + if (!conn->sent_handshake) { + lo += HANDSHAKE_LEN; + hi += HANDSHAKE_LEN; + } + log_assert(blocksize >= lo && blocksize <= hi); struct evbuffer *xmit_pending = bufferevent_get_input(up_buffer); size_t avail = evbuffer_get_length(xmit_pending); opcode_t op = op_DAT; - if (avail > blocksize - MIN_BLOCK_SIZE) - avail = blocksize - MIN_BLOCK_SIZE; + if (avail > blocksize - lo) + avail = blocksize - lo; else if (avail > SECTION_LEN) avail = SECTION_LEN; else if (upstream_eof && !sent_fin) @@ -783,7 +801,7 @@ chop_circuit_t::send_targeted(chop_conn_t *conn, size_t blocksize) // this direction; mark it as such op = op_FIN; - return send_targeted(conn, avail, (blocksize - MIN_BLOCK_SIZE) - avail, + return send_targeted(conn, avail, (blocksize - lo) - avail, op, xmit_pending); } @@ -868,6 +886,10 @@ chop_circuit_t::pick_connection(size_t desired, size_t *blocksize) desired += MIN_BLOCK_SIZE; + // If we have any data to transmit, ensure we do not send a block + // that contains no data at all. + size_t lo = MIN_BLOCK_SIZE + (desired == MIN_BLOCK_SIZE ? 0 : 1); + log_debug(this, "target block size %lu bytes", (unsigned long)desired); // Find the best fit for the desired transmission from all the @@ -880,18 +902,25 @@ chop_circuit_t::pick_connection(size_t desired, size_t *blocksize) continue; } - size_t room = conn->steg->transmit_room(); - - if (room <= MIN_BLOCK_SIZE) - room = 0; + size_t shake = conn->sent_handshake ? 0 : HANDSHAKE_LEN; + size_t room = conn->steg->transmit_room(desired + shake, lo + shake, + MAX_BLOCK_SIZE + shake); + if (room == 0) { + log_debug(conn, "offers 0 bytes (%s)", + conn->steg->cfg()->name()); + continue; + } - if (room > MAX_BLOCK_SIZE) - room = MAX_BLOCK_SIZE; + if (room < lo + shake || room >= MAX_BLOCK_SIZE + shake) + log_abort(conn, "steg size request (%lu) out of range [%lu, %lu]", + (unsigned long)room, + (unsigned long)(lo + shake), + (unsigned long)(MAX_BLOCK_SIZE + shake)); log_debug(conn, "offers %lu bytes (%s)", (unsigned long)room, conn->steg->cfg()->name()); - if (room >= desired) { + if (room >= desired + shake) { if (room < minabove) { minabove = room; targabove = conn; @@ -915,7 +944,7 @@ chop_circuit_t::pick_connection(size_t desired, size_t *blocksize) // their initial values, so we'll return NULL and set blocksize to 0, // which callers know how to handle. if (targabove) { - *blocksize = desired; + *blocksize = minabove; return targabove; } else { *blocksize = maxbelow; @@ -1086,7 +1115,7 @@ chop_conn_t::send(struct evbuffer *block) upstream ? '+' : '-', upstream ? upstream->circuit_id : 0); if (evbuffer_prepend(block, (void *)&upstream->circuit_id, - sizeof(upstream->circuit_id))) { + HANDSHAKE_LEN)) { log_warn(this, "failed to prepend handshake to first block"); return -1; } @@ -1332,29 +1361,28 @@ chop_conn_t::send() } else { log_debug(this, "must send (no upstream)"); - size_t room = steg->transmit_room(); - if (room < MIN_BLOCK_SIZE) { - log_warn(this, "send() called without enough transmit room " - "(have %lu, need %lu)", (unsigned long)room, - (unsigned long)MIN_BLOCK_SIZE); - conn_do_flush(this); - return; - } + size_t room = steg->transmit_room(MIN_BLOCK_SIZE, MIN_BLOCK_SIZE, + MAX_BLOCK_SIZE); + if (room < MIN_BLOCK_SIZE || room >= MAX_BLOCK_SIZE) + log_abort(this, "steg size request (%lu) out of range [%lu, %lu]", + (unsigned long)room, + (unsigned long)MIN_BLOCK_SIZE, + (unsigned long)MAX_BLOCK_SIZE); // Since we have no upstream, we can't encrypt anything; instead, // generate random bytes and feed them straight to steg_transmit. struct evbuffer *chaff = evbuffer_new(); struct evbuffer_iovec v; - if (!chaff || evbuffer_reserve_space(chaff, MIN_BLOCK_SIZE, &v, 1) != 1 || - v.iov_len < MIN_BLOCK_SIZE) { + if (!chaff || evbuffer_reserve_space(chaff, room, &v, 1) != 1 || + v.iov_len < room) { log_warn(this, "memory allocation failed"); if (chaff) evbuffer_free(chaff); conn_do_flush(this); return; } - v.iov_len = MIN_BLOCK_SIZE; - rng_bytes((uint8_t *)v.iov_base, MIN_BLOCK_SIZE); + v.iov_len = room; + rng_bytes((uint8_t *)v.iov_base, room); if (evbuffer_commit_space(chaff, &v, 1)) { log_warn(this, "evbuffer_commit_space failed"); if (chaff) diff --git a/src/steg.h b/src/steg.h index a044afb..ad6b829 100644 --- a/src/steg.h +++ b/src/steg.h @@ -52,11 +52,22 @@ struct steg_t /** Return the steg_config_t from which this steg_t was created. */ virtual steg_config_t *cfg() = 0; - /** Report the maximum number of bytes that could be transmitted on - your connection at this time. You must be prepared to handle a - subsequent request to transmit any _smaller_ number of bytes on - this connection. */ - virtual size_t transmit_room() = 0; + /** The protocol using this steg module would like to transmit PREF + bytes on your connection. Return an adjusted number of bytes; + you may adjust down to indicate that you cannot transmit all of + the available data, or up to indicate that it should be padded. + + Returning zero indicates that your connection cannot transmit at + all right now; if you do this, transmit() will not be called. + Returning any nonzero value indicates that you want to transmit + exactly that number of bytes. The protocol may or may not call + transmit() after you return a nonzero value, but if it does, it + will provide the number of bytes you requested. + + If you return a nonzero value, it MUST be greater than or equal + to MIN, and less than or equal to MAX. PREF is guaranteed to be + in this range already. */ + virtual size_t transmit_room(size_t pref, size_t min, size_t max) = 0; /** Consume all of the data in SOURCE, disguise it, and write it to the outbound buffer for your connection. Return 0 on success, -1 @@ -94,32 +105,33 @@ steg_config_t *steg_new(const char *name, config_t *cfg); /* Macros for use in defining steg modules. */ -#define STEG_DEFINE_MODULE(mod) \ - /* new_ dispatchers */ \ - static steg_config_t *mod##_new(config_t *cfg) \ - { return new mod##_steg_config_t(cfg); } \ - \ - /* canned methods */ \ - const char *mod##_steg_config_t::name() { return #mod; } \ - \ - /* module object */ \ - extern const steg_module s_mod_##mod = { \ - #mod, mod##_new \ +#define STEG_DEFINE_MODULE(mod) \ + /* new_ dispatchers */ \ + static steg_config_t *mod##_new(config_t *cfg) \ + { return new mod##_steg_config_t(cfg); } \ + \ + /* canned methods */ \ + const char *mod##_steg_config_t::name() \ + { return #mod; } \ + \ + /* module object */ \ + extern const steg_module s_mod_##mod = { \ + #mod, mod##_new \ } /* deliberate absence of semicolon */ -#define STEG_CONFIG_DECLARE_METHODS(mod) \ - mod##_steg_config_t(config_t *cfg); \ - virtual ~mod##_steg_config_t(); \ - virtual const char *name(); \ - virtual steg_t *steg_create(conn_t *conn) \ +#define STEG_CONFIG_DECLARE_METHODS(mod) \ + mod##_steg_config_t(config_t *); \ + virtual ~mod##_steg_config_t(); \ + virtual const char *name(); \ + virtual steg_t *steg_create(conn_t *) \ /* deliberate absence of semicolon */ -#define STEG_DECLARE_METHODS(mod) \ - virtual ~mod##_steg_t(); \ - virtual steg_config_t *cfg(); \ - virtual size_t transmit_room(); \ - virtual int transmit(struct evbuffer *source); \ - virtual int receive(struct evbuffer *dest) \ +#define STEG_DECLARE_METHODS(mod) \ + virtual ~mod##_steg_t(); \ + virtual steg_config_t *cfg(); \ + virtual size_t transmit_room(size_t, size_t, size_t); \ + virtual int transmit(struct evbuffer *); \ + virtual int receive(struct evbuffer *) \ /* deliberate absence of semicolon */ #endif diff --git a/src/steg/embed.cc b/src/steg/embed.cc index f24c210..d301620 100644 --- a/src/steg/embed.cc +++ b/src/steg/embed.cc @@ -163,7 +163,7 @@ embed_steg_t::cfg() } size_t -embed_steg_t::transmit_room() +embed_steg_t::transmit_room(size_t, size_t lo, size_t hi) { if (is_finished() || !is_outgoing()) return 0; @@ -173,6 +173,9 @@ embed_steg_t::transmit_room() // 2 bytes for data length, 4 bytes for the index of a new trace size_t room = get_pkt_size() - 2; if (cur_pkt == 0) room -= 4; + + if (room < lo) room = lo; + if (room > hi) room = hi; return room; } diff --git a/src/steg/http.cc b/src/steg/http.cc index 77ea859..a4fd790 100644 --- a/src/steg/http.cc +++ b/src/steg/http.cc @@ -36,6 +36,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #include "connections.h" #include "protocol.h" #include "steg.h" +#include "rng.h" + #include "payloads.h" #include "cookies.h" #include "swfSteg.h" @@ -184,64 +186,59 @@ http_steg_t::cfg() return config; } -size_t -http_steg_t::transmit_room() +static size_t +clamp(size_t val, size_t lo, size_t hi) { - unsigned int mjc; + if (val < lo) return lo; + if (val > hi) return hi; + return val; +} +size_t +http_steg_t::transmit_room(size_t pref, size_t lo, size_t hi) +{ if (have_transmitted) /* can't send any more on this connection */ return 0; - if (config->is_clientside) { - return (MIN_COOKIE_SIZE + rand() % (MAX_COOKIE_SIZE - MIN_COOKIE_SIZE)) / 4; + // MIN_COOKIE_SIZE and MAX_COOKIE_SIZE are *after* base64'ing + if (lo < MIN_COOKIE_SIZE*3/4) + lo = MIN_COOKIE_SIZE*3/4; + + if (hi > MAX_COOKIE_SIZE*3/4) + hi = MAX_COOKIE_SIZE*3/4; } else { - if (!have_received) return 0; switch (type) { - case HTTP_CONTENT_SWF: - return 1024; + if (hi >= 1024) + hi = 1024; + break; case HTTP_CONTENT_JAVASCRIPT: - mjc = config->pl.max_JS_capacity / 2; - if (mjc > 1024) { - // it should be 1024 + ...., but seems like we need to be a little bit smaller (chopper bug?) - int rval = 512 + rand()%(mjc - 1024); - // fprintf(stderr, "returning rval %d, mjc %d\n", rval, mjc); - return rval; - } - log_warn("js capacity too small\n"); - exit(-1); + if (hi >= config->pl.max_JS_capacity / 2) + hi = config->pl.max_JS_capacity / 2; + break; case HTTP_CONTENT_HTML: - mjc = config->pl.max_HTML_capacity / 2; - if (mjc > 1024) { - // it should be 1024 + ...., but seems like we need to be a little bit smaller (chopper bug?) - int rval = 512 + rand()%(mjc - 1024); - // fprintf(stderr, "returning rval %d, mjc %d\n", rval, mjc); - return rval; - } - log_warn("js capacity too small\n"); - exit(-1); + if (hi >= config->pl.max_HTML_capacity / 2) + hi = config->pl.max_HTML_capacity / 2; + break; case HTTP_CONTENT_PDF: - // return 1024 + rand()%(get_max_PDF_capacity() - 1024) - return PDF_MIN_AVAIL_SIZE; + if (hi >= PDF_MIN_AVAIL_SIZE) + hi = PDF_MIN_AVAIL_SIZE; + break; } - - return SIZE_MAX; } -} - - - - + log_assert(hi >= lo); + return clamp(pref + rng_range_geom(hi - lo, 8), lo, hi); +} int lookup_peer_name_from_ip(const char* p_ip, char* p_name) { @@ -346,7 +343,7 @@ http_client_cookie_transmit (http_steg_t *s, struct evbuffer *source, // substitute / with _, + with ., = with - that maybe inserted anywhere in the middle sanitize_b64(data2, len); - + cookie_len = gen_b64_cookie_field(cookiebuf, data2, len); cookiebuf[cookie_len] = 0; @@ -356,7 +353,10 @@ http_client_cookie_transmit (http_steg_t *s, struct evbuffer *source, log_debug("cookie generation failed\n"); return -1; } - + log_debug(conn, "cookie input %ld encoded %d final %d", + sbuflen, len, cookie_len); + log_debug(conn, "cookie encoded: %s", data2); + log_debug(conn, "cookie final: %s", cookiebuf); // add uri field rval = evbuffer_add(dest, buf, strstr(buf, "\r\n") - buf + 2); @@ -657,28 +657,27 @@ http_server_receive(http_steg_t *s, conn_t *conn, struct evbuffer *dest, struct char *p; char *pend; - char outbuf[MAX_COOKIE_SIZE]; + char outbuf[MAX_COOKIE_SIZE * 3/2]; char outbuf2[MAX_COOKIE_SIZE]; int sofar = 0; //int cookie_mode = 0; if (s2.pos == -1) { - log_debug("Did not find end of request %d", (int) evbuffer_get_length(source)); - // evbuffer_dump(source, stderr); + log_debug(conn, "Did not find end of request %d", + (int) evbuffer_get_length(source)); return RECV_INCOMPLETE; } - log_debug("SERVER received request header of length %d", (int)s2.pos); + log_debug(conn, "SERVER received request header of length %d", (int)s2.pos); data = (char*) evbuffer_pullup(source, s2.pos+4); if (data == NULL) { - log_debug("SERVER evbuffer_pullup fails"); + log_debug(conn, "SERVER evbuffer_pullup fails"); return RECV_BAD; } - data[s2.pos+3] = 0; type = find_uri_type((char *)data, s2.pos+4); @@ -691,19 +690,14 @@ http_server_receive(http_steg_t *s, conn_t *conn, struct evbuffer *dest, struct p = data + sizeof "GET /" -1; pend = strstr(p, "\r\n"); - - if (pend == NULL || (pend - p > MAX_COOKIE_SIZE)) { - fprintf(stderr, "incorrect cookie recovery \n"); - exit(-1); - - } - - + log_assert(pend); + if (pend - p > MAX_COOKIE_SIZE * 3/2) + log_abort(conn, "cookie too big: %lu (max %lu)", + (unsigned long)(pend - p), (unsigned long)MAX_COOKIE_SIZE); bzero(outbuf, sizeof(outbuf)); int cookielen = unwrap_b64_cookie((char*) p, (char*) outbuf, pend - p); - desanitize_b64(outbuf, cookielen); outbuf[cookielen] = '\n'; bzero(outbuf2, sizeof(outbuf2)); @@ -711,25 +705,19 @@ http_server_receive(http_steg_t *s, conn_t *conn, struct evbuffer *dest, struct base64::decoder D; sofar = D.decode(outbuf, cookielen+1, outbuf2); + if (sofar <= 0) + log_warn(conn, "base64 decode failed\n"); - if (sofar <= 0) - log_warn("decode failed\n"); - - - if (sofar >= MAX_COOKIE_SIZE) { - log_warn("cookie buffer overflow????\n"); - exit(-1); - } - + if (sofar >= MAX_COOKIE_SIZE) + log_abort(conn, "cookie decode buffer overflow\n"); if (evbuffer_add(dest, outbuf2, sofar)) { - log_debug("Failed to transfer buffer"); + log_debug(conn, "Failed to transfer buffer"); return RECV_BAD; } evbuffer_drain(source, s2.pos + sizeof("\r\n\r\n") - 1); } while (evbuffer_get_length(source)); - s->have_received = 1; s->type = type; @@ -737,16 +725,6 @@ http_server_receive(http_steg_t *s, conn_t *conn, struct evbuffer *dest, struct return RECV_GOOD; } - - - - - - - - - - int http_steg_t::receive(struct evbuffer *dest) { diff --git a/src/steg/nosteg.cc b/src/steg/nosteg.cc index df80c89..328a1d6 100644 --- a/src/steg/nosteg.cc +++ b/src/steg/nosteg.cc @@ -87,9 +87,9 @@ nosteg_steg_t::cfg() } size_t -nosteg_steg_t::transmit_room() +nosteg_steg_t::transmit_room(size_t pref, size_t, size_t) { - return SIZE_MAX; + return pref; } int diff --git a/src/steg/nosteg_rr.cc b/src/steg/nosteg_rr.cc index 8b316bb..adde6c8 100644 --- a/src/steg/nosteg_rr.cc +++ b/src/steg/nosteg_rr.cc @@ -93,9 +93,9 @@ nosteg_rr_steg_t::cfg() } size_t -nosteg_rr_steg_t::transmit_room() +nosteg_rr_steg_t::transmit_room(size_t pref, size_t, size_t) { - return can_transmit ? SIZE_MAX : 0; + return can_transmit ? pref : 0; } int

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[stegotorus/master] Merge branch 'master' of https://git.safdef.isc.org/git/stegotorus
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 092842af7faace09e0b6325f7ae40b112367c8e6 Merge: 5513c95 00d4889 Author: Zack Weinberg <zackw(a)panix.com> Date: Wed Apr 4 18:01:44 2012 -0700 Merge branch 'master' of https://git.safdef.isc.org/git/stegotorus src/steg/http.cc | 6 +++++- src/steg/payloads.cc | 4 +--- 2 files changed, 6 insertions(+), 4 deletions(-)

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[stegotorus/master] Remove a hack from the configure script and a reference to Crypto++ from the README.
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 5513c95762305224973d614cd6f4e839ef948cc3 Author: Zack Weinberg <zackw(a)panix.com> Date: Wed Apr 4 18:01:27 2012 -0700 Remove a hack from the configure script and a reference to Crypto++ from the README. --- README | 2 +- configure.ac | 8 +------- 2 files changed, 2 insertions(+), 8 deletions(-) diff --git a/README b/README index b3b82b4..e1f45b3 100644 --- a/README +++ b/README @@ -1,6 +1,6 @@ This doesn't work yet. -It requires Crypto++ 5.6.0 or later. +It requires OpenSSL 1.0.1 or later. It requires Libevent 2.0 or later. diff --git a/configure.ac b/configure.ac index 69f4150..87cb713 100644 --- a/configure.ac +++ b/configure.ac @@ -5,12 +5,6 @@ AC_LANG([C++]) AM_INIT_AUTOMAKE([foreign nostdinc silent-rules subdir-objects]) AM_MAINTAINER_MODE([enable]) -dnl The stock definition of AC_INCLUDES_DEFAULT performs a whole bunch -dnl of completely unnecessary checks *even if* you override its -dnl mostly-useless default header list at invocation time. -dnl Replace it with a version that does nothing unless requested. -m4_pushdef([AC_INCLUDES_DEFAULT], [$1]) - ### Programs ### AC_PROG_CXX @@ -64,7 +58,7 @@ LIBS="$LIBS $ws32_LIBS" ### Language features ### -AC_CHECK_HEADERS([execinfo.h],,, [AC_INCLUDES_DEFAULT()]) +AC_CHECK_HEADERS([execinfo.h],,,[/**/]) AX_CXXFLAGS_STDCXX_11([ext]) AX_CXX_DELETE_METHOD

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[stegotorus/master] Add a cast to make gcc 4.4 happy.
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 8140b7a818a799dfa43f47c13edeb74f1f0daa20 Author: Zack Weinberg <zackw(a)cmu.edu> Date: Mon Apr 16 14:49:44 2012 -0700 Add a cast to make gcc 4.4 happy. --- src/protocol/chop.cc | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/protocol/chop.cc b/src/protocol/chop.cc index ad8ac9f..dac4ea2 100644 --- a/src/protocol/chop.cc +++ b/src/protocol/chop.cc @@ -1158,7 +1158,7 @@ chop_conn_t::recv_handshake() sizeof circuit_id) != sizeof circuit_id) return -1; - chop_circuit_table::value_type in(circuit_id, 0); + chop_circuit_table::value_type in(circuit_id, (chop_circuit_t *)0); std::pair<chop_circuit_table::iterator, bool> out = this->config->circuits.insert(in); chop_circuit_t *ck;

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[stegotorus/master] Don't enable reading and writing on half-open sockets.
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit fc44f29e5cf79b6db5171cb42c9efa5f498b0bd9 Author: Zack Weinberg <zackw(a)cmu.edu> Date: Mon Apr 16 15:02:31 2012 -0700 Don't enable reading and writing on half-open sockets. --- src/network.cc | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/src/network.cc b/src/network.cc index 55944fe..f312067 100644 --- a/src/network.cc +++ b/src/network.cc @@ -674,7 +674,6 @@ circuit_open_upstream(circuit_t *ckt) return -1; success: - bufferevent_enable(buf, EV_READ|EV_WRITE); circuit_add_upstream(ckt, buf, peername); return 0; } @@ -717,7 +716,6 @@ create_one_outbound_connection(circuit_t *ckt, struct evutil_addrinfo *addr, bufferevent_setcb(buf, downstream_read_cb, downstream_flush_cb, is_socks ? downstream_socks_connect_cb : downstream_connect_cb, conn); - bufferevent_enable(buf, EV_READ|EV_WRITE); return true; } @@ -790,7 +788,6 @@ create_outbound_connections_socks(circuit_t *ckt) ckt->add_downstream(conn); bufferevent_setcb(buf, downstream_read_cb, downstream_flush_cb, downstream_socks_connect_cb, conn); - bufferevent_enable(buf, EV_READ|EV_WRITE); return; failure:

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[stegotorus/master] fixed race condition in connection establishment
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 83c892603a3953829a88a40c1ead3fa1088494b3 Author: Steven Cheung <steven.cheung(a)sri.com> Date: Mon Apr 16 16:25:21 2012 -0700 fixed race condition in connection establishment --- src/connections.h | 3 ++- src/network.cc | 20 +++++++++++++++----- 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/src/connections.h b/src/connections.h index 9b51ce5..ddf787a 100644 --- a/src/connections.h +++ b/src/connections.h @@ -19,8 +19,9 @@ struct conn_t { unsigned int serial; bool connected : 1; bool flushing : 1; + bool ever_received : 1; - conn_t() : connected(false), flushing(false) {} + conn_t() : connected(false), flushing(false), ever_received(false) {} /** Close and deallocate a connection. If the connection is part of a circuit, disconnect it from the circuit; this may cause the circuit diff --git a/src/network.cc b/src/network.cc index f312067..fb17e99 100644 --- a/src/network.cc +++ b/src/network.cc @@ -312,6 +312,8 @@ downstream_read_cb(struct bufferevent *bev, void *arg) { conn_t *down = (conn_t *)arg; + down->ever_received = 1; + log_debug(down, "%lu bytes available", (unsigned long)evbuffer_get_length(bufferevent_get_input(bev))); @@ -375,6 +377,11 @@ downstream_event_cb(struct bufferevent *bev, short what, void *arg) { conn_t *conn = (conn_t *)arg; + log_debug(conn, "what=%04hx enabled=%x inbound=%ld outbound=%ld", + what, bufferevent_get_enabled(bev), + evbuffer_get_length(bufferevent_get_input(bev)), + evbuffer_get_length(bufferevent_get_output(bev))); + if (what & (BEV_EVENT_ERROR|BEV_EVENT_EOF|BEV_EVENT_TIMEOUT)) { if (what & BEV_EVENT_ERROR) log_info(conn, "network error in %s: %s", @@ -393,7 +400,8 @@ downstream_event_cb(struct bufferevent *bev, short what, void *arg) /* Peer is done sending us data. */ conn->recv_eof(); if (bufferevent_get_enabled(bev) || - evbuffer_get_length(bufferevent_get_input(bev)) > 0) { + evbuffer_get_length(bufferevent_get_input(bev)) > 0 || + evbuffer_get_length(bufferevent_get_output(bev)) > 0) { log_debug(conn, "acknowledging EOF downstream"); shutdown(bufferevent_getfd(bev), SHUT_RD); } else { @@ -444,14 +452,15 @@ downstream_flush_cb(struct bufferevent *bev, void *arg) { conn_t *conn = (conn_t *)arg; size_t remain = evbuffer_get_length(bufferevent_get_output(bev)); - log_debug(conn, "%lu bytes still to transmit%s%s%s", + log_debug(conn, "%lu bytes still to transmit%s%s%s%s", (unsigned long)remain, conn->connected ? "" : " (not connected)", conn->flushing ? "" : " (not flushing)", - conn->circuit() ? "" : " (no circuit)"); + conn->circuit() ? "" : " (no circuit)", + conn->ever_received ? "" : " (never received)"); if (remain == 0 && ((conn->flushing && conn->connected) - || !conn->circuit())) { + || (!conn->circuit() && conn->ever_received))) { bufferevent_disable(bev, EV_WRITE); if (bufferevent_get_enabled(bev)) { log_debug(conn, "sending EOF downstream"); @@ -822,5 +831,6 @@ conn_do_flush(conn_t *conn) if (remain == 0) downstream_flush_cb(conn->buffer, conn); else - log_debug(conn, "flushing %lu bytes to peer", (unsigned long)remain); + log_debug(conn, "flushing %lu bytes to peer [enabled=%x]", (unsigned long)remain, + bufferevent_get_enabled(conn->buffer)); }

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[stegotorus/master] Thorough spring-cleaning on pdfSteg.cc; less thorough on swfSteg.cc and some other headers.
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 0538c5a704adaf8149b3a78c84200a77dc657506 Author: Zack Weinberg <zackw(a)cmu.edu> Date: Mon Apr 23 14:49:52 2012 -0700 Thorough spring-cleaning on pdfSteg.cc; less thorough on swfSteg.cc and some other headers. --- Makefile.am | 1 + src/steg/pdfSteg.cc | 389 ++++++++++++++------------------------------ src/steg/pdfSteg.h | 38 +++-- src/steg/swfSteg.cc | 18 +-- src/steg/swfSteg.h | 23 +--- src/steg/zpack.h | 11 +- src/test/tinytest_macros.h | 8 +- src/util.cc | 3 - src/util.h | 3 + 9 files changed, 167 insertions(+), 327 deletions(-) diff --git a/Makefile.am b/Makefile.am index 6ba1b51..86ed489 100644 --- a/Makefile.am +++ b/Makefile.am @@ -49,6 +49,7 @@ stegotorus_SOURCES = \ UTGROUPS = \ src/test/unittest_crypt.cc \ + src/test/unittest_pdfsteg.cc \ src/test/unittest_socks.cc \ src/test/unittest_config.cc \ src/test/unittest_transfer.cc diff --git a/src/steg/pdfSteg.cc b/src/steg/pdfSteg.cc index c67b0f8..3b4bbf0 100644 --- a/src/steg/pdfSteg.cc +++ b/src/steg/pdfSteg.cc @@ -1,7 +1,13 @@ -#include "payloads.h" +#include "util.h" #include "pdfSteg.h" +#include "connections.h" +#include "payloads.h" +#include <event2/buffer.h> + +/* pdfSteg: A PDF-based steganography module */ -void buf_dump(unsigned char* buf, int len, FILE *out); +#define PDF_DELIMITER '?' +#define PDF_DELIMITER2 '.' #define STREAM_BEGIN ">>stream" #define STREAM_BEGIN_SIZE 8 @@ -10,45 +16,42 @@ void buf_dump(unsigned char* buf, int len, FILE *out); #define DEBUG - /* - * pdfSteg: A PDF-based steganography module - * - */ - - -/* - * addDelimiter processes the input buffer (inbuf) of length inbuflen, - * copies it to output buffer (outbuf) of size outbufsize, + * pdf_add_delimiter processes the input buffer (inbuf) of length + * inbuflen, copies it to output buffer (outbuf) of size outbufsize, * and adds a two-char-long, end-of-data pattern at the end of outbuf * based on delimiter1 and delimiter2. * * The end-of-data pattern consists of delimiter1 followed by a char * that is not delimiter1. Thus, delimiter1 and delimiter2 must be * different. - * - * If delimiter1 appears in the input buffer, addDelimiter puts two - * delimiter1 char in output buffer (to enable removeDelimiter to perform - * the back transformation) * - * addDelimiter returns the length of the data written to outbuf, including - * the end-of-data pattern, if the transformation succeeds; - * otherwise, it returns -1 + * If delimiter1 appears in the input buffer, pdf_add_delimiter puts two + * delimiter1 characters in the output buffer, so that the transformation + * is reversible. + * + * pdf_add_delimiter returns the length of the data written to outbuf, + * including the end-of-data pattern, if the transformation succeeds; + * otherwise, it returns -1. * */ -int -addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, - const char delimiter1, const char delimiter2) +ssize_t +pdf_add_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + const char delimiter1, const char delimiter2) { - int cnt; - char *ibp, ic, rc; + size_t cnt; + const char *ibp; + char ic, rc; - if (delimiter1 == delimiter2) return -1; + log_assert(delimiter1 != delimiter2); + if (inbuflen > SIZE_T_CEILING || outbuflen > SIZE_T_CEILING) + return -1; cnt = 0; ibp = inbuf; - while ((ibp-inbuf)<inbuflen && cnt<(outbuflen-2)) { - ic = *(ibp++); + while (size_t(ibp-inbuf) < inbuflen && cnt < outbuflen-2) { + ic = *ibp++; if (ic != delimiter1) { outbuf[cnt++] = ic; } else { @@ -57,8 +60,9 @@ addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, } } - // error if outbuf is no large enough for storing the resulting data - if (cnt >= (outbuflen-2)) return -1; + // error if outbuf is not large enough for storing the resulting data + if (cnt >= outbuflen-2) + return -1; // put delimiter1 and a char that is not a delimiter1 // as the end-of-data pattern at the end of outbuf @@ -75,8 +79,9 @@ addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, /* - * removeDelimiter performs the reverse transformation of addDelimiter. - * + * pdf_remove_delimiter performs the reverse transformation of + * pdf_add_delimiter. + * * returns the length of data written to outbuf, if succeed; * otherwise, it returns -1 * @@ -84,20 +89,23 @@ addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, * delimiter1 followed by non-delimiter1) is detected * * escape indicates if a dangling delimiter1 has been - * seen in the previous invocation of removeDelimiter + * seen in the previous invocation of pdf_remove_delimiter */ -int -removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, - const char delimiter1, int *endFlag, int *escape) +ssize_t +pdf_remove_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + char delimiter1, bool *endFlag, bool *escape) { - int cnt; - char *ibp, ic1, ic2; + size_t cnt; + const char *ibp; + char ic1, ic2; cnt = 0; - *endFlag = 0; + *endFlag = false; ibp = inbuf; - if (inbuflen <= 0) return -1; + if (inbuflen > SIZE_T_CEILING || outbuflen > SIZE_T_CEILING) + return -1; // special case: 2-char, end-of-data pattern could be in two buffers // if *escape == true, we need to see if @@ -113,9 +121,9 @@ removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, } } - *escape = 0; - while ((ibp-inbuf+1)<inbuflen && cnt<outbuflen) { - ic1 = *(ibp++); + *escape = false; + while (size_t(ibp-inbuf+1) < inbuflen && cnt < outbuflen) { + ic1 = *ibp++; if (ic1 != delimiter1) { outbuf[cnt++] = ic1; } else { @@ -125,13 +133,14 @@ removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, if (ic2 == delimiter1) { outbuf[cnt++] = delimiter1; ibp++; } else { // end-of-data pattern detected - *endFlag = 1; + *endFlag = true; return cnt; } } } - if (ibp-inbuf == inbuflen) return cnt; + if (size_t(ibp-inbuf) == inbuflen) + return cnt; // handling the last char in inbuf, if needed ic1 = *ibp; @@ -139,40 +148,46 @@ removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, outbuf[cnt++] = ic1; } else { // look at the next stream obj to handle the special cases - *escape = 1; + *escape = true; } return cnt; } - - /* - * pdfWrap embeds data of length dlen inside the stream objects of the PDF + * pdf_wrap embeds data of length dlen inside the stream objects of the PDF * document (length plen) that appears in the body of a HTTP msg, and * stores the result in the output buffer of size outsize * - * pdfWrap returns the length of the pdf document with the data embedded + * pdf_wrap returns the length of the pdf document with the data embedded * inside, if succeed; otherwise, it returns -1 to indicate an error - * - */ -int -pdfWrap (char *data, unsigned int dlen, - char *pdfTemplate, unsigned int plen, - char *outbuf, unsigned int outbufsize) + * + */ +ssize_t +pdf_wrap(const char *data, size_t dlen, + const char *pdfTemplate, size_t plen, + char *outbuf, size_t outbufsize) { char data2[dlen*2+2]; - char *tp, *dp, *op, *streamStart, *streamEnd, *plimit; - int data2len, cnt, size, size2; + const char *tp, *dp, *plimit; + char *op, *streamStart, *streamEnd; + size_t data2len, cnt, size, size2; + ssize_t rv; - // assumption: pdfWrap is length-preserving - if (outbufsize < plen) return -1; + if (dlen > SIZE_T_CEILING || plen > SIZE_T_CEILING || + outbufsize > SIZE_T_CEILING) + return -1; - data2len = addDelimiter(data, dlen, data2, HTTP_MSG_BUF_SIZE, PDF_DELIMITER, PDF_DELIMITER2); - if (data2len < 1) return -1; + // assumption: pdf_wrap is length-preserving + if (outbufsize < plen) return -1; + rv = pdf_add_delimiter(data, dlen, data2, HTTP_MSG_BUF_SIZE, + PDF_DELIMITER, PDF_DELIMITER2); + if (rv < 1) + return -1; + data2len = rv; - op = outbuf; // current pointer for output buffer + op = outbuf; // current pointer for output buffer tp = pdfTemplate; // current pointer for http msg template dp = data2; // current pointer for data2 cnt = 0; // number of data char encoded @@ -185,7 +200,7 @@ pdfWrap (char *data, unsigned int dlen, log_warn("Cannot find stream in pdf"); return -1; } - + // copy everything between tp and "stream" (inclusive) to outbuf size = streamStart - tp + STREAM_BEGIN_SIZE; memcpy(op, tp, size); @@ -206,18 +221,17 @@ pdfWrap (char *data, unsigned int dlen, size2 = data2len - cnt; if (size < size2) { memcpy(op, dp, size); - op += size; tp += size; dp += size; + op += size; tp += size; dp += size; memcpy(op, tp, STREAM_END_SIZE); op += STREAM_END_SIZE; tp += STREAM_END_SIZE; cnt += size; } else { // done encoding data memcpy(op, dp, size2); - op += size2; tp += size2; dp += size2; + op += size2; tp += size2; dp += size2; cnt += size2; - // printf("Encoded %d char in pdf. Done encoding\n", size2); break; } - log_debug("Encoded %d char in pdf", size); + log_debug("Encoded %lu bytes in pdf", (unsigned long)size); } else { // empty stream memcpy(op, tp, STREAM_END_SIZE); op += STREAM_END_SIZE; tp += STREAM_END_SIZE; @@ -228,25 +242,27 @@ pdfWrap (char *data, unsigned int dlen, // copy the rest of pdfTemplate to outbuf size = plimit-tp; - log_debug("copying the rest of pdfTemplate to outbuf (size %d)", size); + log_debug("copying the rest of pdfTemplate to outbuf (size %lu)", + (unsigned long)size); memcpy(op, tp, size); op += size; return (op-outbuf); } - - - /* - * pdfUnwrap is the inverse operation of pdfWrap + * pdf_unwrap is the inverse operation of pdf_wrap */ -int -pdfUnwrap (char *data, unsigned int dlen, - char *outbuf, unsigned int outbufsize) +ssize_t +pdf_unwrap(const char *data, size_t dlen, + char *outbuf, size_t outbufsize) { - char *dp, *op, *streamStart, *streamEnd, *dlimit, *olimit; - int cnt, size, size2, endFlag; - int escape = 0; + const char *dp, *dlimit; + char *op, *streamStart, *streamEnd, *olimit; + size_t cnt, size, size2; + bool endFlag, escape = false; + + if (dlen > SIZE_T_CEILING || outbufsize > SIZE_T_CEILING) + return -1; dp = data; // current pointer for data op = outbuf; // current pointer for outbuf @@ -272,11 +288,13 @@ pdfUnwrap (char *data, unsigned int dlen, // count the number of usable char between tp and streamEnd size = streamEnd-dp; - if (size > 0) { - size2 = removeDelimiter(dp, size, op, olimit-op, PDF_DELIMITER, &endFlag, &escape); - if (size2 < 0) { + if (size > 0) { + ssize_t rv = pdf_remove_delimiter(dp, size, op, olimit-op, PDF_DELIMITER, + &endFlag, &escape); + if (rv < 0) return -1; - } + + size2 = rv; cnt += size2; if (endFlag) { // Done decoding break; @@ -292,22 +310,16 @@ pdfUnwrap (char *data, unsigned int dlen, return cnt; } - - - - int -http_server_PDF_transmit (payloads& pl, struct evbuffer *source, - conn_t *conn) +http_server_PDF_transmit(payloads &pl, struct evbuffer *source, + conn_t *conn) { - struct evbuffer *dest = conn->outbound(); size_t sbuflen = evbuffer_get_length(source); unsigned int mpdf; char *pdfTemplate = NULL, *hend; int pdfTemplateSize = 0; - // char data1[HTTP_MSG_BUF_SIZE]; - char data1[(int) sbuflen]; + char data1[sbuflen]; char outbuf[HTTP_MSG_BUF_SIZE]; int cnt, hLen, outbuflen, i; @@ -317,10 +329,6 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, struct evbuffer_iovec *iv; int nv; - // for debugging pdfWrap and pdfUnwrap - // char data2[(int) sbuflen]; - // int data2len; - log_debug("Entering SERVER PDF transmit with sbuflen %d", (int)sbuflen); nv = evbuffer_peek(source, sbuflen, NULL, NULL, 0); @@ -357,8 +365,10 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, return -1; } - if (get_payload(pl, HTTP_CONTENT_PDF, sbuflen, &pdfTemplate, &pdfTemplateSize) == 1) { - log_debug("SERVER found the next HTTP response template with size %d", pdfTemplateSize); + if (get_payload(pl, HTTP_CONTENT_PDF, sbuflen, &pdfTemplate, + &pdfTemplateSize) == 1) { + log_debug("SERVER found the next HTTP response template with size %d", + pdfTemplateSize); } else { log_warn("SERVER couldn't find the next HTTP response template"); return -1; @@ -371,39 +381,19 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, } hLen = hend+4-pdfTemplate; - - log_debug("SERVER calling pdfWrap for data1 with length %d", cnt); - outbuflen = pdfWrap(data1, cnt, hend+4, pdfTemplateSize-hLen, outbuf, HTTP_MSG_BUF_SIZE); + + log_debug("SERVER calling pdf_wrap for data1 with length %d", cnt); + outbuflen = pdf_wrap(data1, cnt, hend+4, pdfTemplateSize-hLen, outbuf, + HTTP_MSG_BUF_SIZE); if (outbuflen < 0) { - log_warn("SERVER pdfWrap fails"); + log_warn("SERVER pdf_wrap fails"); return -1; } - log_debug("SERVER pdfSteg sends resp with hdr len %d body len %d", hLen, outbuflen); - - - // debugging - // buf_dump((unsigned char *)data1, cnt, stderr); - - // data2len = pdfUnwrap(outbuf, outbuflen, data2, sbuflen); - // if ((int)sbuflen == data2len) { - // log_warn("sbuflen == data2len == %d", (int)sbuflen); - // if (memcmp(data1, data2, sbuflen) == 0) { - // log_warn("data1 and data2 match"); - // } else { - // log_warn("data1 and data2 DO NOT match!! Dumping data1 ..."); - // buf_dump((unsigned char *)data1, cnt, stderr); - // log_warn("data1 and data2 DO NOT match!! Dumping data2..."); - // buf_dump((unsigned char *)data2, data2len, stderr); - // } - // } else { - // log_warn("*** sbuflen = %d, data2len = %d *** Dumping data1 ...", (int)sbuflen, data2len); - // buf_dump((unsigned char *)data1, cnt, stderr); - // log_warn("*** sbuflen = %d, data2len = %d *** Dumping data2 ...", (int)sbuflen, data2len); - // buf_dump((unsigned char *)data2, data2len, stderr); - // } - - - newHdrLen = gen_response_header((char*) "application/pdf", 0, outbuflen, newHdr, sizeof(newHdr)); + log_debug("SERVER pdfSteg sends resp with hdr len %d body len %d", + hLen, outbuflen); + + newHdrLen = gen_response_header((char*) "application/pdf", 0, + outbuflen, newHdr, sizeof(newHdr)); if (newHdrLen < 0) { log_warn("SERVER ERROR: gen_response_header fails for pdfSteg"); return -1; @@ -413,10 +403,6 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, log_warn("SERVER ERROR: evbuffer_add() fails for newHdr"); return -1; } - // if (evbuffer_add(dest, pdfTemplate, hLen)) { - // log_warn("SERVER ERROR: evbuffer_add() fails for pdfTemplate"); - // return -1; - // } if (evbuffer_add(dest, outbuf, outbuflen)) { log_warn("SERVER ERROR: evbuffer_add() fails for outbuf"); @@ -426,14 +412,13 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, evbuffer_drain(source, sbuflen); conn->cease_transmission(); - // downcast_steg(s)->have_transmitted = 1; return 0; } - - int -http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, struct evbuffer* source) { +http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, + struct evbuffer* source) +{ struct evbuffer_ptr s2; unsigned int response_len = 0, hdrLen; char outbuf[HTTP_MSG_BUF_SIZE]; @@ -444,8 +429,8 @@ http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, st s2 = evbuffer_search(source, "\r\n\r\n", sizeof ("\r\n\r\n") -1 , NULL); if (s2.pos == -1) { - log_warn("CLIENT Did not find end of HTTP header %d", (int) evbuffer_get_length(source)); - // evbuffer_dump(source, stderr); + log_warn("CLIENT Did not find end of HTTP header %d", + (int) evbuffer_get_length(source)); return RECV_INCOMPLETE; } @@ -480,154 +465,26 @@ http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, st return RECV_BAD; } - httpBody = httpHdr + hdrLen; - - outbuflen = pdfUnwrap(httpBody, content_len, outbuf, HTTP_MSG_BUF_SIZE); + outbuflen = pdf_unwrap(httpBody, content_len, outbuf, HTTP_MSG_BUF_SIZE); if (outbuflen < 0) { - log_warn("CLIENT ERROR: pdfUnwrap fails\n"); + log_warn("CLIENT ERROR: pdf_unwrap fails\n"); return RECV_BAD; } log_debug("CLIENT unwrapped data of length %d:", outbuflen); - if (evbuffer_add(dest, outbuf, outbuflen)) { log_warn("CLIENT ERROR: evbuffer_add to dest fails\n"); return RECV_BAD; } - // log_debug("Drained source for %d char\n", response_len); if (evbuffer_drain(source, response_len) == -1) { log_warn("CLIENT ERROR: failed to drain source\n"); return RECV_BAD; } - // downcast_steg(s)->have_received = 1; conn->expect_close(); return RECV_GOOD; } - - - - -/***** -int main() { - char data1[] = "this is a test?? yes!"; - char data2[100]; - char data3[100]; - int dlen1, dlen2, dlen3, end; - char last = ' '; - printf("hello world\n"); - - dlen2 = addDelimiter(data1, strlen(data1), data2, 100, '?', '.'); - printf("dlen2 = %d\n", dlen2); - dlen3 = removeDelimiter(data2, dlen2, data3, 100, '?', &end, &last); - printf("endflag = %d", end); - printf("dlen3 = %d\n", dlen3); - if (memcmp(data1, data3, dlen3) == 0) { - data1[dlen3] = 0; - printf("removeDelimiter(addDelimiter(x)) == x for |%s|\n", data1); - } else { - printf("removeDelimiter(addDelimiter(x)) != x for |%s|\n", data1); - } - return 1; -} - *****/ - -/***** -int main() { - char data1[] = "12345"; - char data2[] = "123456789012"; - char data3[] = "12345678901"; - char data4[] = "1234567890?"; - char pdf1[] = "[PDFHDR][STUFFS1]>>streamABCDEFGHIJYYendstream[STUFFS2]>>streamABCDEFGHIJYYendstream[STUFF3][PDFTRAILER]"; - char out[200]; - char orig[200]; - int r1, r2; - - printf("********************\n"); - printf("pdfwrap for %s\n", data1); - printf("strlen(pdf1) = %d\n", (int)strlen(pdf1)); - r1 = pdfWrap(data1, strlen(data1), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - printf("********************\n"); - printf("pdfwrap for %s\n", data2); - r1 = pdfWrap(data2, strlen(data2), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - printf("********************\n"); - printf("pdfwrap for %s\n", data3); - r1 = pdfWrap(data3, strlen(data3), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - printf("********************\n"); - printf("pdfwrap for %s\n", data4); - r1 = pdfWrap(data4, strlen(data4), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - return 0; -} - *****/ diff --git a/src/steg/pdfSteg.h b/src/steg/pdfSteg.h index 3d494e1..0bd3a43 100644 --- a/src/steg/pdfSteg.h +++ b/src/steg/pdfSteg.h @@ -1,29 +1,31 @@ #ifndef _PDFSTEG_H #define _PDFSTEG_H +struct payloads; -#include <stdio.h> -#include <string.h> -#include <ctype.h> -#include "util.h" -#include "connections.h" -#include "steg.h" -#include <event2/buffer.h> +// These are the public interface. -struct payloads; +int http_server_PDF_transmit(payloads &pl, struct evbuffer *source, + conn_t *conn); +int http_handle_client_PDF_receive(steg_t *s, conn_t *conn, + struct evbuffer *dest, + struct evbuffer* source); -#define PDF_DELIMITER '?' -#define PDF_DELIMITER2 '.' +// These are exposed only for the sake of unit tests. -int pdfWrap (char *data, unsigned int dlen, char *pdfTemplate, unsigned int plen, char *outbuf, unsigned int outbufsize); -int pdfUnwrap (char *data, unsigned int dlen, char *outbuf, unsigned int outbufsize); +ssize_t pdf_add_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + char delimiter1, char delimiter2); -int addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, const char delimiter1, const char delimiter2); -int removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, const char delimiter1, int* endFlag, int* escape); +ssize_t pdf_remove_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + char delimiter1, bool *endFlag, bool *escape); -int http_server_PDF_transmit (payloads& pl, struct evbuffer *source, conn_t *conn); -int -http_handle_client_PDF_receive(steg_t *s, conn_t *conn, struct evbuffer *dest, struct evbuffer* source); +ssize_t pdf_wrap(const char *data, size_t dlen, + const char *pdfTemplate, size_t plen, + char *outbuf, size_t outbufsize); -#endif +ssize_t pdf_unwrap(const char *data, size_t dlen, + char *outbuf, size_t outbufsize); +#endif diff --git a/src/steg/swfSteg.cc b/src/steg/swfSteg.cc index cd371f3..c8a18c1 100644 --- a/src/steg/swfSteg.cc +++ b/src/steg/swfSteg.cc @@ -1,5 +1,11 @@ +#include "util.h" #include "swfSteg.h" +#include "connections.h" +#include "payloads.h" +#include "zlib.h" +#include "zpack.h" +#include <event2/buffer.h> static const char http_response_1[] = "HTTP/1.1 200 OK\r\n" @@ -9,17 +15,7 @@ static const char http_response_1[] = "Content-Type: application/x-shockwave-flash\r\n" "Content-Length: "; - - - - - - - - - - -unsigned int +unsigned int swf_wrap(payloads& pl, char* inbuf, int in_len, char* outbuf, int out_sz) { char* swf; diff --git a/src/steg/swfSteg.h b/src/steg/swfSteg.h index 712a3a3..b8336b2 100644 --- a/src/steg/swfSteg.h +++ b/src/steg/swfSteg.h @@ -1,38 +1,21 @@ #ifndef _SWFSTEG_H #define _SWFSTEG_H - -#include "util.h" -#include "connections.h" -#include "steg.h" -#include "payloads.h" -#include "cookies.h" -#include "pdfSteg.h" -#include "zpack.h" - - -#include <event2/buffer.h> -#include <stdio.h> - struct payloads; #define SWF_SAVE_HEADER_LEN 1500 #define SWF_SAVE_FOOTER_LEN 1500 - -unsigned int +unsigned int swf_wrap(payloads& pl, char* inbuf, int in_len, char* outbuf, int out_sz); -unsigned int +unsigned int swf_unwrap(char* inbuf, int in_len, char* outbuf, int out_sz); -int +int http_server_SWF_transmit(payloads& pl, struct evbuffer *source, conn_t *conn); - int http_handle_client_SWF_receive(steg_t *s, conn_t *conn, struct evbuffer *dest, struct evbuffer* source); #endif - - diff --git a/src/steg/zpack.h b/src/steg/zpack.h index 65cd28d..d0e5cb2 100644 --- a/src/steg/zpack.h +++ b/src/steg/zpack.h @@ -1,10 +1,5 @@ -#include <stdio.h> -#include <string.h> -#include <assert.h> -#include <time.h> -#include <stdlib.h> -#include "zlib.h" - +#ifndef _ZPACK_H +#define _ZPACK_H int def(char *source, int slen, char *dest, int dlen, int level); int inf(char *source, int slen, char *dest, int dlen); @@ -12,3 +7,5 @@ void zerr(int ret); int gzInflate(char *source, int slen, char *dest, int dlen); int gzDeflate(char* start, off_t insz, char *buf, off_t outsz, time_t mtime); unsigned int generate_crc32c(char *buffer, size_t length); + +#endif diff --git a/src/test/tinytest_macros.h b/src/test/tinytest_macros.h index 40d17e2..cf5a2a2 100644 --- a/src/test/tinytest_macros.h +++ b/src/test/tinytest_macros.h @@ -168,6 +168,10 @@ tt_assert_test_type(a,b,#a" "#op" "#b,void*, \ (_val1 op _val2),"%p") +#define tt_char_op(a,op,b) \ + tt_assert_test_type(a,b,#a" "#op" "#b,int, \ + (_val1 op _val2),"'%c'") + #define tt_str_op(a,op,b) \ tt_assert_test_type(a,b,#a" "#op" "#b,const char *, \ (strcmp(_val1,_val2) op 0),"<%s>") @@ -176,7 +180,7 @@ tt_assert_test_fmt_type(a,b,#a" "#op" "#b, \ const char *, \ (strncmp(_val1, _val2, len) op 0), \ - char *, "%s", \ + char *, "<%s>", \ { _print = xstrndup(_value, len); }, \ { free(_print); } \ ); @@ -185,7 +189,7 @@ tt_assert_test_fmt_type(a,b,#a" "#op" "#b, \ const char *, \ (memcmp(_val1, _val2, len) op 0), \ - char *, "%s", \ + char *, "<%s>", \ { _print = tt_base16_encode(_value, len); }, \ { free(_print); } \ ); diff --git a/src/util.cc b/src/util.cc index b813ae9..a667abd 100644 --- a/src/util.cc +++ b/src/util.cc @@ -17,9 +17,6 @@ #include <sys/un.h> #endif -/** Any size_t larger than this amount is likely to be an underflow. */ -#define SIZE_T_CEILING (SIZE_MAX/2 - 16) - /**************************** Memory Allocation ******************************/ static void ATTR_NORETURN diff --git a/src/util.h b/src/util.h index 05bc6d0..167af8e 100644 --- a/src/util.h +++ b/src/util.h @@ -57,6 +57,9 @@ struct event_base; /***** Memory allocation. *****/ +/** Any size_t larger than this amount is likely to be an underflow. */ +#define SIZE_T_CEILING (SIZE_MAX/2 - 16) + /* Because this isn't Tor and functions named "tor_whatever" would be confusing, I am instead following the GNU convention of naming allocate-memory-or-crash functions "xwhatever". Also, at this time

1 0

[stegotorus/master] Const- and size_t-correctness, minor other cleanups for crc32 and zpack.
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 343d961f4055f69a61bd9749d498e61234339bfc Author: Zack Weinberg <zackw(a)cmu.edu> Date: Mon Apr 23 15:40:28 2012 -0700 Const- and size_t-correctness, minor other cleanups for crc32 and zpack. --- src/steg/crc32.cc | 7 +- src/steg/crc32.h | 18 +---- src/steg/zpack.cc | 235 ++++++++++++++++------------------------------------- src/steg/zpack.h | 13 ++-- 4 files changed, 83 insertions(+), 190 deletions(-) diff --git a/src/steg/crc32.cc b/src/steg/crc32.cc index 7fdc847..1b18544 100644 --- a/src/steg/crc32.cc +++ b/src/steg/crc32.cc @@ -1,3 +1,4 @@ +#include "util.h" #include "crc32.h" #define CRC32C(c,d) (c=(c>>8)^crc_c[(c^(d))&0xFF]) @@ -69,8 +70,9 @@ static const unsigned int crc_c[256] = { 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d, }; - -unsigned int generate_crc32c(char *buffer, size_t length) { +unsigned int +generate_crc32c(const char *buffer, size_t length) +{ size_t i; unsigned int crc32 = ~0L; @@ -79,4 +81,3 @@ unsigned int generate_crc32c(char *buffer, size_t length) { } return ~crc32; } - diff --git a/src/steg/crc32.h b/src/steg/crc32.h index 780e7bd..0a1ee03 100644 --- a/src/steg/crc32.h +++ b/src/steg/crc32.h @@ -1,18 +1,6 @@ -#ifndef __crc32cr_table_h__ -#define __crc32cr_table_h__ +#ifndef _CRC32_H +#define _CRC32_H -#ifdef HAVE_CONFIG_H -# include "config.h" -#endif - -#include <sys/types.h> - -#if defined HAVE_STDINT_H -# include <stdint.h> -#elif defined HAVE_INTTYPES_H -# include <inttypes.h> -#endif - -unsigned int generate_crc32c(char *string, size_t length); +unsigned int generate_crc32c(const char *string, size_t length); #endif diff --git a/src/steg/zpack.cc b/src/steg/zpack.cc index 63aa412..c3c650f 100644 --- a/src/steg/zpack.cc +++ b/src/steg/zpack.cc @@ -1,19 +1,7 @@ -#include <stdio.h> -#include <string.h> -#include <assert.h> -#include <time.h> -#include <stdlib.h> -#include "zlib.h" +#include "util.h" #include "zpack.h" - - -#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__) -# include <fcntl.h> -# include <io.h> -# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) -#else -# define SET_BINARY_MODE(file) -#endif +#include "zlib.h" +#include "crc32.h" #define CHUNK 16384 @@ -24,15 +12,18 @@ version of the library linked do not match, or Z_ERRNO if there is an error reading or writing the files. */ - -int def(char *source, int slen, char *dest, int dlen, int level) +ssize_t +def(const char *source, size_t slen, char *dest, size_t dlen, int level) { int ret, flush; - unsigned have; + size_t have; z_stream strm; unsigned char in[CHUNK]; unsigned char out[CHUNK]; - int dlen_orig = dlen; + size_t dlen_orig = dlen; + + if (slen > SIZE_T_CEILING || dlen > SIZE_T_CEILING) + return -1; /* allocate deflate state */ strm.zalloc = Z_NULL; @@ -44,7 +35,6 @@ int def(char *source, int slen, char *dest, int dlen, int level) /* compress until end of file */ do { - if (slen > CHUNK) strm.avail_in = CHUNK; else @@ -63,30 +53,28 @@ int def(char *source, int slen, char *dest, int dlen, int level) strm.avail_out = CHUNK; strm.next_out = out; ret = deflate(&strm, flush); /* no bad return value */ - assert(ret != Z_STREAM_ERROR); /* state not clobbered */ + log_assert(ret != Z_STREAM_ERROR); /* state not clobbered */ have = CHUNK - strm.avail_out; - if ((unsigned int) dlen < have) { - fprintf(stderr, "dest buf too small!\n"); - return Z_ERRNO; + if (dlen < have) { + log_warn("dest buf too small - have %lu, need %lu", + (unsigned long)dlen, (unsigned long)have); + return Z_ERRNO; } memcpy(dest, out, have); dest += have; dlen = dlen - have; } while (strm.avail_out == 0); - assert(strm.avail_in == 0); /* all input will be used */ + log_assert(strm.avail_in == 0); /* all input will be used */ /* done when last data in file processed */ } while (flush != Z_FINISH); - assert(ret == Z_STREAM_END); /* stream will be complete */ + log_assert(ret == Z_STREAM_END); /* stream will be complete */ /* clean up and return */ - (void)deflateEnd(&strm); - - printf("hello here...\n"); + deflateEnd(&strm); return (dlen_orig - dlen); - // return Z_OK; } /* Decompress from file source to file dest until stream ends or EOF. @@ -96,18 +84,18 @@ int def(char *source, int slen, char *dest, int dlen, int level) the version of the library linked do not match, or Z_ERRNO if there is an error reading or writing the files. */ - - - -int inf(char *source, int slen, char *dest, int dlen) +ssize_t +inf(const char *source, size_t slen, char *dest, size_t dlen) { int ret; - unsigned have; + size_t have; z_stream strm; unsigned char in[CHUNK]; unsigned char out[CHUNK]; - int dlen_orig = dlen; + size_t dlen_orig = dlen; + if (slen > SIZE_T_CEILING || dlen > SIZE_T_CEILING) + return -1; /* allocate inflate state */ strm.zalloc = Z_NULL; @@ -121,10 +109,9 @@ int inf(char *source, int slen, char *dest, int dlen) /* decompress until deflate stream ends or end of file */ do { - if (slen == 0) break; - + if (slen > CHUNK) strm.avail_in = CHUNK; else @@ -133,9 +120,6 @@ int inf(char *source, int slen, char *dest, int dlen) memcpy(in, source, strm.avail_in); slen = slen - strm.avail_in; source = source + strm.avail_in; - - - strm.next_in = in; /* run inflate() on input until output buffer not full */ @@ -143,21 +127,20 @@ int inf(char *source, int slen, char *dest, int dlen) strm.avail_out = CHUNK; strm.next_out = out; ret = inflate(&strm, Z_NO_FLUSH); - assert(ret != Z_STREAM_ERROR); /* state not clobbered */ + log_assert(ret != Z_STREAM_ERROR); /* state not clobbered */ switch (ret) { case Z_NEED_DICT: - ret = Z_DATA_ERROR; /* and fall through */ case Z_DATA_ERROR: case Z_MEM_ERROR: - (void)inflateEnd(&strm); - return ret; + inflateEnd(&strm); + return ret; } have = CHUNK - strm.avail_out; - - if ((unsigned int) dlen < have) { - fprintf(stderr, "dest buf too small!\n"); - return Z_ERRNO; + if (dlen < have) { + log_warn("dest buf too small - have %lu, need %lu", + (unsigned long)dlen, (unsigned long)have); + return Z_ERRNO; } memcpy(dest, out, have); @@ -170,57 +153,27 @@ int inf(char *source, int slen, char *dest, int dlen) } while (ret != Z_STREAM_END); /* clean up and return */ - (void)inflateEnd(&strm); + inflateEnd(&strm); if (ret == Z_STREAM_END) return dlen_orig - dlen; return Z_DATA_ERROR; } -/* report a zlib or i/o error */ -void zerr(int ret) - -{ - fputs("zpipe: ", stderr); - switch (ret) { - case Z_ERRNO: - if (ferror(stdin)) - fputs("error reading stdin\n", stderr); - if (ferror(stdout)) - fputs("error writing stdout\n", stderr); - break; - case Z_STREAM_ERROR: - fputs("invalid compression level\n", stderr); - break; - case Z_DATA_ERROR: - fputs("invalid or incomplete deflate data\n", stderr); - break; - case Z_MEM_ERROR: - fputs("out of memory\n", stderr); - break; - case Z_VERSION_ERROR: - fputs("zlib version mismatch!\n", stderr); - } -} - - - - - - - - /* assumes that we know there is exactly 10 bytes of gzip header */ -int gzInflate(char *source, int slen, char *dest, int dlen) +ssize_t +gzInflate(const char *source, size_t slen, char *dest, size_t dlen) { int ret; - unsigned have; + size_t have; z_stream strm; unsigned char in[CHUNK]; unsigned char out[CHUNK]; - int dlen_orig = dlen; + size_t dlen_orig = dlen; + if (slen > SIZE_T_CEILING || dlen > SIZE_T_CEILING) + return -1; /* allocate inflate state */ strm.zalloc = Z_NULL; @@ -229,7 +182,6 @@ int gzInflate(char *source, int slen, char *dest, int dlen) strm.avail_in = 0; strm.next_in = Z_NULL; - ret = inflateInit2(&strm, -MAX_WBITS); if (ret != Z_OK) return ret; @@ -239,10 +191,9 @@ int gzInflate(char *source, int slen, char *dest, int dlen) /* decompress until deflate stream ends or end of file */ do { - if (slen == 0) break; - + if (slen > CHUNK) strm.avail_in = CHUNK; else @@ -251,9 +202,6 @@ int gzInflate(char *source, int slen, char *dest, int dlen) memcpy(in, source, strm.avail_in); slen = slen - strm.avail_in; source = source + strm.avail_in; - - - strm.next_in = in; /* run inflate() on input until output buffer not full */ @@ -261,20 +209,21 @@ int gzInflate(char *source, int slen, char *dest, int dlen) strm.avail_out = CHUNK; strm.next_out = out; ret = inflate(&strm, Z_NO_FLUSH); - assert(ret != Z_STREAM_ERROR); /* state not clobbered */ + log_assert(ret != Z_STREAM_ERROR); /* state not clobbered */ switch (ret) { case Z_NEED_DICT: - ret = Z_DATA_ERROR; /* and fall through */ + ret = Z_DATA_ERROR; /* and fall through */ case Z_DATA_ERROR: case Z_MEM_ERROR: - (void)inflateEnd(&strm); - return ret; + inflateEnd(&strm); + return ret; } have = CHUNK - strm.avail_out; - if ((unsigned int) dlen < have) { - fprintf(stderr, "dest buf too small!\n"); - return Z_ERRNO; + if (dlen < have) { + log_warn("dest buf too small - have %lu, need %lu", + (unsigned long)dlen, (unsigned long)have); + return Z_ERRNO; } memcpy(dest, out, have); @@ -287,45 +236,43 @@ int gzInflate(char *source, int slen, char *dest, int dlen) } while (ret != Z_STREAM_END); /* clean up and return */ - (void)inflateEnd(&strm); + inflateEnd(&strm); if (ret == Z_STREAM_END) return dlen_orig - dlen; return Z_DATA_ERROR; } - - - - - - -int gzDeflate(char* start, off_t insz, char *buf, off_t outsz, time_t mtime) { +ssize_t +gzDeflate(const char *source, size_t slen, char *dest, size_t dlen, + time_t mtime) +{ unsigned char *c; unsigned long crc; z_stream z; + if (slen > SIZE_T_CEILING || dlen > SIZE_T_CEILING) + return -1; + z.zalloc = Z_NULL; z.zfree = Z_NULL; z.opaque = Z_NULL; if (Z_OK != deflateInit2(&z, - Z_DEFAULT_COMPRESSION, - Z_DEFLATED, - -MAX_WBITS, /* supress zlib-header */ - 8, - Z_DEFAULT_STRATEGY)) { + Z_DEFAULT_COMPRESSION, + Z_DEFLATED, + -MAX_WBITS, /* supress zlib-header */ + 8, + Z_DEFAULT_STRATEGY)) return -1; - } - z.next_in = (unsigned char *)start; - z.avail_in = insz; + z.next_in = (Bytef *)source; + z.avail_in = slen; z.total_in = 0; - /* write gzip header */ - c = (unsigned char *) buf; + c = (unsigned char *)dest; c[0] = 0x1f; c[1] = 0x8b; c[2] = Z_DEFLATED; @@ -338,19 +285,17 @@ int gzDeflate(char* start, off_t insz, char *buf, off_t outsz, time_t mtime) { c[9] = 0x03; /* UNIX */ z.next_out = c + 10; - z.avail_out = outsz - 10 - 8; + z.avail_out = dlen - 10 - 8; z.total_out = 0; - if (Z_STREAM_END != deflate(&z, Z_FINISH)) { + if (deflate(&z, Z_FINISH) != Z_STREAM_END) { deflateEnd(&z); return -1; } + crc = generate_crc32c(source, slen); - crc = generate_crc32c(start, insz); - - c = (unsigned char *)buf + 10 + z.total_out; - + c = (unsigned char *)dest + 10 + z.total_out; c[0] = (crc >> 0) & 0xff; c[1] = (crc >> 8) & 0xff; c[2] = (crc >> 16) & 0xff; @@ -360,49 +305,7 @@ int gzDeflate(char* start, off_t insz, char *buf, off_t outsz, time_t mtime) { c[6] = (z.total_in >> 16) & 0xff; c[7] = (z.total_in >> 24) & 0xff; - - - if (Z_OK != deflateEnd(&z)) { + if (deflateEnd(&z) != Z_OK) return -1; - } - return 10 + z.total_out + 8; - } - - - - - -/* compress or decompress from stdin to stdout */ -/* int main(int argc, char **argv) */ -/* { */ -/* int ret; */ -/* char buf1[32] = "abcasdfadfadfadf23fasdfa23sdfsdf"; */ -/* char buf2[100]; */ -/* char buf3[100]; */ -/* int i; */ - -/* bzero(buf2, sizeof(buf2)); */ -/* bzero(buf3, sizeof(buf3)); */ - - -/* // ret = def(buf1, 3, buf2, 100, Z_DEFAULT_COMPRESSION); */ -/* ret = gzDeflate(buf1, sizeof(buf1), buf2, sizeof(buf2), time(NULL)); */ -/* if (ret <= 0) */ -/* zerr(ret); */ - -/* /\* for (i=0; i < ret; i++) */ -/* putc(buf2[i], stdout); */ -/* *\/ */ - - -/* // printf("len = %d\n", ret); */ - -/* ret = gzInflate(buf2, ret, buf3, 100); */ -/* if (ret <= 0) */ -/* zerr(ret); */ -/* printf("hello %s\n", buf3); */ - - -/* } */ diff --git a/src/steg/zpack.h b/src/steg/zpack.h index d0e5cb2..5d3f82f 100644 --- a/src/steg/zpack.h +++ b/src/steg/zpack.h @@ -1,11 +1,12 @@ #ifndef _ZPACK_H #define _ZPACK_H -int def(char *source, int slen, char *dest, int dlen, int level); -int inf(char *source, int slen, char *dest, int dlen); -void zerr(int ret); -int gzInflate(char *source, int slen, char *dest, int dlen); -int gzDeflate(char* start, off_t insz, char *buf, off_t outsz, time_t mtime); -unsigned int generate_crc32c(char *buffer, size_t length); +ssize_t def(const char *source, size_t slen, char *dest, size_t dlen, + int level); +ssize_t inf(const char *source, size_t slen, char *dest, size_t dlen); + +ssize_t gzInflate(const char *source, size_t slen, char *dest, size_t dlen); +ssize_t gzDeflate(const char *source, size_t slen, char *dest, size_t dlen, + time_t mtime); #endif

1 0

[stegotorus/master] Thorough spring-cleaning on pdfSteg.cc; less thorough on swfSteg.cc
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 177ba0f8b4265d09c321d6903eeab040faeca430 Author: Zack Weinberg <zackw(a)cmu.edu> Date: Mon Apr 23 14:49:52 2012 -0700 Thorough spring-cleaning on pdfSteg.cc; less thorough on swfSteg.cc and some other headers. Add beginnings of unit tests for pdfSteg. --- Makefile.am | 1 + src/steg/pdfSteg.cc | 389 +++++++++++++----------------------------- src/steg/pdfSteg.h | 38 +++-- src/steg/swfSteg.cc | 18 +-- src/steg/swfSteg.h | 23 +--- src/steg/zpack.h | 11 +- src/test/tinytest_macros.h | 8 +- src/test/unittest_pdfsteg.cc | 82 +++++++++ src/util.cc | 3 - src/util.h | 3 + 10 files changed, 249 insertions(+), 327 deletions(-) diff --git a/Makefile.am b/Makefile.am index 6ba1b51..86ed489 100644 --- a/Makefile.am +++ b/Makefile.am @@ -49,6 +49,7 @@ stegotorus_SOURCES = \ UTGROUPS = \ src/test/unittest_crypt.cc \ + src/test/unittest_pdfsteg.cc \ src/test/unittest_socks.cc \ src/test/unittest_config.cc \ src/test/unittest_transfer.cc diff --git a/src/steg/pdfSteg.cc b/src/steg/pdfSteg.cc index c67b0f8..3b4bbf0 100644 --- a/src/steg/pdfSteg.cc +++ b/src/steg/pdfSteg.cc @@ -1,7 +1,13 @@ -#include "payloads.h" +#include "util.h" #include "pdfSteg.h" +#include "connections.h" +#include "payloads.h" +#include <event2/buffer.h> + +/* pdfSteg: A PDF-based steganography module */ -void buf_dump(unsigned char* buf, int len, FILE *out); +#define PDF_DELIMITER '?' +#define PDF_DELIMITER2 '.' #define STREAM_BEGIN ">>stream" #define STREAM_BEGIN_SIZE 8 @@ -10,45 +16,42 @@ void buf_dump(unsigned char* buf, int len, FILE *out); #define DEBUG - /* - * pdfSteg: A PDF-based steganography module - * - */ - - -/* - * addDelimiter processes the input buffer (inbuf) of length inbuflen, - * copies it to output buffer (outbuf) of size outbufsize, + * pdf_add_delimiter processes the input buffer (inbuf) of length + * inbuflen, copies it to output buffer (outbuf) of size outbufsize, * and adds a two-char-long, end-of-data pattern at the end of outbuf * based on delimiter1 and delimiter2. * * The end-of-data pattern consists of delimiter1 followed by a char * that is not delimiter1. Thus, delimiter1 and delimiter2 must be * different. - * - * If delimiter1 appears in the input buffer, addDelimiter puts two - * delimiter1 char in output buffer (to enable removeDelimiter to perform - * the back transformation) * - * addDelimiter returns the length of the data written to outbuf, including - * the end-of-data pattern, if the transformation succeeds; - * otherwise, it returns -1 + * If delimiter1 appears in the input buffer, pdf_add_delimiter puts two + * delimiter1 characters in the output buffer, so that the transformation + * is reversible. + * + * pdf_add_delimiter returns the length of the data written to outbuf, + * including the end-of-data pattern, if the transformation succeeds; + * otherwise, it returns -1. * */ -int -addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, - const char delimiter1, const char delimiter2) +ssize_t +pdf_add_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + const char delimiter1, const char delimiter2) { - int cnt; - char *ibp, ic, rc; + size_t cnt; + const char *ibp; + char ic, rc; - if (delimiter1 == delimiter2) return -1; + log_assert(delimiter1 != delimiter2); + if (inbuflen > SIZE_T_CEILING || outbuflen > SIZE_T_CEILING) + return -1; cnt = 0; ibp = inbuf; - while ((ibp-inbuf)<inbuflen && cnt<(outbuflen-2)) { - ic = *(ibp++); + while (size_t(ibp-inbuf) < inbuflen && cnt < outbuflen-2) { + ic = *ibp++; if (ic != delimiter1) { outbuf[cnt++] = ic; } else { @@ -57,8 +60,9 @@ addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, } } - // error if outbuf is no large enough for storing the resulting data - if (cnt >= (outbuflen-2)) return -1; + // error if outbuf is not large enough for storing the resulting data + if (cnt >= outbuflen-2) + return -1; // put delimiter1 and a char that is not a delimiter1 // as the end-of-data pattern at the end of outbuf @@ -75,8 +79,9 @@ addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, /* - * removeDelimiter performs the reverse transformation of addDelimiter. - * + * pdf_remove_delimiter performs the reverse transformation of + * pdf_add_delimiter. + * * returns the length of data written to outbuf, if succeed; * otherwise, it returns -1 * @@ -84,20 +89,23 @@ addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, * delimiter1 followed by non-delimiter1) is detected * * escape indicates if a dangling delimiter1 has been - * seen in the previous invocation of removeDelimiter + * seen in the previous invocation of pdf_remove_delimiter */ -int -removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, - const char delimiter1, int *endFlag, int *escape) +ssize_t +pdf_remove_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + char delimiter1, bool *endFlag, bool *escape) { - int cnt; - char *ibp, ic1, ic2; + size_t cnt; + const char *ibp; + char ic1, ic2; cnt = 0; - *endFlag = 0; + *endFlag = false; ibp = inbuf; - if (inbuflen <= 0) return -1; + if (inbuflen > SIZE_T_CEILING || outbuflen > SIZE_T_CEILING) + return -1; // special case: 2-char, end-of-data pattern could be in two buffers // if *escape == true, we need to see if @@ -113,9 +121,9 @@ removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, } } - *escape = 0; - while ((ibp-inbuf+1)<inbuflen && cnt<outbuflen) { - ic1 = *(ibp++); + *escape = false; + while (size_t(ibp-inbuf+1) < inbuflen && cnt < outbuflen) { + ic1 = *ibp++; if (ic1 != delimiter1) { outbuf[cnt++] = ic1; } else { @@ -125,13 +133,14 @@ removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, if (ic2 == delimiter1) { outbuf[cnt++] = delimiter1; ibp++; } else { // end-of-data pattern detected - *endFlag = 1; + *endFlag = true; return cnt; } } } - if (ibp-inbuf == inbuflen) return cnt; + if (size_t(ibp-inbuf) == inbuflen) + return cnt; // handling the last char in inbuf, if needed ic1 = *ibp; @@ -139,40 +148,46 @@ removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, outbuf[cnt++] = ic1; } else { // look at the next stream obj to handle the special cases - *escape = 1; + *escape = true; } return cnt; } - - /* - * pdfWrap embeds data of length dlen inside the stream objects of the PDF + * pdf_wrap embeds data of length dlen inside the stream objects of the PDF * document (length plen) that appears in the body of a HTTP msg, and * stores the result in the output buffer of size outsize * - * pdfWrap returns the length of the pdf document with the data embedded + * pdf_wrap returns the length of the pdf document with the data embedded * inside, if succeed; otherwise, it returns -1 to indicate an error - * - */ -int -pdfWrap (char *data, unsigned int dlen, - char *pdfTemplate, unsigned int plen, - char *outbuf, unsigned int outbufsize) + * + */ +ssize_t +pdf_wrap(const char *data, size_t dlen, + const char *pdfTemplate, size_t plen, + char *outbuf, size_t outbufsize) { char data2[dlen*2+2]; - char *tp, *dp, *op, *streamStart, *streamEnd, *plimit; - int data2len, cnt, size, size2; + const char *tp, *dp, *plimit; + char *op, *streamStart, *streamEnd; + size_t data2len, cnt, size, size2; + ssize_t rv; - // assumption: pdfWrap is length-preserving - if (outbufsize < plen) return -1; + if (dlen > SIZE_T_CEILING || plen > SIZE_T_CEILING || + outbufsize > SIZE_T_CEILING) + return -1; - data2len = addDelimiter(data, dlen, data2, HTTP_MSG_BUF_SIZE, PDF_DELIMITER, PDF_DELIMITER2); - if (data2len < 1) return -1; + // assumption: pdf_wrap is length-preserving + if (outbufsize < plen) return -1; + rv = pdf_add_delimiter(data, dlen, data2, HTTP_MSG_BUF_SIZE, + PDF_DELIMITER, PDF_DELIMITER2); + if (rv < 1) + return -1; + data2len = rv; - op = outbuf; // current pointer for output buffer + op = outbuf; // current pointer for output buffer tp = pdfTemplate; // current pointer for http msg template dp = data2; // current pointer for data2 cnt = 0; // number of data char encoded @@ -185,7 +200,7 @@ pdfWrap (char *data, unsigned int dlen, log_warn("Cannot find stream in pdf"); return -1; } - + // copy everything between tp and "stream" (inclusive) to outbuf size = streamStart - tp + STREAM_BEGIN_SIZE; memcpy(op, tp, size); @@ -206,18 +221,17 @@ pdfWrap (char *data, unsigned int dlen, size2 = data2len - cnt; if (size < size2) { memcpy(op, dp, size); - op += size; tp += size; dp += size; + op += size; tp += size; dp += size; memcpy(op, tp, STREAM_END_SIZE); op += STREAM_END_SIZE; tp += STREAM_END_SIZE; cnt += size; } else { // done encoding data memcpy(op, dp, size2); - op += size2; tp += size2; dp += size2; + op += size2; tp += size2; dp += size2; cnt += size2; - // printf("Encoded %d char in pdf. Done encoding\n", size2); break; } - log_debug("Encoded %d char in pdf", size); + log_debug("Encoded %lu bytes in pdf", (unsigned long)size); } else { // empty stream memcpy(op, tp, STREAM_END_SIZE); op += STREAM_END_SIZE; tp += STREAM_END_SIZE; @@ -228,25 +242,27 @@ pdfWrap (char *data, unsigned int dlen, // copy the rest of pdfTemplate to outbuf size = plimit-tp; - log_debug("copying the rest of pdfTemplate to outbuf (size %d)", size); + log_debug("copying the rest of pdfTemplate to outbuf (size %lu)", + (unsigned long)size); memcpy(op, tp, size); op += size; return (op-outbuf); } - - - /* - * pdfUnwrap is the inverse operation of pdfWrap + * pdf_unwrap is the inverse operation of pdf_wrap */ -int -pdfUnwrap (char *data, unsigned int dlen, - char *outbuf, unsigned int outbufsize) +ssize_t +pdf_unwrap(const char *data, size_t dlen, + char *outbuf, size_t outbufsize) { - char *dp, *op, *streamStart, *streamEnd, *dlimit, *olimit; - int cnt, size, size2, endFlag; - int escape = 0; + const char *dp, *dlimit; + char *op, *streamStart, *streamEnd, *olimit; + size_t cnt, size, size2; + bool endFlag, escape = false; + + if (dlen > SIZE_T_CEILING || outbufsize > SIZE_T_CEILING) + return -1; dp = data; // current pointer for data op = outbuf; // current pointer for outbuf @@ -272,11 +288,13 @@ pdfUnwrap (char *data, unsigned int dlen, // count the number of usable char between tp and streamEnd size = streamEnd-dp; - if (size > 0) { - size2 = removeDelimiter(dp, size, op, olimit-op, PDF_DELIMITER, &endFlag, &escape); - if (size2 < 0) { + if (size > 0) { + ssize_t rv = pdf_remove_delimiter(dp, size, op, olimit-op, PDF_DELIMITER, + &endFlag, &escape); + if (rv < 0) return -1; - } + + size2 = rv; cnt += size2; if (endFlag) { // Done decoding break; @@ -292,22 +310,16 @@ pdfUnwrap (char *data, unsigned int dlen, return cnt; } - - - - int -http_server_PDF_transmit (payloads& pl, struct evbuffer *source, - conn_t *conn) +http_server_PDF_transmit(payloads &pl, struct evbuffer *source, + conn_t *conn) { - struct evbuffer *dest = conn->outbound(); size_t sbuflen = evbuffer_get_length(source); unsigned int mpdf; char *pdfTemplate = NULL, *hend; int pdfTemplateSize = 0; - // char data1[HTTP_MSG_BUF_SIZE]; - char data1[(int) sbuflen]; + char data1[sbuflen]; char outbuf[HTTP_MSG_BUF_SIZE]; int cnt, hLen, outbuflen, i; @@ -317,10 +329,6 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, struct evbuffer_iovec *iv; int nv; - // for debugging pdfWrap and pdfUnwrap - // char data2[(int) sbuflen]; - // int data2len; - log_debug("Entering SERVER PDF transmit with sbuflen %d", (int)sbuflen); nv = evbuffer_peek(source, sbuflen, NULL, NULL, 0); @@ -357,8 +365,10 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, return -1; } - if (get_payload(pl, HTTP_CONTENT_PDF, sbuflen, &pdfTemplate, &pdfTemplateSize) == 1) { - log_debug("SERVER found the next HTTP response template with size %d", pdfTemplateSize); + if (get_payload(pl, HTTP_CONTENT_PDF, sbuflen, &pdfTemplate, + &pdfTemplateSize) == 1) { + log_debug("SERVER found the next HTTP response template with size %d", + pdfTemplateSize); } else { log_warn("SERVER couldn't find the next HTTP response template"); return -1; @@ -371,39 +381,19 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, } hLen = hend+4-pdfTemplate; - - log_debug("SERVER calling pdfWrap for data1 with length %d", cnt); - outbuflen = pdfWrap(data1, cnt, hend+4, pdfTemplateSize-hLen, outbuf, HTTP_MSG_BUF_SIZE); + + log_debug("SERVER calling pdf_wrap for data1 with length %d", cnt); + outbuflen = pdf_wrap(data1, cnt, hend+4, pdfTemplateSize-hLen, outbuf, + HTTP_MSG_BUF_SIZE); if (outbuflen < 0) { - log_warn("SERVER pdfWrap fails"); + log_warn("SERVER pdf_wrap fails"); return -1; } - log_debug("SERVER pdfSteg sends resp with hdr len %d body len %d", hLen, outbuflen); - - - // debugging - // buf_dump((unsigned char *)data1, cnt, stderr); - - // data2len = pdfUnwrap(outbuf, outbuflen, data2, sbuflen); - // if ((int)sbuflen == data2len) { - // log_warn("sbuflen == data2len == %d", (int)sbuflen); - // if (memcmp(data1, data2, sbuflen) == 0) { - // log_warn("data1 and data2 match"); - // } else { - // log_warn("data1 and data2 DO NOT match!! Dumping data1 ..."); - // buf_dump((unsigned char *)data1, cnt, stderr); - // log_warn("data1 and data2 DO NOT match!! Dumping data2..."); - // buf_dump((unsigned char *)data2, data2len, stderr); - // } - // } else { - // log_warn("*** sbuflen = %d, data2len = %d *** Dumping data1 ...", (int)sbuflen, data2len); - // buf_dump((unsigned char *)data1, cnt, stderr); - // log_warn("*** sbuflen = %d, data2len = %d *** Dumping data2 ...", (int)sbuflen, data2len); - // buf_dump((unsigned char *)data2, data2len, stderr); - // } - - - newHdrLen = gen_response_header((char*) "application/pdf", 0, outbuflen, newHdr, sizeof(newHdr)); + log_debug("SERVER pdfSteg sends resp with hdr len %d body len %d", + hLen, outbuflen); + + newHdrLen = gen_response_header((char*) "application/pdf", 0, + outbuflen, newHdr, sizeof(newHdr)); if (newHdrLen < 0) { log_warn("SERVER ERROR: gen_response_header fails for pdfSteg"); return -1; @@ -413,10 +403,6 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, log_warn("SERVER ERROR: evbuffer_add() fails for newHdr"); return -1; } - // if (evbuffer_add(dest, pdfTemplate, hLen)) { - // log_warn("SERVER ERROR: evbuffer_add() fails for pdfTemplate"); - // return -1; - // } if (evbuffer_add(dest, outbuf, outbuflen)) { log_warn("SERVER ERROR: evbuffer_add() fails for outbuf"); @@ -426,14 +412,13 @@ http_server_PDF_transmit (payloads& pl, struct evbuffer *source, evbuffer_drain(source, sbuflen); conn->cease_transmission(); - // downcast_steg(s)->have_transmitted = 1; return 0; } - - int -http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, struct evbuffer* source) { +http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, + struct evbuffer* source) +{ struct evbuffer_ptr s2; unsigned int response_len = 0, hdrLen; char outbuf[HTTP_MSG_BUF_SIZE]; @@ -444,8 +429,8 @@ http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, st s2 = evbuffer_search(source, "\r\n\r\n", sizeof ("\r\n\r\n") -1 , NULL); if (s2.pos == -1) { - log_warn("CLIENT Did not find end of HTTP header %d", (int) evbuffer_get_length(source)); - // evbuffer_dump(source, stderr); + log_warn("CLIENT Did not find end of HTTP header %d", + (int) evbuffer_get_length(source)); return RECV_INCOMPLETE; } @@ -480,154 +465,26 @@ http_handle_client_PDF_receive(steg_t *, conn_t *conn, struct evbuffer *dest, st return RECV_BAD; } - httpBody = httpHdr + hdrLen; - - outbuflen = pdfUnwrap(httpBody, content_len, outbuf, HTTP_MSG_BUF_SIZE); + outbuflen = pdf_unwrap(httpBody, content_len, outbuf, HTTP_MSG_BUF_SIZE); if (outbuflen < 0) { - log_warn("CLIENT ERROR: pdfUnwrap fails\n"); + log_warn("CLIENT ERROR: pdf_unwrap fails\n"); return RECV_BAD; } log_debug("CLIENT unwrapped data of length %d:", outbuflen); - if (evbuffer_add(dest, outbuf, outbuflen)) { log_warn("CLIENT ERROR: evbuffer_add to dest fails\n"); return RECV_BAD; } - // log_debug("Drained source for %d char\n", response_len); if (evbuffer_drain(source, response_len) == -1) { log_warn("CLIENT ERROR: failed to drain source\n"); return RECV_BAD; } - // downcast_steg(s)->have_received = 1; conn->expect_close(); return RECV_GOOD; } - - - - -/***** -int main() { - char data1[] = "this is a test?? yes!"; - char data2[100]; - char data3[100]; - int dlen1, dlen2, dlen3, end; - char last = ' '; - printf("hello world\n"); - - dlen2 = addDelimiter(data1, strlen(data1), data2, 100, '?', '.'); - printf("dlen2 = %d\n", dlen2); - dlen3 = removeDelimiter(data2, dlen2, data3, 100, '?', &end, &last); - printf("endflag = %d", end); - printf("dlen3 = %d\n", dlen3); - if (memcmp(data1, data3, dlen3) == 0) { - data1[dlen3] = 0; - printf("removeDelimiter(addDelimiter(x)) == x for |%s|\n", data1); - } else { - printf("removeDelimiter(addDelimiter(x)) != x for |%s|\n", data1); - } - return 1; -} - *****/ - -/***** -int main() { - char data1[] = "12345"; - char data2[] = "123456789012"; - char data3[] = "12345678901"; - char data4[] = "1234567890?"; - char pdf1[] = "[PDFHDR][STUFFS1]>>streamABCDEFGHIJYYendstream[STUFFS2]>>streamABCDEFGHIJYYendstream[STUFF3][PDFTRAILER]"; - char out[200]; - char orig[200]; - int r1, r2; - - printf("********************\n"); - printf("pdfwrap for %s\n", data1); - printf("strlen(pdf1) = %d\n", (int)strlen(pdf1)); - r1 = pdfWrap(data1, strlen(data1), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - printf("********************\n"); - printf("pdfwrap for %s\n", data2); - r1 = pdfWrap(data2, strlen(data2), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - printf("********************\n"); - printf("pdfwrap for %s\n", data3); - r1 = pdfWrap(data3, strlen(data3), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - printf("********************\n"); - printf("pdfwrap for %s\n", data4); - r1 = pdfWrap(data4, strlen(data4), pdf1, strlen(pdf1), out, (int)sizeof(out)); - if (r1 > 0) { - printf("pdfWrap returns %d\n", r1); - out[r1] = 0; - printf("out[] contains |%s|\n", out); - } else { - printf("pdfWrap returns %d\n", r1); - } - - r2 = pdfUnwrap(out, r1, orig, (int)sizeof(orig)); - if (r2 > 0) { - printf("pdfUnwrap returns %d\n", r2); - orig[r2] = 0; - printf("orig[] contains |%s|\n", orig); - } else { - printf("pdfUnwrap returns %d\n", r2); - } - - return 0; -} - *****/ diff --git a/src/steg/pdfSteg.h b/src/steg/pdfSteg.h index 3d494e1..0bd3a43 100644 --- a/src/steg/pdfSteg.h +++ b/src/steg/pdfSteg.h @@ -1,29 +1,31 @@ #ifndef _PDFSTEG_H #define _PDFSTEG_H +struct payloads; -#include <stdio.h> -#include <string.h> -#include <ctype.h> -#include "util.h" -#include "connections.h" -#include "steg.h" -#include <event2/buffer.h> +// These are the public interface. -struct payloads; +int http_server_PDF_transmit(payloads &pl, struct evbuffer *source, + conn_t *conn); +int http_handle_client_PDF_receive(steg_t *s, conn_t *conn, + struct evbuffer *dest, + struct evbuffer* source); -#define PDF_DELIMITER '?' -#define PDF_DELIMITER2 '.' +// These are exposed only for the sake of unit tests. -int pdfWrap (char *data, unsigned int dlen, char *pdfTemplate, unsigned int plen, char *outbuf, unsigned int outbufsize); -int pdfUnwrap (char *data, unsigned int dlen, char *outbuf, unsigned int outbufsize); +ssize_t pdf_add_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + char delimiter1, char delimiter2); -int addDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, const char delimiter1, const char delimiter2); -int removeDelimiter(char *inbuf, int inbuflen, char *outbuf, int outbuflen, const char delimiter1, int* endFlag, int* escape); +ssize_t pdf_remove_delimiter(const char *inbuf, size_t inbuflen, + char *outbuf, size_t outbuflen, + char delimiter1, bool *endFlag, bool *escape); -int http_server_PDF_transmit (payloads& pl, struct evbuffer *source, conn_t *conn); -int -http_handle_client_PDF_receive(steg_t *s, conn_t *conn, struct evbuffer *dest, struct evbuffer* source); +ssize_t pdf_wrap(const char *data, size_t dlen, + const char *pdfTemplate, size_t plen, + char *outbuf, size_t outbufsize); -#endif +ssize_t pdf_unwrap(const char *data, size_t dlen, + char *outbuf, size_t outbufsize); +#endif diff --git a/src/steg/swfSteg.cc b/src/steg/swfSteg.cc index cd371f3..c8a18c1 100644 --- a/src/steg/swfSteg.cc +++ b/src/steg/swfSteg.cc @@ -1,5 +1,11 @@ +#include "util.h" #include "swfSteg.h" +#include "connections.h" +#include "payloads.h" +#include "zlib.h" +#include "zpack.h" +#include <event2/buffer.h> static const char http_response_1[] = "HTTP/1.1 200 OK\r\n" @@ -9,17 +15,7 @@ static const char http_response_1[] = "Content-Type: application/x-shockwave-flash\r\n" "Content-Length: "; - - - - - - - - - - -unsigned int +unsigned int swf_wrap(payloads& pl, char* inbuf, int in_len, char* outbuf, int out_sz) { char* swf; diff --git a/src/steg/swfSteg.h b/src/steg/swfSteg.h index 712a3a3..b8336b2 100644 --- a/src/steg/swfSteg.h +++ b/src/steg/swfSteg.h @@ -1,38 +1,21 @@ #ifndef _SWFSTEG_H #define _SWFSTEG_H - -#include "util.h" -#include "connections.h" -#include "steg.h" -#include "payloads.h" -#include "cookies.h" -#include "pdfSteg.h" -#include "zpack.h" - - -#include <event2/buffer.h> -#include <stdio.h> - struct payloads; #define SWF_SAVE_HEADER_LEN 1500 #define SWF_SAVE_FOOTER_LEN 1500 - -unsigned int +unsigned int swf_wrap(payloads& pl, char* inbuf, int in_len, char* outbuf, int out_sz); -unsigned int +unsigned int swf_unwrap(char* inbuf, int in_len, char* outbuf, int out_sz); -int +int http_server_SWF_transmit(payloads& pl, struct evbuffer *source, conn_t *conn); - int http_handle_client_SWF_receive(steg_t *s, conn_t *conn, struct evbuffer *dest, struct evbuffer* source); #endif - - diff --git a/src/steg/zpack.h b/src/steg/zpack.h index 65cd28d..d0e5cb2 100644 --- a/src/steg/zpack.h +++ b/src/steg/zpack.h @@ -1,10 +1,5 @@ -#include <stdio.h> -#include <string.h> -#include <assert.h> -#include <time.h> -#include <stdlib.h> -#include "zlib.h" - +#ifndef _ZPACK_H +#define _ZPACK_H int def(char *source, int slen, char *dest, int dlen, int level); int inf(char *source, int slen, char *dest, int dlen); @@ -12,3 +7,5 @@ void zerr(int ret); int gzInflate(char *source, int slen, char *dest, int dlen); int gzDeflate(char* start, off_t insz, char *buf, off_t outsz, time_t mtime); unsigned int generate_crc32c(char *buffer, size_t length); + +#endif diff --git a/src/test/tinytest_macros.h b/src/test/tinytest_macros.h index 40d17e2..cf5a2a2 100644 --- a/src/test/tinytest_macros.h +++ b/src/test/tinytest_macros.h @@ -168,6 +168,10 @@ tt_assert_test_type(a,b,#a" "#op" "#b,void*, \ (_val1 op _val2),"%p") +#define tt_char_op(a,op,b) \ + tt_assert_test_type(a,b,#a" "#op" "#b,int, \ + (_val1 op _val2),"'%c'") + #define tt_str_op(a,op,b) \ tt_assert_test_type(a,b,#a" "#op" "#b,const char *, \ (strcmp(_val1,_val2) op 0),"<%s>") @@ -176,7 +180,7 @@ tt_assert_test_fmt_type(a,b,#a" "#op" "#b, \ const char *, \ (strncmp(_val1, _val2, len) op 0), \ - char *, "%s", \ + char *, "<%s>", \ { _print = xstrndup(_value, len); }, \ { free(_print); } \ ); @@ -185,7 +189,7 @@ tt_assert_test_fmt_type(a,b,#a" "#op" "#b, \ const char *, \ (memcmp(_val1, _val2, len) op 0), \ - char *, "%s", \ + char *, "<%s>", \ { _print = tt_base16_encode(_value, len); }, \ { free(_print); } \ ); diff --git a/src/test/unittest_pdfsteg.cc b/src/test/unittest_pdfsteg.cc new file mode 100644 index 0000000..cf9e97d --- /dev/null +++ b/src/test/unittest_pdfsteg.cc @@ -0,0 +1,82 @@ +/* Copyright 2011, 2012 SRI International + See LICENSE for other credits and copying information */ + +#include "util.h" +#include "unittest.h" +#include "../steg/pdfSteg.h" + +static void +test_pdf_add_remove_delimiters(void *) +{ + const char *data1 = "this is a test?? yes!"; + char data2[100]; + char data3[100]; + int dlen2, dlen3; + bool end = false, escape = false; + + memset(data2, 0, sizeof data2); + memset(data3, 0, sizeof data3); + + dlen2 = pdf_add_delimiter(data1, strlen(data1), data2, 100, '?', '.'); + tt_int_op(dlen2, ==, 25); + tt_stn_op(data2, ==, "this is a test???? yes!?", 24); + tt_char_op(data2[24], !=, '?'); + + dlen3 = pdf_remove_delimiter(data2, dlen2, data3, 100, '?', &end, &escape); + tt_int_op(dlen3, ==, 21); + tt_str_op(data3, ==, data1); + tt_bool_op(end, ==, true); + tt_bool_op(escape, ==, false); + + end:; +} + +static void +test_pdf_wrap_unwrap(void *) +{ + const char *pdf = + "[PDFHDR][STUFFS1]>>streamABCDEFGHIJYYendstream" + "[STUFFS2]>>streamABCDEFGHIJYYendstream[STUFF3][PDFTRAILER]"; + + const char *const tests[] = { + "12345", + "123456789012", + "12345678901", + "1234567890?", + 0 + }; + + char out[200]; + char orig[200]; + int i; + size_t r1, r2; + ssize_t rv; + + for (i = 0; tests[i]; i++) { + memset(out, 0, sizeof out); + memset(orig, 0, sizeof out); + rv = pdf_wrap(tests[i], strlen(tests[i]), + pdf, strlen(pdf), + out, sizeof out); + tt_int_op(rv, >, 0); + r1 = rv; + tt_int_op(r1, ==, strlen(pdf)); + + rv = pdf_unwrap(out, r1, orig, sizeof orig); + tt_int_op(rv, >, 0); + r2 = rv; + tt_int_op(r2, ==, strlen(tests[i])); + tt_stn_op(orig, ==, tests[i], r2); + } + + end:; +} + +#define T(name) \ + { #name, test_pdf_##name, 0, 0, 0 } + +struct testcase_t pdf_tests[] = { + T(add_remove_delimiters), + T(wrap_unwrap), + END_OF_TESTCASES +}; diff --git a/src/util.cc b/src/util.cc index b813ae9..a667abd 100644 --- a/src/util.cc +++ b/src/util.cc @@ -17,9 +17,6 @@ #include <sys/un.h> #endif -/** Any size_t larger than this amount is likely to be an underflow. */ -#define SIZE_T_CEILING (SIZE_MAX/2 - 16) - /**************************** Memory Allocation ******************************/ static void ATTR_NORETURN diff --git a/src/util.h b/src/util.h index 05bc6d0..167af8e 100644 --- a/src/util.h +++ b/src/util.h @@ -57,6 +57,9 @@ struct event_base; /***** Memory allocation. *****/ +/** Any size_t larger than this amount is likely to be an underflow. */ +#define SIZE_T_CEILING (SIZE_MAX/2 - 16) + /* Because this isn't Tor and functions named "tor_whatever" would be confusing, I am instead following the GNU convention of naming allocate-memory-or-crash functions "xwhatever". Also, at this time

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[stegotorus/master] Merge branch 'master' of https://git.safdef.isc.org/git/stegotorus
by zwol＠torproject.org 20 Jul '12

20 Jul '12

commit 560b952671f90505ca7193371410c370c9769f62 Merge: 343d961 0538c5a Author: Zack Weinberg <zackw(a)cmu.edu> Date: Mon Apr 23 15:41:50 2012 -0700 Merge branch 'master' of https://git.safdef.isc.org/git/stegotorus Conflicts: src/steg/zpack.h

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