commit 884c0ffe3b4266e66adbd6bb914c3b3b00401acb
parent 3830599a63e09008f7b17c1b37db277bf38d526f
Author: Nick Mathewson <nickm@torproject.org>
Date: Tue, 20 Jun 2017 20:29:00 -0400
Merge branch 'maint-0.3.1'
Diffstat:
5 files changed, 121 insertions(+), 20 deletions(-)
diff --git a/changes/bug22669 b/changes/bug22669
@@ -0,0 +1,4 @@
+ o Minor bugfixes (compression):
+ - When serving directory votes compressed with zlib,
+ do not claim to have compressed them with zstd. Fixes bug 22669;
+ bugfix on 0.3.1.1-alpha.
diff --git a/changes/bug22672 b/changes/bug22672
@@ -0,0 +1,5 @@
+ o Minor features (compression, defensive programming):
+ - Detect and break out of infinite loops in our compression code.
+ We don't think that any such loops exist now, but it's best to be
+ safe. Closes ticket 22672.
+
diff --git a/src/common/compress.c b/src/common/compress.c
@@ -150,13 +150,7 @@ tor_compress_impl(int compress,
method, compression_level, (unsigned long)in_len);
goto err;
} else {
- if (in_len != 0) {
- log_fn(protocol_warn_level, LD_PROTOCOL,
- "Unexpected extra input while decompressing");
- log_debug(LD_GENERAL, "method: %d level: %d at len: %lu",
- method, compression_level, (unsigned long)in_len);
- goto err;
- } else {
+ if (in_len == 0) {
goto done;
}
}
@@ -548,28 +542,42 @@ tor_compress_process(tor_compress_state_t *state,
int finish)
{
tor_assert(state != NULL);
+ const size_t in_len_orig = *in_len;
+ const size_t out_len_orig = *out_len;
+ tor_compress_output_t rv;
switch (state->method) {
case GZIP_METHOD:
case ZLIB_METHOD:
- return tor_zlib_compress_process(state->u.zlib_state,
- out, out_len, in, in_len,
- finish);
+ rv = tor_zlib_compress_process(state->u.zlib_state,
+ out, out_len, in, in_len,
+ finish);
+ break;
case LZMA_METHOD:
- return tor_lzma_compress_process(state->u.lzma_state,
- out, out_len, in, in_len,
- finish);
+ rv =tor_lzma_compress_process(state->u.lzma_state,
+ out, out_len, in, in_len,
+ finish);
+ break;
case ZSTD_METHOD:
- return tor_zstd_compress_process(state->u.zstd_state,
- out, out_len, in, in_len,
- finish);
+ rv = tor_zstd_compress_process(state->u.zstd_state,
+ out, out_len, in, in_len,
+ finish);
+ break;
case NO_METHOD:
- return tor_cnone_compress_process(out, out_len, in, in_len,
- finish);
+ rv = tor_cnone_compress_process(out, out_len, in, in_len,
+ finish);
+ break;
+ default:
case UNKNOWN_METHOD:
goto err;
}
+ if (BUG((rv == TOR_COMPRESS_OK) &&
+ *in_len == in_len_orig &&
+ *out_len == out_len_orig)) {
+ return TOR_COMPRESS_ERROR;
+ }
+ return rv;
err:
return TOR_COMPRESS_ERROR;
}
diff --git a/src/or/directory.c b/src/or/directory.c
@@ -4190,13 +4190,14 @@ static int
handle_get_status_vote(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
- const compress_method_t compress_method =
- find_best_compression_method(args->compression_supported, 1);
{
int current;
ssize_t body_len = 0;
ssize_t estimated_len = 0;
+ /* This smartlist holds strings that we can compress on the fly. */
smartlist_t *items = smartlist_new();
+ /* This smartlist holds cached_dir_t objects that have a precompressed
+ * deflated version. */
smartlist_t *dir_items = smartlist_new();
int lifetime = 60; /* XXXX?? should actually use vote intervals. */
url += strlen("/tor/status-vote/");
@@ -4247,6 +4248,26 @@ handle_get_status_vote(dir_connection_t *conn, const get_handler_args_t *args)
write_http_status_line(conn, 404, "Not found");
goto vote_done;
}
+
+ /* We're sending items from at most one kind of source */
+ tor_assert_nonfatal(smartlist_len(items) == 0 ||
+ smartlist_len(dir_items) == 0);
+
+ int streaming;
+ unsigned mask;
+ if (smartlist_len(items)) {
+ /* We're taking strings and compressing them on the fly. */
+ streaming = 1;
+ mask = ~0u;
+ } else {
+ /* We're taking cached_dir_t objects. We only have them uncompressed
+ * or deflated. */
+ streaming = 0;
+ mask = (1u<<NO_METHOD) | (1u<<ZLIB_METHOD);
+ }
+ const compress_method_t compress_method = find_best_compression_method(
+ args->compression_supported&mask, streaming);
+
SMARTLIST_FOREACH(dir_items, cached_dir_t *, d,
body_len += compress_method != NO_METHOD ?
d->dir_compressed_len : d->dir_len);
diff --git a/src/test/test_util.c b/src/test/test_util.c
@@ -2399,6 +2399,59 @@ test_util_compress(void *arg)
}
static void
+test_util_decompress_concatenated_impl(compress_method_t method)
+{
+ char input[4096];
+ char *c1 = NULL, *c2 = NULL, *c3 = NULL;
+ char *result = NULL;
+ size_t sz1, sz2, sz3, szr;
+ int r;
+
+ crypto_rand(input, sizeof(input));
+
+ /* Compress the input in two chunks. */
+ r = tor_compress(&c1, &sz1, input, 2048, method);
+ tt_int_op(r, OP_EQ, 0);
+ r = tor_compress(&c2, &sz2, input+2048, 2048, method);
+ tt_int_op(r, OP_EQ, 0);
+
+ /* concatenate the chunks. */
+ sz3 = sz1 + sz2;
+ c3 = tor_malloc(sz3);
+ memcpy(c3, c1, sz1);
+ memcpy(c3+sz1, c2, sz2);
+
+ /* decompress the concatenated result */
+ r = tor_uncompress(&result, &szr, c3, sz3, method, 0, LOG_WARN);
+ tt_int_op(r, OP_EQ, 0);
+ tt_int_op(szr, OP_EQ, sizeof(input));
+ tt_mem_op(result, OP_EQ, input, sizeof(input));
+
+ done:
+ tor_free(c1);
+ tor_free(c2);
+ tor_free(c3);
+ tor_free(result);
+}
+
+static void
+test_util_decompress_concatenated(void *arg)
+{
+ const char *methodname = arg;
+ tt_assert(methodname);
+
+ compress_method_t method = compression_method_get_by_name(methodname);
+ tt_int_op(method, OP_NE, UNKNOWN_METHOD);
+ if (! tor_compress_supports_method(method)) {
+ tt_skip();
+ }
+
+ test_util_decompress_concatenated_impl(method);
+ done:
+ ;
+}
+
+static void
test_util_gzip_compression_bomb(void *arg)
{
/* A 'compression bomb' is a very small object that uncompresses to a huge
@@ -5819,6 +5872,11 @@ test_util_get_unquoted_path(void *arg)
{ "compress/" #name, test_util_compress, 0, &passthrough_setup, \
(char*)(identifier) }
+#define COMPRESS_CONCAT(name, identifier) \
+ { "compress_concat/" #name, test_util_decompress_concatenated, 0, \
+ &passthrough_setup, \
+ (char*)(identifier) }
+
#ifdef _WIN32
#define UTIL_TEST_NO_WIN(n, f) { #n, NULL, TT_SKIP, NULL, NULL }
#define UTIL_TEST_WIN_ONLY(n, f) UTIL_TEST(n, (f))
@@ -5848,6 +5906,11 @@ struct testcase_t util_tests[] = {
COMPRESS(lzma, "x-tor-lzma"),
COMPRESS(zstd, "x-zstd"),
COMPRESS(none, "identity"),
+ COMPRESS_CONCAT(zlib, "deflate"),
+ COMPRESS_CONCAT(gzip, "gzip"),
+ COMPRESS_CONCAT(lzma, "x-tor-lzma"),
+ COMPRESS_CONCAT(zstd, "x-zstd"),
+ COMPRESS_CONCAT(none, "identity"),
UTIL_TEST(gzip_compression_bomb, TT_FORK),
UTIL_LEGACY(datadir),
UTIL_LEGACY(memarea),
