Now, if a router ever changes its microdescriptor, but the new
microdescriptor SHA256 hash has the same 160-bit prefix as the old
one, we treat it as a new microdescriptor when deciding whether to
copy status information.
(This function also is used to compare SHA1 digests of router
descriptors, but don't worry: the descriptor_digest field either holds
a SHA256 hash, or a SHA1 hash padded with 0 bytes.)
Silence clang warnings under --enable-expensive-hardening, including:
+ implicit truncation of 64 bit values to 32 bit;
+ const char assignment to self;
+ tautological compare; and
+ additional parentheses around equality tests. (gcc uses these to
silence assignment, so clang warns when they're present in an
equality test. But we need to use extra parentheses in macros to
isolate them from other code).
By now, support in the network is widespread and it's time to require
more modern crypto on all Tor instances, whether they're clients or
servers. By doing this early in 0.2.6, we can be sure that at some point
all clients will have reasonable support.
Ensure we securely wipe keys from memory after
crypto_digest_get_digest and init_curve25519_keypair_from_file
have finished using them.
Fixes bug 13477.
Add unit tests for tor_timegm signed overflow,
tor_timegm and parse_rfc1123_time validity checks,
and correct_tm year clamping.
Unit tests (visible) fixes in bug 13476.
Check all date/time values passed to tor_timegm
and parse_rfc1123_time for validity, taking leap
years into account.
Improves HTTP header validation.
Avoid unlikely signed integer overflow in tor_timegm
on systems with 32-bit time_t.
Fixes bug 13476.
1. The test that adds things to the cache needs to set the clock back so
that the descriptors it adds are valid.
2. We split ROUTER_NOT_NEW into ROUTER_TOO_OLD, so that we can
distinguish "already had it" from "rejected because of old published
date".
3. We make extrainfo_insert() return a was_router_added_t, and we
make its caller use it correctly. This is probably redundant with
the extrainfo_is_bogus flag.
We didn't really have test coverage for these parsing functions, so
I went and made some. These tests also verify that the parsing
functions set the list of invalid digests correctly.
One pain point in evolving the Tor design and implementing has been
adding code that makes clients reject directory documents that they
previously would have accepted, if those descriptors actually exist.
When this happened, the clients would get the document, reject it,
and then decide to try downloading it again, ad infinitum. This
problem becomes particularly obnoxious with authorities, since if
some authorities accept a descriptor that others don't, the ones
that don't accept it would go crazy trying to re-fetch it over and
over. (See for example ticket #9286.)
This patch tries to solve this problem by tracking, if a descriptor
isn't parseable, what its digest was, and whether it is invalid
because of some flaw that applies to the portion containing the
digest. (This excludes RSA signature problems: RSA signatures
aren't included in the digest. This means that a directory
authority can still put another directory authority into a loop by
mentioning a descriptor, and then serving that descriptor with an
invalid RSA signatures. But that would also make the misbehaving
directory authority get DoSed by the server it's attacking, so it's
not much of an issue.)
We already have a mechanism to mark something undownloadable with
downloadstatus_mark_impossible(); we use that here for
microdescriptors, extrainfos, and router descriptors.
Unit tests to follow in another patch.
Closes ticket #11243.
