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.
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.
Fix an instance of integer overflow in format_time_interval() when
taking the absolute value of the supplied signed interval value.
Fixes bug 13393.
Create unit tests for format_time_interval().
Bitwise check for the BRIDGE_DIRINFO flag, rather than checking for
equality.
Fixes a (potential) bug where directories offering BRIDGE_DIRINFO,
and some other flag (i.e. microdescriptors or extrainfo),
would be ignored when looking for bridge directories.
Final fix in series for bug 13163.
Nick Mathewson
Roger Dingledine
teor