This creates a random 100 KiB buffer, and incrementally hashes
(SHA3-512) between 1 and 5 * Rate bytes in a loop, comparing the running
digest with the equivalent one shot call from the start of the buffer.
This is an eXtendable-Output Function with the following claimed
security strengths against *all* adversaries:
Collision: min(d/2, 256)
Preimage: >= min(d, 256)
2nd Preimage: min(d, 256)
where d is the amount of output used, in bits.
* DIGEST_SHA3_[256,512] added as supported algorithms, which do
exactly what is said on the tin.
* test/bench now benchmarks all of the supported digest algorithms,
so it's possible to see just how slow SHA-3 is, though the message
sizes could probably use tweaking since this is very dependent on
the message size vs the SHA-3 rate.
This will give relay operators the ability of disabling the caching of
directory data. In general, this should not be necessary, but on some
lower-resource systems it may beneficial.
According to the POSIX standard the option value is a pointer to void
and the option length a socklen_t. The Windows implementation makes the
option value be a pointer to character and the option length an int.
Casting the option value to a pointer to void conforms to the POSIX
standard while the implicit cast to a pointer to character conforms to
the Windows implementation.
The casts of the option length to the socklen_t data type conforms to
the POSIX standard. The socklen_t data type is actually an alias of an
int so it also conforms to the Windows implementation.
When a relay does not have an open directory port but it has an
orport configured and is accepting client connections then it can
now service tunnelled directory requests, too. This was already true
of relays with an dirport configured.
We also conditionally stop advertising this functionality if the
relay is nearing its bandwidth usage limit - same as how dirport
advertisement is determined.
Partial implementation of prop 237, ticket 12538
These IPv6 addresses must be quoted, because : is the port separator,
and "acce" is a valid hex block.
Add unit tests for assumed actions in IPv6 policies.
"Tor has included a feature to fetch the initial consensus from nodes
other than the authorities for a while now. We just haven't shipped a
list of alternate locations for clients to go to yet.
Reasons why we might want to ship tor with a list of additional places
where clients can find the consensus is that it makes authority
reachability and BW less important.
We want them to have been around and using their current key, address,
and port for a while now (120 days), and have been running, a guard,
and a v2 directory mirror for most of that time."
Features:
* whitelist and blacklist for an opt-in/opt-out trial.
* excludes BadExits, tor versions that aren't recommended, and low
consensus weight directory mirrors.
* reduces the weighting of Exits to avoid overloading them.
* places limits on the weight of any one fallback.
* includes an IPv6 address and orport for each FallbackDir, as
implemented in #17327. (Tor won't bootstrap using IPv6 fallbacks
until #17840 is merged.)
* generated output includes timestamps & Onionoo URL for traceability.
* unit test ensures that we successfully load all included default
fallback directories.
Closes ticket #15775. Patch by "teor".
OnionOO script by "weasel", "teor", "gsathya", and "karsten".
