As a matter of good crypto practice, we shouldn't use
short-circuiting checks to compare keys or key-like objects, since
the amount of time taken by those checks can leak information about
their inputs.
I don't think it's actually _necessary_ to use a constant-time
operation in this case, but let's establish the precedent.
This is a follow-up to !724.
Because we want to work more on ensuring that our semver stability
story is solid, we are _not_ bumping arti-client to 1.0.0 right now.
Here are the bumps we _are_ doing. Crates with "minor" bumps have
had API breaks; crates with "patch" bumps have had new APIs added.
Note that `tor-congestion` is not bumped here: it's a new crate, and
hasn't been published before.
```
tor-basic-utils minor
fs-mistrust minor
tor-config minor
tor-rtcompat minor
tor-rtmock minor
tor-llcrypto patch
tor-bytes patch
tor-linkspec minor
tor-cell minor
tor-proto minor
tor-netdoc patch
tor-netdir minor
tor-persist patch
tor-chanmgr minor
tor-guardmgr minor
tor-circmgr minor
tor-dirmgr minor
arti-client minor
arti-hyper minor
arti major
arti-bench minor
arti-testing minor
```
This will be convenient for managing when to send these negotiation
messages.
While we're here, edit the comment to explain how this is (going to
be) used.
Do _not_ bump the dependency versions on crates that have had no
changes since arti 0.0.5, since those crates do not depend on the
new APIs.
```
cargo set-version -p tor-basic-utils --bump patch
cargo set-version -p tor-llcrypto --bump patch
git restore crates/tor-checkable
git restore crates/tor-consdiff
git restore crates/tor-rtmock
```
This comprises four renames:
```
write_onto -> write_onto_infallible
write_into -> write_into_infallible
write -> write_infallible
writer_and_consume -> write_and_consume_infallible.
```
The rest of this branch will be concerned with replacing these
`_infallible` methods with ones that return a `Result`. This is
part of #513.
This implements a higher-level API for the ntor v3 handshake, in line
with that exposed by the ntor handshake. It does not, however, use the
existing `ClientHandshake` trait, due to fundamental differences in the
handshakes (namely, that the v3 handshake can include some additional
extra extension data).
Currently, the higher-level API assumes circuit extension, and copies
the (undocumented!) magic verification string from c-tor that indicates
this usage.
A rudimentary set of functions for serializing and deserializing
extensions to be sent with the handshake is also included, implementing
the protocol in proposal 332 § A.2. Currently, it only implements the
congestion control extensions specified in proposal 324 § 10.3.
part of arti#88
According to doc/Errors.md, and in keeping with current best
practices, we should not include display an error's `source()` as
part of that error's display method. Instead, we should let the
caller decide to call source() and display that error in turn.
Part of #323.
The "full" feature is a catch-all for all features, _except_:
* Those that select a particular implementation (like
tor-llcrypto/with-openssl) or build flag (like "static")
* Those that are experimental or unstable (like "experimental-api")
* Those that are testing-only.