This commit breaks session handling (which matters with Bridge) and
regresses Bridge to an older code state. Both of these issues will be
rectified in subsequent commits.
Explanation of this big API reshuffle follows:
* protocols are moved to trezorlib.transport, and to a single common file.
* there is a cleaner definition of Transport and Protocol API (see below)
* fully valid mypy type hinting
* session handle counters and open handle counters mostly went away. Transports
and Protocols are meant to be "raw" APIs; TrezorClient will implement
context-handler-based sessions, session tracking, etc.
I'm calling this a "reshuffle" because it involved very small number of
code changes. Most of it is moving things around where they sit better.
The API changes are as follows.
Transport is now a thing that can:
* open and close sessions
* read and write protobuf messages
* enumerate and find devices
Some transports (all except bridge) are technically bytes-based and need
a separate protocol implementation (because we have two existing protocols,
although only the first one is actually used). Hence a protocol superclass.
Protocol is a thing that *also* can:
* open and close sessions
* read and write protobuf messages
For that, it requires a `handle`.
Handle is a physical layer for a protocol. It can:
* open and close some sort of device connection
(this is distinct from session! Connection is a channel over which you can
send data. Session is a logical arrangement on top of that; you can have
multiple sessions on a single connection.)
* read and write 64-byte chunks of data
With that, we introduce ProtocolBasedTransport, which simply delegates
the appropriate Transport functionality to respective Protocol methods.
hid and webusb transports are ProtocolBasedTransport-s that provide separate
device handles. HidHandle and WebUsbHandle existed before, but the distinction
of functionality between a Transport and its Handle was unclear. Some methods
were moved and now the handles implement the Handle API, while the transports
provide the enumeration parts of the Transport API, as well as glue between
the respective Protocols and Handles.
udp transport is also a ProtocolBasedTransport, but it acts as its own handle.
(That might be changed. For now, I went with the pre-existing structure.)
In addition, session_begin/end is renamed to begin/end_session to keep
consistent verb_noun naming.
There is no good reason to do that and it hides situations when
the field mistakenly doesn't exist.
Added comment explains that missing "vendor" field might by caused
by trezor-common mismatch, which fixes#328
- drop set_tx_api method and its usage from trezorctl
- drop _prepare_sign_tx which is not used anymore
- adapt trezorctl to new signing API
- make trezorctl signing smarter, ahead of moving it elsewhere
this fixes a problem when checking signature (and therefore
reconstructing) of a vendor header that doesn't have a VendorTrust of
all zeroes, e.g., the vendor header for test builds
We can now locally verify firmware signatures and hashes. We also
recognize min_firmware_version, so this resolves#308
This also helps with #273, as trezorlib is now mostly usable for signing
firmware images.
from https://github.com/pyca/ed25519
This makes the calculations several orders of magnitude faster, which
allows us to run the CoSi test in Travis. It also doesn't stop firmware
update for several seconds while we validate the CoSi signatures.
It's still essentially the same insecure implementation, fallible to all
the same timing attacks, and it shouldn't be used for anything except
validating public signatures of public data. But now it also takes about
as much time as it should on modern hardware.
This allows us to return early from a `write`, which we need in cases
where we want to perform an operation inbetween `read` and `write` -
namely, callback for ButtonRequest should technically be invoked after
returning ButtonAck but before waiting for device's response.
Of course that doesn't really work. The callback will actually be
invoked _before_ ButtonAck, so there's still the condition that it must
return immediately or the device gets stuck with a black screen.
But doing this allows us to write code *as if* it worked, which lets the
other transports run free and wild, by which I mean, do the Right Thing
