fixes https://github.com/spesmilo/electrum/issues/8813 regression fromeef9680743We started setting the witness field in above commit to be able to provide the witnesses for already pre-signed external inputs to the device, e.g. for a coinjoin. Trezor One fw has pretty strict limits on the witness field: max 109 bytes, probably because that's a ~tight upper bound for a p2wpkh witness: <num_witness_items> <len(sig)> <sig> <len(pubkey)> <pubkey>, it comes out to 3+73(high-S and high-R)+33.ed1785a985/legacy/firmware/protob/messages-bitcoin.options (L35)Trezor model T seems to have higher limits. tx_inputs is called for the tx being signed (for_sig=True), and for its parents/prev_txes (for_sig=False). The witness is only useful for the tx being signed, I think. Users reported seeing a "DataError: bytes overflow" exception when using a Trezor One to sign 2of3 p2wsh multisig txs. There were no external inputs involved so for the tx being signed all witnesses were None, however we were also setting the witness for the inputs of prev_txes. The witness for a 2of3 pw2sh multisig input is around ~253 bytes. To sidestep the problem, we now only set the witness in the for_sig=True case. Note that this means if someone tries to do a coinjoin with a Trezor One involving non-trivial external inputs, they will run into the same limit and exception.
Electrum - Lightweight Bitcoin client
Licence: MIT Licence
Author: Thomas Voegtlin
Language: Python (>= 3.8)
Homepage: https://electrum.org/
Getting started
(If you've come here looking to simply run Electrum, you may download it here.)
Electrum itself is pure Python, and so are most of the required dependencies, but not everything. The following sections describe how to run from source, but here is a TL;DR:
$ sudo apt-get install libsecp256k1-dev
$ python3 -m pip install --user ".[gui,crypto]"
Not pure-python dependencies
If you want to use the Qt interface, install the Qt dependencies:
$ sudo apt-get install python3-pyqt5
For elliptic curve operations, libsecp256k1 is a required dependency:
$ sudo apt-get install libsecp256k1-dev
Alternatively, when running from a cloned repository, a script is provided to build libsecp256k1 yourself:
$ sudo apt-get install automake libtool
$ ./contrib/make_libsecp256k1.sh
Due to the need for fast symmetric ciphers, cryptography is required. Install from your package manager (or from pip):
$ sudo apt-get install python3-cryptography
If you would like hardware wallet support, see this.
Running from tar.gz
If you downloaded the official package (tar.gz), you can run Electrum from its root directory without installing it on your system; all the pure python dependencies are included in the 'packages' directory. To run Electrum from its root directory, just do:
$ ./run_electrum
You can also install Electrum on your system, by running this command:
$ sudo apt-get install python3-setuptools python3-pip
$ python3 -m pip install --user .
This will download and install the Python dependencies used by
Electrum instead of using the 'packages' directory.
It will also place an executable named electrum in ~/.local/bin,
so make sure that is on your PATH variable.
Development version (git clone)
(For OS-specific instructions, see here for Windows, and for macOS)
Check out the code from GitHub:
$ git clone https://github.com/spesmilo/electrum.git
$ cd electrum
$ git submodule update --init
Run install (this should install dependencies):
$ python3 -m pip install --user -e .
Create translations (optional):
$ sudo apt-get install python3-requests gettext qttools5-dev-tools
$ ./contrib/pull_locale
Finally, to start Electrum:
$ ./run_electrum
Run tests
Run unit tests with pytest:
$ pytest electrum/tests -v
To run a single file, specify it directly like this:
$ pytest electrum/tests/test_bitcoin.py -v
Creating Binaries
Contributing
Any help testing the software, reporting or fixing bugs, reviewing pull requests and recent changes, writing tests, or helping with outstanding issues is very welcome. Implementing new features, or improving/refactoring the codebase, is of course also welcome, but to avoid wasted effort, especially for larger changes, we encourage discussing these on the issue tracker or IRC first.
Besides GitHub,
most communication about Electrum development happens on IRC, in the
#electrum channel on Libera Chat. The easiest way to participate on IRC is
with the web client, web.libera.chat.