newchain-keyfile 0.2.0

A library for handling the encrypted keyfiles used to store newchain private keys.

Ethereum Keyfile

A library for handling the encrypted keyfiles used to store ethereum private keys

This library and repository was previously located at https://github.com/pipermerriam/ethereum-keyfile. It was transferred to the Ethereum foundation github in November 2017 and renamed to eth-keyfile. The PyPi package was also renamed from ethereum-keyfile to eth-keyfile.

Installation

pip install eth-keyfile

Development

pip install -e .[dev]

Running the tests

You can run the tests with:

py.test tests

Or you can install tox to run the full test suite.

Releasing

Pandoc is required for transforming the markdown README to the proper format to render correctly on pypi.

For Debian-like systems:

apt install pandoc

Or on OSX:

brew install pandoc

To release a new version:

make release bump=$$VERSION_PART_TO_BUMP$$

How to bumpversion

The version format for this repo is {major}.{minor}.{patch} for stable, and {major}.{minor}.{patch}-{stage}.{devnum} for unstable (stage can be alpha or beta).

To issue the next version in line, specify which part to bump, like make release bump=minor or make release bump=devnum.

If you are in a beta version, make release bump=stage will switch to a stable.

To issue an unstable version when the current version is stable, specify the new version explicitly, like make release bump="--new-version 2.0.0-alpha.1 devnum"

Documentation

newchain_keyfile.load_keyfile(path_or_file_obj) --> keyfile_json

Takes either a filesystem path represented as a string or a file object and returns the parsed keyfile json as a python dictionary.

>>> from newchain_keyfile import load_keyfile
>>> load_keyfile('path/to-my-keystore/keystore.json')
{
    "crypto" : {
        "cipher" : "aes-128-ctr",
        "cipherparams" : {
            "iv" : "6087dab2f9fdbbfaddc31a909735c1e6"
        },
        "ciphertext" : "5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46",
        "kdf" : "pbkdf2",
        "kdfparams" : {
            "c" : 262144,
            "dklen" : 32,
            "prf" : "hmac-sha256",
            "salt" : "ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd"
        },
        "mac" : "517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2"
    },
    "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
    "version" : 3
}

newchain_keyfile.create_keyfile_json(private_key, password, kdf="pbkdf2", work_factor=None, salt_size=16) --> keyfile_json

Takes the following parameters:

• private_key: A bytestring of length 32
• password: A bytestring which will be the password that can be used to decrypt the resulting keyfile.
• kdf: The key derivation function. Allowed values are pbkdf2 and scrypt. By default, pbkdf2 will be used.
• work_factor: The work factor which will be used for the given key derivation function. By default 1000000 will be used for pbkdf2 and 262144 for scrypt.
• salt_size: Salt size in bytes.

Returns the keyfile json as a python dictionary.

>>> private_key = b'\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01'
>>> create_keyfile_json(private_key, b'foo')
{
    "address" : "1a642f0e3c3af545e7acbd38b07251b3990914f1",
    "crypto" : {
        "cipher" : "aes-128-ctr",
        "cipherparams" : {
            "iv" : "6087dab2f9fdbbfaddc31a909735c1e6"
        },
        "ciphertext" : "5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46",
        "kdf" : "pbkdf2",
        "kdfparams" : {
            "c" : 262144,
            "dklen" : 32,
            "prf" : "hmac-sha256",
            "salt" : "ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd"
        },
        "mac" : "517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2"
    },
    "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
    "version" : 3
}

newchain_keyfile.decode_keyfile_json(keyfile_json, password) --> private_key

Takes the keyfile json as a python dictionary and the password for the keyfile, returning the decoded private key.

>>> keyfile_json = {
...     "crypto" : {
...         "cipher" : "aes-128-ctr",
...         "cipherparams" : {
...             "iv" : "6087dab2f9fdbbfaddc31a909735c1e6"
...         },
...         "ciphertext" : "5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46",
...         "kdf" : "pbkdf2",
...         "kdfparams" : {
...             "c" : 262144,
...             "dklen" : 32,
...             "prf" : "hmac-sha256",
...             "salt" : "ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd"
...         },
...         "mac" : "517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2"
...     },
...     "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
...     "version" : 3
... }
>>> decode_keyfile_json(keyfile_json, b'foo')
b'\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01'

newchain_keyfile.extract_key_from_keyfile(path_or_file_obj, password) --> private_key

Takes a filesystem path represented by a string or a file object and the password for the keyfile. Returns the private key as a bytestring.

>>> extract_key_from_keyfile('path/to-my-keystore/keyfile.json', b'foo')
b'\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01'