eth-keys 0.3.3

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=$$VERSION_PART_TO_BUMP$$

KeyAPI(backend=None)

The KeyAPI object is the primary API for interacting with the eth-keys libary. The object takes a single optional argument in its constructor which designates what backend will be used for eliptical curve cryptography operations. The built-in backends are:

• eth_keys.backends.NativeECCBackend: A pure python implementation of the ECC operations.

• eth_keys.backends.CoinCurveECCBackend: Uses the `coincurve <https://github.com/ofek/coincurve>`__ library for ECC operations.

By default, eth-keys will try to use the CoinCurveECCBackend, falling back to the NativeECCBackend if the coincurve library is not available.

Note: The coincurve library is not automatically installed with eth-keys and must be installed separately.

The backend argument can be given in any of the following forms.

• Instance of the backend class

• The backend class

• String with the dot-separated import path for the backend class.

>>> from eth_keys import KeyAPI
>>> from eth_keys.backends import NativeECCBackend
# These are all the same
>>> keys = KeyAPI(NativeECCBackend)
>>> keys = KeyAPI(NativeECCBackend())
>>> keys = KeyAPI('eth_keys.backends.NativeECCBackend')
# Or for the coincurve base backend
>>> keys = KeyAPI('eth_keys.backends.CoinCurveECCBackend')

The backend can also be configured using the environment variable ECC_BACKEND_CLASS which should be set to the dot-separated python import path to the desired backend.

>>> import os
>>> os.environ['ECC_BACKEND_CLASS'] = 'eth_keys.backends.CoinCurveECCBackend'

KeyAPI.ecdsa_sign(message_hash, private_key) -> Signature

This method returns a signature for the given message_hash, signed by the provided private_key.

• message_hash: must be a byte string of length 32

• private_key: must be an instance of PrivateKey

KeyAPI.ecdsa_verify(message_hash, signature, public_key) -> bool

Returns True or False based on whether the provided signature is a valid signature for the provided message_hash and public_key.

• message_hash: must be a byte string of length 32

• signature: must be an instance of Signature

• public_key: must be an instance of PublicKey

KeyAPI.ecdsa_recover(message_hash, signature) -> PublicKey

Returns the PublicKey instances recovered from the given signature and message_hash.

• message_hash: must be a byte string of length 32

• signature: must be an instance of Signature

KeyAPI.private_key_to_public_key(private_key) -> PublicKey

Returns the PublicKey instances computed from the given private_key instance.

• private_key: must be an instance of PublicKey

Common APIs for PublicKey, PrivateKey and Signature

There is a common API for the following objects.

• PublicKey

• PrivateKey

• Signature

Each of these objects has all of the following APIs.

• obj.to_bytes(): Returns the object in it’s canonical bytes serialization.

• obj.to_hex(): Returns a text string of the hex encoded canonical representation.

KeyAPI.PublicKey(public_key_bytes)

The PublicKey class takes a single argument which must be a bytes string with length 64.

Note that there are two other common formats for public keys: 65 bytes with a leading \x04 byte and 33 bytes starting with either \x02 or \x03. To use the former with the PublicKey object, remove the first byte. For the latter, refer to PublicKey.from_compressed_bytes.

The following methods are available:

KeyAPI.PrivateKey(private_key_bytes)

The PrivateKey class takes a single argument which must be a bytes string with length 32.

The following methods and properties are available

KeyAPI.Signature(signature_bytes=None, vrs=None)

The Signature class can be instantiated in one of two ways.

• signature_bytes: a bytes string with length 65.

• vrs: a 3-tuple composed of the integers v, r, and s.

  Note: If using the signature_bytes to instantiate, the byte string should be encoded as r_bytes | s_bytes | v_bytes where | represents concatenation. r_bytes and s_bytes should be 32 bytes in length. v_bytes should be a single byte \x00 or \x01.

Signatures are expected to use 1 or 0 for their v value.

The following methods and properties are available

Exceptions