Ethereum Keys
A common API for Ethereum key operations with pluggable backends.
This library and repository was previously located at https://github.com/pipermerriam/ethereum-keys. It was transferred to the Ethereum foundation github in November 2017 and renamed to
eth-keys
. The PyPi package was also renamed fromethereum-keys
toeth-keys
.
Installation
pip install eth-keys
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"
QuickStart
>>> from eth_keys import keys
>>> pk = keys.PrivateKey(b'\x01' * 32)
>>> signature = pk.sign_msg(b'a message')
>>> pk
'0x0101010101010101010101010101010101010101010101010101010101010101'
>>> pk.public_key
'0x1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f70beaf8f588b541507fed6a642c5ab42dfdf8120a7f639de5122d47a69a8e8d1'
>>> signature
'0xccda990dba7864b79dc49158fea269338a1cf5747bc4c4bf1b96823e31a0997e7d1e65c06c5bf128b7109e1b4b9ba8d1305dc33f32f624695b2fa8e02c12c1e000'
>>> pk.public_key.to_checksum_address()
'0x1a642f0E3c3aF545E7AcBD38b07251B3990914F1'
>>> signature.verify_msg(b'a message', pk.public_key)
True
>>> signature.recover_public_key_from_msg(b'a message') == pk.public_key
True
Documentation
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 thecoincurve
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 witheth-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 32private_key
: must be an instance ofPrivateKey
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 32signature
: must be an instance ofSignature
public_key
: must be an instance ofPublicKey
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 32signature
: must be an instance ofSignature
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 ofPublicKey
PublicKey
, PrivateKey
and Signature
Common APIs for 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 canonicalbytes
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 some libraries prefix the byte serialized public key with a leading
\x04
byte which must be removed before use with thePublicKey
object.
The following methods are available:
PublicKey.from_private(private_key) -> PublicKey
This classmethod
returns a new PublicKey
instance computed from the
given private_key
.
private_key
may either be a byte string of length 32 or an instance of theKeyAPI.PrivateKey
class.
PublicKey.recover_from_msg(message, signature) -> PublicKey
This classmethod
returns a new PublicKey
instance computed from the
provided message
and signature
.
message
must be a byte stringsignature
must be an instance ofKeyAPI.Signature
PublicKey.recover_from_msg_hash(message_hash, signature) -> PublicKey
Same as PublicKey.recover_from_msg
except that message_hash
should be the Keccak
hash of the message
.
PublicKey.verify_msg(message, signature) -> bool
This method returns True
or False
based on whether the signature is a valid
for the given message.
PublicKey.verify_msg_hash(message_hash, signature) -> bool
Same as PublicKey.verify_msg
except that message_hash
should be the Keccak
hash of the message
.
PublicKey.to_address() -> text
Returns the hex encoded ethereum address for this public key.
PublicKey.to_checksum_address() -> text
Returns the ERC55 checksum formatted ethereum address for this public key.
PublicKey.to_canonical_address() -> bytes
Returns the 20-byte representation of the ethereum address for this public key.
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
PrivateKey.public_key
This property holds the PublicKey
instance coresponding to this private key.
PrivateKey.sign_msg(message) -> Signature
This method returns a signature for the given message
in the form of a
Signature
instance
message
must be a byte string.
PrivateKey.sign_msg_hash(message_hash) -> Signature
Same as PrivateKey.sign
except that message_hash
should be the Keccak
hash of the message
.
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 integersv
,r
, ands
.
Note: If using the
signature_bytes
to instantiate, the byte string should be encoded asr_bytes | s_bytes | v_bytes
where|
represents concatenation.r_bytes
ands_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
Signature.v
This property returns the v
value from the signature as an integer.
Signature.r
This property returns the r
value from the signature as an integer.
Signature.s
This property returns the s
value from the signature as an integer.
Signature.vrs
This property returns a 3-tuple of (v, r, s)
.
Signature.verify_msg(message, public_key) -> bool
This method returns True
or False
based on whether the signature is a valid
for the given public key.
message
: must be a byte string.public_key
: must be an instance ofPublicKey
Signature.verify_msg_hash(message_hash, public_key) -> bool
Same as Signature.verify_msg
except that message_hash
should be the Keccak
hash of the message
.
Signature.recover_public_key_from_msg(message) -> PublicKey
This method returns a PublicKey
instance recovered from the signature.
message
: must be a byte string.
Signature.recover_public_key_from_msg_hash(message_hash) -> PublicKey
Same as Signature.recover_public_key_from_msg
except that message_hash
should be the Keccak hash of the message
.
Exceptions
eth_api.exceptions.ValidationError
This error is raised during instantaition of any of the PublicKey
,
PrivateKey
or Signature
classes if their constructor parameters are
invalid.
eth_api.exceptions.BadSignature
This error is raised from any of the recover
or verify
methods involving
signatures if the signature is invalid.