问题
I have generated master pub/priv key pairs from 24 word mnemonics for Alice.
master_private_key='9f74f4534cbdf01a1f925e20108d86045bd96849af9c94534a10ef2a26ff133b',
master_public_key="0308de0952b00ebc83a41830794534ae912b86d3718832a36ce98c256ab5bfdc4e"
mnemonic='flash city relief spirit federal own metal history great hello toy volcano same subway loan bleak rapid swamp pigeon secret pyramid spoon famous blouse',
Similarly I have repeated the same process to generate keys for Bob. Now I want to generate Diffie-Hellman keys from Alice's private key and Bob's public key. All the implementations of Diffie-Hellman in python generates their own public/private key pair.
From secp256k1 python documentation:
ecdh(scalar) -> bytes
compute an EC Diffie-Hellman secret in constant time. The instance
public_key is used as the public point, and the scalar specified must be
composed of 32 bytes. It outputs 32 bytes representing the ECDH secret
computed. If the scalar is invalid, an Exception is raised.
NOTE: ecdh can only be used if the secp256k1 C library is compiled with support for it. If there is no support, an Exception will be raised when calling it.
I just don't know how to compile this library with libsecp256k1. I think Diffie-Hellman ECC version is more suitable here.
This is the error I am getting:
from sawtooth_signing.secp256k1 import Secp256k1PublicKey
bob_pub='033036dd96b7bef82556fe09eef42bef5e66545317c92a5deca99275f616729fef'
public_key = Secp256k1PublicKey.from_hex(bob_pub)
public_key.secp256k1_public_key.ecdh(alice_private_key)
----------------------
Exception Traceback (most recent call last)
<ipython-input-4-5175cf593934> in <module>()
----> 1 public_key.secp256k1_public_key.ecdh("dsds")
~/SawtoothClient/SawtoothClient/lib/python3.6/site-packages/secp256k1-0.13.2-py3.6-linux-x86_64.egg/secp256k1/__init__.py in ecdh(self, scalar)
305 assert self.public_key, "No public key defined"
306 if not HAS_ECDH:
--> 307 raise Exception("secp256k1_ecdh not enabled")
308 if not isinstance(scalar, bytes) or len(scalar) != 32:
309 raise TypeError('scalar must be composed of 32 bytes')
Exception: secp256k1_ecdh not enabled
I have tried to install https://github.com/bitcoin-core/secp256k1, followed the instructions and it got installed with output:
Libraries have been installed in:
/usr/local/lib
Now when I tried installing secp256k1 with python 3.6 again, as mentioned on their git page:
INCLUDE_DIR=include/ LIB_DIR=/usr/local/lib pip install --no-binary secp256k1,
I get this error:
ERROR: You must give at least one requirement to install (see "pip help install")
回答1:
I did it using another library coincurve.
import coincurve
alice_priv = "29307c4354b7d9d311d2cec4878c0de56c93a921d300273c19577e9004de3c9f"
alice_pub = "02f3c25355c29f64ea8e9b4e11b583ac0a7d0d8235f156cffec2b73e5756aab206"
bob_pub = "03a1db8e8b047e1350958a55e0a853151d0e1f685fa5cf3772e01bccc5aa5cb2eb"
bob_priv = "4138d1b6dde34f81c38cef2630429e85847dd5b70508e37f53c844f66f19f983"
alice_coin_priv = coincurve.PrivateKey.from_hex(alice_priv)
bob_coin_priv = coincurve.PrivateKey.from_hex(bob_priv)
binascii.hexlify(alice_coin_priv.ecdh(bob_coin_priv.public_key.public_key))
hex encoded shared secret is
b'92959cb394b71a05d440e0e2973bc9d0e7182eb86bb94d3a260ce8353c7a0317'
Verification works
bob_coin_priv.ecdh(alice_coin_priv.public_key.public_key)== alice_coin_priv.ecdh(bob_coin_priv.public_key.public_key)
来源：https://stackoverflow.com/questions/52505432/diffie-hellman-encryption-scheme-in-python