UnicodeDecodeError：将以太坊私钥的 python 字节串转换为字符串？

Question

I'm using eth-keyfile to extract a private key from an ethereum keyfile.

# https://github.com/ethereum/eth-keyfile
from eth_keyfile import extract_key_from_keyfile

password = b'secretpassword'
extracted = extract_key_from_keyfile('testkey.json', password)
print(extracted.decode('utf-8'))

I get a UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd4 in position 0: invalid continuation byte . I've tried other encodings as well (utf-16, latin-1).

How do I find out what encoding to use?

Answer 1

I don't know much about ethereum, but as far as I can tell from a quick Google search you probably want the bytestring represented in the form of a hex string.

Assuming you're using Python 3+; This should probably do the trick:

from eth_keyfile import extract_key_from_keyfile

password = b'secretpassword'
extracted = extract_key_from_keyfile('testkey.json', password)
print(extracted.hex())

To better understand whats going on I've made this little demo:

>> # Python bytestring filled with the byte 0x41
>> bytes = b"\x41\x41\x41\x41"

>> # 0x41 is the ascii representation of the character 'a' so:
>> print(bytes.decode('utf-8'))
>> "aaaa"

>> # Now we have a regular string with the characters '4' '1':
>> print(bytes.hex())
>> "41414141"