Error message

[EklectikDesign2020]

After encrypt() when I want to decrypt I get a data is not a valid scrypt-encryption block

[holgern]

Please provide some python example code

[bgiarrizzo]

I had the same issue here, at the decrypt step, i've got the error message :

E       UnicodeDecodeError: 'utf-8' codec can't decode byte 0x82 in position 0: invalid start byte

Here is the code as it was used :

def generate_password_hash(password: str) -> str:
    return scrypt.encrypt(input=os.urandom(8), password=password, maxtime=0.1)


def verify_password(plain_password: str, hashed_password: bytes) -> bool:
    try:
        scrypt.decrypt(
            input=hashed_password,
            password=plain_password,
            maxtime=0.5,
        )
        return True
    except scrypt.error:
        return False

The failure happened at the decrypt step, when decoding the output bytes.

The thing i've done was to generate random 32chars string via the libs string & random, and use it as passphrase.

import string
import random

def generate_password_hash(password: str) -> str:
    passphrase = "".join(random.choice(string.ascii_lowercase) for i in range(32))
    return scrypt.encrypt(input=passphrase, password=password, maxtime=0.1)


def verify_password(plain_password: str, hashed_password: bytes) -> bool:
    try:
        scrypt.decrypt(input=hashed_password, password=plain_password, maxtime=0.5)
        return True
    except scrypt.error:
        return False

And now, no errors on the decrypt step.