sql_app: crypto: added crypto python helper fucntions

Idea is to isolate cryptography from database managment
	code.

Signed-off-by: HeshamTB <hishaminv@gmail.com>
This commit is contained in:
HeshamTB 2022-03-16 22:30:57 +03:00
parent 3922d659da
commit 75984d1f1f
Signed by: Hesham
GPG Key ID: 74876157D199B09E

29
sql_app/crypto.py Normal file
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import os
from hashlib import pbkdf2_hmac
PASS_ENCODING='utf-8'
HASH_FUNC='sha256'
NUM_ITIRATIONS=100000
def get_new_salt(n_bytes : int = 32) -> bytes:
if type(n_bytes) != int:
n_bytes = 32 # Forece in case of misuse
return os.urandom(n_bytes)
"""
Generate a new key and salt to store.
Returns (key, salt)
"""
def gen_new_key(plain_passwd : str) -> tuple:
salt = get_new_salt(32)
return (calc_key(plain_passwd, salt), salt)
def verify_key(plain_passwd : str, salt : bytes, stored_key : bytes) -> bool:
key_tmp = calc_key(plain_passwd, salt)
return (stored_key == key_tmp)
def calc_key(passwd: str, salt : bytes) -> bytes:
return pbkdf2_hmac(HASH_FUNC, passwd.encode(PASS_ENCODING), salt, NUM_ITIRATIONS)