This is an implementation of PBKDF2-HMAC-SHA256-AES-GCM encryption as a SPA made with React.js, Chakra UI, Forge and TypeScript.
From the name (which is quite long), it uses the most popular key derivation function - PBKDF2 alongside with HMAC and SHA256 (5000 iterations) to derive 256-bit-long encryption key which is used in AES-GCM cipher later. The product of encrypt function is base64-encoded string (omit spaces): mac(tag) salt iv ciphertext
| Part | Length (base64, chars) |
|---|---|
| MAC | 24 |
| Salt | 44 |
| IV | 44 |
| Ciphertext | * |
Hence, for decryption, one must extract the mentioned parts from the encrypted string, decode them from base64 and then use resulting data in the decryption process.
from base64 import b64decode
from hashlib import pbkdf2_hmac
from Cryptodome.Cipher import AES
encrypted = "3wVs6d7tOKl3acE8gfwvWw==/gQ6Xs7Di2BEFDJsAodnX3eQOXh9MOjmxNygiU81Ge0=jgLtCWt85LMuB+xJikCPu3cREHBwIbwqMgdFa31oFq8=58TUlUHCxzWijq4cQh1RWA=="
tag = encrypted[:24]
salt = encrypted[24:68]
iv = encrypted[68:112]
ciphertext = encrypted[112:]
password = "password"
cipher = AES.new(
pbkdf2_hmac("sha256", password.encode(), b64decode(salt), 5000),
AES.MODE_GCM,
nonce=b64decode(iv), # It's called nonce for whatever reason, afaik, IV and Nonce aren't the same but ok, I guess
)
decrypted = cipher.decrypt_and_verify(
b64decode(ciphertext),
b64decode(tag),
)
print("Decrypted:", decrypted.decode())