gallery.encrypteddb decryption

decrypt_gallery_encrypteddb.py

import os
from Crypto.Cipher import AES

enc_db = open('gallery.encrypteddb').read()
enc_db_size = os.path.size(db_path)

header_size = 0x10
page_size=0x400
header = enc_db.read(header_size)
salt_sz = 0x10
hmac_sz = 0x20
reserved_sz = salt_sz + hmac_sz
max_page = int(enc_db_size / default_page_size)

def decrypt_page(page_offset):
    if page_offset == 0:
        page_data = enc_db.read(page_size - header_size)
    else:
        page_data = enc_db.read(page_size)
    
    iv = page_data[-reserved_sz:-reserved_sz+salt_sz]
    decryption_suite = AES.new(key[:32], AES.MODE_CBC, iv)
    plain_text = decryption_suite.decrypt(page_data[:-reserved_sz])
    
    return plain_text
    
with open(os.path.join(out_path,'snapchat-decrypted.sqlite'),'wb') as decrypted:
    decrypted.write(b'SQLite format 3\x00')
    
    for page in range(0,max_page):
        decrypted.write(decrypt_page(page))
        decrypted.write(b'\x00'*reserved_sz)