mirror of
https://github.com/beemdevelopment/Aegis
synced 2024-07-05 16:48:37 +00:00
94 lines
2.7 KiB
Python
Executable File
94 lines
2.7 KiB
Python
Executable File
#!/usr/bin/env python3
|
|
|
|
# this depends on the 'cryptography' package
|
|
# pip install cryptography
|
|
|
|
# example usage: ./scripts/decrypt.py --input ./app/src/test/resources/com/beemdevelopment/aegis/importers/aegis_encrypted.json
|
|
# password: test
|
|
|
|
import argparse
|
|
import base64
|
|
import getpass
|
|
import io
|
|
import json
|
|
import sys
|
|
|
|
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
|
|
from cryptography.hazmat.primitives.kdf.scrypt import Scrypt
|
|
from cryptography.hazmat.backends import default_backend
|
|
import cryptography
|
|
backend = default_backend()
|
|
|
|
def die(msg, code=1):
|
|
print(msg, file=sys.stderr)
|
|
exit(code)
|
|
|
|
def main():
|
|
parser = argparse.ArgumentParser(description="Decrypt an Aegis vault")
|
|
parser.add_argument("--input", dest="input", required=True, help="encrypted Aegis vault file")
|
|
parser.add_argument("--output", dest="output", default="-", help="output file ('-' for stdout)")
|
|
args = parser.parse_args()
|
|
|
|
# parse the Aegis vault file
|
|
with io.open(args.input, "r") as f:
|
|
data = json.load(f)
|
|
|
|
# ask the user for a password
|
|
password = getpass.getpass().encode("utf-8")
|
|
|
|
# extract all password slots from the header
|
|
header = data["header"]
|
|
slots = [slot for slot in header["slots"] if slot["type"] == 1]
|
|
|
|
# try the given password on every slot until one succeeds
|
|
master_key = None
|
|
for slot in slots:
|
|
# derive a key from the given password
|
|
kdf = Scrypt(
|
|
salt=bytes.fromhex(slot["salt"]),
|
|
length=32,
|
|
n=slot["n"],
|
|
r=slot["r"],
|
|
p=slot["p"],
|
|
backend=backend
|
|
)
|
|
key = kdf.derive(password)
|
|
|
|
# try to use the derived key to decrypt the master key
|
|
cipher = AESGCM(key)
|
|
params = slot["key_params"]
|
|
try:
|
|
master_key = cipher.decrypt(
|
|
nonce=bytes.fromhex(params["nonce"]),
|
|
data=bytes.fromhex(slot["key"]) + bytes.fromhex(params["tag"]),
|
|
associated_data=None
|
|
)
|
|
break
|
|
except cryptography.exceptions.InvalidTag:
|
|
pass
|
|
|
|
if master_key is None:
|
|
die("error: unable to decrypt the master key with the given password")
|
|
|
|
# decode the base64 vault contents
|
|
content = base64.b64decode(data["db"])
|
|
|
|
# decrypt the vault contents using the master key
|
|
params = header["params"]
|
|
cipher = AESGCM(master_key)
|
|
db = cipher.decrypt(
|
|
nonce=bytes.fromhex(params["nonce"]),
|
|
data=content + bytes.fromhex(params["tag"]),
|
|
associated_data=None
|
|
)
|
|
|
|
db = db.decode("utf-8")
|
|
if args.output != "-":
|
|
with io.open(args.output, "w") as f:
|
|
f.write(db)
|
|
else:
|
|
print(db)
|
|
|
|
if __name__ == "__main__":
|
|
main()
|