Encrypting and decrypting
If you don’t choose to encrypt your file when you run
jrnl for the first time, you can encrypt
your existing journal file or change its password using this:
If it is already encrypted, you will first be asked for the current password. You can then enter a new password and your plain journal will replaced by the encrypted file. Conversely,
will replace your encrypted journal file with a journal in plain text. You
can also specify a filename, i.e.
jrnl --decrypt plain_text_copy.txt,
to leave your original file untouched.
Storing passwords in your keychain
Whenever you encrypt your journal, you are asked whether you want to store the encryption password in your keychain. If you do this, you won’t have to enter your password every time you want to write or read your journal.
If you don’t initially store the password in the keychain but decide to
do so at a later point – or maybe want to store it on one computer but
not on another – you can run
jrnl --encrypt on an encrypted
journal and use the same password again.
A note on security
jrnl follows best practices, total security is an illusion.
There are a number of ways that people can at least partially
jrnl data. See the Privacy and Security
documentation for more information.
No password recovery
There is no method to recover or reset your
jrnl password. If you lose it,
your data is inaccessible.
Should you ever want to decrypt your journal manually, you can do so with any program that supports the AES algorithm in CBC. The key used for encryption is the SHA-256-hash of your password, the IV (initialisation vector) is stored in the first 16 bytes of the encrypted file. The plain text is encoded in UTF-8 and padded according to PKCS#7 before being encrypted. Here’s a Python script that you can use to decrypt your journal:
#!/usr/bin/env python3 import argparse from Crypto.Cipher import AES import getpass import hashlib import sys parser = argparse.ArgumentParser() parser.add_argument("filepath", help="journal file to decrypt") args = parser.parse_args() pwd = getpass.getpass() key = hashlib.sha256(pwd.encode('utf-8')).digest() with open(args.filepath, 'rb') as f: ciphertext = f.read() crypto = AES.new(key, AES.MODE_CBC, ciphertext[:16]) plain = crypto.decrypt(ciphertext[16:]) plain = plain.strip(plain[-1:]) plain = plain.decode("utf-8") print(plain)