ppvtcrypt

This is an intentionally minimal encryption tool. It does not attempt to do
signing, integrity checking, or authentication. The only operations are
encrypting and decrypting a stream of bytes, with a single cipher using a single
KDF. Run “ppvtcrypt -h” for a synopsis.


    1.0 Examples


    1.1 Encrypting a backup

Archive the directory “directory_to_store” into the encrypted, LZIP compressed
POSIX.1-2001 format tar archive “backup.tar.lz.ppen”:

    tar -cvf - --posix --lzip directory_to_store | ppvtcrypt >backup.tar.lz.ppen


    1.2 Unpacking a random file for view

Decrypt the file “ciphertext.text.ppen” into “plaintext.text”, pass phrase will
be requested from the controlling TTY:

    ppvtcrypt -d <ciphertext.text.ppen >plaintext.text

When reading the pass phrase from the terminal, ppvtcrypt turns off terminal
echo and waits for input with the following prompt: ?


    2.0 Building

The build.zsh script will run tests and build everything using venv. If you have
the necessary dependencies installed on the host, running the make targets
directly is another option. The sledgehammer approach of adding the bin
directory to your PATH and the src directory to your PYTHONPATH works too, at
least for quick testing. Quick build and install:

    ./build.zsh
    pip3 install --user ./dist/ppvtcrypto-x.y.z.tar.gz

The ppvtcrypt script will then usually be installed to: ~/.local/bin


    3.0 Reading passwords from a file

Putting cleartext passwords in a file is rarely a good idea, the intention of
ppvtcrypt's “-p” option is reading the password from a FIFO. (For integration
with a password vault.)


    4.0 Tools

The subdirectory “tools” contain a collection of different scripts which build
on ppvtcrypt or were used when writing ppvtcrypt.


    5.0 Licence

Copyright 2019-2021 Steinar Knutsen

Licensed under the EUPL, Version 1.2 or – as soon they will be approved by the
European Commission – subsequent versions of the EUPL (the “Licence”); You may
not use this work except in compliance with the Licence. You may obtain a copy
of the Licence at:

https://joinup.ec.europa.eu/collection/eupl/eupl-text-eupl-12

Unless required by applicable law or agreed to in writing, software distributed
under the Licence is distributed on an “AS IS” basis, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied. See the Licence for the
specific language governing permissions and limitations under the Licence.