NAME

csxs-ppcrypt -- simple passphrase-based encryption and decryption

SYNOPSIS

csxs-ppcrypt -E myfile.txt
echo 'some output' | csxs-ppcrypt -E -o somefile.txt -

csxs-ppcrypt -D myfile.txt.csxspp
csxs-ppcrypt -D -o otherfile.txt somedir/somefile
csxs-ppcrypt -D -o - myfile.txt.csxpp

DESCRIPTION

This is a simple demo program. It's not intended for much real-world use, but can still be handy. It is meant to be an example of using Crypt::Sodium::XS::secretstream. Encryption keys are generated from passphrase input using Crypt::Sodium::XS::pwhash.

USAGE

csxs-ppcrypt -h
csxs-ppcrypt -D [-o <outfile>] <infile>
csxs-ppcrypt -E [-o <outfile>] <infile>

actions:
  -h        print this help message and exit
  -D        decrypt
  -E        encrypt

options:
  -f        force; overwrite an existing <outfile>
  -o        output file (default: <infile>.csxspp)
arguments:
  <infile>  path to input file, or '-' for stdin
  <outfile> path to output file, or '-' for stdout

FILE FORMAT

From the start of a file encrypted with this tool, there is:

     4 bytes) magic value "CSXS"
     4 bytes) version number, little-endian
              placeholder, reserved for future use.
     4 bytes) "primitives" (algorithms) bitflag, little-endian
              placeholder, reserved for future use.
    16 bytes) salt for pwhash
     8 bytes) opslimit for pwhash
     8 bytes) memlimit for pwhash
    24 bytes) secretstream header
  4113 bytes) 0 or more complete encrypted blocks
              all have tag TAG_MESSAGE
<=4113 bytes) 1 final block
              must have tag TAG_FINAL

       no further data is allowed.

AUTHOR

Brad Barden <perlmodules@5c30.org>

COPYRIGHT & LICENSE

Copyright (c) 2025 Brad Barden

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.