User Guide PGPainless-CLI

The module pgpainless-cli contains a command line application which conforms to the Stateless OpenPGP Command Line Interface.

You can use it to generate keys, encrypt, sign and decrypt messages, as well as verify signatures.

Implementation

Essentially, pgpainless-cli is just a very small composing module, which injects pgpainless-sop as a concrete implementation of sop-java into sop-java-picocli.

Install

The pgpainless-cli command line application is available in Debian unstable / Ubuntu 22.10 and can be installed via APT:

$ sudo apt install pgpainless-cli

This method comes with man-pages:

$ man pgpainless-cli

Build

To build a standalone fat-jar:

$ cd pgpainless-cli/
$ gradle shadowJar

The fat-jar can afterwards be found in build/libs/.

To build a distributable:

$ cd pgpainless-cli/
$ gradle installDist

Afterwards, an uncompressed distributable is installed in build/install/. To execute the application, you can call build/install/bin/pgpainless-cli{.bat}

Building / updating man pages is a two-step process. The contents of the man pages is largely defined by the sop-java-picocli source code.

In order to generate a fresh set of man pages from the sop-java-picocli source, you need to clone that repository next to the pgpainless repository:

$ ls
pgpainless
$ git clone https://github.com/pgpainless/sop-java.git
$ ls
pgpainless  sop-java

Next, you need to execute the asciiDoctor gradle task inside the sop-java repository:

$ cd sop-java
$ gradle asciiDoctor

This will generate generic sop manpages in sop-java-picocli/build/docs/manpage/.

Next, you need to execute a script for converting the sop manpages to fit the pgpainless-cli command with the help of a script in the pgpainless repository:

$ cd ../pgpainless/pgpainless-cli
$ ./rewriteManPages.sh

The resulting updated man pages are placed in packaging/man/.

Usage

Hereafter, the program will be referred to as pgpainless-cli.

$ pgpainless-cli help
Stateless OpenPGP Protocol
Usage: pgpainless-cli [--stacktrace] [COMMAND]

Options:
      --stacktrace   Print Stacktrace

Commands:
  help           Display usage information for the specified subcommand
  armor          Add ASCII Armor to standard input
  dearmor        Remove ASCII Armor from standard input
  decrypt        Decrypt a message from standard input
  inline-detach  Split signatures from a clearsigned message
  encrypt        Encrypt a message from standard input
  extract-cert   Extract a public key certificate from a secret key from
                   standard input
  generate-key   Generate a secret key
  sign           Create a detached signature on the data from standard input
  verify         Verify a detached signature over the data from standard input
  inline-sign    Create an inline-signed message from data on standard input
  inline-verify  Verify inline-signed data from standard input
  version        Display version information about the tool

Exit Codes:
   0   Successful program execution
   1   Generic program error
   3   Verification requested but no verifiable signature found
  13   Unsupported asymmetric algorithm
  17   Certificate is not encryption capable
  19   Usage error: Missing argument
  23   Incomplete verification instructions
  29   Unable to decrypt
  31   Password is not human-readable
  37   Unsupported Option
  41   Invalid data or data of wrong type encountered
  53   Non-text input received where text was expected
  59   Output file already exists
  61   Input file does not exist
  67   Cannot unlock password protected secret key
  69   Unsupported subcommand
  71   Unsupported special prefix (e.g. "@ENV/@FD") of indirect parameter
  73   Ambiguous input (a filename matching the designator already exists)
  79   Key is not signing capable

To get help on a subcommand, e.g. encrypt, just call the help subcommand followed by the subcommand you are interested in (e.g. pgpainless-cli help encrypt).

Examples

$ # Generate a key
$ pgpainless-cli generate-key "Alice <alice@pgpainless.org>" > key.asc
$ # Extract a certificate from a key
$ cat key.asc | pgpainless-cli extract-cert > cert.asc
$ # Create an encrypted signed message
$ echo "Hello, World!" | pgpainless-cli encrypt cert.asc --sign-with key.asc > msg.asc
$ # Decrypt an encrypted message and verify the signature
$ cat msg.asc | pgpainless-cli decrypt key.asc --verify-with cert.asc --verifications-out verifications.txt
Hello, World!
$ cat verifications.txt
2022-11-15T21:25:48Z 4FF67C69150209ED8139DE22578CB2FABD5D7897 9000235358B8CEA6A368EC86DE56DC2D942ACAA4

Indirect Data Types

Some commands take options whose arguments are indirect data types. Those are arguments which are not used directly, but instead they point to a place where the argument value can be sourced from, such as a file, an environment variable or a file descriptor.

It is important to keep in mind, that options like --with-password or --with-key-password are examples for such indirect data types. If you want to unlock a key whose password is sw0rdf1sh, you cannot provide the password like --with-key-password sw0rdf1sh, but instead you have to either write out the password into a file and provide the file’s path (e.g. --with-key-password /path/to/file), store the password in an environment variable and pass that (e.g. --with-key-password @ENV:myvar), or provide a numbered file descriptor from which the password can be read (e.g. --with-key-password @FD:4).

Note, that environment variables and file descriptors can only be used to pass input data to the program. For output parameters (e.g. --verifications-out) only file paths are allowed.