The dotsig software lets you create and verify digital signatures using RSA cryptography (PKCS1 v1.5), PGP and elliptic-curve cryptography (ECDSA).

You can find the reference documentation here.

This software is released under the 3-Clause BSD License.

Releases

The dotsig software is currently under active development and frequent changes to the source code are to be expected until the software reaches a stable tag.

The latest release as of May 2nd 2024 is: v1.0.0-beta.

Use dotsig -v to find out the version installed on your system.

Getting started

Build and install the software

A Makefile is provided to overcome the necessity of building the package. This is currently the preferred method to install the dotsig software.

make

make install

:soon: In the short-to-mid-term future, I plan to enable the installation using popular package managers including: apt, rpm and snap.

Cross-platform Identities

Identities' private keys are tentatively exported to encrypted DER-encoded files in the home folder of the user running the program, whereas identities' public keys are tentatively exported to plaintext PEM-encoded files ending with .pub.

For Windows users, the APPDATA environment variable is used and the files are stored in APPDATA%\.dotsig\, whereas on Unix systems (including Mac OS), the identity files are stored in ~/.dotsig.

:white_check_mark: Note that it is possible to re-use your RSA identity file (e.g. -i ~/.ssh/id_rsa) provided that you are in possession of the passphrase that unlocks the private key.

Examples

By default, this software uses the ECDSA standard to sign/verify documents.

To sign/verify a file with ECDSA and your default identity ~/id_ecdsa, use:

dotsig path/to/document

dotsig -c path/to/document.sig

To sign/verify a file with PKCS and your default identity ~/id_rsa, use:

dotsig path/to/document -a pkcs

dotsig -c path/to/document.sig -a pkcs

To sign/verify a message with ECDSA and your default identity, use:

echo 'Hello, World!' | dotsig

echo 'Hello, World!' | dotsig -c path/to/signature.sig

To sign/verify a message with PKCS and your default identity, use:

echo 'Hello, World!' | dotsig -a pkcs

echo 'Hello, World!' | dotsig -c path/to/signature.sig -a pkcs

Example of a full-cycle of creation of a digital signature and later verification of the produced signature file (using STDIN):

echo 'Hello, World!' | dotsig

echo 'Hello, World!' | dotsig -c stdin.sig

Getting help

Use the following available resources to get help:

Find the github repository: evias/dotsig.
Read the reference documentation.
Read the manpage: man dotsig.
Read the usage message: dotsig -h.
Find out about changes in the changelog.
If you found a bug, make sure to open a new issue.

License

Licensed under the 3-Clause BSD License.