Signify ported from OpenBSD to Linux

with these differences:

• Randomness is provided by syscall 'getrandom' (Linux ≥3.18)
• or RDRAND.
• Compiles to a static binary of less than 180KiB (less than 270KiB with Seccomp and musl-libc).

The resulting binary is licensed under the same terms as OpenBSD's signify. For the sources — please see the source files for their licensing terms, and if you are permitted to use them in another work.

Usage

# generate a keypair
$ signify -G -c "Your Name <y.name@example.com>" -p mark.pub -s mark.sec

# sign (usually a small file, like the output of: sha512sum …) "TheFileName"
$ signify -S -x TheFileName.sig -s mark.sec -m TheFileName

# verify
$ signify -V -x TheFileName.sig -p mark.pub -m TheFileName
Signature Verified

Or shorthand for if TheFileName and a similarly named TheFileName.sig exist:

$ signify -V -p mark.pub -m TheFileName
Signature Verified